Guanidinoacetic acid (GAA) is a natural amino acid derivative that is well-recognized for its central role in the biosynthesis of creatine, an essential compound involved in cellular energy metabolism. GAA  has been investigated as an energy-boosting dietary supplement in humans for more than 70 years. GAA is suggested to effectively increase low levels of tissue creatine and improve clinical features of cardiometabolic and neurological diseases, with GAA often outcompeting traditional bioenergetics agents in maintaining ATP status during stress. This perhaps happens due to a favorable delivery of GAA through specific membrane transporters (such as SLC6A6 and SLC6A13), previously dismissed as un-targetable carriers by other therapeutics, including creatine. The promising effects of dietary GAA might be countered by side-effects and possible toxicity. Animal studies reported neurotoxic and pro-oxidant effects of GAA accumulation, with exogenous GAA also appearing to increase methylation demand and circulating homocysteine, implying a possible metabolic burden of GAA intervention. This mini-review summarizes GAA toxicity evidence in human nutrition and outlines functional GAA safety through benefit-risk assessment and multi-criteria decision analysis. N-amidinoglycine) belongs to the class of organic compounds known as alpha amino acids and derivatives. GAA  is produced endogenously in the human body from non-essential amino acids glycine and arginine, in a reaction controlled by an enzyme L-arginine:glycine amidinotransferase (AGAT) (2) from arginine to glycine to synthesize GAA, with ornithine as a byproduct. The reaction mainly takes place in the kidney, liver, and pancreas; however, GAA is also produced in the skeletal muscle, brain, and across the gut [S-adenosyl-L-methionine, a reaction catalyzed by guanidinoacetate N-methyltransferase (GAMT), to produce creatine and S-adenosyl-L-homocysteine. The formation of creatine is a major metabolic fate of GAA, and AGAT-driven reaction is considered a rate-limiting step of creatine biosynthesis [Guanidinoacetic acid  . AGAT ca the gut ,2,3. In ynthesis . Since cynthesis , the GAAynthesis ,7, previynthesis ); monocaynthesis .Plasma and urine GAA concentrations of 2.3 ± 0.8 μmol/L and 31.2 ± 21.7 mmol/mol of creatinine likely illustrate natural equilibrium in GAA metabolism . HoweverThe first documented report of GAA utilization as an experimental nutritional intervention in humans arguaby dates back approximately 70 years ago. The group of Henry Borsook from Caltech University demonstrated the beneficial effects of GAA (combined with betaine) in treating cardiac decompensation . The autAfter this inception, subsequent decades prompted a relatively limited interest in studying dietary GAA until 1999, when a Japanese group put forward GAA as a nutritional supplement to compensate for a disease-driven GAA shortage in patients with chronic renal failure . During S-adenosyl-L-methionine, an excessive GAA intake can hypothetically drain the stores of methyl donors in the human body . The metabolic burden of methyl donor deficiency can perturb many cellular functions, including DNA methylation, neurotransmission, antioxidant defense, and protein synthesis [Even the seminal paper that described the biochemical basis of GAA treatment recognized the possible risk of methyl group depletion following GAA consumption . Since tynthesis . Severalynthesis . We founynthesis , a critiS-adenosyl-l-homocysteine is a byproduct of GAA utilization that is further converted to homocysteine in a simple one-step reaction catalyzed by adenosylhomocysteinase: S-adenosyl-l-homocysteine + H2O <=> l-homocysteine + adenosine. Since hyperhomocysteinemia has been recognized as an independent risk factor for various cardiometabolic diseases [diseases , a possidiseases . Elevatediseases , with a diseases . In the diseases . This trdiseases . Similardiseases ,51. HaviSeveral in vitro and animal studies documented neurotoxic effects of exogenously administered GAA. The group of Angela Wyse reported that the intrastriatal injection of GAA induced inhibition of Na+/K+-ATPase activity , glutamaAn exposure to GAA in animal studies exacerbated ethanol-induced liver injury ,61, stimThe risk-benefit assessment is an emerging concept in the area of food safety ,66, withGAA is an investigational dietary supplement. Preliminary human studies suggest that dietary GAA has a relatively acceptable safety profile, yet medium-term intake appears to provoke unfavorable biochemical abnormalities, such as the rise in serum homocysteine (which could be attanuated by GAA co-ingested with creatine). Other adverse events demonstrated in animal studies with non-enteral administration of GAA are not confirmed in human trials with supplemental GAA thus far. Still, the possible toxic effects of GAA in the nervous system reported in pre-clinical research  remain of high concern, with additional human studies required before advancing GAA for human use. Whether beneficial effects outcompete side effects of GAA currently remains unknown in terms of evidence-based efficacy and safety data. A comparative analysis of supplemental GAA safety using multi-criteria decision analysis remains highly warranted to optimize treatment selection within the settings of nutrition and clinical bioenergetics.


Data about the right ventricular (RV) mechanics adaptation to volume overload in patients with repaired tetralogy of Fallot (rToF) are limited. Accordingly, we sought to assess the mechanics of the functional remodeling occurring in the RV of rToF with severe pulmonary regurgitation.We used three-dimensional transthoracic echocardiography (3DTE) to obtain RV data sets from 33 rToF patients and 30 age- and sex- matched controls. A 3D mesh model of the RV was generated, and RV global and regional longitudinal (LS) and circumferential (CS) strain components, and the relative contribution of longitudinal (LEF), radial (REF) and anteroposterior (AEF) wall motion to global RV ejection fraction (RVEF) were computed using the ReVISION method.Corresponding to decreased global RVEF , rToF patients demonstrated lower absolute values of LEF (17 ± 4 vs 28 ± 4), REF (20 ± 5 vs 25 ± 4) and AEF (17 ± 5 vs 21 ± 4) than controls (p < 0.01). However, only the relative contribution of LEF to global RVEF  was significantly decreased in rToF, whereas the contribution of REF  and AEF  to global RVEF was similar to controls. Accordingly, rToF patients showed lower 3D RV global LS  and CS  than controls. However, looking at the regional RV deformation, the 3D CS was lower in rToF than in controls only in the basal RV free-wall segment (p < 0.01). 3D RV LS was reduced in all RV free-wall segments in rToF (p < 0.0001), but similar to controls in the septum (p > 0.05).3DTE allows a quantitative evaluation of the mechanics of global RVEF. In rToF with chronic volume overload, the relative contribution of the longitudinal shortening to global RVEF is affected more than either the radial or the anteroposterior components. The chronic pulmonary regurgitation and consequent right ventricular (RV) failure in patients after repair of tetralogy of Fallot is an important cause of morbidity and late mortality . PulmonaA previous study demonstrated that the deterioration of RV longitudinal strain has been found in repaired tetralogy of Fallot (rToF) patients with maintained RV ejection fraction (RVEF) , suggestHowever, due to the complex RV anatomy and mechanics it is difficult to obtain a comprehensive imaging of the RV by two-dimensional transthoracic echocardiography (2DTE) . AccordiWe hypothesized that chronic volume overload affects the RV mechanics and that these changes are related to changes in RV function. Accordingly, our aim was to investigate the global and regional RV mechanics in rToF patients with chronic RV volume overload compared with healthy volunteers using 3D echocardiography.We performed a prospective longitudinal study on rToF patients followed up at our centre  between May 2016 and January 2017. We obtained 3DTE data sets of the RV from 33 rToF patients  with chronic severe pulmonary regurgitation without significantly elevated RV systolic pressure . In 29  selected from the Padua “3D Echo Normal” database . RecruitOur study protocol was approved by the University of Padua Ethics Committee (protocol 2380P approved on 06/10/2011). Written informed consent was obtained from all volunteers.Transthoracic echocardiography examinations were performed by an experienced sonographer using the Vivid E9 scanner  equipped with M5S-D and 4 V-D probes with patients in the left lateral decubitus position. In addition to a complete standard 2D and Doppler examination, dedicated 2D and 3DTE acquisitions were obtained according to the study protocol. Digital loops were stored in a dedicated workstation and analyzed offline.To assess the RV systolic function, fractional area change (FAC), M-mode-derived tricuspid annular plane systolic excursion (TAPSE) and systolic pulsed wave tissue Doppler velocity of the lateral tricuspid annulus (s′) were measured .Three consecutive cardiac cycles, ensuring a frame rate between 50 and 80 Hz, were recorded in dedicated apical 4-chamber RV-focused view for RV longitudinal strain (LS) quantifications. Assessment of RV global LS, RV interventricular septum and free wall LS was performed by 2D speckle tracking echocardiography using Q-Analysis package  according to recently published recommendations . SubjectTricuspid and pulmonary regurgitation were quantified using color Doppler and continuous wave Doppler traces according to current guidelines , 13. PulBeyond the conventional echocardiographic protocol, multi-beat (4 or 6) full-volume RV and left ventricular data sets were acquired during end-expiratory breath-hold from the apical approach, including the entire structure in the acquisition, with particular attention to RV anterior wall and outflow tract. Each acquisition was verified to rule out stitching artifacts or incomplete RV visualization. Image depth and sector were optimized to achieve frame rates ≥ 20 Hz.Offline analysis of 3D RV end-systolic and end-diastolic volumes, and ejection fraction were performed by a single experienced investigator using a commercially available 3DE software package  . Quantifwww.revisionmethod.com) [3D RV models can be exported from the commercially available TomTec software serving as input to assess the longitudinal, radial, and anteroposterior RV wall motions and their relative contribution to global RVEF using the ReVISION method   Fig. 1)www.revishod.com) .Fig. 1ThThe qualitative variables were presented using absolute numbers and percentages. The continuous variables were summarized using mean value ± standard deviation. The RV strain parameters were considered negative .The distribution of variables was assessed by Kolmogorov–Smirnov test. Group comparisons (patients vs controls) were performed using Student’s t-test for normally distributed variables and Mann–Whitney U tests otherwise. Wilcoxon Signed Rank Test was used for the comparison of dependent variables. The correlations between RV mechanics and 2DTE, 3DTE and Doppler parameters of RV function  were assessed using Pearson or Spearman correlation coefficient, as appropriate (strain parameters were computed as absolute numbers).To test the reproducibility in the computation of RV volumes, RV endocardial surface detection was repeated in 15 randomly selected rToF patients by the same observer and by a second independent observer, both blinded to all prior measurements. The inter- and intra-operator variability for RV volumes was computed using Lin’s concordance correlation coefficient.Statistical analysis was performed using SPSS version 24.0 for Windows . Differences among variables and correlations were considered significant if p < 0.05.Table 2D regional analysis of RV deformation was technically feasible in 29 rToF patients and 28 controls Table . rToF pa3D echocardiographic parameters of RV mechanics revealed significant differences between the groups Table  and 2. C3D regional analysis of RV deformation parameters was technically feasible in 32 rToF patients and 29 controls , FAC , 2D RV global  and septal  LS demonstrated moderate correlation with global RVEF (strain parameters were computed as absolute numbers). TAPSE and 2D RV free wall LS did not show any significant correlation with RVEF (p > 0.05).Conversely, global and regional RV mechanics assessed by 3DTE, demonstrated stronger correlations with global RVEF than the RV function parameters obtained by 2DTE  and negative correlation with FAC . The relative REF contribution to RVEF correlated moderately only with FAC , whereas the relative contribution of AEF to RVEF did not show a statistically significant correlation with traditional RV function parameters (p > 0.05).3D RV global LS , free wall LS  and septal LS  showed stronger correlations (strain parameters were computed as absolute numbers) with RVEF than 2D LS. 3D RV global CS , free wall CS  and septal CS  showed moderate correlation with RVEF.Among the 2DTE derived RV function parameters, FAC and RV free wall S’ velocity demonstrated moderate-strong positive correlation with RV REF Table . RV 3D gRV LEF showed moderate positive correlation with TAPSE, RV free wall S’ velocity and 2D RV free wall LS Table . 2D RV gFrom 2DTE derived RV function parameters, only FAC had a weak positive correlation with AEF in rToF patients Table . MeanwhiAnalysis of repeated measurements showed good reproducibility: the values for intra-operator and inter-operator variability of the 3D RV end-diastolic and end-systolic volumes were 0.944 (CI 0.867–0.977), 0.855 (CI 0.693–0.935) and 0.955 (CI 0.891–0.982) and 0.891 (CI 0.767–0.951), respectively. As the ReVISION method is a fully automated technique, it adds no further variability on top of the commercially available software for 3-D model reconstruction , 19.i) rToF patients had lower global RVEF compared to age- and sex-matched controls; ii) in terms of the relative contribution to global RVEF, only the longitudinal component of RV wall motion was reduced in rToF, whereas the radial and antero-posterior components were similar between rToF and controls; iii) rToF patients had similar RV septum, free-wall apical and mid segment 3D circumferential strain values, but significantly lower circumferential strain in the basal RV free wall segment; iv) RV 3D longitudinal strain values were reduced in the RV free wall segments in rToF, but they were similar to controls in the septum.Since conventional echocardiography explores mainly the longitudinal component of RV systolic function, there was no comprehensive method to evaluate the relative contribution of the different components of RV wall motion  to global RVEF. Thus, to our knowledge, this is the first study to assess 3DTE-derived global and regional RV mechanics in rToF patients with severe pulmonary regurgitation and their relations with RV pump function. According to our results: Recent studies demonstrated that longitudinal RV deformation is decreased in rToF with pulmonary regurgitation as a sequel , 20. In Furthermore, we demonstrated, that in rToF patients, the radial and anteroposterior components of ejection fraction showed better correlation with global 3D RVEF than the longitudinal one. These findings also emphasize that parameters measuring the longitudinal contraction offer only a partial assessment of the global RV pump function in rToF patients. This is very important because, due to the large surface of RV free wall, even a small amplitude of inward movement of the RV free wall may have a significant effect on the global RV function . HoweverSpeckle-tracking echocardiography has been shown to be more sensitive than conventional measures in detecting changes in myocardial function in rToF . HoweverThe RV anteroposterior shortening is even more neglected in daily clinical practice, thus, data about this component of global RVEF are highly limited. We hypothesize that RV anteroposterior shortening may reflect the left ventricular contraction’s contribution to overall RV function by stretching the RV free wall insertion lines over the interventricular septum. Recently, Lakatos et al. demonstrated comparable RV AEF values between heart transplant recipients and healthy control subjects, and also between elite athletes and sedentary individuals , 19. AccThere are several underlying mechanisms which may explain the RV mechanical remodeling we observed in rToF patients with severe pulmonary regurgitation. First, according to the Frank-Starling law, when preload increases and the RV dilates, the contractile function increases and, for some time, effectively compensates the altered hemodynamic conditions. However, long-term chronic RV volume overload leads to stretching of myofibers with subsequent distorted meshwork, more spherical architecture and re-alignment of myocardial fibers that might modify the contraction pattern to a greater radial contribution , 31. PreThe application of the ReVISION method relies on accurately generated 3D endocardial surface model and therefore, it is dependent on the quality of the 3DTE images. Moreover, in rToF, the acquisition of good 3D datasets could be hampered by a markedly dilated RV. However, experience in 3D acquisition and analysis might minimize this limitation. Nevertheless, ReVISION method assess RV mechanics in a fully automated manner and does not add further variability to that associated with 3D RV volumetric and functional evaluation.Strain measurements based on 3D analysis cannot be compared with measurements performed using commercially available 2D methods. Moreover, the absence of a true reference method to test the accuracy of our measurements could be considered as a limitation of this study, and only prospective outcome studies can assess the clinical value of our approach.According to our knowledge, this is the first study to evaluate the relative changes in RV mechanics in rToF patients, and their relations with global RV pump function using 3DTE.We found that, in rToF patients with RV volume overload due to severe pulmonary regurgitation, the longitudinal component of RV wall displacement is affected more than the radial or anteroposterior one. Moreover, among the longitudinal components of RV function, only the longitudinal function of the RV free wall seems to be affected, whereas the interventricular septum is spared. Finally, global RVEF shows weak correlations with parameters that reflect mainly longitudinal RV shortening. Thus, our results emphasize that, conventional echocardiographic parameters, usually describing only the longitudinal function of the RV, might be insufficient to accurately assess the RV pump function in rToF patients. Conversely, 3D RVEF incorporates the contribution of all motion directions , thus, 3DTE may be the echocardiographic method of choice to accurately measure global RV function in rToF patients.Moreover, 3DTE may provide additional pieces of information which are not available using conventional parameters and improve our understanding of the mechanisms leading to RV failure in rToF patients. However, larger future studies are needed to confirm these findings, and to determine the potential predictive value of the different components of global RVEF on the outcome of rToF patients.


Adult anesthetized pigs underwent left anterior descending coronary artery instrumentation with either 90 min occlusion (n = 17) or without occlusion . After 3 days, in surviving animals a perfluorooctyl bromide nanoemulsion was infused intravenously to label monocytes/macrophages. At day 6, in vivo 1H-CMR was performed with cine, T2 and T2* weighted imaging, T2 and T1 mapping, perfusion and late gadolinium enhancement followed by 19F-CMR. Pigs were sacrificed for subsequent ex vivo scans and histology. Edema extent was 35 ± 8% and IS was 22 ± 6% of LV mass. Six of ten surviving AMI animals displayed both MVO and IMH (3.3 ± 1.6% and 1.9 ± 0.8% of LV mass). The 19F signal, reflecting the presence and density of monocytes/macrophages, was consistently smaller than edema volume or IS and not apparent in remote areas. The 19F signal-to-noise ratio (SNR) > 8 in the infarct border zone was associated with impaired remote systolic wall thickening. A whole heart value of 19F integral (19F SNR × milliliter) > 200 was related to initial LV remodeling independently of edema, IS, MVO, and IMH. Thus, 19F-CMR quantitatively characterizes regional inflammation after AMI and its relation to edema, IS, MVO, IMH and regional and global LV function and remodeling.Inflammatory cell infiltration is central to healing after acute myocardial infarction (AMI). The relation of regional inflammation to edema, infarct size (IS), microvascular obstruction (MVO), intramyocardial hemorrhage (IMH), and regional and global LV function is not clear. Here we noninvasively characterized regional inflammation and contractile function in reperfused AMI in pigs using fluorine (The online version contains supplementary material available at 10.1007/s00395-022-00928-5. All-caufter AMI . However19F)-CMR to monitor monocytes/macrophages in mouse models [19F MRI noninvasively monitors specifically infiltrating monocytes due to their rapid and specific uptake of intravenously applied perfluorocarbon nanoemulsions [19F-CMR approach also in clinical scanners (i.e. field strength of 3 T) [Using experimental high-field 9.4 T) CMR, we established fluorine  . In the Experiments were performed in 22 adult female Aachen minipigs  with a mn = 10 AMI and n = 5 sham) according to previous protocols [The perfluorooctyl bromide nanoemulsion (PFOB) was produced according to established protocols , 33. A drotocols .19F sequences [1H and 19F-sequence protocols and details are reported in supplemental Table I. After in vivo 1H- and 19F-CMR acquisitions, the pigs were euthanized inside the scanner for in situ imaging with arrested hearts. Autopsy was performed, and organs  were explanted and stored in 4% paraformaldehyde (PFA) for analysis of histopathology and distribution of PFOB with high resolution 19F-CMR. A detailed description of the histopathological protocols and analysis, including the immunohistochemistry of TNFα, is provided in the supplemental material & methods and supplemental figure IV and V.After proof of LAD patency 6 days after AMI by invasive angiography, CMR was performed using a whole-body 3.0-T Achieva X-series MR scanner . In vivo CMR was performed according to previously established workflows and protocols for local signal precision with optimized equences . The 1H π/6) * L)3 [19F signals were quantified using the 3D visualization software Amira 4.0 , and image fusion of 1H/19F-datasets was performed with HOROS . The fused images of all 10 animals which were included in the final analysis are shown in the supplemental figure VII. For quantification of 19F-signals, the primary signal in a respective region was corrected according to the coil sensitivity profile as outlined in supplemental figure VIII. The signal-to-noise-ratio (SNR) of respective regions was calculated from the ratio of the signal intensity mean of a region-of-interest (ROI) and the standard deviation of a background-noise ROI in the same slice located out of the thorax at comparable coil distance. 19F volumes were calculated by applying background subtraction with SNR 7, which was sufficient to subtract all unspecific technical background signals (outside the body). The 19F-integral was the product of SNR and volume.Dedicated software  was used for full automatic delineation of ventricular contours, automatic calculation of volumes and analysis of parametric T1 and T2 maps. Due to misalignment of the automated contouring algorithm, significant manual correction of endocardial contours was necessary in 3/10 pigs after AMI. As described in detail in supplemental material & methods and shown in supplemental figure VI, volumes were indexed to body weight to measure end diastolic volume index (EDVi), end systolic volume index (ESVi), stroke volume index (SVi), cardiac index (CI) as well as ejection fraction (EF), global longitudinal strain (GLS), and early longitudinal diastolic strain rate (SRe) . The sph6) * L)3 . T2 weig6) * L)3  and afte6) * L)3 . Volumest test for normally distributed data and Mann–Whitney U test for non-normally distributed data. Pearson’s or Spearman’s correlation were used to assess the relationships between different CMR parameters. Separate linear regression models in pairwise combination with edema, IS, MVO, and IMH were created to adjust the univariate correlations of 19F with LV function and volumes for these parameters to test whether 19F would independently predict LV function and geometry. ROC analysis was used to identify optimal cut-off values for prediction of initial remodeling  (AUC 0.87) or impaired remote systolic wall thickening  (AUC 0.78). The respective p values are reported in the figures.Statistical analysis was performed using SPSS software . Unless otherwise stated, continuous variables are presented as the mean ± standard deviation (SD). Differences between the two groups (sham and AMI) were analyzed by Student’s 2-sided unpaired n = 5), AMI survivors (n = 10) and AMI non-survivors (n = 7) are reported in supplemental Tables II and III. There were no differences in baseline characteristics between survivors and non-survivors. The cause of death (n = 7) was ventricular fibrillation refractory to defibrillation in all pigs. No pig died beyond 90 min of ischemia. There was no serious adverse side reaction when pigs received PFOB on day 3 after AMI . The blood kinetics of PFOB are given in supplemental Figure III and revealed an almost complete clearance from the circulation 3 days after injection. Ten pigs had a patent LAD on day 6 after AMI on coronary angiography and were included in the CMR study.Twenty-two pigs were included in the study. Baseline and procedural characteristics of sham pigs (Edema extent was 35 ± 8% of LV mass and IS was 22 ± 6% of LV mass. Six of 10 surviving pigs had MVO (3.3 ± 1.6% of LV mass), and the same animals also had IMH (1.9 ± 0.8% of LV mass). Figure 19F-information was 18 ± 2 min. Figure 19F-signal intensity and monocyte/macrophage density. 19F-signals were restricted to infarcted tissue and its border zone, as delineated by infarct size imaging with LGE, while remote myocardial areas displayed no 19F-signal  and M2 (CD68low CD163high) macrophages was present within the areas of 19F signal . The mean 19F-signal intensity was quantified considering the coil sensitivity profile  and expressed as myocardial 19F-SNR. The calculated local mean 19F SNR acquired in vivo correlated with the mean monocyte/macrophage density determined by histology . The individual localization of the analyzed regions of interest is given in the supplemental Table V. The 19F detection threshold was 70,000 cells/mm3. In sham pigs, no myocardial 19F signal was observed, and immunohistochemistry did not show signs of acute myocardial inflammation.The average acquisition time of the 3D-whole heart 19F-analysis of all surviving pigs. For inter-individual image comparison, 19F-signals of all 10 pigs are shown in supplemental Figure VII. The monocyte-dependent 19F-signals were also observed in the bone marrow of the sternum and ribs   of the individual increase in circulating leukocytes from baseline until day 3 and the 19F integral .Figure ml) Fig. A, B and ml) Fig. A, C. The19F-CMR derived monocytes/macrophages signals. The correlation of edema extent and IS with the 19F-integral was only fair. Pigs with high 19F integral displayed only minor volume of MVO with concomitant IMH . Increased 19F-integrals over the entire heart correlated with enlarged EDVi and ShVi in univariate analysis. Even when adjusted for edema, IS, MVO and IMH, respectively, in multivariate models, the macrophage/monocyte derived 19F-signal was independently associated with initial LV remodeling .As shown in Fig. ing Fig. B. Histol19F-integral value of 200 combined with a border zone SNR > 8 predicted impairment of remote myocardial contractile function and LV remodeling on day 6 after AMI. Pigs with whole heart 19F-integral > 200 and border zone SNR > 8 (n = 5) had less remote myocardial systolic wall thickening , larger EDVi  and larger ShVi  than pigs with whole heart 19F-integral < 200 and border zone SNR < 8 (n = 5).As demonstrated in Fig. 19F-CMR noninvasively provided quantitative information about regional inflammatory infiltration of monocytes/ macrophages early after AMI and its association with LV contractile function and geometry. Inflammatory infiltration in the infarct border zone correlated with impaired remote myocardial systolic wall thickening and initial LV remodeling. The inflammatory signal over the entire heart correlated to impaired LV contractile function and remodeling independently of myocardial edema, IS, MVO, and IMH.In the present study using a pig model of reperfused AMI, 19F containing nanoemulsions with respect to safety, dose and timing of the emulsion administration [19F measurements were done in explanted hearts to assure easy and sufficient 19F signal acquisition [19F signal distance > factor 100 compared to explanted hearts and respiratory as well as cardiac movement [Our preliminary experiments were conducted to test and prove the applicability of various components and processes necessary for the planning, initiation and conduction of the present study. First, we tested optimal stration . 19F meauisition . Thereafmovement . After tmovement .19F signal, which was also validated by histology.The findings of these preliminary studies  were necessary to efficiently conduct the present study. The specific novelty of the present approach is the comparison of state-of-the-art CMR tissue markers as well as local and global myocardial function after AMI with the in vivo 19F-CMR is essentially background-free, perfluorocarbon nanoemulsions are the primary source of the 19F-signal, and they are preferentially taken up by monocytes/macrophages [19F-signal observed reflected most likely a mixture of a M1 and a M2 macrophage infiltration. Additionally, the 19F-signal was closely associated with altered tissue relaxation properties indicating early tissue reorganization in infarcted myocardium with a high volume and density of monocytes/macrophages.Since rophages , 26. In rophages . Since b19F labeling of immune cells, ultrasmall iron oxide nanoparticles (USPIOs) enhanced 1H-based CMR has been used. USPIOs also preferentially label monocytes/macrophages and significantly affect 1H relaxation properties. This technique, leading to signal voids in the area of monocytes/macrophages, has provided initial, promising diagnostic results in patients after AMI, but its specificity has been hampered by interference with IMH [As an alternative to with IMH , 46. Beywith IMH , 31, 32.3 [19F principle easily works on the widely available CMR platform, with an image resolution (1.35 × 1.35.1.5 mm3) sufficient for imaging inflammatory foci in the AMI border zone with a directly quantifiable signal, without the need for additional specialized equipment and personnel.PET MRI using 18F-fluorodeoxyglucose (18F-FDG) has proven significant value in the detection of atherosclerosis-related inflammation and in predicting restenosis in peripheral artery disease , 8. Ther19F-CMR is a highly promising imaging technique for clinical trials aiming to further evaluate the effects on monocyte/macrophage infiltration in patients early after AMI.With the present CMR approach, the images of monocyte/macrophage infiltration were generated in vivo with a resolution and acquisition time comparable to clinical standard sequences and protocols . The pig model of reperfused AMI in the present study exhibited a similar extent of IS and frequency of MVO or IMH as typical patients with an anterior STEMI , 29. Mor19F-signals revealed not only considerable inter-individual variation, which correlated to the systemic increase in leukocytes , but also a patchy appearance in myocardial infarction, which was validated by histology  had a mean myocardial 19F-SNR of > 10, indicating hot spots of monocyte/macrophage infiltration as known also from human autopsy studies [19F-CMR. Moreover, the incidence of MVO and IMH was even reduced in segments positive for 19F-CMR. Since MVO and IMH coincided in our model (day 6 after AMI), in good agreement to clinical observations [In vivo myocardial ogy Fig. . The spa studies . The arervations , the attrvations , might hrvations .19F-signal correlated inversely with remote myocardial systolic wall thickening. On histology, TNF-α was identified in remote cardiomyocytes Below is the link to the electronic supplementary material.


Microvascular dysfunction is responsible for chest pain in various kinds of patients, including those with obstructive coronary artery disease and persistent symptoms despite revascularization, or those with myocardial disease without coronary stenosis. Its diagnosis can be performed with an advanced imaging technique such as positron emission tomography, which represents the gold standard for diagnosing microvascular abnormalities. In recent years, cardiovascular magnetic resonance and cardiac computed tomography have demonstrated to be emerging modalities for microcirculation assessment. The identification of microvascular disease represents a fundamental step in the characterization of patients with chest pain and no epicardial coronary disease: its identification is important to manage medical strategies and improve prognosis. The present overview summarizes the main techniques and current evidence of these advanced imaging strategies in assessing microvascular dysfunction and, if present, their relationship with invasive evaluation. Chest pain without obstructive coronary disease (CAD) represents a frequent phenomenon in clinical practice. Patel MR et al. demonstrated that nearly 60% of symptomatic patients undergoing invasive diagnostic coronary angiography did not show obstructive CAD . CurrentAs a result, assessing microvascular function would represent a fundamental step in evaluating the increasing population with angina without obstructive CAD  5]. To . To 5]. Myocardial perfusion is governed by dynamic and combined changes in the epicardial coronary vessels and microcirculation. The three components of the coronary arterial vasculature are epicardial coronary arteries, pre-arteriole vessels and the intramural arterioles. The last two have the key role of matching blood supply to myocardial oxygen consumption. At rest, the myocardium extracts 75% of the blood oxygen and any increase in oxygen consumption determines increased oxygen demand, which leads to an increase in myocardial blood flow (MBF) . Pre-artMVD can be recognized in three different settings. First, MVD without obstructive CAD and myocardial diseases due to cardiovascular risk factors . These pRegardless of the mechanism behind MVD, it could be non-invasively assessed. Cardiac Positron Emission Tomography (PET) represents the most validated imaging exam for the non-invasive identification of MVD. It is based on the use of tracers labeled with isotope emitting positrons; it has high sensitivity and temporal resolution, which allows fast dynamic imaging of tracer kinetics . The idep < 0.0001, p for interaction = 0.04) [r = 0.442) [The use of rest and stress PET allows the quantification of some indices of MVD, such as MBF, myocardial perfusion reserve (MPR: MBF at the maximum stress) and myocardial flow reserve  . In part = 0.04) . In anot = 0.04) . PET was = 0.04) . Moreove = 0.04) . In STEM= 0.442) . Therefo= 0.442) . Althoug= 0.442) . CMR seems to be a promising non-invasive imaging technique in the assessment of myocardial perfusion and flow quantification, given its high spatial resolution, lack of radiation, and good diagnostic accuracy . As prevr > 0.90) with microsphere analysis, which represented the gold standard [r = 0.92) between CMR and PET in the assessment of global MBF [r = 0.46, p < 0.001) [However, some limitations should be underlined, such as the MPR index, which is influenced by resting perfusion and by tissue contrast concentration . Quantitstandard ,31. Studobal MBF . In a co< 0.001) . The res< 0.001) . A recen< 0.001) . CMR als< 0.001) : in a co< 0.001) . Mahmod < 0.001) . Recently, the prognostic value of MVD assessment by CMR was investigated. In a cohort of 218 patients with angina and without overt CAD, Zhou W et al. demonstrated that CMR-derived MPR index was an independent predictor of adverse events . FinallyCardiac CT has recently been increasingly used for functional testing . CT angiThe combination of these two techniques allows obtaining both coronary anatomic and myocardial perfusion information in the same study. CTP requires the acquisition of an ECG gated intravenous iodinated contrast-enhanced CT during vasodilator stress. Scan acquisition is performed during the early first pass of contrast into the myocardium to observe differences in the inflow of contrast and, therefore, differences in attenuation of normal and impaired myocardium . Two types of CTP can be identified: static and dynamic. -Static CTP requires only a single image at peak myocardial contrast opacification, which is then compared with a single rest image. This technique requires prospective ECG triggering and is associated with a lower amount of radiation, but it allows only semiquantitative or qualitative perfusion evaluation;-Dynamic CTP obtains several sequential images over time from the first pass to the wash-out of contrast medium, allowing the calculation of the kinetics of iodinated contrast in the arterial blood pool and myocardium over time. As a consequence, a quantitative perfusion estimation is obtained. This method is related to quantifying MBF, but it requires a 3-fold higher radiation exposure than static CTP .The major advantages of CT are shown in However, studies about CTP for the assessment of MVD are still few. In animal models, MBF quantification by CTP correlated well with microsphere measurements and with CMR ,46. r = 0.92) [Alessio AM et al. compared dynamic CTP with rubidium-82 PET in MBF estimation in a prospective trial on high-risk patients. The study demonstrated that CT-derived MBF estimates were, on average, equivalent to quantitative PET estimates ( = 0.92) . As far Despite the relevant advantages of non-invasive techniques, some limitations should be recognized. First, no stressors are available to assess endothelial function or coronary spasms. Indeed, vasodilators used in non-invasive techniques  only assess vasodilator capacity. Second, before formulating the diagnosis of angina due to MVD, obstructive CAD has to be excluded. Therefore, it can be concluded that these techniques have a good negative predictive value but a limited positive predictive value. This concept plays a pivotal role in the setting of diffuse three-vessel CAD, which can be misinterpreted as MVD. To date, the only comprehensive non-invasive technique for the ruling-out of epicardial CAD in clinical practice is cardiac CT. In conclusion, according to current data about advanced non-invasive techniques for the identification of MVD, PET, CMR, and CT could be very promising modalities. Recognizing coronary MVD is of paramount importance because of its prognostic role, and the goal is the definition of therapeutic approaches .


Recent evidence shows an association between coronavirus disease 2019 (COVID-19) infection and a severe inflammatory syndrome in children. Cardiovascular magnetic resonance (CMR) data about myocardial injury in children are limited to small cohorts. The aim of this multicenter, international registry is to describe clinical and cardiac characteristics of multisystem inflammatory syndrome in children (MIS-C) associated with COVID-19 using CMR so as to better understand the real extent of myocardial damage in this vulnerable cohort.Hundred-eleven patients meeting the World Health Organization criteria for MIS-C associated with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), having clinical cardiac involvement and having received CMR imaging scan were included from 17 centers. Median age at disease onset was 10.0 years (IQR 7.0–13.8). The majority of children had COVID-19 serology positive (98%) with 27% of children still having both, positive serology and polymerase chain reaction (PCR). CMR was performed at a median of 28 days (19–47) after onset of symptoms. Twenty out of 111 (18%) patients had CMR criteria for acute myocarditis (as defined by the Lake Louise Criteria) with 18/20 showing subepicardial late gadolinium enhancement (LGE). CMR myocarditis was significantly associated with New York Heart Association class IV ) and the need for mechanical support ). At discharge, 11/111 (10%) patients still had left ventricular systolic dysfunction.No CMR evidence of myocardial damage was found in most of our MIS-C cohort. Nevertheless, acute myocarditis is a possible manifestation of MIS-C associated with SARS-CoV-2 with CMR evidence of myocardial necrosis in 18% of our cohort. CMR may be an important diagnostic tool to identify a subset of patients at risk for cardiac sequelae and more prone to myocardial damage.Clinical trial registration: The study has been registered on ClinicalTrials.gov, Identifier NCT04455347, registered on 01/07/2020, retrospectively registered. Recent evidence shows an association between coronavirus disease 2019 (COVID-19) and a severe inflammatory syndrome in children. Clinical presentation is variable and may include general systemic inflammation, toxic shock syndrome and cardiogenic shock . CardiacCardiovascular magnetic resonance (CMR) imaging allows non-invasive assessment of myocardial inflammation as defined by the Lake Louise Criteria . CMR perIn adults, previous data suggest that up to 20% of hospitalized patients have evidence of cardiac injury , but myoThe aim of this multicenter, international registry is to describe clinical and cardiac characteristics of children hospitalized for MIS-C after confirmed COVID-19 using CMR so as to better understand the full extent of myocardial damage in children.This is an observational, international multicenter cohort study of all consecutive patients between March 2020 and April 2021 who met the World Health Organization (WHO) criteria for MIS-C associated with SARS-CoV-2 , having The study was approved by the Research Ethics Board of the Assistance Publique des Hôpitaux de Paris  and conducted according to MR004 conformity.Local physicians identified eligible patients and reviewed their medical records. Detailed information on demographic, clinical, biological, thoracic and cardiac imaging  scan) features were recorded anonymously on a centralized database. SARS-CoV-2 was defined as “confirmed” by either positive nasopharyngeal polymerace chain reaction (PCR) or positive serology. Cardiac involvement was defined as clinical suspicion of acute myocarditis or left ventricular (LV) ejection fraction (LVEF) < 55% or cardiogenic shock. Myocardial inflammation was diagnosed in the presence of at least two of the Lake Louse Criteria  detailedCMR studies were performed in each participating center according to clinical indication and locally approved imaging protocols. LV dimensions and function were obtained from a short axis stack using a balanced steady-state free precession images (bSSFP), as well as 2 and 4 chamber views. Black-blood prepared T2-weighted (T2-short tau inversion recovery (STIR)/T2 spin echo) images were acquired along the 4-chamber view, 2-chamber view and the short-axis LV planes. These were followed by contrast-enhanced images. Early gadolinium enhancement (EGE) images were obtained with T1-weighted black-blood prepared spin echo and enhanced cine-bSSFP sequences, acquired along the 4-chamber, 2-chamber and short-axis LV stack. Late gadolinium enhancement (LGE) images were acquired with an inversion recovery gradient echo pulse sequence, 8–12 min after injection of contrast media (0.2 mmol/Kg of gadolinium chelate) in the short axis covering the entire LV from the mitral valve plane to the ventricular apex, as well as 2 chamber and 4-chamber views as indicated on case-to-case basis.Myocardial inflammation was diagnosed in the presence of at least two of the Lake Louise criteria : (1) eviThe evaluation of EGE was also performed on cine-bSSFP sequence  soon after contrast injection. This method is not part of Lake Louise Criteria but several authors reported its efficacy in evaluating hyperemia during acute myocarditis. , 19, 20.Due to the lack of consistent reference normal values of tissue mapping in children, we did not apply the updated Lake Louise Criteria .Categorical variables were presented as frequencies with percentages and compared by Fisher’s exact test; odds ratios and their 95% confidence interval (95% CI) were computed. Normally distributed continuous variables were reported by mean ± standard deviation and compared by t-test; non-normally distributed continuous variables were presented as medians with interquartile ranges (IQR) and compared using the Wilcoxon rank sum test. Multiple samples were compared by ANOVA or Kruskal–Wallis, as appropriate. Laboratory variables were normalized in order to bring them to a common scale. Logistic regression was performed to identify independent risk factors for myocarditis. Missing data were not included in the analysis, imputations were not performed for missing data. A p-value < 0.05 was considered statistically significant (two-sided). SAS  was used for statistical analysis.A total of 111 children (42 38%) female) were included. Detailed presentation of demographic, clinical and laboratory characteristics is summarized in Tables 8% femaleMedian duration from symptom onset to hospital admission was 5 days (4–6). Most children  were admitted to the pediatric intensive care unit, 71/100 (71%) required inotropic, 40/98 (41%) ventilatory and 9/103 (9%) mechanical support.Almost half of the patients  had a pathologic electrocardiogram (ECG) at admission. Following abnormalities were found in decreasing order: tachycardia , repolarization or T-wave abnormalities , ST abnormalities , low voltage  and other rhythm anomalies .Almost all children  had echocardiography performed at admission. Mean LVEF at Simpson’s biplane method was 47.7% ± 13.4 and 72/111 (65%) patients had LVEF < 55%.Only 28/108 (26%) patients had a thoracic CT scan with a median time of 9 days (7–20) after symptom onset. Of them, 16/28 (57%) had pathological findings, most commonly parenchymal lesions (7/23 ground glass opacifications and 5/23 consolidation). Nine children were found to have pleural effusion.Imaging characteristics are summarized in Tables Among the 111 children, 20 (18%) were diagnosed with myocarditis (group 1 Myocarditis) based on the Lake Louise criteria.CMR was performed a median of 28 days (19–47) after symptoms onset, without any difference between patients with (group 1) and without myocarditis (group 2) (p = 0.330).There was no difference in age at symptom onset. Children in group 1 more commonly presented with New York Heart Association (NYHA) Class 4 , pairwise comparison with NYHA Class 1). The other pairwise comparisons of the NYHA classes did not find any significant difference between the two groups. During hospital course, children in group 1 more frequently required mechanical support ). In group 1, 21/24 patients presented with a subepicardial pattern of LGE with 12/20 patients having a multi-segment localization as shown in Figs. Regarding laboratory results, lymphocyte counts were significantly higher in group 1 compared to group 2. No other difference in laboratory characteristics was found among the two groups Table .There was no significant difference in LVEF at diagnosis between the two groups.In the multivariate regression analysis, NYHA class (p = 0.014), and mechanical support (p = 0.043) remained significantly associated with myocarditis when adjusted for sex and age.Seventy-nine children (79%) had an echocardiogram performed before discharge, the median discharge LVEF was 61% (56–66) without significant difference between children with and without myocarditis. Among 72 patients with LVEF < 55% at admission , 11 continued to have abnormal function at discharge . Total follow-up duration was 55 43–100) days. No deaths were reported  with evidence of previous SARS-CoV-2 infection and few active viral replications, corroborating the hypothesis that MIS-C is a quite late, immune-mediated complication of viral infection, occurring after the acute phase.All children were discharged alive with no deaths in our cohort, showing a good prognosis even following severe acute presentation with multi-organ dysfunction.LV systolic dysfunction by echocardiography was present in the majority of the cohort (65%) with a good short-term prognosis in terms of functional recovery at hospital discharge, without a significant difference between children with and without myocarditis.Moreover, acute myocarditis, as defined by Lake Louise Criteria, was not frequent, affecting 18% of our cohort, that is at present the largest group of acute phase MIS-C pediatric patients studied by CMR.In fact, Bartoszek et al. reported normal CMR in 19 children COVID-19 MIS-C with initial LV dysfunction but CMR was realized at 2 months of follow up, not in the acute phase . WebsterIn our cohort, factors that were significantly associated with myocarditis presentation were NYHA class IV and the need for mechanical support. Due to the small number of patients with myocarditis, more elaborate statistical analysis such as the development of a predictive score could not be performed.Interestingly, levels of troponin were not associated with myocarditis diagnosis, maybe revealing a non-specific role of troponin in this subset of patients, in agreement with recently reported data by Rajpal et al. .We were not able to identify other clinical, biological, and radiographic differences between the two groups. We therefore speculate—without definitive proof of our data—that the myocarditis phenomenon is part of the same general pathological mechanisms of SARS-CoV-2 infection, with a more specific target of the immunomodulated response localized in the heart as a secondary bystander in susceptible individuals. However, our sample size may lack power to detect small differences between the two groups.Even if the majority of patients presented with reduced LV systolic function, cardiac involvement in terms of myocardial inflammatory compromise as defined by Lake Louise Criteria was not frequent. We speculate that the majority of patients had a transient inflammation without any lasting cardiac tissue compromise or that LV dysfunction was related to hemodynamic causes associated to MIS-C conditions, such as low diastolic pressure and reduced coronary perfusion.However, 18/20 (90%) children of group 1 had CMR evidence of myocardial necrosis as demonstrated by the presence of LGE. In this group only one child did not recover LV systolic function at discharge, confirming that LGE is not necessarily associated with persistent LV systolic dysfunction and therefore only CMR examination may evocate its presence . TherefoIntegrating our results to existing data , 16, 17,This study is a retrospective observational multicenter cohort study, with all associated limitations. In some instances, not all the variables were available from contributing centers. In these instances, the total number of datasets is reflected in the denominator in the results tables. However, a recommended CMR protocol was distributed, which allowed for more consistent imaging data. The limited parametric mapping data available and also the lack of standardized pediatric normative data made use of the updated Lake Louise Criteria impractical. Because parametric mapping may be more sensitive for the diagnosis of myocarditis, it is possible that some cases of myocarditis were missed using the original Lake Louise Criteria. Moreover, we should consider that hospitalized patients, as in our series, represent the cohort with the most severe presentation of COVID-19 infection, excluding from our observation less severe forms.No CMR evidence of myocardial damage was found in most (82%) of our MIS-C cohort, even though about 65% had depressed LVEF at admission. Nevertheless, acute myocarditis, as defined by Lake Louise Criteria, is a possible manifestation of MIS-C associated with COVID-19 with CMR evidence of myocardial necrosis in 18% of our cohort. However, independent of the presence of CMR signs of acute myocarditis, most children demonstrate rapid normalization of cardiac function. CMR may be an important diagnostic tool to identify a subset of patients at risk for cardiac sequelae and more prone to myocardial damage, requiring cardiological follow-up.


The most benign cardiac tumor in the pediatric population is cardiac rhabdomyoma. They are known to be associated with tuberous sclerosis complex. Here we report a case with multiple cardiac rhabdomyomas and another rare anomaly of the heart known as hypoplastic left heart syndrome. The fetus was antenatally diagnosed with echocardiography which showed both rhabdomyoma and hypoplastic left heart. The patient was started on prostaglandin immediately after birth. He was confirmed postnatally to have inoperable congenital hypoplastic left heart syndrome. On the third day, the baby started to have progressive bradycardia and then died. Rhabdomyomas can be categorized into cardiac and extracardiac tumors, which are considered rare mesenchymal tumors . The majAnother rare congenital heart disease is hypoplastic left heart syndrome (HLHS). It is an abnormal development of the left side of the heart that obstructs the left ventricle's blood flow. Moreover, the abnormality affects the development of the left ventricle, aorta, and arch of the aorta. This syndrome can also be accompanied by mitral atresia or stenosis. The degree of the blood flow obstruction, amount of involvement of the left side of the heart, and underdevelopment of both the aorta and left ventricle vary, causing a wide range of severity for this syndrome . HLHS isIt is very uncommon to have a combination of these two congenital heart diseases. To our knowledge, there have been only two reported cases of patients having these two cardiac malformations together. In this report, we present another case diagnosed with multiple cardiac rhabdomyomas and HLHS, a complex congenital heart disease. In addition to atrial septal defect (ASD) and large patent ductus arteriosus (PDA) shown in the echocardiography. The first similar case was reported back in 1991, describing a patient with both CR and HLHS. Prenatal echocardiography was done for this patient that revealed a massive tumor in the left ventricle of the fetus's heart. The patient died of congestive heart failure 11 days after delivery. The patient's condition involved aortic atresia and underdevelopment of the ascending aorta . The secStudying this rare case and comparing it with the previously reported cases will help to gain a better understanding of future similar cases. It will also help to test the theories presented by previous studies regarding the connection between HLHS and rhabdomyomas.We present a case of a newborn male, the third child of a healthy Saudi consanguineous parent of a second degree, who had two normal siblings. The mother is 29 years old, Para three, and has one abortion with a history of rheumatic heart disease known to have hypothyroidism, and she is on thyroxine hormone. During pregnancy, echocardiography was done for her fetus at King Abdulaziz Medical City in Jeddah. The fetus was diagnosed as a case of cardiac rhabdomyoma and hypoplastic left heart syndrome. Multiple echogenic masses in the right ventricle without inflow and outflow obstruction, hypoplastic left heart, and hypoplastic ascending aorta were seen in the echocardiography. The neonate was a product of a spontaneous vaginal delivery at 38 weeks of gestational age with a birth weight of 3010 grams and appearance, pulse, grimace, activity, and respiration (APGAR) score of 8/1 and 9/5. The baby was admitted to the neonatal intensive care unit on his first day. Upon examination, the vital signs of the infant were as follows: heart rate 140-160 beats per minute, blood pressure 55-75/ 30-40 mmHg, respiratory rate 40-50 breaths per minute, and oxygen saturation 89-93 %. The baby was active and moving all his limbs. For the cardiovascular exam, he had normal heart sounds with a systolic murmur. Depending on the fetal echocardiography, the patient was started on prostaglandin infusion 0.05 mic/kg/hr immediately after birth for the patency of the ductus arteriosus.Following this baby's birth, echocardiography revealed levocardia, abdominal situs solitus, atrial situs solitus, S normal position of great vessels, and no pericardial effusion. Systemic and pulmonary venous drainage were both normal, and there was a moderate right atrial dilatation. Moreover, multiple echogenic masses (five at least) were seen in the ventricle, the largest one is 9x8 mm, and they were not causing any inflow or outflow obstruction Figure . EchocarOn the second day, an abdominal x-ray was done, and it did not show any obvious pathology. In addition, the prostaglandin was discontinued after a meeting that was done with the pediatric cardiologist, cardiac surgeon, cardiac intensivist, and neonatal intensivist, who all agreed on not proceeding since the patient had very complex anatomy. On the third day, the lab tests added that the patient had renal failure. Moreover, the baby started to have progressive bradycardia then asystole.Wacker-Gussmann et al. reported an incidence of heart tumors in fetuses falls between 0.08% to 0.2% . HoweverOne of the several hypotheses of the development of HLHS is the interference with blood flow from the ventricles, which may lead to hypoplastic ventricles, and lack of outflow through the aortic valve may lead to underdevelopment of the ascending aorta, which emphasize that the location of CR is the most critical feature . This caCR can have a strong association with TSC, as Pietro Sciacca et al. reported some cases of CR associated with TSC where 93.9% of the patients he studied were diagnosed clinically with TSC, 9% confirmed the diagnosis with genetic tests, and 24.2% had a family history with this genetic disease . On the In conclusion, HLHS and CR are both rare heart disorders. These two disorders can be detected antenatally, and usually, the HLHS is known to be a result of a left ventricular outflow obstruction caused by CR. However, this study showed a case that has both HLHS and CR but without an outflow obstruction.


Fbn1C1039G/+ mice and in patients with MFS in comparison with wild type (WT) mice and healthy humans. PST was more frequent in MFS than in WT mice (p < 0.05). MFS mice with PST showed larger aorta than those without PST. Patients with MFS showed larger aorta, poorer LV function and a higher prevalence of PST (56%) than did the healthy controls (23%); p = 0.003. Blood pressure was similar. The higher prevalence of PST in an experimental murine model and in MFS patients, regardless of systemic arterial pressure, suggests an increased afterload on the LV myocardium. This finding supports the use of PST as an indicator of myocardial damage and encourage searching for novel early preventive therapy.The mechanisms leading to cardiac remodeling in Marfan syndrome (MFS) are a matter of debate since it could be either due to structural dysfunction of the myocardial extracellular matrix or to increased afterload caused by the dilated aorta. We aim to characterize the presence of abnormal myocardial function in MFS and to investigate its potential association with increased afterload. Aorta, left ventricle (LV) and the postsystolic thickening (PST) were analyzed in echocardiography in  Previous clinical5 and animal experimental6 studies in MFS have also reported intrinsic cardiac remodeling and mildly impaired ventricular function in the absence of significant valvular insufficiencies, raising the potential hypothesis of the existence of structural dysfunction of the extracellular matrix of the myocardium. Nonetheless, MFS patients with abnormal aortic wall could also be more susceptible to changes in pressure, showing more aortic wall stress and, consequently, increased myocardial afterload. The effect of pressure overload on the myocardial structure and function in MFS remains an open question.Marfan syndrome (MFS) is an autosomal dominant inherited disorder that affects skeletal, ocular and cardiovascular tissues. The main cardiovascular manifestations in MFS are ascending aorta dilation, especially localized at the level of the aortic root sinuses, aortic regurgitation and mitral valve prolapse with or without regurgitation10, and involves adverse functional myocardial remodeling. PST can be observed in the setting of altered loading conditions as hypertension in M-mode7, Tissue Doppler and 2D Speckle Tracking modalities of echocardiography. There is usually good correlation between those modalities in optimal conditions of experimental studies11. M-mode has the advantage of a higher temporal resolution which provides additional sensitivity to detect PST when image quality is limited or at situations of very initial stages of myocardial dysfunction.Postsystolic thickening (PST) is an abnormal longitudinal myocardial thickening/shortening occurring after the closure of the aortic valve. It has been well described as a marker of segmental heterogeneity of loading or contractility, mainly in the setting of pressure overload and myocardial ischaemiaFbn1C1039G/+ ), a well-established animal model of MFS12. In addition, an analysis has been conducted on a group of young humans affected from Marfan syndrome and healthy controls. We have examined the presence of PST in both experimental and clinical groups and its potential relationship with blood pressure and the development of aortic aneurysm.We hypothesize that MFS patients may be more sensitive to blood pressure, despite their basal arterial pressures being in the normal range, and consequently they develop more segmental wall stress heterogeneity due to underlying abnormal arterial and/or myocardial wall tissue. Our purpose is to determine whether or not there is abnormal myocardial deformation in MFS and whether or not this deformation is related to typical altered regional deformation patterns that occur in response to increased afterload. As a first approach to this aim, we have chosen an experimental murine model of MFS mice (Fbn1C1039G/+ mice and wild type (WT) mice were obtained from Jackson Laboratory  and used as a validated MFS animal model. Both Wild Type (WT) and Fbn1C1039G/+ mice  were bred on a C57BL/6 background. Comparisons were made between contemporary littermates. All mice were housed in a controlled environment (12/12-h light/dark cycle) and provided with ad libitum access to food and water. Animal care and experimentation conformed to the European Union (Directive 2010/63/EU) ARRIVE and Spanish guidelines (RD 53/2013) for the use of experimental animals. For the animal experiments, ethical approval was obtained from the local animal ethics committee .The animal population consisted of two groups: group 1, consisting of 108 9 months (mo) age mice (53 MFS and 55 WT mice) in order to analyze the prevalence of PST as a marker of increased afterload in a large number of animals, and group 2, consisting of 39 4 mo-age mice (18 MFS and 21 WT mice) in a controlled study, with systematic determinations of arterial pressure in order to explore the association of PST with blood pressure levels.Systemic blood pressure (BP) was noninvasively measured in the group of 4 mo-age mice by a tail cuff system . Briefly, mice were placed in a warming/restraining box (34 °C), with the tail carefully inserted into an inflatable cuff. Systolic blood pressure (SBP) and diastolic blood pressure (DBP) were automatically measured. Before the final BP measurements, all mice were placed in the setup as many times as needed until they became adapted, thereby minimizing stress associated with the procedure.The group of Marfan patients consisted of 45 patients with established diagnoses of MFS by specialized cardiologists and according to the revised Ghent criteria. The healthy controls included 35 subjects examined by cardiac ultrasound as part of a familial screening for MFS disease and bicuspid aortic valve. Human subjects with more than mild valvular insufficiency or other significant forms of cardiomyopathy were excluded from the study. Clinical data was obtained from clinical records. The protocol was approved by the ethics committee of our institution  in accordance with relevant guidelines and regulations. All participants gave informed consent. The data which supports the findings of this study is available upon reasonable request.13, and on conscious humans. Images were obtained from mice using a 10 to 13-MHz phased-array linear transducer  with a Vivid Q system  and from humans using a Vivid E9  with a transthoracic probe. All images were recorded and analyzed offline using commercially available software . The aortic root and ascending thoracic aorta were measured in the parasternal long axis view. End-diastolic diameters were measured from inner to inner edge in mice and from leading edge to leading edge in humans at the aortic sinus level (for the aortic root) and at 1 mm and 1 cm above the sinotubular junction (for the ascending aorta) in mice and humans, respectively.A two-dimensional transthoracic echocardiogram was performed on all animals, mildly anesthetized, with 1.5% inhaled isoflurane3/2.4 + LVEDD and LVESV = 7*LVESD3/2.4 + LVESD were computed by the Teichholz formula and used as surrogates for LV systolic function. LV mass was calculated from the Devereux formula for LV mass (g) = 0.8{1.04[([LVEDD + IVSd + PWd]3−LVEDD3)]} + 0.6.In the case of mice, an M-mode echocardiographic trace was acquired at the papillary muscle level in a parasternal short axis view, where LV dimensions at both end-diastole (LVDD) and end-systole (LVSD) were measured. The same M-mode trace was performed on humans in the basal parasternal long axis view. The interventricular septum and posterior wall thickness at end-diastole were measured at the same level as the LV chamber dimensions. LV ejection fraction (LVEF) was subsequently calculated as follows: LVEF = ((LVEDV−LVESV)/LVEDV)*100 where LVEDV = 7*LVEDD0.425 × H0.725) × 0.007184 where the weight (W) is in kilograms and the height (H) is in centimeters.The blood pressure value in human subjects was registered the day of the echocardiography examination. Body surface area (BSA) was calculated using the DuBois method: BSA =  during the ejection period, followed by an ongoing deformation (second peak) after aortic valve closure and within the isovolumic relaxation time period in the entire recording with at least 10 beats (AVC)  was used to compare continuous variables if normally distributed and the Mann–Whitney U test was used otherwise. Categorical variables were compared using the χ2 test. The inter-observer and intra-observer reproducibility of PST values was assessed using Cohen’s Kappa statistics on ten randomly selected cases, considering Kappa values < 0.2 as poor, 0.2–0.4 as fair, 0.4–0.6 as moderate, 0.6–0.8 as good, and 0.8–1.0 as very good concordance. Statistical significance was set at 5% for all the tests. The statistical analysis was conducted using SPSS version 21.0 .Continuous variables were expressed as mean ± standard deviation (SD). Assessment of normal distribution was performed using the Kolmogorov–Smirnov test or Shapiro–Wilk test, depending on the size of the group assessed. Categorical variables were expressed as percentages and absolute values. To assess the presence of any difference between MFS and WT groups, the two-sample Table Among the 9 mo-age mice, the aortic and LV dimensions were significantly larger in MFS mice than they were in WT mice, while LV performance, assessed through the LV ejection fraction, was lower in the MFS mice. In the 4 mo-age mice, the aortic dimensions were larger, and LV walls thicker, in MFS mice as compared to those observed in the WT mice. This was in agreement with the observations from the 9 mo-age mice, although no differences in LV chamber dimensions or function were present in the 4 mo-age mice (both MFS and WT mice showed similar LV ejection fraction). No significant differences in blood pressure were observed between MFS and WT animals at the 4 mo-age Table .. Inter-observer reliability was high for the measurement of PST  in the murine model.PST was present in both MFS and WT mice, but it was significantly more frequent in MFS than it was in WT mice Fig. . A high Table Table Table 14, we focused on the youngest group of MFS subjects, from the first age tertile of the MFS population . In this MFS patient subgroup, PST was indeed associated with larger aortic dimensions: 19.4 ± 3 vs 15.5 ± 3 in PST ( +) vs PST (−) youngest MFS, respectively . Blood pressure was similar in the two groups of youngest MFS patients, both without PST (n = 11) and with PST (n = 5): 115 ± 9 vs 106 ± 10  for SBP and 69 ± 7 vs 63 ± 9  for DBP.As PST has been described in older healthy individualsNone of the healthy controls received blood pressure lowering treatment. Conversely, 67% of patients with MFS were on medical therapy with losartan or beta-blockers. Age, blood pressure and LV cavity dimensions were similar in those with and without medication, but the aortic root was larger in those receiving medical treatment. Finally, those two groups of patients with MFS had a similar prevalence of PST Table . Because15. In the controlled murine group of 4 mo-age the PST presence was associated with the aortic root dilation despite no difference in blood pressure. Interestingly, the MFS human subjects show lower systolic blood pressure than the controls and association of PST with the age. Due to the natural increasing stiffness of the aorta with aging, the presence of PST has been described to increase in the elder population25. Accordingly, and in order to avoid, at least to some extent, the potential influence of aging on PST prevalence, the youngest tertile (18–24 years-old) of our group of MFS patients was selected. Notably, humans under 24 years of age would seem to be the most comparable, in terms of age, with the 4 mo-age mice group, considering the usual life-span of mice (18–20 mo-age.). Therefore, we sought to analyze the presence of PST and its relationship with blood pressure and aortic dilation in that young adult individuals. Notably, despite the small number of subjects , a significant association between the presence of PST (PST +) and aortic dilation was observed in the youngest patients with MFS. Both groups of young subjects (young MFS mice and young patients) showed the same association between PST and aortic root dilation. With aging, other confounding factors might influence aortic wall stress potentially explaining that this association was not observed in older subjects with MFS. Further longitudinal and controlled clinical studies will shed more light on this potential association.The study’s main finding was the increased prevalence of PST in MFS. These findings were detected both in a murine experimental model and in a cohort of patients with MFS. In humans we have set the presence of PST at the level of 5% bigger than the systolic curve in order to detect myocardial dysfunction in early stage of the disease despite the majority of experiments differentiate the physiologic PST from pathologic PST if it is approximately 10–20% bigger than the systolic curve16 as well as in humans17. The myocardial involvement in MFS includes impaired biventricular deformation with a subsequent reduction in long axis systolic function, as well as biventricular and atrial mild diastolic dysfunction. Altogether this has raised the hypothesis of the existence of a primary cardiomyopathy in MFS18. Patients with MFS can potentially develop myocardial injury such as fibrosis and myocardial architecture disorder caused by abnormal collagen deposition and organization. Tae et al. reported that the early remodeling expressed as myocardial hypertrophy in 2- and 4 mo-age MFS mice was not associated with hemodynamic overload , but likely triggered by an intrinsic mechanism related to the altered myocardial matrix causing persistent mechanical stress19. In an experiment with mild transverse aortic constriction, Rouf et al. demonstrated that Fbn1C1039G/+ mice are more predisposed to load-induced heart failure than their WT littermates20. Likewise, they support the hypothesis previously reported that the canonical TGF-β signaling contributes to this load-induced cardiac decompensation16. An interesting novel in vivo mouse model of Cavanaugh et al. consisting of subcutaneously delivered angiotensin II in MFS mice causes accelerated aortic aneurysm formation and dilated cardiomyopathy even without aortic insufficiency, suggesting a potential intrinsic aetiology for the diseased myocardium21.Several investigators have demonstrated that dilation of the aortic root and ascending aorta is accompanied by LV dilation and impaired left ventricular function in MFS mice11. According to the geometry of the LV, the greatest pressure overload can be expected to occur in the basal segment of the IVS as it has a greater local radius of anatomic curvature in comparison with the free wall or the apex of the LV. A regional increase in parietal stress occurs at that location, resulting both in segment interaction and PST. In the event of pressure overload, the basal IVS segment is the first parameter to evidence the associated systolic deformation reduction due to its flatter geometry22. The development of postsystolic deformation, along with localized hypertrophy, can even be observed before visual assessment of wall thickening. Previous studies have shown an association of PST with more advanced left ventricular and atrial dysfunction among patients with well-controlled systemic hypertension23.PST is an easy parameter to be clinically and experimentally obtained and evaluated. The data included in this study can demonstrably be reproduced using two different methodologies: DTI and M-mode echocardiography. PST in the basal septum is a marker of pressure overload that can be easily detected by conventional echocardiography as several clinical study show in hypertensive and ischemic patients24 altogether contribute to the local wall stress mainly on cardiomyocytes, finally leading to pressure overload signs such as high LV mass and PST. Our findings suggest that the LV myocardial tissue of patients with MFS is at risk despite these patients having ‘normal blood pressures’, and would encourage searching for novel preventive therapies especially at very young age.From the observations gathered on LV remodeling, PST, and its association with aortic dilation in very young subjects, we would conclude that individuals with MFS show the same sign that is observed in hypertensive cardiac remodeling despite having normal blood pressures. There are two possible explanations. First, the potentially abnormal arterial wall composition in MFS, and its associated stiffening, would alter flow propagation and pressure wave reflections, thus impacting the LV performance, even though peripheral blood pressure values remain within normal ranges. The mechanism of this effect remains still not elucidated. Second, extracellular matrix assembly alterations caused by mutated fibrillin-1, altered TGFβ signaling, and associated cardiac fibrosis26. While agents such as losartan have a vasodilator effect, its cardiovascular impact likely also occurs via non-hemodynamic modulation of TGFβ and fibrotic pathways, which has been evidenced in multiple animal studies but in clinics is much less known. Unfortunately, our study does not provide new data in this respect. Nevertheless, the ultrasound analysis of LV regional deformation patterns (as shown by PST) can easily be integrated into the clinical setting (by using M-mode or DTI) and detect signs of myocardial injury even in early stages of the disease (as in very young adults). Elucidating the mechanisms of cardiac dysfunction in MFS has important implications for the timing of surgical valve repair and for the development of novel medical therapies to prevent heart failure. The demonstration of mechanistic evidence of myocardial susceptibility in MFS heart would support the rationale for more intensive preventive therapy in still-early, asymptomatic stages of the disease, even when patients show normal peripheral blood pressure.Preventing aortic dilation and rupture in patients with hypertension and aortic dilation is of vital importance and the benefits of vasodilator drugs in this scenario are well established. However, the role of vasodilation in preventing aortic remodeling in MFS without classical hypertension remains unclearThe study has several strengths and limitations. Murine heart evaluation is challenging because of the smallness and high heart rate of the mice. Despite these limitations, evaluation of cardiac function has demonstrated to be feasible and reproducible in most mice following a strict methodology with high frame rate acquisitions. Despite a higher mean arterial pressure has been reported in mice using the tail cuff method as compared to the more robust methods of either intra-arterial catheter or telemetry, we chose the tail cuff measurements because of their non-invasiveness to avoid complications. The absolute number of systolic or especially diastolic blood pressure cannot be taken into account as referential for the small animals. However, we believe that it can be used to compare the values in a group of animals that are being exposed to the same conditions of assessment.The inherent higher noise level in tissue Doppler assessment encouraged us establishing the M-mode modality as a referential of PST presence. Although we are conscious that the very sensitive level of PST detection (5% of difference) could provide some percentage of physiological examples we believe that it would not change the overall message of the study in such high difference between PST presence in MFS subjects and healthy subjects. We also acknowledge the limited sample size of the very young human population limiting the confidence of some conclusions. The transversal nature of this observational study and the absence of follow-up data make it impossible to demonstrate the impact of blood pressure lowering drugs on LV performance or whether or not these drugs can modulate the association of PST with an aortic aneurysm. The role of vasodilator therapy as a modifier of myocardial remodeling in murine MFS models is an objective of our upcoming studies. Regarding the mechanism leading to the presence of PST, data from cardiac MRI to depict myocardial fibrosis and gain a better estimation of aortic stiffness with 4D flow sequences, as well as histological studies on aorta and myocardial wall structure, will shed more light on this important topic. Further studies are needed to confirm our findings and to support our mechanistic hypothesis of an increased prevalence of PST in MFS patients. Follow-up studies are needed to evaluate the impact of vasodilator drugs on LV performance and whether or not these drugs can modulate the association of PST with an aortic aneurysm.The prevalence of PST is significantly increased both in MFS mice and patients, suggesting early LV damage. It provides a potential diagnostic tool to monitor and potentially to interfere with cardiac programming. This observation suggests the suitability of initiating early preventive therapy in patients with MFS even having normal blood pressure levels. In any case, further prospective and controlled studies are needed to examine the impact of vasodilator therapy and particularly its titration, on PST and myocardial function and aortic stiffness in patients with MFS. Mice models represent also a perfect controlled experimental setting to prove this, once that we have shown in the current study that PST measurement is feasible and reproducible in them.Supplementary Information.


A low LAAeV was the only important independent predictor of AF recurrence within 1 year after first RFCA.Atrial fibrillation (AF) recurrence after radiofrequency catheter ablation (RFCA) remains a challenging issue. This study aims to explore the left atrial appendage function by transesophageal echocardiography (TEE) and assess its value in predicting AF recurrence following RFCA in paroxysmal AF patients. Eighty-one patients with paroxysmal AF that underwent RFCA were recruited. TEE was performed before ablation with the assessment of left atrial appendage emptying flow velocity (LAAeV). AF recurrence occurred in 24 patients (29.6%) within 12 months after RFCA. The left atrium diameter (LAD) and left atrium volume index (LAVI) were both significantly higher in the recurrence group compared to the non-recurrence group, while the LAAeV was significantly lower in the recurrence group. LAD, LAVi and LAAeV were univariately significant risk factors for AF recurrence after ablation. Based on receiver operating curve (ROC), LAAeV < 40.5 cm/s, LAVi > 40.5 mL and LAD > 41 mm were identified as cut-off values for predicting AF recurrence. In multivariate regression analysis LAAeV < 40.5 cm/s (HR 8.194, 95% CI 2.980–22.530,  Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia, with a lifetime AF risk of about one in three individuals of European ancestry over 55 years of age ,2. The pPatients with symptomatic, paroxysmal AF who had undergone the first RFCA for AF in the Cardiology Department of the Rehabilitation Hospital from Cluj-Napoca, between December 2018 and January 2020 were enrolled. AF was defined as paroxysmal if AF terminated within 7 days of onset (spontaneously or with intervention). The exclusion criteria were as follows: poor quality of TEE image acquisition, reversible causes for AF, prior cardiac surgery, severe valvular disease, congenital heart disease and decompensated heart failure. The study design was approved by the Ethics Committee of Rehabilitation Hospital Cluj-Napoca and written informed consent prior to the procedure and participation in the study was obtained from each patient.All patients underwent both transthoracic echocardiography (TTE) and transesophageal echocardiography (TEE) within 24 h before RFCA. All the parameters were performed according to the American Society of Echocardiography guidelines. During TTE left ventricular end-systolic, and end-diastolic volumes , and the left ventricular ejection fraction (LVEF) were measured. Left atrial diameter (LAD) was obtained on the parasternal long-axis view, while the left atrial volume (LAV) was calculated by the modified Simpson’s method. LAVI was obtained using body surface area correction. During TEE evaluation, LAA was visualized from the mid-oesophageal view at multiple omni-plane angles, between 45 and 100°. For pulsed-wave Doppler interrogation, the angle that provided the longest LAA dimension was used. The LAAeV was defined as a late diastolic positive outflow signal, and it was measured using a 4 mm sample volume positioned at the entry of the LAA orifice. In patients with paroxysmal AF at the time of TEE, LAAeV was described as the average value of five consecutive cardiac cycles . All carThree-dimensional mapping of LA was performed with an Ensite NAVX Velocity  or a CARTO 3  system. To create ablation lesions an open-irrigated 7-french 3.5 mm ablation catheter  or the FlexAbility irrigated ablation catheter  were used. Continuous radiofrequency ablation was performed by encircling the ipsilateral PVs until electrical isolation was achieved. The isolation of the electric field was considered to be complete in the absence of PV potential within each antrum, using a circular mapping catheter .All patients were scheduled for clinical visits to undergo 12-lead electrocardiography (ECG) and 24-h Holter recording at 3, 6, and 12 months after RFCA. Patients were also advised to present to our cardiology department if they experienced palpitations. AF recurrence was defined as any atrial tachyarrhythmia that lasted for more than 30 s captured by ECG or Holter monitoring. Transient episodes of arrhythmia recurrence during the first 3 months after ablation were counted as a blanking period.p value of <0.05 was considered statistically significant.SPSS 21.0 statistical software  was used to analyze the data. Continuous variables were checked for normality of distribution  and are presented as mean ± standard deviation, or median with interquartile range . Categorical variables are described as frequency and percentage. Data were compared between the AF recurrence and non-recurrence groups using Mann–Whitney, Student’s t test or chi-square tests, when appropriate. Univariate and multivariate Cox proportional risk regression models were used to identify the risk factors associated with AF recurrence. ROC (receiver operating curve) analysis was used to calculate the best cut-off value of predictors of AF recurrence. Inter-observer reliability analysis was carried out using Cronbach’s alpha. A A total of 81 consecutive patients with paroxysmal AF who underwent RFCA for the first time were enrolled, aged 55.3 ± 9 years, 48 (59.3%) men and 33 (40.7%) women. The median follow-up time was 12  months. After the blanking period of 3 months, 24 patients (29.6%) had had AF recurrence (recurrence group) and 57 patients (70.4%) had maintained sinus rhythm (nonrecurrence group).The clinical characteristics of patients with and without AF recurrence were compared in p < 0.05) lower for the patients with AF recurrence when compared to the patients who maintained a sinus rhythm . An LAAeV cutoff value of 40.5 cm/s was selected for predicting rhythm outcome after catheter ablation with 89% sensitivity and 75% specificity (AUC 0.869). A LAD cutoff value over 41 mm was selected for predicting rhythm outcome after catheter ablation with 50% sensitivity and 84% specificity (AUC 0.670). The AUC for LAD was statistically significantly lower than the AUC for LAAeV (p = 0.001), but not than the AUC for LAVI (p = 0.146). The AUC for LAVI was not statistically significantly lower than the AUC for LAAeV (p = 0.184).ROC curve analysis was used to evaluate the predictive efficiency of LAVI, LAAeV and LAD. The best cut-off value of the LAVI for the prediction of an AF recurrence was 40.5 mL/mLAVI, LAAeV and LAD were introduced in multivariate analysis, after they were redefined according to their cut-off values . LAAeV u2 and LAD > 41 mm; (3) only LAAeV was identified as independent predictor of AF recurrence after RFCA.Our study demonstrated that (1) LAD and LAVI were significantly elevated in patients with AF recurrence compared with those without recurrence, whereas LAAeV was significantly decreased in the recurrence than non-recurrence group; (2) the cut off points with the highest predictive efficacy for AF recurrence were LAAeV < 40.5 cm/s, LAVi < 40.5 mL/mEven though RFCA is an effective therapeutic approach for patients with paroxysmal AF, recurrence of AF still remains problematic. In this study, the rate of AF recurrence following RFCA was 29.6%, which is consistent with previous research . The recIt is well known that LA enlargement is associated with AF recurrence after ablation. A meta-analysis of 22 studies has reported left atrium diameter to be a predictor of AF recurrence after ablation . HoweverKanda et al. used LAAeV as a surrogate factor of the LA function and were the first that demonstrated that a low LAAeV is associated with AF recurrence after catheter ablation . They deXin-Xin et al. evaluated whether LAAeV and/or NT-proBNP levels are associated with AF recurrence after RFCA . They shAnother study that included 193 patients who underwent successful electrical cardioversion found a similar cutoff for LAAeV of >40 cm/s measured by TEE that predicted long-term SR [Patients with paroxysmal AF are usually in the early stages of LA remodeling. Chronic pressure overload causes LA enlargement, while impairment of LA function precedes LA dilatation. Therefore, functional parameters, such as LAAeV, may be more sensitive markers for AF recurrence after ablation than LA size, particularly in patients with paroxysmal AF. Our findings support this hypothesis, since LAVI and LAD were not associated with rhythm recurrence based on multivariate logistic regression and only LAAeV independently predicted AF recurrence.Although the value of LAA in AF recurrence following radiofrequency ablation is of major importance, it has been scarcely explored. In practice, preprocedural observation of LAA by TEE is conventionally performed to detect thrombus formation. An LAAeV of less than 40 cm/s best predicts thromboembolic risk, while a value of more than 40 cm/s is correlated with successful AF cardioversion and sinus rhythm maintenance ,21,22. HThe current study presented several limitations. Although we closely monitored patients using periodic ECG and Holter monitoring, asymptomatic episodes of AF may have been missed, which may have resulted in underestimation of the AF recurrence rate. We included a small cohort of patients, and thus our preliminary findings should be validated by future research including a larger number of patients.In summary the left atrial diameter and the left atrial volume were significantly increased, while the left atrial appendage emptying flow velocity was significantly decreased in recurrence than in non-recurrence after radiofrequency ablation. A low left atrial appendage emptying flow velocity was the only independent predictor of AF recurrence within 1 year after radiofrequency ablation.