European Heart Failure Association.Com o aumento da expectativa de vida da população e a maior frequência de fatores de risco como obesidade, hipertensão arterial e diabetes, espera-se um aumento na prevalência de insuficiência cardíaca com fração de ejeção preservada (ICFEp). Entretanto, no momento, o diagnóstico e o tratamento de pacientes com ICFEp permanecem desafiadores. O diagnóstico sindrômico de ICFEp inclui diversas etiologias e doenças com tratamentos específicos, mas que apresentam pontos em comum em relação à apresentação clínica e à avaliação laboratorial no que diz respeito aos biomarcadores como BNP e NT-ProBNP, à avaliação ecocardiográfica do remodelamento cardíaco e às pressões de enchimento diastólico ventricular esquerdo. Extensos ensaios clínicos randomizados envolvendo a terapia nesta síndrome falharam na demonstração de benefícios para o paciente, fazendo-se necessária uma reflexão acerca do diagnóstico, dos mecanismos de morbidade, da taxa de mortalidade e da reversibilidade. Na revisão, serão abordados os conceitos atuais, as controvérsias e, especialmente, os desafios no diagnóstico da ICFEp através de uma análise crítica do escore da  O diagnóstico sindrômico de ICFEp inclui diversas etiologias e doenças com tratamentos específicos, mas que apresentam pontos em comum em relação à apresentação clínica, à avaliação laboratorial no que diz respeito aos biomarcadores como BNP e NT-ProBNP e à avaliação ecocardiográfica do remodelamento cardíaco e das pressões de enchimento diastólico ventricular esquerdo.European Heart Failure Association .1Na revisão, serão abordados os conceitos atuais, controvérsias e, especialmente, os desafios no diagnóstico da ICFEp, analisando criticamente o escore da Heart Failure Association (HFA), da European Society of Cardiology (ESC), um novo posicionamento para o diagnóstico de ICFEp, que inclui o papel das comorbidades clínicas e um sistema fundamentado em escore com valores atualizados dos critérios ecocardiográficos e a dosagem de biomarcadores, além do papel dos testes feitos sob esforço  pode evidenciar sinais de hipertrofia ventricular esquerda  e/ou sobrecarga atrial esquerda, mas sua principal indicação é detectar a presença de fibrilação atrial (FA), altamente preditiva de ICFEp subjacente.10 É importante lembrar que os valores de corte podem variar de acordo com a idade, gênero, peso corporal, função renal e presença de FA. Assim, são recomendados critérios menores e maiores de acordo com o grau de alteração na presença dos fatores modificadores acima descritos.1O racional para o emprego do escore baseia-se no fato de que nenhum critério não invasivo é suficiente de maneira isolada para o diagnóstico de ICFEp. Por isso, recomenda-se a avaliação integrada das informações clínicas, das medidas dos níveis séricos de PN e da estrutura e função cardíaca pela ecocardiografia.12 Até o momento, valores de corte definitivos para o diagnóstico de ICFEp em pacientes em ritmo sinusal ou FA não foram bem estabelecidos.1 Os valores sugeridos para o diagnóstico de ICFEp são descritos na Valores de PN em pacientes em ritmo de FA podem ser até três vezes maiores do que em pacientes em ritmo sinusal. Por isso, os valores de corte são diferenciados para as duas populações de pacientes.1A ecocardiografia é o método de imagem cardíaca de escolha na avaliação do paciente com sinais e sintomas de IC. O ecocardiograma permite a avaliação anatômica funcional pelas medidas dos diâmetros e volumes das cavidades cardíacas, estimativa da massa ventricular esquerda e análise da função sistólica pela fração de ejeção, além da função longitudinal global e segmentar miocárdica. É o método não invasivo de escolha para a análise da função diastólica e das pressões de enchimento ventricular esquerdo e da artéria pulmonar.14O VolAEi está relacionado às pressões de enchimento do VE e a outros índices de função diastólica, sendo a medida mais acurada do remodelamento crônico do AE quando é comparada ao diâmetro e área do AE.2 é preditor independente de morte, IC, FA e acidente vascular encefálico isquêmico.16 Em pacientes com ICFEp e FA permanente, o VolAEi foi 35% maior do que nos pacientes com ICFEp em ritmo sinusal.11 Pacientes com FA permanente podem apresentar maiores VolAEi, mesmo na ausência de disfunção diastólica. Assim, recomenda-se valores de corte distintos de VolAEi para o diagnóstico de ICFEp de pacientes em ritmo sinusal e FA .18 A análise da IMVE e da ERP permite a categorização da hipertrofia em concêntrica , excêntrica  e remodelamento concêntrico .18O índice de IMVE é definido como a massa ventricular esquerda indexada pela superfície corpórea. A hipertrofia é o aumento do IMVE, de acordo com os seguintes valores de referência: ≥95 g/m1 Dessa forma, são considerados os critérios descritos na Em pacientes com ICFEp, é possível observar os padrões de remodelamento ou hipertrofia concêntrica. No entanto, a ausência de hipertrofia ventricular esquerda não exclui o diagnóstico de ICFEp.strain ) longitudinal global ventricular esquerda (GLS) pela técnica de speckle tracking independe do ângulo de insonação do ultrassom confere vantagem em relação à medida do strain obtida pelo Doppler e é considerada a técnica de eleição.19A medida da deformação miocárdica  ao Doppler contínuo. Tais medidas são importantes nas estimativas de elevação das pressões de enchimento e, consequentemente, para o diagnóstico de ICFEp.20Ao 24Medidas elevadas de pressão sistólica em artéria pulmonar (PSAP) e redução da função ventricular direita são importantes preditores de mortalidade em pacientes com ICFEp. Valores da velocidade de pico do jato de insuficiência tricúspide > 2,8 m/s são marcadores indiretos de disfunção diastólica e estão associados ao diagnóstico de ICFEp.Doppler tecidual pulsátil são um parâmetro fundamental em pacientes com ICFEp.25 Todas as medidas devem representar a média de três ou mais ciclos cardíacos consecutivos, e, preferencialmente, devem ser realizadas as medidas das velocidades das ondas e’ septal e lateral, em particular para o cálculo da relação E/e’.25As medidas das velocidades de pico diastólicas precoces (ondas e’) nas paredes septal e lateral ao 27 A velocidade da onda e” diminui com a idade e, por isso, são recomendados valores de referência de acordo com a idade para o cálculo do escore para o diagnóstico de ICFEp , conforme a seguir. Na prática e de maneira estruturada, os passos 1 e 2 podem ser resumidos no fluxograma da O escore apresenta domínios funcionais, morfológicos e relacionados aos biomarcadores, e cada critério maior atribui 2 pontos e cada critério menor 1 ponto   . É impoNas No caso real da Além disso, a paciente apresentava limitação para realizar teste sob esforço por conta de obesidade e alterações degenerativas articulares e não prosseguiu com a investigação etiológica sugerida pelo protocolo da HFA.25É importante considerar que, em pacientes com diagnóstico de estenose mitral, a onda E pode não refletir a função diastólica. Em pacientes com insuficiência tricúspide importante, a velocidade do jato de insuficiência tricúspide pode estar reduzida devido à equalização entre as pressões de VD e AD, subestimando a estimativa da PSAP.34Em pacientes com pontuação intermediária no escore diagnóstico, é indicada uma avaliação complementar com ecocardiografia e sob esforço físico, pois muitos pacientes apresentam apenas sintomas relacionados aos esforços. Dessa forma, sintomas compatíveis com ICFEp podem ser confirmados a partir de anormalidades hemodinâmicas como reduções do débito cardíaco e do volume sistólico e a elevação das pressões de enchimento do VE em repouso ou durante o esforço físico.34O ecocardiograma sob esforço pode revelar disfunção sistólica e diastólica durante o exercício. Os parâmetros mais empregados para essa análise na suspeita de ICFEp são a relação E/e’ e a velocidade de pico do jato de insuficiência tricúspide. Recomenda-se a realização do exame em repouso, durante todo o esforço, ou logo após o pico da atividade. Contudo, até o momento não existem protocolos universalmente aceitos, os exames são realizados de acordo com a disponibilidade e a experiência de cada serviço.34A relação E/e’ e a velocidade de pico do jato da insuficiência tricúspide devem ser adquiridas no momento basal e em cada estágio, incluindo o pico do esforço, durante o estágio submáximo e/ou nos primeiros dois minutos da fase de recuperação.34O ecocardiograma sob esforço deve ser considerado anormal quando a relação E/e’ obtida no pico do esforço for ≥15, com ou sem aumento da velocidade de pico da IT para um valor >3,4 m/s. Um aumento isolado na velocidade da IT não deve ser considerado para o diagnóstico de ICFEp, uma vez que essa alteração pode ser meramente causada por uma resposta hiperdinâmica normal ao exercício (aumento do fluxo pulmonar) e na ausência disfunção diastólica do VE. Uma relação E/e’ durante o esforço ≥15 soma 2 pontos ao escore da HFA. Uma relação E/e’ ≥ 15 e a velocidade de pico da IT >3,4 m/s acrescentam 3 pontos ao escore a partir do passo 2 (E). Então, a associação do escore combinado a partir dos passos 2 (E) e 3 (F1) ≥ 5 confirma o diagnóstico de ICFEp.31 Além disso, em nosso país, a disponibilidade de serviços que realizam o ecocardiograma sob esforço físico é bastante escassa, mesmo em cidades com grandes serviços de referência em Cardiologia. No exemplo da 34Entretanto, algumas limitações são passíveis de ocorrer: a relação E/e’ pode não ser analisável em cerca de 10% dos pacientes durante o esforço submáximo (20W), a velocidade da IT ser mensurável em apenas 50% dos pacientes e cerca de 20% dos pacientes podem ser considerados “falsos positivos”.1 A última diretriz da EACVI25 sugere a avaliação hemodinâmica invasiva sob esforço; porém, em nosso país, essa é uma prática utilizada muito raramente e apenas em pacientes específicos. Na prática clínica, pode ser realizada a avaliação invasiva para confirmar a elevação das pressões de enchimento ventriculares esquerdas em repouso  e o diagnóstico de ICFEp.1 A avaliação invasiva também deve ser considerada para a exclusão de doença coronária ou em populações específicas.35Finalmente, os dados obtidos a partir da ecocardiografia sob esforço não são suficientes para substituir medidas hemodinâmicas invasivas. Quando o escore persistir <5 pontos ou o ecocardiograma sob esforço não puder ser realizado, recomenda-se a avaliação invasiva quando surgirem dúvidas.38 Uma vez diagnosticada a ICFEP, a investigação de cada etiologia especifica deve ser pautada pela suspeição clínica e realizada de maneira direcionada na dependência do diagnóstico presuntivo. É fundamental detectar as etiologias específicas, uma vez que esses achados podem se traduzir em terapêuticas específicas. Também é importante considerar que as etiologias não relacionadas ao miocárdio podem apresentar quadro clínico semelhante à ICFEp, como pericardite constritiva, doenças valvares primárias e insuficiência cardíaca de alto débito.1A maioria dos casos de ICFEp está relacionado a fatores de risco e comorbidades comuns. Porém, a possibilidade de uma etiologia subjacente especifica deve sempre ser considerada: cardiomiopatia hipertrófica, miocardite, doenças autoimunes, cardiomiopatias infiltravas, doenças de depósito e endomiocardiofibrose são exemplos.39 Além disso, os resultados dos testes podem ser limitados a este grupo de pacientes, em estágios diferentes da doença e com heterogeneidade de etiologias.1A ICFEp é uma síndrome clínica com múltiplos fatores contribuintes, etiologias e mecanismos fisiopatológicos distintos, de maneira que é impossível a criação de um algoritmo único capaz de realizar o diagnóstico de um grupo tão diversificado de doenças.10 É importante considerar estes fatores, uma vez que, isoladamente, os demais parâmetros dissociados do quadro clínico e exame físico perdem a acurácia diagnóstica. Além disso, outras situações clínicas que não a IC podem levar a elevações dos níveis séricos de biomarcadores como doenças crônicas renais, pulmonares e processos infecciosos, limitando sua aplicação no contexto do paciente com suspeita de IC, uma vez que neste grupo de pacientes a ocorrência destas doenças não é infrequente.40O escore da HFA não atribui pontuação aos fatores de risco clínicos, e sinais e sintomas ao exame físico conforme proposto por autores americanos.41 Nesse contexto, outros parâmetros ecocardiográficos em um futuro próximo poderão ser incorporados ao escore, aumentando a sensibilidade diagnóstica e o detalhamento da fisiopatologia da ICFEp.Atualmente, fenótipos distintos tem sido reconhecidos na apresentação clínica dos pacientes com ICFEp, como em relação à caracterização da função atrial esquerda, pressões pulmonares e função ventricular direita.strain ) atrial esquerda apresentam importância crescente na avaliação da função diastólica e nas pressões de enchimento do ventrículo esquerdo. O desenvolvimento de softwares dedicados à avaliação do strain atrial tem permitido a avaliação mais detalhada da função atrial esquerda e também a análise da rigidez atrial esquerda. Este último é um parâmetro que apresenta correlação logarítmica com as pressões de enchimento do VE e melhor acurácia na predição de valores >15 mmHg da pressão diastólica final do VE em relação à relação E/e’.44 Adicionalmente, outros parâmetros como a deformação do ventrículo direito  desempenham papel promissor no diagnóstico da ICFEp.46Variáveis como os índices de deformação ou , and the prevalence rate varies between 3.8 and 7.4% among the studies, considering the different methodologies used for the diagnosis.1 In contrast to heart failure with reduced ejection fraction (HFrEF), no treatment has yet convincingly shown a reduction in morbidity or mortality in HFpEF, making it necessary to reflect on the diagnosis, mechanisms of morbidity, mortality and reversibility in this syndrome.5However, until now, the diagnosis and treatment of patients with HFpEF remain challenging. The syndromic diagnosis of HFpEF includes several etiologies and diseases with specific treatments but has points in common regarding the clinical presentation, laboratory evaluation related to biomarkers, such as BNP and NT-ProBNP, and echocardiographic evaluation of cardiac remodeling and left ventricular diastolic filling pressures.European Heart Failure Association score for the diagnosis of HFpEF.1In this review, the current concepts, controversies and challenges will be addressed, especially regarding the diagnosis, critically analyzing the 8In 2019, the Heart Failure Association (HFA) of the European Society of Cardiology (ESC) published a new statement on the diagnosis of HFpEF, including the role of clinical comorbidities and a system based on a score with updated values of echocardiographic criteria, biomarker measurement, and the role of stress tests   .6 - 81The initial evaluation should take into account the anamnesis, while addressing the risk factors and comorbidities and the presence of symptoms and signs on the physical examination of heart failure that suggest the diagnosis of HFpEF, according to the diagram below   . In thi10The electrocardiogram (ECG) may show signs of left ventricular hypertrophy (Sokolow-Lyon Index ≥ 3.5 mV) and/or left atrial overload, but its main indication is to detect the presence of atrial fibrillation (AF), which is highly predictive of underlying HFpEF.10 It is important to remember that the cutoff values may vary according to age, gender, body weight, renal function and the presence of atrial fibrillation. Thus, minor and major criteria are recommended according to the degree of change in the presence of the modifying factors described above.1The rationale for the use of the score is based on the fact that no noninvasive criterion alone is sufficient for the diagnosis of HFpEF and, therefore, an integrated evaluation of clinical information, measurements of serum levels of natriuretic peptide and evaluation of cardiac structure and function by echocardiography is suggested.12 To date, definitive cutoff values for the diagnosis of HFpEF in patients with sinus rhythm or AF have yet to be established.1 The suggested values for the diagnosis of HFpEF are described in Table 2.Natriuretic peptide levels in patients with AF rhythm may be up to three times higher than in patients in sinus rhythm; therefore, the cutoff values are different for these two patient populations.1Echocardiography is the cardiac imaging method of choice in the evaluation of patients with signs and symptoms of HF. The echocardiogram allows cardiac functional and anatomical evaluation by measuring the diameters and volumes of the cardiac cavities, estimating the left ventricular mass, and analyzing systolic function by the ejection fraction, in addition to global longitudinal and segmental myocardial function. It is the noninvasive method of choice for the analysis of diastolic function, left ventricular filling pressures and pulmonary artery pressures.14LAVI is related to LV filling pressures and other diastolic function indices, being the most accurate measure of chronic LA remodeling when compared to LA diameter and area.2is an independent predictor of death, heart failure (HF), atrial fibrillation and ischemic stroke.16 In patients with HFpEF and permanent AF, the LAVI was 35% higher than that of patients with HFpEF in sinus rhythm.11 Patients with permanent AF may have higher LAVI even in the absence of diastolic dysfunction. Thus, different LAVI cutoff values are recommended for the diagnosis of HFpEF in patients with sinus rhythm and AF  or heart valve disease, LAVI > 34 ml/m and AF   and 2 .11 These measurements should be obtained preferentially in 2D mode or 2D-guided M mode according to the formula recommended by the American Society of Echocardiography.18In the HFA score, the left ventricular thickness at the end of diastole of the septal and posterior walls are considered morphological criteria for the diagnosis of HFpEF.2in women and ≥ 115 g/m2in men.18 It is also important to consider the calculation of the left ventricular relative wall thickness (RWT).18 The analysis of LVMI and RWT allows the categorization of hypertrophy into concentric (increase in LVMI and RWT >0.42) and eccentric (increase in LVMI and RWT <0.42) or concentric remodeling .18The left ventricular myocardial mass index (LVMI) is defined as the left ventricular mass indexed by the body surface area. Hypertrophy is defined as an increase in LVMI according to the following reference values: ≥ 95 g/m1 Thus, for the diagnosis of HFpEF, the criteria described in Remodeling patterns or concentric hypertrophy can be seen in patients with HFpEF. The absence of left ventricular hypertrophy, however, does not exclude the diagnosis of HFpEF.19The measurement of LV global longitudinal myocardial deformation or strain (GLS) by speckle tracking is independent of the ultrasound insonation angle, conferring an advantage over the strain evaluated by Doppler, being considered the technique of choice.1 Low values of GLS are predictors of hospitalization for HF, cardiovascular death or cardiorespiratory arrest, showing good correlation with LV stiffness and biomarkers.20It is important to consider that equipment by different manufacturers can show variations between GLS values acquired from the same patient. An absolute value of GLS <16% can be considered abnormal and a minor criterion for the diagnosis of HFpEF see  .1 Low v20On conventional Doppler, E-wave measurements are obtained by Pulsed Doppler analysis of the mitral valve to calculate the E/e´ ratio and the tricuspid regurgitation (TR) jet peak velocity is obtained by continuous Doppler. These measurements are important for estimating the increase in filling pressures and, consequently, for the diagnosis of HFpEF.24High levels of pulmonary artery systolic pressure (PASP) and right ventricular function reduction are important predictors of mortality in patients with HFpEF. TR jet peak velocity values >2.8 m/s are indirect markers of diastolic dysfunction and are associated with the HFpEF diagnosis.25 All measurements should represent the mean of three or more consecutive cardiac cycles, and preferably, the measurements of the e´ wave of the septal and lateral velocities should be performed, especially for the calculation of the E/e´ ratio.25The measurements of early diastolic peak velocities (e´ waves) in the septal and lateral walls by pulsed tissue Doppler constitute a key parameter in patients with HFpEF.27 The e´ wave velocity decreases with age; therefore, reference values are recommended according to the age range to calculate the score for the HFpEF diagnosis , as follows. In a structured manner, in practice, steps 1 and 2 can be summarized in the flowchart of Table 2.The score includes functional, morphological and biomarker-related domains, with each major criterion assigning 2 points and each minor criterion assigning 1 point to the score (Table 2). It is important to remember that not all parameters of each domain can be analyzed. A total score ≥ 5 points is considered diagnostic for HFpEF, while scores ≤ 1 point indicate a very unlikely diagnosis and make the investigation of differential diagnoses mandatory.In the real-life case of This case is also illustrative because it shows the limitation of the suggested measurements in real cases. In this patient, it was not possible to measure the pulmonary artery systolic pressure due to the absence of tricuspid regurgitation, which is not uncommon in daily practice.In addition, this patient had limitations in performing the test under exertion due to obesity and degenerative joint abnormalities and did not continue the etiological investigation suggested by the HFA protocol.25It is important to consider that in patients diagnosed with mitral stenosis, the E wave may not reflect diastolic function, as in patients with significant tricuspid regurgitation, in which the tricuspid regurgitation velocity may be reduced due to the equalization between RV and RA, underestimating the measurement of PASP.34In patients with intermediate diagnostic scores, the performance of complementary evaluation with echocardiography under physical exertion is indicated because many patients only exhibit symptoms on exertion. Thus, symptoms compatible with HFpEF can be confirmed by hemodynamic abnormalities, such as reduced cardiac output, reduced systolic volume and increased LV filling pressures at rest or during physical exertion.34The stress echocardiography may disclose systolic and diastolic dysfunction during exercise testing. The parameters most frequently used for this analysis when HFpEF is suspected are the E/e´ ratio and the TR jet peak velocity. It is advisable to perform the test at rest and throughout the exertion or immediately after the peak of the exertion. However, to date, there are no universally accepted protocols, and the tests are performed according to the availability and experience of each service.34The E/e´ ratio and the TR jet peak velocity should be acquired at baseline and at each stage, including the peak of exertion, and during the submaximal stage or during the first two minutes of the recovery phase.34The stress echocardiogram should be considered abnormal if the E/e´ ratio obtained at peak effort is ≥ 15, with or without an increase in the TR peak velocity to a value >3.4 m/s. An isolated increase in the TR peak velocity should not be considered for the diagnosis of HFpEF, as this change may be caused merely by a normal hyperdynamic response to exercise (with increased pulmonary flow) in the absence of LV diastolic dysfunction. An E/e´ ratio during exertion ≥ 15 adds 2 points to the HFA score. An E/e´ ratio ≥ 15 and TR peak velocity >3.4 m/s add 3 points to the score from Step 2 (E). The association of the combined score from Step 2 (E) and Step 3 (F1) ≥ 5 confirms, then, the diagnosis of HFpEF.31 In addition, in our country, the availability of services that perform echocardiography under physical exertion is very scarce, even in cities with large cardiology referral services. As shown in 34However, some limitations may occur: the E/e´ ratio might not be analyzed in approximately 10% of patients during submaximal effort (20 W), the TR peak velocity was measurable in only 50% of patients, and approximately 20% of the patients could be considered false positive cases.1 The last European Association of Cardiovascular Imaging (EACVI) guideline25 recommends invasive hemodynamic evaluation under stress; however, this test is very rarely used and only in specific patients in the Brazilian population. In clinical practice, the invasive evaluation can be performed to confirm the elevation of LV filling pressures at rest (LV end-diastolic pressure ≥ 16 mmHg), confirming the HFpEF diagnosis.1 An invasive evaluation should also be considered for the exclusion of coronary disease or in specific populations.35Finally, the data obtained from the stress echocardiography are not sufficient to replace invasive hemodynamic measures. When the score remains <5 points or if the stress echocardiogram cannot be performed, the invasive evaluation is recommended in case of doubt.38 Once the diagnosis of HFpEF syndrome is made, the investigation of each specific etiology should be guided by clinical suspicion and conducted in a targeted manner, depending on the presumptive diagnosis. The diagnosis of specific etiologies is essential, because these findings can be translated into specific therapies. It is also important to consider that etiologies unrelated to the myocardium may present a clinical picture similar to that of HFpEF, such as constrictive pericarditis, primary valve diseases and high output heart failure.1The majority of HFpEF cases are related to risk factors and comorbidities; however, the possibility of a specific underlying etiology should always be considered, such as hypertrophic cardiomyopathy, myocarditis, autoimmune diseases, infiltrative cardiomyopathies, deposit diseases and endomyocardial fibrosis.39 In addition, the results of the tests may be limited in this group of patients at different stages of the disease and with heterogeneous etiologies.1HFpEF is a clinical syndrome with multiple contributing factors, etiologies and distinct pathophysiological mechanisms; hence, it is impossible to create a single algorithm capable of diagnosing such a diverse group of diseases.10 It is important to consider these factors because, individually, the other parameters dissociated from the clinical condition and physical examination lose diagnostic accuracy. Moreover, clinical conditions other than HF, for example, may lead to elevated serum levels of biomarkers, such as chronic kidney and lung diseases and infectious processes, limiting their application in the context of patients with suspected HF, since the occurrence of these diseases in this group of patients is not uncommon.40The HFA score does not assign a score to the clinical risk factors and signs and symptoms on physical examination as proposed by American authors.41 In this context, other echocardiographic parameters may be incorporated into the score in the near future, increasing the diagnostic sensitivity and detailing the pathophysiology of HFpEF.Currently, distinct phenotypes have also been recognized in the clinical presentation of patients with HFpEF, such as the characterization of left atrial function, pulmonary pressures and right ventricular function.44 In addition, other parameters, such as right ventricular deformation , also have a promising role in the diagnosis of HFpEF.46Variables such as left atrial strain indices are increasingly important in the evaluation of diastolic function and left ventricular filling pressures. The development of software dedicated to the evaluation of LA strain has allowed a more accurate evaluation of left atrial function and the analysis of left atrial stiffness, a parameter that shows a logarithmic correlation with LV filling pressures and better accuracy in predicting values >15 mmHg of the LV end-diastolic pressure in relation to the E/e´ ratio.49In the near future, it will probably be possible to perform a noninvasive morphological analysis of cardiac chamber volumes integrated with hemodynamic parameters such as systolic volume, cardiac output and LV filling pressures in association with new markers of systolic and diastolic function, adding diagnostic and prognostic value to the significance of LVEF in the characterization of HF.49The use of modern imaging methods in an integrated manner can provide the abovementioned data in addition to dynamic analyses on arterial and endothelial function and myocardial perfusion, which can be coupled with the demographic data, including classic risk factors and new biomarkers, with data on proteomics, metabolomics and genetics. This information may be processed by artificial intelligence and may be useful to define the pathophysiology and diagnosis, in addition to therapeutic guidance and outcome prediction.Thus, despite the development of updated scores for the diagnosis of HFpEF in the light of new knowledge, especially in relation to echocardiographic techniques and biomarker values, refinements and incorporation of more clinical and echocardiographic indices are still needed, which will allow not only the syndromic diagnosis but also recommendations on the final etiology of patients with HFpEF.


Exposure to high altitudes represents physiological stress that leads to significant changes in cardiovascular properties. However, long-term cardiovascular adaptions to high altitude migration of lowlanders have not been described. Accordingly, we measured changes in cardiovascular properties following prolonged hypoxic exposure in acclimatized Han migrants and Tibetans.n = 64) and highly adapted Han migrant  residence in Tibet  using speckle tracking echocardiography were compared to those of age-matched native Tibetans (n = 75) and Han lowlanders living at 1,400 m (n = 60).Echocardiographic features of recently adapted Han migrant , enlarged right ventricles (RVs), and decreased fractional area change (FAC) with decreased RV longitudinal strain . While left ventricular ejection fraction (LVEF) was preserved, LV diameter  and LV longitudinal strain  decreased. Compared with recent migrants, longer-term migrants had recovered RV structure and functions with slightly improved RV and LV longitudinal strain, though still lower than lowlander controls; LV size remained small with increased mass index . In contrast, native Tibetans had slightly increased PASP  with minimally altered cardiac deformation compared to lowlanders.Short-term acclimatized migrants showed increased estimated pulmonary artery systolic pressure (PASP)  migrants to high altitudes but improved during the long-term dwelling. LV remodeling persists in long-term migrants (>5 years) but without impairment of LV systolic or diastolic function. In contrast, cardiac size, structure, and function of native Tibetans are more similar to those of lowland dwelling Hans. High altitude exposure is associated with pulmonary hypertension and pulmonary vasoconstriction resulting in significant changes in cardiovascular properties . There aHowever, there is limited information concerning how healthy lowlanders  adapt to longer-term (months-to-years) exposure to high altitudes ; in particular, there are no data concerning changes in cardiac mechanics under such conditions. An example is when healthy Han individuals (the most common race in China) born and living at low altitudes  migrate to the Tibet plateau . It is not uncommon for young adults to live and work at high altitudes over periods of months to years, which provides the opportunity to study long-term cardiovascular adaptations to chronic hypoxia in these extreme conditions.Accordingly, the purpose of this study was to provide a comprehensive characterization of changes in cardiac structure, function, and longitudinal strain during prolonged (month-to-years) exposure to high altitude  in Han migrants and compare them to characteristics of native Tibetans. We hypothesized that (1) cardiac structure  and function  of long-term (>5 years) Han migrants are more highly adapted to high altitude than recent acclimatized Hans (<1 year) and (2) despite long-term dwelling (>5 years), these same indexes of cardiac structure and function of Han migrants are not as highly adapted to high altitude as native Tibetans.n = 82); (2) short-term acclimatized Hans (n = 64), who were defined as Han migrants with residence time in Tibet of more than 3 months but less than 1 year; (3) long-term acclimatized Hans (n = 71), who were defined as Han migrants with residence time in Tibet for more than 5 years; and (4) native Tibetans (n = 75). The protocol was approved by the Chinese PLA General Hospital Ethics Committee, and each participant provided written informed consent.Han lowlanders were recruited in Yecheng, Xinjiang ; Han migrants and Tibetans were recruited in the Ali district of Tibet . A total of 328 volunteers completed a questionnaire and were given free physical and echocardiographic examinations. The questionnaire included age, ethnicity, duration of residence, family medical history, questions related to physical and psychological discomfort, and medications. As the aim of the study was to investigate the normal process of cardiac adaption to chronic hypoxia of young and healthy migrants from lowland, the criteria for being included in this study were as follows: age between 18 and 32 years, male, and a normal physical examination. Exclusion criteria included any history of smoking, self-reported history of any cardiorespiratory disease, obesity, or intake of any medication within a month before participation in this study. After excluding 36 subjects due to insufficient image quality, 292 participants were included in this study, including 217 Hans and 75 Tibetans. Participants enrolled were grouped according to ethnicity, altitude, and adaptation periods into one of 4 groups: (1) Han lowlanders (2 saturation (SpO2), and blood samples. BP and HR were measured  in the supine position after 10 min of rest. SpO2 was measured using finger-pulse oximetry  after finger warming and signal stabilization. Hemoglobin concentration (HB) and hematocrit (HCT) measurements  were performed by peripheral venous sampling. From these data, body surface area (BSA) and body mass index (BMI) were calculated.Data were collected by two physicians and an experienced sonographer who traveled between Yecheng and Ali. Measurement included height, weight, blood pressure (BP), heart rate (HR), arterial OEchocardiographic image acquisition included 2D and Doppler echocardiography and was saved in the DICOM format. The procedure was performed by a certified sonographer using a portable ultrasound machine  in the left lateral decubitus position according to society guideline recommendations , 9. MeasPTR, in mmHg) from the modified Bernoulli equation  was estimated by the diameter of the inferior vena cava and its variation during inspiration as detailed previously (PTR + RAP. Mean PAP (PAMP) was calculated from PASP as PAMP = 0.61 PASP + 2 mmHg (Right ventricular end-diastolic and end-systolic areas (EDA and ESA) were measured from planar tracings of the endocardial border in the apical 4C view, and RV FAC was calculated by (EDA-ESA)/EDA. Right and left atrial EDVs and ESVs were determined from planar tracings of the endocardial border in the apical 4C view by using the Simpson's method; atrial emptying fractions were calculated by (EDV-ESV)/EDV. Finally, volumes and dimensions were indexed to BSA to balance differences in body sizes. Early (E) and late (A) diastolic filling velocities were assessed using pulsed-wave Doppler recordings, and free wall velocities  were measured using tissue Doppler imaging at both mitral and tricuspid annular levels. Isovolumic relaxation time (IVRT) and deceleration time (DT) were measured at the level of the mitral annulus. Tricuspid annular plane systolic excursion (TAPSE) was measured from M-mode tracings. Systolic tricuspid regurgitation (TR) flow velocity was used to estimate pressure gradient  by an experienced physician. LV GLS was assessed from apical 2-, 3- and 4-chamber views according to recommendations . RV GLS,t-tests  as a post hoc test to compare recent Han migrants with Han lowlanders and with long-term acclimatized Han migrants and to compare Native Tibetans with long-term Hans. p-values were adjusted for multiple comparisons using Bonferroni corrections. Statistical significance was declared when p < 0.05.Statistical analyses were performed using SPSS (version 17.0). Data were expressed as mean ± SD, and a test for normality was performed using the Kolmogorov–Smirnov test. The effects of hypoxic exposure on conventional echocardiographic parameters and cardiac mechanics were assessed by analysis of variance among the Han population and Tibetans. When a significant main effect was found, we used modified 2. Native Tibetans exhibited unique characteristics compared with to Han population, including relatively smaller BSAs and BMIs. They also had relatively lower BP, Hb, and hematocrits compared to highly acclimatized Hans.Characteristics of the study population are summarized in Compared with short-term Han migrants (3–12 months), RV FAC and TAPSE improved during a longer period of acclimatization (>5 years), and changes were also accompanied by reductions of RV end-diastolic and end-systolic area, almost back to the normal values as lowlanders. There was also evidence of RV anterior wall thickening. Importantly, RV GLS of longer migrants was also higher with improvements in RV-PA coupling .Tibetans had higher RV FACs without thickening of the RV wall compared with long-term Han migrants. PASP in Tibetans was lower than in Han migrants and showed better RV-arterial coupling. Notably, Tibetans had nearly unchanged RV GLS compared to lowlanders, demonstrating more favorable adaptation to chronic hypoxia than highly acclimatized Han migrants.Left heart echocardiographic parameters are summarized in Compared with short-term Han migrants, LA and LV volumes of longer migrants (>5 years) remained small, and LVEF was also preserved. Notably, LV mass index was higher due to increased interventricular septum and posterior wall thicknesses. Mitral E/A and E/e′ remained low. IVRT and DT increased with preserved LA and LV GLS. This suggested that longer exposure to hypoxia caused significant LV thickening but no evidence of diastolic dysfunction or depression of cardiac mechanics.In contrast, Tibetans had relatively larger LAs and LVs compared to highly acclimatized Hans, but no differences were noted in LVEF. Also, the LV mass index was smaller in Tibetans as they had no significant LV thickening. Additionally, LV GLS was also maintained within a normal range. Thus, overall, Tibetans demonstrated a more highly adapted pattern of cardiac characteristics than long-term acclimatized Han migrants.Although previous studies evaluated cardiovascular alterations in response to acute hypoxia at high altitudes, this study is the first to investigate the effects of different stages of chronic exposure on biventricular structure, function, and mechanics. By comparing clinic and echocardiographic measures among recent (3–12 months) Han migrants, long-term (>5 years) Han migrants, and native Tibetans, we observed that (1) recent Han migrants showed a significant response to hypoxia that was characterized by increased RV size, decreased RV FAC, and decreased longitudinal strain of both ventricles; (2) all of these factors improved during long-term (>5 years) dwelling, and while there was improved right ventricular-pulmonary arterial coupling, there was persistent ventricular thickening; (3) even after long-term exposure, significant differences in cardiac structure, function, and mechanics existed compared to the more highly adapted native Tibetans. The major findings of this study, along with proposed links between high altitude dwelling, cardiac structure and function, are summarized in One of the important findings of our study was the adaptability of the RV and pulmonary vasculature of Han migrants to prolonged high altitude dwelling. Prior studies have shown that elevated PASP is the most immediate and prominent hemodynamic response to high altitude , 17. A rInterestingly, the RV demonstrated significant adaptability, as we observed near normalization of RV size and functions in migrants with more than 5 years of adaption. The reasons for improvement may be partly explained by the concomitant decreases in PASP, increase in pulmonary oxygenation, and improved RV-PA coupling. Based on prior literature, mechanisms contributing to these improvements may include hypoxia-related activation of sympathetic tone, increased ventilation, and hypocapnia-induced hypovolemia . EvidencHan migrants showed significant LV remodeling characterized by decreased chamber size and increased wall thickness during the high-altitude dwelling. RV–LV interactions may have played an important role in the altered LV structure during 3–12 time frames. As shown in Moreover, despite the RV structure of Han migrants improving nearly back to normal during >5 years of adaption, the LV remained small with the increasingly thickened wall . The smaNotably, such LV remodeling may not cause a significant decrease in diastolic function in these young healthy migrants. Previous studies reported that age was the most significant risk factor for the occurrence of left ventricular diastolic dysfunction among high-altitude dwellers . HoweverAnother finding of our study was that cardiac properties of highly acclimatized Hans do not fully return to normal. In contrast, native Tibetans show minimal differences in cardiac properties compared to lowlanders. In terms of cardiovascular properties, Tibetans have minimally altered cardiac structure, function, or mechanics. First, Tibetans showed a slight increase in PASP and a more favorable RV-PA coupling which did not cause a significant decrease in RV functions compared to Han migrants. In addition, relatively lower HR and BP in Tibetans suggest lower sympathetic tone and, therefore, would be less prone to LV thickening during long-term hypoxia exposure . In termThis study has several limitations. First, this was a cross-sectional study comparing changes in cardiovascular properties in response to hypoxia in short vs. long-term migrants and long-term Hans vs. Tibetans; this cannot rule out the impact of individual variability on the results compared with a longitudinal study. Second, we did not analyze subjects of migrants with 1–5 years of adaptation due to the small number of subjects falling within this timeframe. Third, we did not enroll patients with high altitude pulmonary edema (HAPE) or CMS whose cardiovascular features have been reported in previous studies. In this regard, the results of this study provide important information concerning cardiovascular adaptations of healthy migrants to high altitudes.Han migrants show improved RV structure and function during the long-term dwelling. However, LV remodeling persists without impairment of LV systolic or diastolic function. Despite after >5 years of acclimatization, cardiac properties of Han migrants do not fully return to normal. In contrast, native Tibetans show minimal differences in cardiac properties compared to lowlanders.The original contributions presented in the study are included in the article/supplementary material, further inquiries can be directed to the corresponding author/s.The studies involving human participants were reviewed and approved by Chinese PLA General Hospital Ethics Committee. The patients/participants provided their written informed consent to participate in this study.XC, DB, and KH contributed to conception and design of the study. BL, QJ, and WC organized the database. FY and WW performed the statistical analysis. XC wrote the first draft of the manuscript. LY, ZL, QZ, and YL wrote sections of the manuscript. PZ and HP made charts and figures. All authors contributed to manuscript revision, read, and approved the submitted version.This study was supported by the Science and Technology Innovation Special Zone: No. 19-163-12-ZD-037-003-02.HP and PZ were employed by BioMind Technology Company. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.


Cardiomyopathies are a heterogeneous group of structural, mechanical, and electrical heart muscle disorders which often correlate with life-threatening arrhythmias and progressive heart failure accounting for significant cardiovascular morbidity and mortality. Currently, cardiomyopathies still represent a leading reason for heart transplantation worldwide. The last years have brought remarkable advances in the field of cardiomyopathies especially in terms of understanding the molecular basis as well as the diagnostic evaluation and management. Although most cardiomyopathy treatments had long focused on symptom management, much of the current research efforts aim to identify and act on the disease-driving mechanisms. Regarding risk assessment and primary prevention of sudden cardiac death, additional data are still pending in order to pave the way for a more refined and early patient selection for defibrillator implantation. This review summarizes the current knowledge of hypertrophic, dilated and arrhythmogenic cardiomyopathy with a particular emphasis on their pathophysiology, clinical features, and diagnostic approach. Furthermore, the relevant ongoing studies investigating novel management approaches and main gaps in knowledge are highlighted. Cardiomyopathies encompass a diverse group of diseases characterized by structural and functional disorders of the heart in the absence of coronary artery disease, hypertension, valvular disease, and congenital heart disease sufficient to cause the observed myocardial abnormality. They can be either inherited and/or acquired and represent a leading cause of heart failure-related morbidity and mortality. Cardiomyopathies can present with heterogeneous clinical courses, ranging from an asymptomatic to a severely symptomatic phenotype which can present with heart failure, malignant arrhythmias, or sudden cardiac death . During HCM is the most common inherited cardiomyopathy. It involves mutations in numerous genes encoding sarcomeric proteins and is transmitted in an autosomal dominant manner with variable penetrance. Historically, HCM was first defined in 1868 by Vulpian et al. as an idiopathic hypertrophic subaortic stenosis . In the HCM is defined as the presence of an increase in wall thickness (greater than 14 mm) in one or more LV segments, as measured by an imaging technique, which cannot be justified by abnormal loading conditions. The estimated prevalence according to epidemiological studies ranges from 1:200 to 1:500 with an annual mortality rate of approximately 1.4% . Di. Di32]. Septal reduction therapy at experienced centers is indicated in patients with a resting or provoked obstructive disease who remain symptomatic despite optimal medical therapy (Class I-recommendation)  33]. Co. Co33]. According to the latest European guidelines, a 5-year-SCD assessment is recommended (Class I-recommendation) in all HCM patients in order to identify candidates who will benefit from primary prevention using an implantable cardioverter-defibrillator (ICD) . To thisAdvances in understanding the genetic mechanisms of HCM has led to an increasing interest to develop targeted molecular therapies which improve symptoms and positively influence the disease course .Recently, mavacamten (MYK-461) has emerged as a novel allosteric inhibitor of cardiac myosin adenosine) triphosphatase (ATPase) sarcomere level, causing a reduction of the cardiomyocyte hypercontractility and promoting cardiac muscle relaxation. Its beneficial effects on HCM patients were first shown in the phase 2 PIONEER-HCM trial. The results were promising since mavacamten was associated with improvement of post-exercise LVOT-gradient and exercise capacity in patients with obstructive HCM . FollowiHCM cardiomyocytes are characterized by an enhanced late sodium current activity, leading to increased levels of intracellular calcium which ultimately contribute to arrhythmic propensity. Moreover, the intracellular sodium overload promotes the cardiomyocyte diastolic dysfunction and impaired myocardial perfusion ,45. RanoThe inefficient phosphate metabolism observed in HCM patients is another target of novel therapies. Perhexiline  was initially utilized as an antianginal treatment because of its coronary dilatator effects. Successively, this agent had demonstrated positive effects on the myocardial energetic status by shifting the myocardial metabolism from fatty acid to glucose utilization and consequently ameliorating the myocardial efficiency by increasing ATP production . This obDCM is defined as dilatation of the left or both ventricles and systolic dysfunction in the absence of abnormal loading conditions  or significant coronary artery disease sufficient to explain a global systolic impairment . DCM repThe causes of DCM are heterogeneous and can be broadly classified into genetic and nongenetic. Gene mutations occur in up to 40% of DCM cases and usually involve genes encoding for cytoskeletal, sarcomere and nuclear envelope proteins . InteresMore than 50 DCM-related genes have been shown to be implicated in the pathogenesis of DCM. Most of these genetic alterations have an autosomal dominant inheritance pattern; however, other patterns have been reported including autosomal recessive, x-linked, mitochondrial and polygenic . MutatioAbout 5% of DCM cases are linked to mutations in the Lamin A/C (LMNA) gene encoding to lamin proteins A and C involved in the stabilization of the inner nuclear lamina in cardiomyocytes. Notably, LMNA mutations have been shown to be associated with malignant ventricular arrhythmias and a high incidence of SCD. Moreover, LMNA mutations have been described in patients with muscular dystrophy Emery-Dreyfus (EDMD), limb-girdle-dystrophy, axonal neuropathy type 2 Charcot- Marie-Tooth, and familiar partial lipodystrophy . Other mTo date, mutations in metabolic genes as a direct cause of DCM have not yet been reported in humans. However, recent findings from an animal model showed that suppression of cardiac low-density lipoprotein receptor-related protein 6 (LRP6) expression is associated with altered cardiac fatty acid utilization and lethal DCM. Subsequently, further human studies to determine the extent of contribution of fatty acids metabolism in the pathogenesis of DCM could help to elucidate disease pathogenic events .Although myocarditis usually heals completely, it is reported that up to 6–30% of cases may shift in DCM with worsening of cardiac function . MyocardIn the western countries, excessive alcohol intake has been shown to be associated with up to 36% of DCM cases . The posPeripartum cardiomyopathy (PPCM) is a rare, often dilated, cardiomyopathy with heart failure secondary to LV systolic dysfunction affecting childbearing women in late pregnancy or up to 5 months postpartum. Potential risk factors for PPCM include race (mainly Afro-Caribbean descent), multiparity, advanced maternal age and presence of hypertension with or without pre-eclampsia. Although the exact pathogenesis of PPCM is still not fully established, the proposed etiology is multifactorial. A main proposed mechanism suggests an unbalanced peripartum oxidative stress that triggers the cleavage of the nursing hormone prolactin into a potent antiangiogenic and proinflammatory fragment leading to endothelial and cardiomyocyte dysfunction . Recent Usually, DCM presents typical signs and symptoms of congestive heart failure as progressive dyspnea, ankle swelling and orthopnea. Other forms of initial presentation include arrhythmias , thromboembolic events and SCD. In fewer cases, asymptomatic cardiomegaly may be the first presenting sign .Echocardiography has crucial importance in the diagnosis, follow-up and family screening of DCM. The main echocardiographic diagnostic feature is characterized by presence of LVEF < 45% and LV end-diastolic diameter (LVEDD) or volume greater than two standard deviations according to nomograms corrected by age, gender and body surface area . These fThe presence of right ventricular dilatation and dysfunction correlates usually with a worse functional status and more advanced stages of heart failure . Recent CMR offers a highly sensitive assessment of global biventricular size and function. Moreover, CMR enables through LGE assessment detection of myocardial fibrosis and oedema, which allows a differentiation among various causes of DCM . In thisIschemic cardiomyopathy can be differentiated from DCM by echocardiography in the vast majority of cases. However, ischemic cardiomyopathy may present as global hypokinesis mimicking DCM. In these situations, coronary angiography should be considered to exclude ischemic cause, especially in the presence of risk factors for coronary artery disease . In patiCurrently, the American and European Heart Rhythm Societies recommend genetic testing for DCM patients and their first-degree relatives in the presence of significant conduction disease and/or a family history of SCD. Relatives who do not carry a pathogenic variant are reassured and discharged from ongoing cardiac follow-up. On the other hand, carriers of a familial variant should undergo close clinical surveillance ,77.The management of DCM is focused on reducing congestive heart failure symptoms as well as early surveillance and treatment of arrhythmia.The pharmacological treatment of heart failure in DCM patients with reduced LVEF follows the current guideline-directed therapies which includes angiotensin-converting enzyme (ACE) inhibitors (or Angiotensin receptor blockers (ARBs)), in association with beta-blockers, and mineralocorticoid antagonists . Incremep = 0.002) ..113].An International Task Force Consensus Statement proposed a risk stratification algorithm for preventive implantation of ICD, based on a review of observational cohort studies in patients with right ventricular variants of ACM . AccordiCurrent management in ACM patients is limited to symptom relief and prevention of SCD. However, novel therapeutic approaches targeting the underlying genetic and molecular mechanisms are on the horizon.In preclinical ACM models, application of adeno-associated virus (AAV) gene therapy targeting PLN-gene mutation by delivering antisense ribonucleic acid (RNA) has been shown to restore normal calcium handling .Recent promising findings from a translational study highlighted an involvement of extra-cardiac bone marrow (BM)-mesenchymal stem cells (MSCs) in the pathogenesis of ACM. The examination of both cardiac- and BM- MSCs isolated from DSG2-mutant mice showed profound alterations in cytoskeletal organization, which are directly caused by DSG2 downregulation. Interestingly, the mutant circulating BM-MSCs have shown an increased propensity to migrate to the injured region of the heart . This fiIn recent years, we have witnessed growing improvements in cardiovascular imaging modalities as well as a deeper knowledge of genotype–phenotype correlations in the field of cardiomyopathies, which in return brought significant advances in the diagnostic and therapeutic decision-making. On the other hand, there are still a number of unanswered questions due to knowledge gaps.In HCM, SCD remains the most devastating and challenging presentation since it may occur without preceding symptoms. Indeed, the developed risk stratification models adopted by the American and European societies are still imperfect since they are primarily based on registries, retrospective, or prospective small-scale studies.Another issue is related to the assessment of myocardial fibrosis by CMR through LGE. In fact, there is still no universal standardized technique for the quantification of LGE  technique) . FurtherConcerning familial cases of DCM, recommendations for familial cascade screening to identify relatives at risk of developing the disease have been well established by current guidelines. However, there is still no specific evidence for early pharmacological treatment in phenotype-negative carriers of pathogenic genetic variants to prevent LV remodeling or cardiovascular mortality.Although the fact that around one-third of patients with DCM experience a relapse in chronic disease after an initial recovery of LVEF, current guideline recommendations for DCM treatment still do not vary from general heart failure management . TherefoAnother remarkable challenge emerged from the refinement of primary ICD indication in non-ischemic DCM by respective guidelines which well delineated the limitation of relying mainly on LVEF . New insLastly, a growing body of evidence based on pathological and clinical studies in patients with right-sided phenotypic variants of ACM has provided significant insights into the clinical manifestations, risk stratification, and indications for primary SCD-prevention. However, prospective data on clinical outcome and predictors of arrhythmic burden in patients with biventricular or left-dominant ACM are still lacking in the current guidelines’ recommendations. Another issue to overcome concerns the effectiveness and safety of applying catheter ablation techniques in the management of atrial arrhythmias in ACM. Further, psychosocial stress has been recently suggested as an independent risk factor involved in the pathogenesis of ACM by promoting disease penetration . In the


No difference in PVBs’ occurrence was found between near normal valve BAV and pathological BAV, nor was a difference in echocardiographic characteristics found between patients with and without outflow tract arrhythmias. Conclusions: A possible causal link between BAV and PVBs was highlighted, but no association between PVBs and complicated BAV was emphasized.Background: The aim of this study was to identify a possible link between bicuspid aortic valve (BAV) and premature ventricular beats (PVBs), particularly from left and right ventricular outflow tracts, and to investigate possible associations between these arrhythmias and echocardiographic abnormalities. Methods: A comparison of sportspeople with and without BAV was performed to identify PVBs’ occurrence in these two series. Then, subdividing the BAV group on the presence of cardiovascular complications due to BAV, we compared arrhythmic features between these two subgroups and echocardiographic findings between athletes with and without left and right outflow tract PVBs. Results: PVBs in 343 athletes with BAV were compared with 309 athletes without BAV, showing an increased frequency (29% vs. 11.8%,  Bicuspid aortic valve (BAV) is one of the most frequent congenital heart diseases, with a prevalence of 0.5–2%  in the general population [BAV can be found as an isolated defect or associated with other abnormalities, such as aortic dilatation  and aortEven though the pathogenetical basis of BAV remains to be fully elucidated, most evidence supports the current interpretation of BAV as a multifactorial disease, in which both genetic and hemodynamic factors seem to play a key role in explaining the heterogeneity of phenotypes and natural history .Some authors have hypothesized a role for neural crest (NC) cells in the pathogenesis of BAV. In fact, from an embryological point of view, the neural crest (NC) plays an important role in the development of cardiac structures, in particular the outflow tract and the aortic arch ,14, and Assessing the eligibility for competitive and/or professional sports of athletes with BAV can be challenging. In fact, all possible co-pathologies and complications must be researched and “weighed” in the overall assessment, also considering that the impact of regular training on the natural course of BAV is not fully established ,19. For One of the less investigated aspects is the link between BAV, sport activity and the incidence of premature ventricular beats (PVBs), especially those originating from the left and right ventricular outflow tracts .PVBs are a common ECG finding in the general population and are recorded in up to 75% of healthy individuals undergoing 24-h ambulatory ECG monitoring, with an age-related increase in prevalence ,22 but nUnder the hypothesis that BAV is a malformation linked to an anomalous migration of the neural crest cells, which are involved in in the development of the outflow tracts, we sought to test the hypothesis that there is a correlation between this anomaly and arrhythmias originating from these cardiac areas, and that these arrhythmias are not related to a worsening of the patient’s overall clinical profile. For this reason, we tried to assess whether BAV is linked to PVBs from the left and right outflow tracts, and that these arrhythmias are not related to the morphological and functional status of the aortic valve, aortic root and left ventricle.We retrospectively analysed the database of Sport Medicine Unit, Fondazione Policlinico Universitario A. Gemelli IRCCS, between 1987 and 2020, in order to extract the records of sportspeople (competitive and non-competitive) with BAV (BAV), discovered incidentally during pre-participation screening or who came to our centre for counselling after diagnosis. We compared these subjects with a group of athletes without BAV, matched for age and sex (NOT-BAV). We defined competitive athletes according to the 16th Bethesda conference, which defines a “competitive athlete” as an individual who participates in an organized team or in a sport that requires regular competition against others, places a high premium on excellence and achievement and requires some form of systematic and intense training . FurtherPracticing sports on a non-competitive, competitive or professional level.Having undergone a 12-lead resting electrocardiogram (ECG), stress-test ECG and 2-dimensional trans-thoracic echocardiography (ECHO).No cardiovascular symptoms, known cardiovascular disease (other than BAV) and ECG abnormalities except for the possible presence of PVBs.As for the control group, no ECHO evidence of cardiovascular anomalies, i.e., normal chamber size; normal volume and wall thickness; normal left ventricular systolic and diastolic function; absence of intracardiac shunts; normal valvular function and morphology; absence of pericardial effusion; normal size of ascending aorta and arch with normal flow velocities.No history of cardiac surgery.The inclusion criteria were:–Morphology: LVOT origin for PVBs with left bundle branch block pattern, negative complex in V1, precordial S/R transition before V3 and inferior QRS axis in the limb leads, suggestive of the origin from the left ventricular outflow tract; right ventricular outflow tract (RVOT) origin for PVBs with negative QRS complex in V1, precordial S/R transition beyond V4 and inferior QRS axis in the limb leads; fascicular origin for PVBs with right bundle branch block pattern, superior or inferior axis in the limb leads and QRS ≤ 120 msec; other for all other morphologies.–Number of morphologies: monomorphic if only one morphology was found per patient; polymorphic if more than one morphology was present per patient.–Complexity: complex if PVB couplets and/or triplets and/or ventricular tachycardia (VT) were present.–Relationship with exertion: exercise-related PVBs if present only during the exercise phase of the stress-test ECG, not exercise-related PVBs if present at rest and/or during the recovery phase of the stress-test ECG.In both the BAV and the NOT-BAV group, we took into account any athlete who showed at least one PVB during ECG or stress-test ECG. We classified ventricular arrhythmias, based on current criteria , as follStress-test ECG was performed using a cycle ergometer and incremental protocol of 30 watt/2 min until muscle exhaustion or the criteria defined by international guidelines for discontinuation were reached , with coFinally, we tested the hypothesis that BAV athletes with PVBs from left and right outflow tracts had no worse echocardiographic status than athletes without this sort of ventricular arrhythmias.The normal distribution of all continuous variables was examined using the Shapiro–Wilk test, and data are presented as mean ± SD or median (IQR) accordingly. Categorical variables were reported as absolute numbers and percentages.Comparisons were performed using chi-squared or Fisher exact tests in case of categorical variables, whereas Mann–Whitney U-test was used to check differences in case of continuous variables.p < 0.05. Statistical analysis was carried out with SPSS 26.0.Differences were considered significant with a We found 343 records of sportsmen with BAV meeting the inclusion criteria , of which 186 (54.2%) were competitive and 157 (45.8%) non-competitive athletes.The NOT-BAV group was composed of 309 sportsmen , of which 208 (67.3%) were competitive and 101 (32.7%) non-competitive. The two populations were homogeneous for age and gender .p < 0.001; OR 3.1; CI 2.1–4.7).We found a 29% occurrence (100/343 people) of PVBs in the BAV group vs. 11.8% (36/309 people) in the NOT-BAV group ; instead, comparing the BAV and NOT-BAV groups, as expected, BAV athletes showed more frequently both exercise-related  and not exercise-related PVBs .As regard the relationship with the exertion, in the BAV group a higher occurrence of exercise-related PVBs in respect to not exercise-related PVBs was not noted , RVOT in 52 (15.2%), LVOT and RVOT (polymorphic) in 15 (4.4%), fascicular in 4 (1.2%) and other in 20 (5.8%). In the control group, the morphology was LVOT in 10 cases out of 309 (3.2%), RVOT in 11 (3.6%), LVOT and RVOT in 2 (0.6%), fascicular in 3 (1.0%) and other in 1 (4.9%). A statistically significant difference between BAV and NOT-BAV was present as regard the rate of occurrence of RVOT and LVOT morphologies, whereas no significant difference was found for fascicular PVBs and other morphologies.p < 0.001; OR 5.7, CI 2.0–16.7); these complex PVBs in the BAV group were monomorphic in all cases, and they arose from outflow tracts in most of the cases .Among the BAV, 24 subjects out of 343 (7.0%) had complex PVBs, whereas in the NOT-BAV they were present in 4 cases out of 309 .  BAV athletes, whereas among NOT-BAV athletes they were found in 10 (3.2%) people (.8–3.6). .p = 0.8; OR 1.2; CI 0.3–4.1; 12.7% vs. 7.2% in NOT-BAV, p = 0.207; OR 0.53; CI 0.9–1.4).When comparing non-competitive and competitive sportspeople with regard to the presence of PVBs within both the BAV group and the NOT-BAV group, no significant differences were found . According to this subdivision, the NNV group consisted of 99 people, while the PBAV numbered 244. When comparing the arrhythmias  between these two series, no difference was noted; specifically, there was no different occurrence of PVBs from LVOT and/or RVOT between the two series .To confirm the absence of a relationship between the occurrence of ventricular outflow tract arrhythmias and echocardiographic abnormalities, we finally tried to compare the echocardiographic parameters between people with and without these type of PVBs : our anaBicuspid aortic valve (BAV) is a congenital valvular heart disease with a natural history that sometimes evolves into complications ; hence, the focus of follow-up is on echocardiography in order to identify cases that should be addressed by surgical correction ,30. As iOur study, for the first time, showed an increased frequency of ventricular arrhythmias both at rest and during exercise in a group of sportspeople with BAV in comparison to a control group with normal hearts. As expected, the level of sports practice (competitive or non-competitive) does not seem to affect the occurrence of PVBs.Moreover, these arrhythmias seem to originate mainly from the right and left outflow tracts, which embryologically derive from neural crest cells, the same cells that originate the cardiac conduction system: in fact, no difference in the occurrence of PVBs between the two groups was found for PVBs with fascicular morphology or with morphologies other than LVOT or RVOT. According to recent work by Corrado et al., PVBs from outflow tracts are defined as having a “common” morphology, as they are often found in athletes, typically in association with normal cardiac morphology and function and generally without an increased risk of sport-related sudden cardiac death . TherefoIn light of our results, we believe that the identification of outflow tract arrhythmias should also be considered a “common” finding in BAV, which should prompt careful evaluation, but which could be considered “favourable”, until proven otherwise, as in apparently “healthy” athletes.In this regard, we would like to recall that, nowadays, the Italian guidelines on competitive sport eligibility recommend an ECHO, a stress-test ECG and a 24-h Holter ECG, possibly including a training session to evaluate competitive athletes with BAV , while oFirstly, as our population consisted exclusively of athletes with BAV, our considerations are limited to them and cannot be generalised .Our series does not allow us to provide indications on the role of PVBs on the natural history of bicuspid aortic valve, as we have not carried out follow-up analysis (which are in progress): thus, we limited ourselves to highlighting the possible clinical implications of the observed relationship between BAV and PVBs.Furthermore, we do not have any further data on 24-h ambulatory ECG monitoring, which could add different information about PVBs  and on other diagnostic examinations, in particular imaging studies , electrophysiological studies and/or genetic screening, which could allow us to evaluate the presence of any kind of pathological issue.Lastly, we are also aware of the possibility of the misinterpretation of PVBs’ morphology, commonly due to the variable spread of excitation through the ventricle (in particular in patients with coronary artery disease), the presence of different degrees of fusion with the subsequent sinus complex and additional aberrant conduction secondary to the short RR interval in the second beat of a couplet .BAV is very common in the general population, with a possible risk of serious complications. To date, there is no certainty that intensive sports practice does not increase the risk of these complications in the long term. Therefore, competitive sports practice for athletes with BAV requires extensive evaluation and proper follow-up over time. The relationship between PVBs and BAV has been scarcely explored in recent years. Our series demonstrated that PVBs are more frequent in athletes with BAV than in the general population and that they mainly originate from the left ventricular and right ventricular outflow tracts. Moreover, no difference was found in the occurrence of PVBs between people with near normal and pathological BAV. Lastly, echocardiographic findings were similar by dividing the BAV group into people with and without outflow tract arrhythmias. Our study, for the first time, highlights a possible causal link between BAV and PVBs from the outflow tracts and points out no association between the presence of PVBs and complicated BAV.


The LA total emptying fraction was the only functional index that showed a statistically significant improvement. The initial LA peak’s late negative strain rate (SRa) was the only parameter with a significant predictive power of major adverse cardiac events under univariable  and multivariable Cox survival analysis when adjusted by LA strain parameters , LA strain and functional parameters , and LA and biventricular strain and functional parameters . Thus, our findings indicate that CMR strain is useful for monitoring LA and ventricular function in suspected myocarditis, that LA function may recover preceding ventricular function changes, and that LA strain may serve as an incremental tool to predict adverse outcomes.To assess the variation in left atrial (LA) and biventricular strain and its prognostic value in the course of suspected myocarditis, this retrospective study included 55 patients with clinically suspected myocarditis who underwent cardiac magnetic resonance (CMR) examinations at baseline and follow-up periods. Cine images were used for feature tracking analysis. Paired Student’s  Myocarditis is an inflammatory disease that often occurs in young adults and is the leading cause of cardiac morbidity and mortality in young athletes ,2. AthleCurrently, cardiac magnetic resonance (CMR) is the non-invasive gold standard imaging modality for the diagnosis and follow-up of myocarditis, the diagnostic criteria being referred to as “Lake Louis Criteria” (LLC) ,7. MyocaA total of 79 patients, diagnosed with clinically suspected myocarditis (according to the 2013 ESC guidelines) [Three different 3.0 T systems, namely, Magnetom Verio , Achieva , and Discovery MR750w , were used for CMR examinations. Respiratory navigation electrocardiographic gating and parallel imaging techniques were applied. After the initial survey, HASTE black blood sequencing was performed. This was followed by the capture of short-axis T2WI-STIR (black blood T2-weighted imaging short tau inversion recovery) images, as well as cine images of the short-axis and 2-, 3-, and 4-chamber long-axis views. Approximately 10 min after the intravenous injection (at a dose of 0.2 mmol/kg) of gadolinium-based contrast agent , LGE images of short-axis and 2- and 4-chamber long-axis views were acquired. T1 and T2 mapping images were not acquired. The sequences used in the second CMR examination were the same as those used in the first. The detailed sequence parameters are provided in the Two experienced radiologists with more than 5 years of experience in cardiac medical imaging interpreted the CMR images. Myocardial edema, detected in T2WI-STIR images, and the presence of nonischemic LGE were visually evaluated. Cvi42 software version 5.2.0  was used for global LA, LV, and right ventricular (RV) function analysis; volume analysis; and FT analysis. Inter- and intra-observer reproducibility were tested using a random cohort of 14 cases, before FT analysis was performed.Cine images of the short axis were used, the end-systolic and end-diastolic phases of the LV and RV were automatically defined (they can be the same or different), and the endocardium and epicardium of the LV and the endocardium of the RV in each slice were automatically depicted. The papillary muscle was included in LV volume. The inner and outer rims of the LV and inner rim of the RV were manually adjusted until they could be accurately tracked. Thereafter, indices of the LV and RV function and volume were acquired, including left ventricular end-diastolic volume (LVEDV), left ventricular end-systolic volume (LV-ESV), left ventricular stroke volume (LV-SV), left ventricular ejection fraction (LVEF), LV mass, right ventricular end-diastolic volume (RV-EDV), right ventricular end-systolic volume (RV-ESV), right ventricular stroke volume (RV-SV), and right ventricular ejection fraction (RVEF).Cine images of 2- and 4-chamber views were used, and the inner rim of the LA (excluding the LA appendage and pulmonary veins) was automatically defined at LV end-diastole, before (LAVpac) and after (LAVmin) LA contraction, as well as at LV end-systole (LAVmax). LA functional indices, including the left total atrial emptying fraction (LAEF), the passive atrial emptying fraction (LAPEF), and the active atrial emptying fraction (LAAEF), were calculated as described in a previous study .3D global LV and RV and LA myocardial strain analyses are shown in All patients were followed up through chart reviews or telephone interviews. The primary endpoint was major adverse cardiac events (MACE), including cardiac death, ventricular tachycardia, and rehospitalization due to myocarditis recurrence. The follow-up time was calculated by subtracting the date on which MACE occurred, or the follow-up date, from the date of the second CMR examination.t test, and categorical variables were compared using McNemar’s test. Cox proportional hazards regression was used to determine univariable and multivariable associations with MACE, and the results were reported with a 95% confidence interval (CI). A p < 0.05 was considered statistically significant.SPSS  was used for statistical analysis. After testing for normal distribution, continuous variables were expressed as mean ± standard deviation or median with interquartile range. Categorical variables were presented as counts and percentages. To evaluate the reproducibility of CMR-FT analysis, inter- and intra-observer agreement was analyzed using intraclass correlation coefficients. Continuous variables were compared using paired Student’s Inter- and intra-observer agreement assessments of the LA and biventricular strain parameters were performed by two experienced radiologists. To interpret the 14 randomly selected cases, repeated analysis was performed after a 2-week interval. The reproducibility was good for all analyzed strain parameters see .The median age of the study population was 15 (range: 10–64) years. The baseline clinical characteristics of the study cohort are summarized in p = 0.033). However, RVEF decreased slightly , although the difference was not statistically significant. The absolute value of strain parameters of LV, RV, and LA all increased to a certain extent, and the difference was statistically significant for LVGLS , RVGRS , εs , εe , and SRa . In the multivariable model for MACE (p = 0.010); LA strain and functional parameters ; and all LA, LV, and RV strain and functional parameters .When all the second laboratory and CMR parameters were subjected to univariable Cox proportional hazards regression analysis, none of them showed a significant association with MACE see . The profor MACE , SRa alsCMR plays an important role in the follow-up of patients with myocarditis. Our study included patients with clinically suspected myocarditis who underwent two CMR examinations. This is the first study to comprehensively evaluate the alterations in LA and biventricular strain and the relationship between strain parameters and MACE during follow-up. The key findings of this study are as follows: (1) LA and biventricular myocardial strain improved upon follow-up, and LAEF was the only significantly recovered functional parameter; and (2) the initial LA SRa was the only significant predictor of MACE upon follow-up.During the follow-up period, acute myocarditis progressed into the chronic phase; the electrocardiogram tended to normalize; the levels of serum markers of myocardial injury, inflammation, and heart failure were reduced; and the proportion of patients with visible myocardial edema and myocardial injury decreased. Over the course of myocarditis, as reported earlier by Luetkens et al. , LV and LA function in cardiac disorders has attracted wide attention in recent years, and its dysfunction plays an important role in cardiovascular diseases, including atrial fibrillation, cardiomyopathies, heart failure, and valvular heart diseases ,24. HoweIn our study, LA strain improvement was statistically significant, and the initial LA SRa was the only significant predictor of MACE, while the second LA strain upon follow-up was not associated with poor patient outcomes. The prognostic value of LA strain has been validated in the context of other cardiovascular diseases. Zhou et al. found that LA strain was more sensitive than LV GLS in evaluating the primary endpoint in hypertrophic cardiomyopathy and hypertension . A studyOur study has some limitations. First, the enrolled patients were diagnosed with clinically suspected myocarditis, “LLC” was not satisfied in all patients; parametric imaging, including mapping and assessments of extracellular volume (ECV), was absent; no patients received endomyocardial biopsy (EMB) confirmation. Second, the sample size of the study was relatively small. Further studies with larger sample size are needed to verify our findings.During the course of suspected myocarditis, CMR strain analysis is useful for monitoring both atrial and ventricular function, and LA function may recover before LV and RV function changes. Initial LA strain may serve as a useful tool to predict adverse outcomes during follow-up, and may be incremental to ventricular strain parameters.


Although the angiotensin receptor-neprilysin inhibitor (ARNI) sacubitril/valsartan started a new era in heart failure (HF) treatment, less is known about the tissue-level effects of the drug on the atrial myocardial functional reserve and arrhythmogenesis.n = 42) undergoing open-heart surgery, and functional experiments were conducted in muscle strips (n = 101). B-type natriuretic peptide (BNP) did not modulate systolic developed force in human myocardium during β-adrenergic stimulation, but it significantly reduced diastolic tension (p < 0.01) and the probability of arrhythmias (p < 0.01). In addition, patient's plasma NTproBNP positively correlated with isoproterenol-induced contractile reserve in atrial tissue in vitro . Sacubitrilat+valsartan  did not show positive inotropic effects on atrial trabeculae function but reduced arrhythmogeneity. Atrial and ventricular biopsies from patients with end-stage HF (n = 10) confirmed that neprilysin (NEP) is equally expressed in human atrial and ventricular myocardium. RA NEP expression correlates positively with RA ejection fraction (EF)  and left ventricle (LV) NEP correlates inversely with left atrial (LA) volume .Right atrial (RA) biopsies were retrieved from patients (in vitro. Myocardial NEP expression is downregulated with declining myocardial function, suggesting a compensatory mechanism in HF.BNP ameliorates diastolic tension during adrenergic stress in human atrial myocardium and may have positive long-term effects on the inotropic reserve. BNP and Sac/Val reduce atrial arrhythmogeneity during adrenergic stress  Heart failure (HF) is a major burden in Western societies, both economically and in terms of disability-adjusted life years lost. Its prevalence is increasing with age up to 10% in the 8th decade of life . HF withOne of the pivotal enzymes involved in NP degradation is neprilysin (NEP), an endopeptidase located on the extracellular portion of the cell membrane . The regIn 2014, the PARADIGM-HF trial introduced the first of its kind angiotensin receptor-neprilysin inhibitor (ARNI), sacubitril/valsartan, which exerts its function by a dual mechanism, namely, angiotensin receptor blockage and NEP inhibition . BesidesIn this study, we, therefore, investigated the functional and antiarrhythmic effects of BNP and Sac without and with Val on human atrial myocardium. Furthermore, we also analyzed the expression of NEP in failing human left ventricular (LV) and right atrial (RA) myocardial samples.The study was performed in line with the 1975 Declaration of Helsinki ethical guidelines. Sample acquisition at Charité Campus Virchow-Klinikum and German Heart Center Berlin (DHZB) was approved by the Local Ethics Committee of the Charité (EA2/167/15) and the Ethics vote for the Biobank at the DHZB (EA4/028/12). All patients were ≥18 years old and provided written informed consent prior to enrolment. Patients with active malignancy, congenital heart disease, and endocarditis were not enrolled in our study, and one patient was excluded due to reported chronic right coronary artery occlusion. RA myocardial tissue and peripheral blood serum samples were obtained as part of the routine surgical procedure for patients undergoing heart surgery with extracorporeal circulation . Relevant medical and drug history was obtained from the patients' files.Transthoracic echocardiography was performed within a week before surgery by an experienced investigator, using an Epiq 7G station  with a 2.5-MHz probe, and loops were recorded using standardized protocols. Echo data sets on (preoperative) ventricular and atrial function were reviewed and reanalyzed as applicable regarding the relevant readouts by an independent examiner (U.P.). According to the local standard operating procedure, left atrial (LA) and RA speckle-tracking analysis was performed using TomTec software .max), as also described previously  as part of the standard surgical procedure for patients undergoing open-heart surgery with extracorporeal circulation . RAA biopsies from 42 patients with cumulative 101 muscle strips were included in our study collected between December 2018 and April 2020. Trabeculae were excised using microsurgical scissors and forceps. Human atrial muscle strips  were isolated, as the risk of central ischemia increases with muscle diameter. Directly after the end of the functional measurements, all muscle strips were snap-frozen in liquid nitrogen and stored for further molecular biology analysis. Functional atrial myocardium measurements were performed with a force transducer that recorded every muscle contraction (developed force) and relaxation. Muscle strips were stimulated at 1 Hz and 5 ms rectangular field stimulation and then prestretched up to the point of maximal force development (Leviously . The acqn = 101 muscle strips). Atrial trabecula were all treated with the physiological stressor isoproterenol (ISO), which is an unspecific beta-adrenoreceptor (β-AR) agonist. A concentration of 20 nM was used, as this marks a half-maximal saturation of the protein kinase A (PKA)-mediated phosphorylation , and the combination of Sac with Val  on atrial functional reserve and arrhythmogenesis in the presence of physiological stressors and varying stimulation frequency  in 42 patients -Ser239 and -Ser157 phosphorylation was investigated in human atrial muscle strips  using Western blot analysis (see n = 10) with end-stage HF. Tissue was analyzed by the enzyme-linked immunosorbent assay (ELISA) kit  according to the manufacturer's instruction. The total protein concentration in supernatants was determined via Pierce BCA assay (Thermo Scientific). Samples were then diluted in the ratio of 1:5 and assessed in duplicate. The concentration (ng/ml) was normalized to total protein content . See NEP levels were determined in LV and RA biopsies from patients  if not stated otherwise. Multiple comparisons of functional parameters (developed systolic force and diastolic tension) were analyzed with a two-way analysis of variance (ANOVA) with repeated measures (RMs) and Sidak hoc test . Comparitest 4A; , and arrtest 4A; . Correlat . Most patients suffered from at least one cardiovascular risk factor  during adrenergic stimulation with 20 nM ISO over 70 min on diastolic tension and developed systolic force (n = 40 muscle strips from 17 patients). Developed systolic force in the presence of ISO decreased with higher frequency stimulation (2 and 3 Hz) and recovered with 0.5 Hz  (p = 0.09).Furthermore, we investigated the effects of BNP on frequency-dependent modulation of the functional response to ISO (h 0.5 Hz . Treatmeh 0.5 Hz . At 3 anwith RM) . The sloin vitro correlated well with preoperative plasma NTproBNP values of the same patient . Preincubation (1 h) and the presence of Sac in combination with Val in concentrations matching the peak plasma levels found in patients treated orally with an ARNI showed a slight trend toward an increased inotropy with ISO compared to control .We evaluated the effects of the NEP inhibitor Sac on the atrial functional reserve. Preincubation (1 h) and the presence of Sac alone did not affect the developed force or diastolic tension after ISO at different stimulation frequencies . The antiarrhythmic effect of BNP was more pronounced in atrial muscle strips exposed to ISO and frequency stair (n = 40 trabeculae from 17 patients), with a pronounced reduction of arrhythmias in the recovery phase (0.5 Hz) following 3 Hz stimulation  = 0.37; During ISO treatment, some of the atrial muscle strips developed arrhythmias .Sac/Val preincubation and presence tended to decrease overall arrhythmia burden during ISO and frequency stair .Sac treatment without Val had no impact on the prevalence of arrhythmias during adrenergic and frequency-dependent atrial stress (in n = 15 from 5 patients) treated with either Sac/Val or vehicle  and undergoing the frequency protocol, VASP phosphorylation at Ser239 and Ser157 was studied. We did not observe any difference in VASP phosphorylation between Sac/Val-treated atrial muscle strips and control group  that either underwent heart transplantation (70%) or left ventricular assistant device implantation (30%). We also measured NEP in the LV of these patients. The detailed patient characteristics can be found in r = −0.81; p < 0.01, Spearman r test; NEP protein expression was measured in RA biopsies from patients with end-stage HF  NEP is equally present in human atrial and ventricular myocardium, but its expression is reduced with a progression of cardiac dysfunction; and (iii) the combination of Sac and Val does not influence the adrenergic functional reserve in isolated atrial muscle but reduces arrhythmias in response to adrenergic stimulation.This study investigated the effects of BNP and Sac/Val on the functional reserve of human atrial myocardium. To the best of our knowledge, this is the first study to show that (i) BNP ameliorates increased diastolic tension during adrenergic stress and alleviates stress-induced atrial arrhythmogeneity in vitro study. The previously described mechanism of NEP downregulation in HF, therefore, may be, just like other compensatory mechanisms in HF [e.g., myocardial hypertrophy , thus establishing BNP's effectiveness in improving lusitropy in isolated atrial myocardium after ISO treatment.Sac/Val inhibits the degradation of NPs in the myocardium and, therefore, increases the tissue concentration of ANP and BNP. In isolated atrial tissue as used in our study, however, Sac/Val did not reproduce the effect of supramaximal BNP treatment. We, therefore, conclude that the BNP levels intrinsically recruitable (by stretch and adrenergic stimulation) are not sufficient to see an acute effect of Sac/Val treatment on diastolic atrial tension.in vitro, which suggests that long-term effects of (B)NP on adrenergic signaling may play a role in modulating the atrial myocardial functional reserve. Especially, the interplay of cAMP- and cGMP regulated by PDEs, such as PDE3, may serve as an explanation for this effect, as PDE3 degrades up to 50% of cellular cAMP, but can be inhibited by cGMP (cGMP inhibited cAMP PDE)  . Constanp = 0.07; ns)  , 37. For.07; ns) . These f.07; ns) .Despite that, observational clinical data also suggested that ARNI treatment may lower the risk for the development of (recurring) atrial fibrillation and lower the disease burden and frequency of arrhythmic events in patients with non-permanent atrial fibrillation –41.2+ spark frequency (CaSF) and reactive oxygen species (ROS) production on a cellular level . In ventricular tissue, it has been shown that ANP (10 nM) significantly suppresses ISO-induced Caar level . Eiringhreatment . Interesreatment , 20. Thawith ANP .In light of the potential antiarrhythmic properties of Sac/Val on atrial tissue, ARNI treatment should be evaluated in high-risk patients with simultaneous HF and atrial fibrillation or atrial remodeling in future studies. Especially, in this patient group with high morbidity and mortality, it is likely that early ARNI treatment could exert major beneficial effects beyond the classically known ARNI effects by suppressing the induction of atrial arrhythmias and, therefore, maintaining atrial function.In this study, we could demonstrate that both BNP and Sac/Val exert beneficial effects on human atrial myocardium and that NEP expression in progressing HF with reduced EF is downregulated as part of an adaptive mechanism, and our data suggest that the favorable effects of Sac/Val are partly due to the increased concentration of NPs in the myocardium and that these effects are already achieved in therapeutic clinical doses.For this study, we were working with human myocardial samples obtained from routine heart surgeries. As these human samples are not available on a large scale, we had to work with rather small sample sizes. Furthermore, all patients come with a unique combination of comorbidities and genetic variations. Therefore, we had to deal with a heterogeneous group in terms of underlying conditions, which, on the positive side, realistically reflects the clinical variation of patients. For the experiments with Sac and Val, we had to use DMSO as a solvent. More recently, DMSO was identified to influence human cellular processes and to exert toxicity already on low doses , 45. To The original contributions presented in the study are included in the article/The studies involving human participants were reviewed and approved by Local Ethics Committee of the Charité (EA2/167/15) and the Ethics Vote for the Biobank at the DHZB (EA4/028/12). The patients/participants provided their written informed consent to participate in this study.FRH and UP conceived the study design and obtained patients informed consent. FRH obtained Ethics Committee approval and funding. UP collected the patients' clinical data and performed echocardiography analysis. FH, FB, CK, VF, and HG collected right atrial appendages from all patients. PD acquired and analyzed right atrial trabeculae function and assisted in molecular biology. KT contributed to acquisition and analysis of tissue preparation and right atrial trabeculae function. CK furthermore provided patient characteristics for molecular biology studies on NEP expression. DL provided methodological support and contributed to interpretation of the results. PW performed Western Blot and ELISA and interpretation of these results. UP and PD equally contributed to the analysis. FRH, UP, and PD drafted the manuscript and interpretation of all data. BP and FH provided valuable feedback to the manuscript draft. All authors contributed to the manuscript and approved the submitted version.This project was funded by a research grants from Novartis Deutschland GmbH. PD received an MD scholarship from the DZHK. FRH is supported by research grants from the German Research Foundation (DFG: CRC1470 and HE 7737/4-1).The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.