Right ventricular (RV) functional assessment has received considerable attention in veterinary medicine since various diseases, such as cardiovascular, respiratory, endocrine, and neoplastic disease, may affect RV function. Heart rate (HR) is an important factor that can influence RV function through changes in loading condition and contractility. However, no study has yet evaluated the association between HR and RV function in the same individuals. This study aimed to evaluate the influence of elevated HR on RV function using right heart catheterization and echocardiography, and investigate the association between right heart catheterization and echocardiographic indices.3seg) showed no significant changes with the increase in HR; however, there was an increase in the RV strain rate of the RV global analysis (RV-SrL6seg). Multiple regression analysis revealed that HR, RV FACn, and RV- SrL6seg had significant associations with the Ees, and the TAPSEn and RV-SrL3seg with Ees/Ea.Right atrial pacing was performed in eight dogs at 120, 140, 160, and 180 bpm. With an increase in HR, the RV systolic volume, RV diastolic volume, and stroke volume significantly decreased; however, the cardiac output, end-systolic elastance (Ees), and effective arterial elastance (Ea) significantly increased. Significant changes were not observed in RV pressure and Ees/Ea. The RV area normalized by body weight, RV fractional area change normalized by body weight (RV FACn), and tricuspid annular plane systolic excursion normalized by body weight (TAPSEn) significantly decreased with increased HR. Peak systolic myocardial velocity of the lateral tricuspid annulus (RV s’), RV strain, and RV strain rate of only the RV free wall analysis (RV-SrL6seg could be a useful tool for Ees estimation. Additionally, the RV-SrL3seg could detect RV performance, reflecting the balance between RV contractility and RV afterload.Decreased venous return and shortened relaxation time decreased the RV FAC, TAPSE, RV s’, and RV strain, and might underestimate the RV function. Ees increased with the increase in HR, reflecting the myocardial force-frequency relation; as a result, RV-SrL Right ventricular (RV) function is affected by various diseases, such as cardiovascular, respiratory, endocrine, and neoplastic disease . Recent Heart rate (HR) is an important factor influencing cardiac loading conditions. Some echocardiographic indices for RV function have been shown to correlate with HR in previous clinical studies , 17. IndThis study aimed to evaluate the influence of HR on RV morphology and function with RV pressure–volume loops and echocardiography in healthy anesthetized dogs. The echocardiographic variables which reflect RV function regardless of changes in HR were also explored. We hypothesized that increased HR could influence volume loading conditions and RV contractility, and would affect the echocardiographic RV variables; additionally, 2D-STE indices could reflect the precise changes in myocardial function.All the datasets obtained from eight healthy anesthetized beagles were used for the statistical analyses. Right atrial pacing was completed in all the dogs; the range of HR at baseline was 70–112 bpm. The end-tidal partial pressure of carbon dioxide, tissue oxygen saturation, and oscillometric method-derived blood pressure were within the expected ranges for healthy dogs throughout the study.p = 0.028). Contrarily, cardiac output was significantly increased at 140 bpm, 160 bpm, and 180 bpm compared with the baseline . The Ees and Ea were significantly increased with increased HR. The Ees/Ea showed no significant change with increased HR.The hemodynamic variable measurements obtained from the RV pressure–volume loops are summarized in Table Table 3seg) showed no significant change with the increased HR (p = 0.090)  was significantly increased with increased HR  of each segmental analysis showed no significant change with increased HR, although RV-SL had the tendency to decrease at 160 bpm and 180 bpm   , while TAPSEn and RV-SrL3seg were significantly associated with Ees/Ea .Table 41) Fig. A. FurtheResults of the intra- and inter-observer measurement variability are summarized in Table 6seg showed a significant association with the Ees, as did the RV-SrL3seg with the Ees/Ea. Our results indicated that the 2D-STE-derived RV-SrL could reflect intrinsic RV contractility and RV performance regardless of fluctuations in HR.In this study, the RV size indicators, including catheterization-derived RV volume and echocardiography-derived RVEDA and RVESA, significantly decreased with increased HR. These results might reflect the incomplete myocardial relaxation and decreased venous return caused by higher HR. As the HR increased, certain echocardiographic indices, including RV FACn, TAPSEn, RV s’, and RV-SL decreased. However, catheterization-derived Ees increased, suggesting that these echocardiographic indices were sensitive to the decrease in preload and thus could underestimate RV systolic function. Nonetheless, the RV-SrLSeveral conventional echocardiographic indices used for the assessment of RV function, including RV FACn and TAPSEn, significantly decreased with increased HR; however, the Ees, which indicates intrinsic cardiac contractility, increased. Additionally, the 2D-STE-derived RV-SL and RV s’ showed no significant increases with increased HR; interestingly, RV-SL tended to decrease at rates of 160 and 180 bpm. An increase in HR would shorten ejection time and relaxation time, and decrease the venous return (incomplete relaxation ). A prev6seg had a significant association with Ees, but RV-SL and RV-SrL3seg did not. A previous study reported that the left ventricular strain rate more closely reflects myocardial contractility with load-independency than did left ventricular strain [6seg might reflect intrinsic RV myocardial contractility regardless of HR. However, the 2D-STE method could not separate the myocardial function of the interventricular septum into right and left ventricular components. Further studies that also assess left ventricular function are warranted in the future.The RV-SrL showed a significant positive correlation with HR as well as Ees, although certain conventional echocardiographic indices, such as RV FACn, TAPSEn, and RV s’, showed either no correlations or significant negative correlations. The 2D-STE method enables assessment of the RV myocardial function without the influences of angle-dependency, translation, or tethering of the heart , 21, andr strain . Additior strain , 24. The3seg and TAPSEn demonstrated an association with the Ees/Ea in the regression analyses, and the RV-SrL3seg had the highest correlation with Ees/Ea. The Ees/Ea is an indicator of RV performance, reflecting the relationship between RV contractility and afterload [3seg may be the most suitable tool to evaluate RV performance regardless of HR fluctuation. Additionally, RV-SrL3seg had a higher correlation with Ees/Ea than with TAPSEn in this study. Since RV myocardial motility could vary in different regions of the RV free wall [3seg) may be necessary to estimate the RV performance.In addition to the increase in Ees associated with the force-frequency relation, Ea was significantly increased at 180 bpm when compared with that at 120 bpm. Previous canine studies reported that the left ventricular Ea approximates peripheral vascular resistance multiplied by HR , 26. Altree wall , 28, TAPThis study had certain limitations. The primary limitation of this study was the relatively small sample size. As we did not perform an a priori power calculation, the small sample size could have influenced the statistical power necessary to detect the changes in specific RV morphological and functional variables as HR increased. Second, the influence of HR on RV morphology and function was assessed using healthy anesthetized beagles. Certain drugs used for anesthesia, especially isoflurane, could have affected RV afterload and contractility , 30. Add6seg could be a useful tool to estimate the Ees. Additionally, the RV-SrL3seg may detect RV performance assessed by Ees/Ea, reflecting the balance between RV contractility and afterload.In this study, echocardiographic indices of RV function, namely RV FACn, TAPSEn, RV s’, and 2S-STE-derived RV-SL, decreased with increased HR. This indicated that the aforementioned indices were sensitive to decreased venous return and incomplete relaxation and could underestimate RV systolic function. However, the intrinsic RV contractility assessed with Ees was increased according to the force-frequency relation/Bowditch effect; RV-SrLThis was a hypothesis-driven, experimental study. All procedures followed the Guidelines for Institutional Laboratory Animal Care and Use of Nippon Veterinary and Life Science University in Tokyo, Japan. The study was approved by the ethical committee for laboratory animal use of the Nippon Veterinary and Life Science University in Tokyo, Japan .iV Diff, Sysmex Corporation, Hyogo, Japan), serum blood chemistry profile , electrocardiography , thoracic and abdominal radiography , transthoracic and abdominal ultrasonography , and oscillometric blood pressure measurement .Eight healthy beagles owned by our laboratory  were used in this study. Each dog was determined to be healthy based on the findings of a complete physical examination, complete blood cell count  and midazolam hydrochloride , and received cefazolin sodium hydrate . Anesthesia was induced with propofol  and dogs were intubated and maintained on 1.5% isoflurane. Each dog received an intravenous infusion of lactated Ringer’s solution at a rate of 3.0 mL/kg/h throughout the experiments. Pressure-controlled mechanical ventilation at a rate of 10 breaths per minute was maintained throughout the study. End-tidal partial pressure of carbon dioxide, transcutaneously measured tissue oxygen saturation, heart rate, and oscillometric blood pressure were assessed throughout the study with a multiparameter monitor .All dogs were restrained in a supine position, and the left and right sides of the neck were clipped, aseptically prepared, and draped. A 6-Fr sheath introducer  was inserted into the left and right jugular veins using a Seldinger retainment technique. After the insertion of the sheath introducers, the dogs were positioned in left lateral recumbency. A 5-Fr pressure–volume catheter  was positioned in the right ventricle with the aid of fluoroscopic guidance  and manually adjusted to obtain accurate RV pressure–volume loops. Additionally, a 4-Fr pacing catheter  was positioned in the right atrium and manually adjusted to obtain accurate right atrial pacing with the aid of fluoroscopic guidance and electrocardiography. After a 10-min stabilization period, hemodynamic measurements  and echocardiography  were performed to obtain baseline data. Right atrial pacing was subsequently performed using an external programmable pacemaker ; heart rates of 120 bpm, 140 bpm, 160 bpm, and 180 bpm were randomly generated. After 5 min of continuous right atrial pacing, hemodynamic measurements and echocardiography were performed at each pacing rate. When all of the experimental protocols were completed, the catheters and sheath introducers were removed and manual astriction was performed at the catheterization sites. All dogs were then recovered from anesthesia, and administered cephalexin  and robenacoxib . After completing the study protocol, all dogs were transferred for another study at our institution.Right heart catheterizations and hemodynamic analyses were performed by a single observer using a ventricular pressure–volume measurement device  and analysis software . RV pressure–volume loops were recorded for 30 s.The mean values of five consecutive pressure–volume loops at the end of the expiratory phase were used in the statistical analysis to eliminate the influence of respiratory variations . The folConventional 2D, M-mode, and Doppler examinations were performed using an echocardiography system  and a 3.5–6.9 MHz transducer. Lead II electrocardiography was performed simultaneously and results were displayed on the images. Data were obtained from at least 5 consecutive cardiac cycles in each dog while in lateral recumbency. All images were analyzed using an offline workstation .The means of the five consecutive cardiac cycles measured during paced rhythms were used in all analyses of the right heart echocardiographic indices. Furthermore, all indices were measured at the end-expiratory phase. The RVEDA and RVESA were measured as RV morphological indicators. These indices were obtained from the left apical four-chamber view optimized for the right heart (RV focus view) , 37, 38,For assessing RV function, the following indices were measured: TAPSE, RV FAC, and RV s’. These indices were obtained from the RV focus view , 37, 38.The TAPSE and RV FAC values normalized by body weight  were calculated using the following formulae , 41:The RV s’ was measured as the peak systolic velocity obtained from the tissue Doppler imaging-derived lateral tricuspid annular motion wave .3seg), as well as the systolic strain rate (RV-SrL3seg) , as well as the systolic strain rate (RV-SrL6seg)  Fig. A. The RVeg) Fig. B. ManualIntra-observer measurement variability was performed by the same observer who performed all the echocardiographic analyses. The echocardiographic indices of RV morphology and function for three dogs at baseline and at each pacing rate were measured on different days using the same echocardiogram and heart cycles. A second blinded observer measured the same echocardiographic indices to obtain interobserver measurement variability using the same five cardiac cycles. The mean values from two different days and from two different observers assessing the same cardiac cycles were used to evaluate intra- and interobserver measurement variability, respectively.All statistical analyses were performed using R software version 2.8.1. Continuous variables were reported as mean ± standard deviation for normally distributed data and median (interquartile range) for non-normally distributed data.r| was > 0.7, moderate if 0.4 to 0.7, weak if 0.2 to 0.4, and no correlation if < 0.2. The indices with p < 0.10 in the univariate analysis were entered into the multiple regression analysis.Data normality was tested using the Shapiro–Wilk test. Continuous variables were compared between the baseline and each pacing rate using a repeated-measures analysis of variance, with subsequent pairwise comparisons using Tukey’s multiple comparison test for normally distributed data. The Friedman test with subsequent pairwise comparisons using the Steel–Dwass test was used for non-normally distributed data. To evaluate the influence of HR on RV morphological and functional variables, Pearson’s and Spearman’s correlation coefficients were calculated. Additionally, univariate and multiple regression analyses were performed to identify the relationships between specific RV hemodynamic indices (Ees and Ees/Ea) and echocardiographic indices. The correlation was considered to be strong if the absolute value of the correlation coefficient |p < 0.05.Intra- and inter-observer measurement variability was quantified by the coefficient of variation (CV) using a root mean square method, as previously described . Additio


Flecainide is the first-line antiarrhythmic agent used in patients without structural heart disease. It is a class IC antiarrhythmic drug that inhibits inward sodium current through its dose-dependent blockade of voltage-gated calcium channels within the cardiac membrane. It has been shown to slow the conduction in the left bundle branch block. Unmonitored toxicity can cause ventricular dyssynchrony or fatal arrhythmia. We present a case in which flecainide use caused a new left bundle branch block (LBBB). Atrial fibrillation is a common arrhythmia seen primarily in adult patients with several comorbidities. Risk factors for atrial fibrillation include metabolic syndrome, hyperthyroidism, excessive intake of alcohol, sepsis, electrolyte abnormalities, etc. Treatment options in patients with atrial fibrillation vary based on symptoms, cardiac structure and function, and the presence of systolic heart failure.When deciding treatment options for atrial fibrillation two options of medical management are available: rate control and rhythm control. In patients with concern for decompensated heart failure, rhythm control is preferred. In patients with co-existing heart failure, atrial fibrillation is often poorly tolerated and can increase the risk of decompensation and worsening cardiomyopathy . Rhythm A 57-year-old female with a past medical history of hypertension, heart failure with a preserved ejection fraction of 55% to 60%, paroxysmal atrial fibrillation status post cardioversion (on Xarelto and flecainide), and hypothyroidism, was admitted following a motor vehicle accident. Upon admission, initial vitals were significant for a blood pressure of 140/98 mmHg, heart rate (HR) of 117 beats per minute, respiration of 20 respirations per minute, and oxygen saturation of 99% on room air. A computed tomography angiography (CTA) of trauma to the thoracic aorta demonstrated right breast lesions suggestive of hematoma, and large right pleural effusion. Arm X-rays demonstrated distal radial fracture with dorsal angulation, and comminuted distal tibial and fibular fractures with lateral displacement. A chest X-ray demonstrated cardiomegaly, and a trace right pleural effusion versus right subsegmental atelectasis was seen on CT as well. Laboratory results were unremarkable. An electrocardiogram (EKG) demonstrated normal sinus rhythm. The remainder of the labs were within normal limits. The patient was scheduled for external fixation of the left ankle and support non-operative management for the right distal radius. Twelve days following the external fixation of the left ankle, the patient was taken back to the operation room for removal of external fixation and definite fixation of the left ankle. Following surgery, the patient was noted to have an acute kidney injury with a blood urea nitrogen (BUN) of 43 and a creatinine of 2.50mg/dL (baseline 0.99). The patient’s EKG was notable for sinus rhythm, HR of 96bpm with a new left bundle branch block (LBBB) (Figure Flecainide, much like the other antiarrhythmics, has membrane-stabilizing activity. It is the first-line antiarrhythmic in patients with atrial fibrillation without structural heart disease . As a clAs seen with the patient presented above, flecainide use is not without its side effects. Its toxicity level has been associated with the plasma level of the drug . FlecainAlthough flecainide is one of the first-line antiarrhythmic agents in patients without structural heart disease, caution should be exercised with its use. Obtaining a baseline EKG prior to initiation of the drug is important to assess baseline intervals. Additionally, echocardiography and further workup for ischemic diseases should be considered if systolic dysfunction is discovered to prevent worsening left ventricular contractility that can result from the use of flecainide.


Bone marrow mesenchymal stem cells (BMSCs) are commonly used in regenerative medicine. However, it is not clear whether transplantation of BMSCs can improve cardiac function of the X-Linked Muscular Dystrophy Mice (mdx) and how to detect it. We aimed to investigate the role of speckle tracking echocardiography (STE) in detecting cardiac function of the BMSCs-transplanted mdx in comparison with the untreated mdx.The experimental mice were divided into the BMSCs-transplanted mdx, untreated mdx, and control mice groups (n = 6 per group). The BMSCs were transplanted via tail vein injections into a subset of mdx at 20 weeks of age. After four weeks, the cardiac functional parameters of all the mice in the 3 groups were analyzed by echocardiography. Then, all the mice were sacrificed, and the cardiac tissues were harvested and analyzed by immunofluorescence. The serum biochemical parameters were also analyzed to determine the beneficial effects of BMSCs transplantation.P < 0.05). However, BMSCs-transplanted mdx showed improvements in several STE parameters including significant increases in a few STE parameters (P < 0.05). Immunofluorescence staining of the myocardium tissues showed statistically significant differences between the mdx and the control mice (P < 0.05), and the mdx transplanted with BMSCs demonstrated significantly improvement compared with the untreated mdx (P < 0.05).Traditional echocardiography parameters did not show statistically significant differences after BMSCs transplantation for the three groups of mice. In comparison with the control group, mdx showed significantly lower left ventricular (LV) STE parameters in both the long-axis and short-axis LV images (This study demonstrated that the early reduction in the LV systolic and diastolic function in the mdx were accurately detected by STE. Furthermore, our study demonstrated that the transplantation of BMSCs significantly improved myocardial function in the mdx. Duchenne muscular dystrophy (DMD) is the most common X linked recessive myopathy with an incidence rate of 1/3000–5000 in live male births . The morCurrently, there is no effective cure for DMD. Clinical treatment with glucocorticoids delays the disease progression but does not alter the outcome of the disease . Long-teBone marrow mesenchymal stem cells (BMSCs) are early progenitor cells in the mesoderm developmental pathway that can differentiate into multiple cellular lineages and tissues including the muscle tissue. Mesenchymal stem cells (MSCs) are commonly used for clinical repair and cell transplantation therapy of diseased tissues in the human body, and have been used for tissue engineering studies in the recent years . MSCs arHowever, it is not known if cardiac dysfunction can be ameliorated by stem cell therapy. Early detection of myocardial dysfunction in the subclinical phase may facilitate timely intervention . Hence, The X-linked muscular dystrophy mouse (mdx) is a well-established mouse model of DMD and has been frequently used in the pathological, diagnostic, and therapeutic studies of DMD. The mdx harbor a recessive X-linked sporadic point mutation in exon 23 of the dystrophin gene and show similar pathological changes as the DMD patients , 20. Theem3Cd4/Gpt) and the corresponding wild type C57BL/6J mice were purchased from Gem Pharmatech Co., Ltd . C57BL/6 mouse-derived bone marrow mesenchymal stem cells (BMSCs) were purchased from Linyun Biotechnology Co., Ltd .The animal experiments were approved by the Institutional Animal Care and Use Ethics Committee of Guangzhou Medical University . Twelve-week-old mdx (C57BL/10ScSnJGpt-Dmd5 BMSCs (9th passage) were injected via the tail vein into each of the six mdx in the group 1. The group 2 and group 3 mice were injected with the vehicle  via the tail vein. The health status  of all the mice was analyzed once every week after the injections. After four weeks, cardiac function was evaluated by echocardiography. Then, all the mice were sacrificed and examined by histopathology  equipped with a single-crystal mechanical transducer (RMV 707B) and a central frequency of 30 MHz (15–45 MHz) was used to acquire the ultrasound images. Briefly, the mice were anesthetized with 3% inhaled isoflurane initially mixed with 100% oxygen and then maintained at 1.5% oxygen. The mice were laid in a supine position on a heated platform. The legs were taped to the electrocardiographic electrodes for recording. The chest hair was removed with a chemical hair remover before imaging.M-mode echocardiography was performed to evaluate the cardiac morphology and function in the left ventricular (LV) long-axis view at the midpapillary muscle level. The M-mode gate was set in the middle between the two papillary muscles to measure the ejection fraction (EF) and fractional shortening (FS). LV end-diastolic dimension (LVEDD) and heart rate (HR) values were also estimated from the M-mode images.For the STE examinations, short-axis two-dimension mode cine loops were acquired at the mid-level (midpapillary muscle level), and the long-axis cine loops were recorded by placing the scan head along the left sternal border for a clear view of the apex and the LV outflow tract. The frame rates of the regions of interest (ROIs) were adjusted up to 120 frames/sec. The image gain and other parameters were adjusted carefully to delineate all the myocardial segments. All the images were acquired for at least three successive and stable cardiac cycles. The raw data was stored digitally in a hard drive for offline analysis.STE analysis was performed using the 17 TomTec Image Arena 4.0 software . Strain and strain rate (SR) were estimated by manual tracing and editing of the ROIs and semi-automated tracking of the entire LV myocardial deformation from the epicardial to the endocardial border. The software automatically divided the long-axis LV images into six segments, namely, basal anterior, mid anterior, apical anterior, apical posterior, mid posterior, and basal posterior. The software also divided the short-axis images into six segments, namely, anterior, anterior septum, posterior septum, inferior, posterior, and lateral. Strain measurements in each segment were averaged to evaluate the global strain, which included estimation of radial strain (L-RS) and longitudinal strain (L-LS) derived from the long-axis view, as well as radial strain (S-RS) and circumferential strain (S-CS) derived from the short-axis view. We also estimated global SR including radial strain rate (L-RSR) and longitudinal strain rate (L-LSR) from the long-axis view, as well as radial strain rate (S-RSR) and circumferential strain rate (S-CSR) from the short-axis view Fig. . The revTwo observers independently analyzed ten randomly selected mice (5 mdx and 5 control mice) at various times and the intra- and inter-observer variability of the strain parameters were estimated. To determine intra-observer variability, the first observer analyzed the data twice with an interval of 2 weeks while being blinded to the results of the first set of measurements. The second observer was blinded to the results of the first observer and analyzed the data independently to determine the inter-observer variability. The intra- and inter-observer variability were expressed as intra-class correlation co-efficient (ICCs).Peripheral blood samples were collected from all the mice in each group and the serum levels of liver function parameters , aspartate transaminase (AST), alkaline phosphatase (ALP)) and myocardial zymography indicators (lactate dehydrogenase (LDH), creatine kinase (CK)) were estimated.Myocardial tissue samples were analyzed by immunofluorescence staining with the monoclonal anti-dystrophin antibody from Sanying Biotechnology Co., Ltd  and the content of positively-stained fibers were estimated for all the mice in the 3 groups. The integrated optical density (IOD) of five fields in each section and the corresponding five fields of tissue area were measured separately using Image-Pro Plus 6.0 software, then the mean optical density (MOD) was calculated by total IOD / total tissue area. MOD represented the dystrophin level. Isotype IgG was used as negative control in immunofluorescence staining.Statistical analysis was performed using the SPSS software version 23.0  and the MedCalc software version 18.2.1 . The continuous variables were expressed as means ± standard deviation (SD). The group differences for the continuous variables were compared using one-way analysis of variance. Bonferroni adjustment method was used for pairwise comparison of the means when comparing the differences between multiple groups of data. Two-tailed P-values < 0.05 were considered statistically significant. The intra-observer and inter-observer variability was reported as the coefficient of variation, which were calculated by dividing the standard deviation by the mean and expressed as a percentage. The intra- and inter-observer variabilities were expressed as percentiles, which were calculated as follows: (absolute difference between the measurements/mean of the measurements) ×100%.All the mice underwent high-frequency echocardiography examinations as well as biochemical and immunofluorescence examinations. Traditional echocardiography parameters such as LVEDD, LV mass, LVEF, LVFS, and HR did not show any significant differences in the 3 groups of mice Table .Table P < 0.05). Furthermore, mdx transplanted with BMSCs demonstrated significantly higher RS and LS in the long-axis LV images and CS in the short-axis images compared with the untreated mdx (P < 0.05). However, RS in the short-axis images did not show statistically significant differences between the untreated mdx and the BMSCs-transplanted mdx. Except RS in the short-axis in BMSCs transplanted mdx showed significant reduction than RS in control mice (P < 0.05), there were no significant difference in the other LV global strain values between the control mice and the BMSCs-transplanted mdx.The mdx showed significantly lower LV global strain in both the long-axis and the short-axis LV images compared with the control mice (P < 0.05). SR values were higher in all the LV segments of the BMSCs-transplanted mdx compared with the untreated mdx. However, only the longitudinal SR values in the long-axis images were significantly higher in the BMSCs-transplanted mdx compared with the untreated mdx (P < 0.05). There was no significant difference between the control mice and the BMSCs-transplanted mdx in all the LV global SR values.In the long axis and short axis LV images of all the LV segments, the LV SR was significantly reduced in the mdx compared with the control mice .The intraclass correlation coefficients (ICCs) for the intra- and inter-observer variability in the 2D strain parameters including L-RS, L-LS, S-RS, S-CS, L-RSR, L-LSR, S-RSR, and S-CSR were in the range of 0.868–0.916 . There was no significant difference in ALP between the mdx and the control mice. The mdx transplanted with BMSCs showed significantly lower AST compared with the untreated mdx (P < 0.05), and there was no significant difference between the two groups in the other biochemical parameters. Compared with the control mice, the mdx transplanted with BMSCs showed significantly higher ALP, CK, and LDH (P < 0.05), and there was no significant difference between the two groups in ALT and AST. . The mdx transplanted with BMSCs demonstrated significantly higher MOD compared with the untreated mdx (P < 0.05)  Table ; Fig. 4.This is the first study to investigate changes in the cardiac function of mdx after transplantation of BMSCs using high-frequency ultrasound-based two-dimensional STE. The analysis of STE parameters showed myocardial deformation in the mdx. However, conventional M-mode echocardiography did not detect any early LV contractile dysfunction in the mdx. The histopathology and STE parameters showed significant improvements in the myocardial structural parameters of the BMSCs-transplanted mdx compared to the untreated mdx. To our knowledge, this is the first study that used 2D strain and strain rate (SR) values derived from STE to evaluate the impairment of systolic and diastolic function in the hearts of the mdx, and detect changes in myocardial function before and after transplantation of the BMSCs. Our study demonstrated that the BMSCs transplantation therapy improved cardiac function in the mdx, and changes in the cardiac function of mdx after BMSCs transplantation can be detected early by estimating 2D strain and SR using high-frequency ultrasound-based two-dimensional STE. The present study suggested that BMSCs transplantation therapy may be promising for patients with DMD.Our results showed that the myocardial strain and SR derived from STE were significantly reduced in the mdx compared with the control mice. However, the cardiac contractile function parameters such as LVEF and LVFS, which were measured by conventional M-mode echocardiography, did not show any significant differences between the two groups. Therefore, our study confirmed that strain and SR, which reflect myocardial exercise capacity, can be used to detect changes in the myocardial function under pathological conditions. Although M-mode echocardiography-derived parameters such as LVEF, LVFS, LV mass and chamber diameter can be used to evaluate cardiac function and morphology, many previous studies have confirmed that 2D strain is a more sensitive measure of cardiac dysfunction than the conventional M-mode echocardiography parameters in patients with DMD , 22 and STE is a useful technique to detect myocardial deformation by estimating epicardial strain, endocardial strain and other myocardial parameters . In the Several studies have shown that MSCs can be differentiated into cardiomyocyte-like cells . FurtherIn the present study, we also confirmed the amelioration due to BMSC transplantation in the cardiac function and structure of the mdx by biochemical and histopathological examinations. The levels of dystrophin were significantly reduced in the untreated mdx compared to the control group, but increased significantly in the BMSCs-transplanted mdx. Alterations of hepatic enzymes and myocardial zymography indicators in DMD are a response that results from long-term damage to muscle. Although damage of muscle tissue was ameliorated after transplantation of BMSCs and enzyme levels decreased substantially, we considered that there were no statistical differences because of the small sample size and limited follow-up time. This reflected to a certain extent that biochemical indicators were not sensitive in evaluating the efficacy of BMSCs transplantation.The coupling of muscle progenitor cell proliferation with myogenic differentiation is necessary to improve myocardial function by transplanting BMSCs. Previous reports have shown the potential of BMSCs to fuse and form myotubes, and the ability of BMSCs to promote tissue regeneration , 36. FurThis study has a few limitations. Firstly, echocardiography was performed under anesthesia, which can affect myocardial contractility, ejection fraction and strain/SR values. Secondly, the treatment course of BMSCs transplantation in this study was short. In the future, long-term efficacy of the BMSCs needs to be investigated by increasing the number of BMSCs transplantations and prolonging the time course. Thirdly, the sample size was small in the present study. Therefore, in the future studies, a large sample size is required to confirm our results. Finally, this study was performed in an animal model of DMD (mdx), which does not entirely represent the same disease process as the human DMD patients. Therefore, our study needs to be validated in the DMD patients in future studies.This study demonstrated that the 2D STE technique detected early reduction in the LV systolic and diastolic functions of the mdx. Furthermore, this study confirmed that transplantation of BMSCs significantly improved myocardial function in the DMD model mdx. Future experiments in animal models and human trials in DMD patients are necessary to confirm that the transplantation of BMSCs is a safe and effective clinical treatment for DMD.


Quantitative susceptibility mapping (QSM) is a powerful, non-invasive, magnetic resonance imaging (MRI) technique that relies on measurement of magnetic susceptibility. So far, QSM has been employed mostly to study neurological disorders characterized by iron accumulation, such as Parkinson’s and Alzheimer’s diseases. Nonetheless, QSM allows mapping key indicators of cardiac disease such as blood oxygenation and myocardial iron content. For this reason, the application of QSM offers an unprecedented opportunity to gain a better understanding of the pathophysiological changes associated with cardiovascular disease and to monitor their evolution and response to treatment. Recent studies on cardiovascular QSM have shown the feasibility of a non-invasive assessment of blood oxygenation, myocardial iron content and myocardial fibre orientation, as well as carotid plaque composition. Significant technical challenges remain, the most evident of which are related to cardiac and respiratory motion, blood flow, chemical shift effects and susceptibility artefacts. Significant work is ongoing to overcome these challenges and integrate the QSM technique into clinical practice in the cardiovascular field. The magnetic susceptibility distribution is then calculated from the field map, by solving a ‘field-to-source’ problem. Calculation of quantitative susceptibility maps (QSM) cannot be achieved with magnitude gradient-echo images alone, instead phase images acquired at different echo times are needed to measure the B0 maps, by first calculating the rate of phase accrual at each voxel , then converting this to local B0 using the Larmor equation. Although this method is technically challenging, owing to the difficulty of obtaining high fidelity B0 maps and successfully performing the field-to-source reconstruction, QSM can provide key information on the biochemical constituents and microstructure of tissue. So far, QSM research has primarily focused on applications in neurology, particularly the identification of iron containing substances such as hemosiderin associated with hemorrhage, iron more generally, and paramagnetic contrast agents [Spatial variations in magnetic susceptibility distort magnetic fields. These magnetic field distortions commonly lead to undesirable artefacts in magnetic resonance imaging (MRI) images, but since magnetic susceptibility is related to the underlying composition of tissue it can also provide a wealth of information. One clinically efficient approach to quantifying magnetic susceptibility is to first calculate maps of the main , this convention will be used for the remainder of the article. Biological tissues can be diamagnetic , paramagnetic  or ferromagnetic (iron). In CMR, the χ of an organ within the static magnetic field B0 can be quantified by mapping the magnetic field perturbation (δB). To map χ, we first construct the forward problem that expresses how the inhomogeneous susceptibility (χ) distorts the magnetic field B0, after which the inverse problem is solved. The magnetic field distortion δB(r) induced by a susceptibility distribution χ(r) can be computed by convolving the susceptibility distribution by the unit magnetic dipole kernel d(r), resulting in the following equation [0 is assumed to be along z-direction, ⊗ is the convolution operator, and r| and θ being the radial distance and polar angle in the spherical polar coordinate system, respectively. The induced magnetic field perturbation δB map can be calculated from a Larmor resonance frequency shift (δω) map (measured using 3D multi-echo GRE phase images) with the following relationMagnetic susceptibility measures the degree to which a material is magnetized when exposed to a homogenous external magnetic field (H), and is expressed as a dimensionless ratio (χ) between material magnetization (M) and the external magnetic field strength (H), i.e., χ = M/H . Magnetiequation 1\documenr), the measured δB depends on the magnetic susceptibility both within, and outside of the object, making it very challenging to solve Eq. 0 perturbations caused by magnetic susceptibilities located within (δBloc), and outside (δBbkg) of the object withDue to the spatial extent of d·FT(b)) , where7\) method  (which i) method –26 when Step 1: Estimation of the magnetic field perturbation map. A 3D loc map is computed by removal of δBbkg from the δB map based on Eq. Step 2: Estimation of the local magnetic field perturbation map. A 3D δBloc map by solving the field-to-source inverse problem based on Eq. 1- and ℓ2-regularization techniques such as Morphology Enabled Dipole Inversion (MEDI) [Step 3: Estimation of the tissue magnetic susceptibility map. A 3D n (MEDI)  or Homogn (MEDI) .In practice, for cardiac QSM, there are three steps to finding this 3D entclass1pt{minimaQSM measures the spatial distribution of χ produced by the diamagnetic, paramagnetic and ferromagnetic constituents of tissue . The bod2* magnitude imaging by multi-echo GRE is already a well-validated technique to quantify iron deposits, T2* relaxation time (or R2* = 1/T2*) is influenced by local background susceptibility and other sources alongside iron deposits [2* (or R2*) relaxivity, measured by GRE images, can miss pathological iron accumulation due to the competing effect of the diamagnetic myelin, the main white matter component [3+-haeme, is diamagnetic despite Fe3+, in aqueous solution, possessing five unpaired electrons, whereas deoxyhaemoglobin is paramagnetic [Although Tdeposits . For insomponent . The magmagnetic .The application of QSM for studying the cardiovascular system offers an unprecedented opportunity to gain a better understanding of the pathophysiological changes associated with cardiovascular disease. A number of state-of-the-art applications are described in the following sections, each of which has the potential to significantly improve patient care and outcomes in impactful areas of cardiac medicine. Despite this, the field of cardiac QSM is in its infancy, so a number of challenges remain to be solved. The most evident of these challenges are related to cardiac and respiratory motion, blood flow, chemical shift effects at the boundary between the epicardium and epicardial fat, and susceptibility artefacts at the myocardium-lung interface , 43.2) is a relevant biomarker in many cardiovascular diseases, and is commonly used for the identification and quantification intra-cardiac shunts in congenital heart disease. This metric also provides an index of systemic oxygen delivery and consumption in heart failure [2 by measuring the difference in magnetic susceptibility between the venous and arterial blood pools using QSM [2* source images that were then post-processed to generate QSM maps. The latter showed strong differential susceptibility (Δχ) between RV and LV blood pools as a result of the paramagnetic and diamagnetic properties of the deoxygenated and oxygenated hemoglobin, respectively, which allowed them to measure of the blood oxygenation difference (ΔSaO2) using an established formula [4χdeoxyheme is the molar susceptibility of a fully deoxygenated deoxyhemoglobin (151.054 ppb ml/µ) and H is the heme concentration in blood, which is derived from the patient’s measured hematocrit (Hct), the mass concentration of hemoglobin in a red cell , and the molar mass of deoxyhemogloblin (MHb = 6444·10–6 g/µmol) [Oxygen saturation in the arterial blood  .2 than those with preserved systolic function. Remarkably, the 3D approach also showed an excellent correlation) and small bias when compared to invasively measured ΔSaO2 (gold-standard) in 15 patients undergoing cardiac catherization [2, T2*, and T1 relaxation times of the blood pool. For instance, the dependence of T2 relaxation time on blood oxygenation is well established, but requires measuring multiple complex Luz–Meiboom model parameters, restricting its clinical applicability [2 measurements, with different inter-echo pulse spacing, to estimate all the parameters in the Luz-Meiboom model and non-invasively estimate the SaO2 [This approach, however, was complicated by long acquisition time, low signal-to-noise ratio (SNR) and inconsistent positioning of consecutive short-axis slices across the ventricles which lead to non-interpretable source GRE images in 36% of subjects . These lrization . QSM-oxicability . Recentlthe SaO2 , 52. How2) reflects the balance between oxygen delivery and consumption; in patients with heart failure a low vSaO2 is associated with advanced and decompensated hemodynamic status due to insufficient cardiac output, and/or reduced arterial oxygen saturation (aSaO2). It is important to acknowledge that a substantial number of heart failure patients can have a reduced vSaO2 despite a normal cardiac output [2 has been shown to predict clinical outcomes in patients with acute myocardial infarction and patients with primary pulmonary hypertension [QSM-oxymetry has the potential to play a key role in congenital heart disease, where CMR is increasingly used for pre- and post-operative management, as an alternative to invasive catheterization. The non-invasive, ionizing-radiation free, nature of QSM-oximetry is well suited for repeated CMR exams of young patients, complementing phase-contrast velocity-encoding techniques for intra-cardiac shunt diagnosis, management, and follow-up. In addition, QSM-oximetry may provide key information in patients with heart failure or pulmonary hypertension, as well as in establishing the cause of hypoxemia, and may potentially be used to tailor therapy and monitor treatment. Mixed venous oxygen saturation  maps, which are currently used to detect and quantify IMH. This finding is not unexpected since multiple biochemical factors can exert opposite effects on T2* relaxation time in the acutely infarcted myocardium, including shortening due to iron, and lengthening due to edema, fat and collagen deposition. QSM however, directly probes the local magnetic susceptibility [In patients with ST-segment elevation myocardial infarction (STEMI), re-opening of the infarct-related artery is a prerequisite to salvaging the ischemic myocardium. However, reperfusion per se brings about myocardial damage (ischaemia/reperfusion injury) partially negating the benefits of infarct-related artery re-opening. Intramyocardial haemorrhage (IMH) is a hallmark of severe ischemia–reperfusion injury, occurring in about half of patients with a STEMI. This phenomenon is due to the loss of coronary microvasculature integrity with ensuing erythrocyte extravasation and iron accumulation in the myocardium from hemoglobin breakdown. Compelling evidence indicates that IMH is a strong independent predictor of adverse LV remodelling and untoward clinical outcomes in STEMI patients, potentially due to the increased production of reactive oxygen species promoted by elevated iron levels , 57. Thitibility , which ctibility , an impo1 and T2* maps have been used for myocardial iron quantification, although T1-mapping is likely better placed to capture the very early stage of cardiac hemosiderosis [0 field maps which are minimally influenced by liver fibrosis or inflammation. Fat fraction and chemical shift corrected magnetic susceptibility maps can be calcutated with methods such as Chemical QSM, which uses the Dixon-based IDEAL method [QSM may also be applicable to the assessment of patients with hemochromatosis in order to quantify myocardial iron deposition, which strongly affects LV remodelling and clinical outcome , 60. Botiderosis . QSM holiderosis . QSM recL method . MoreoveL method , 64 alth0 orientations. Susceptibility anisotropy originates from the ordered (restrained) spatial arrangement of molecules with diamagnetic  and paramagnetic  properties within a tissue, which then generates a bulk (macroscopic) anisotropic susceptibility. This is exemplified by the ordered distribution of phospholipids in the myelin sheaths which encapsulate axons in the central nervous system, giving rise to measurable macroscopic susceptibility anisotropy [The restrained distribution of molecules in a specific tissue can be gauged by magnetic susceptibility anisotropy using susceptibility tensor imaging (STI), which calculates a susceptibility tensor using multiple images with different Bisotropy .0 appear diamagnetic while those parallel to B0 are paramagnetic relative to the reference susceptibility [0 orientations can be overcome, to the most commonly used technique for mapping myofibre orientation, diffusion tensor imaging (DTI) [Cardiac myofibrils consist of serially repeated sarcomere units, a highly organised structure of repeated of thick and thin myofilaments oriented parallel to the long axis of the myofibril. This myocardial microstructure is altered in cardiomyopathy, myocardial infarction, and congenital heart diseases, where the initial misalignment of myocardial fibres causes increased myocardial stress, which begets further fibre misalignment and promotes adverse cardiac remodelling, eventually culminating in heart failure or life-threatening ventricular arrhythmias –70. Henctibility . In the tibility  This makng (DTI) . While hng (DTI) ), long sng (DTI) ) and a lng (DTI) , 76. On ng (DTI) , and theng (DTI) .1-weighted images, while chronic intraplaque hemorrhage appears markedly hypointense on T1-weighted, T2- or T2* weighted, and time-of-flight images. The differentiation of chronic intraplaque hemorrhage and plaque calcification is challenging, given that both are associated with signal loss on multi-contrast CMR. In contrast, QSM can distinguish diamagnetic calcification from paramagnetic intraplaque hemorrhage [Vulnerable atherosclerotic plaques are characterized by the presence of a lipid-rich necrotic core, intraplaque hemorrhage, a thin ruptured fibrous cap, and to a lesser degree calcification . Currentmorrhage , 81, 82,morrhage . In this2*weighted or R2*-maps, enables the quantification of the inflammatory component of atherosclerotic plaque. Recent studies indicate that QSM implemented with IDEAL water-fat separation can concurrently identify multiple high-risk plaque features , moreover, the addition of IDEAL improves QSM image quality reducing the streaking artefacts caused by chemical frequency shift. Thus, QSM processing could fit within a multi-contrast approach for quantification of atherosclerosis using a single 3D multi-echo GRE acquisition [Ultra-small superparamagnetic iron oxide (USPIO) contrast agents are increasingly used to measure macrophage infiltration. After intravenous injection, this compound enters plaque through its leaky endothelium and is internalised by macrophages. Comparison of pre- and post-USPIO iron-sensitive sequences, such as Tuisition , eliminaDespite the recent breakthroughs in QSM, accurate quantification of magnetic susceptibility is still challenging. Existing methods need to be evaluated systematically under a variety of experimental conditions, and further work is needed to achieve high degrees of consistency. Blood flow and motion cause phase variations that can lead to erroneous magnetic field estimates. Chemical shift, proton exchange and partial volume effect can also influence frequency shift, introducing further errors. Currently, 3D multi-echo GRE acquisition, with a diaphragmatic navigator, is preferred to the breath-hold multi-slice 2D approach as this prevents slice misalignment and non-continuous k-space sampling. However, standard diaphragmatic navigators rely on a tracking factor (commonly set to 0.6) to correct for diaphragmatic and heart motions. Typical navigator gating efficiency (~ 25–60%) and the tracking factor is known to be subject-dependent and highly variable. Prospective respiratory gating techniques may provide higher gating efficiency (up to 100%) and improve motion correction using complex subject-specific models of the diaphragmatic/heart motion relationship –87 or im0 shimming [0 shimming conditions still exists due to short T2* decay, and this issue is particularly relevant in higher magnetic fields (3T/7T), requiring higher-order shimming. Most current cardiovascular QSM literature is based on single-centre studies and there is currently insufficient data characterizing the technique’s accuracy, repeatability, and reproducibility (both within a given site/scanner and between sites/scanners). Different experimental setups may influence QSM, including the choice of the QSM reconstruction algorithm, imaging parameter selection, field strength, and shimming approaches/shim set performance. Therefore, the development of a commercially available QSM phantom together with the site-specific estimation of reference QSM values in healthy subjects/patients may be necessary for calibration and standardization purposes, as is currently the case in other areas such as myocardial T1 mapping [+ [Epicardial fat represents another challenge in cardiovascular QSM. However, Dixon-based fat-water separation methods, such as IDEAL, have been successfully adopted in abdomen or neck QSM , 84 and shimming . Nonethe mapping . Current mapping . Example mapping  for phas mapping , for thepping [+  for calcQSM is a promising method to expand the arsenal of measurable, reproducible and accurate CMR biomarkers in the heart, and therefore enable better understanding of the intricate pathophysiology processes underlying cardiovascular diseases. However, overcoming outstanding technical challenges and validation in large clinical studies are critical steps for a successful integration of cardiovascular QSM into clinical practice.


The systolic and diastolic sarcomere lengths decreased; contraction and relaxation kinetics slowed down with increasing danicamtiv concentrations without changes in intracellular Ca2+ transients in vitro. Danicamtiv evoked remarkable increases in left ventricular ejection fraction and fractional shortening, also reflected by changes in systolic strain. Nevertheless, the systolic ejection time was significantly prolonged, the ratio of diastolic to systolic duration was reduced, and signs of diastolic dysfunction were also observed upon danicamtiv treatment in vivo. Taken together, danicamtiv improves cardiac systolic function, but it can also limit diastolic performance, especially at high drug concentrations.Recent cardiotropic drug developments have focused on cardiac myofilaments. Danicamtiv, the second direct myosin activator, has achieved encouraging results in preclinical and clinical studies, thus implicating its potential applicability in the treatment of heart failure with reduced ejection fraction (HFrEF). Here, we analyzed the inotropic effects of danicamtiv in detail. To this end, changes in sarcomere length and intracellular Ca BasedA new class of positive inotropic drugs, the myosin activators, gained considerable interest about a decade ago. These agents modulate the function of the myosin motor protein by acting on the chemo-mechanical actin–myosin crossbridge cycle ,5. ImporRecent pharmacological efforts led to the development of a new direct myosin activator, danicamtiv, which also binds to the myosin molecule of cardiomyocytes. The dani-camtiv binding site on myosin, and consequently its molecular action, is thought to differ from those of OM ,12. More2+ concentration changes. Complimentary state-of-the-art echocardiographic examinations in rat hearts allowed the analysis of danicamtiv’s effects on LV contractile performance. The combination of in vitro and in vivo studies served as a tool to elucidate the relationship between danicamtiv’s evoked effects on myocardial systolic and diastolic functions. Our results illustrate danicamtiv as a direct myosin activator having a largely similar pharmacological profile to OM and signify the potential for diastolic dysfunction during direct myosin activation in general.In the present study, we aimed to address the contractile effects of danicamtiv at the sarcomere and organ levels. Here, we show the results of a detailed concentration-response analysis in isolated canine cardiomyocytes where danicamtiv effects on sarcomere dynamics are interpreted in view of intracellular Cap = 0.45, p < 0.001, p < 0.001, p < 0.001, respectively)  G. Danicaeatments F.p < 0.001), fractional shortening (FS) , and stroke volume (SV)  increased significantly upon the intravenous administration of 2 mg/kg danicamtiv (p = 0.026)  D, supporp = 0.0001) and systolic ejection time (SET) were significantly prolonged upon danicamtiv treatments in rats  , respectively, p = 0.029, p = 0.004, p < 0.001 and p < 0.001 for 0.3, 0.5, 1, and 2 µM drug concentrations for time to peak interval). Echocardiography revealed a significant decrease in the duration of diastole   A,B. Simi< 0.001) C and in < 0.001) D were ob= 0.008) E, which p < 0.001, N = 9, p = 0.008, N = 10 p = 0.021, p < 0.001 and p < 0.001  and atrial reversal flow duration  were observed, which indicate an augmentation of the left atrial systolic function. No significant changes were seen in the aortic or pulmonary artery mean and peak velocities or gradients developed during danicamtiv treatments  and an increase in the late (A) transmitral filling velocity  transmitral filling velocity (from 720.92 2+ transients were observed (2+ transients were studied (data not shown). When electrocardiac parameters were analyzed , no relevant changes or arrhythmias were observed upon danicamtiv application  no changes in the amplitudes and durations of Caobserved A,B. Morelication .The results of our present investigations illustrate danicamtiv, a new direct myosin activator with an apparent coupling between its systolic and diastolic effects. Our data extend previous danicamtiv-related observations and shed new light on its characteristics for a potential future clinical application as a positive inotrope.Targeted disease-modifying therapies appear as emerging new strategies in current HF guidelines to treat cardiomyopathies . The myo2+ transients in cardiomyocytes, suggesting that the above drug–target interaction is solely responsible for its cardiotonic effects. It follows that danicamtiv-evoked contractile responses will be largely comparable in dogs and rats, as has been formerly also evidenced for OM in identical canine and rodent cardiac preparations [The binding site of direct myosin activators is located on the S1 domain of the β-myosin heavy chain in the cardiomyocytes of canine and rodent hearts. Of note, danicamtiv (similarly to OM) had no effect on intracellular Caarations . Here, warations , and to arations .2+ levels, oxygen consumption, and also mortality in the long term [2+ transient, a mechanism that supposedly avoids the above side effects.The pathophysiological processes occurring in HFrEF lead to significant declines in contractility with manifest reductions of SV . Positivong term ,27,28. I2+ levels, which has been also demonstrated during OM administration [2+ levels by direct myosin activators [Here, we performed comprehensive experiments and showed that danicamtiv has major effects on both the systolic and diastolic functions of enzymatically isolated intact canine LV cardiomyocytes in vitro and in rat hearts in vivo. Danicamtiv evoked a significant decrease both in systolic and diastolic SL in our in vitro experiments, similarly to OM ,29. The stration . Of notestration . The abotivators ,20.Our current assessment on LV contractility revealed significant increases in FS, SV, EF, and CO upon danicamtiv administration, similarly to previous findings obtained with OM . In contThe in vivo and in vitro results with danicamtiv showed similarities when comparing the kinetic parameters of the contraction and relaxation of canine cardiomyocytes to those of systolic and diastolic durations in rat LVs: i.e., contraction kinetics was significantly slowed down in vivo, while time to peak and contraction time values were significantly increased in vitro. The increase in systolic ejection time and systolic contraction time appear as hallmarks of myosin activators, as was shown first for OM treatments ,22. Of nNovel echocardiographic parameters, such as peak radial systolic velocity from strain analysis and the conventional M-mode slope, were also consistent with kinetic parameters measured in canine cardiomyocytes in vitro. Here, we evaluated myocardial strain and velocity by using speckle tracking  echocardiography. Strain rate imaging is a novel approach for assessing myocardial function and has not been included in routine diagnostic methods yet. It is important to note that strain echocardiography, especially in small animals, has also been also less studied, although it provides a very sensitive approach to detect alterations in LV function. Myocardial velocity and strain can be also measured by TDI, though STE 2D-strain is considered to be a superior technique since, in contrast to TDI, the obtained results are angle-independent . In geneAdditionally, 2D-strain echocardiography seems to be a more sensitive tool to assess LV function than measuring EF by classical methods. For example, it has been reported that global longitudinal strain or circumferential strain  can convincingly detect systolic dysfunction even when EF is normal . In our It is to be acknowledged that extrapolation of our results to the failing heart could be limited by the fact that our investigations were carried out on the cardiac preparations of healthy animals. Nevertheless, our results are in accord with those performed in a canine model of heart failure and in a phase 2a trial on danicamtiv .Taken together, the cardiac effects of OM and danicamtiv are largely similar: both compounds effectively enhance LV systolic function, although they can also limit LV diastolic function. The data presented here implicate advantages for danicamtiv over OM, since danicamtiv did not affect IVRT or IVCT. Moreover, left atrial contractile function was enhanced at a relatively low danicamtiv concentration. To our knowledge, similar effects have not been reported for OM yet.Cardiomyocytes with intact membranes isolated from adult mongrel dogs (N = 6 weighed 10.00 ± 3.03 kg (6 to 14 kg), aged 15.03 ± 1.02 months (13.9 to 16.9 months)) were anesthetized with intramuscular injections of ketamine hydrochloride  and xylazine hydrochloride  according to a protocol approved by the local Animal Care Committee (2/2020/DEMÁB).In vivo experiments were performed on 8–12-week-old adult Sprague-Dawley rats  and they were housed in a room with controlled temperature and kept under 12/12 h dark/light cycle. Rats were anaesthetized with ketamine/xylazine combination ; thereafter, chest hair was shaved, tail vein was canulated (the cannula was removed at the end of the experiments), and animals were positioned in a dorsal position on a heating pad (39 °C). During echocardiographic examinations, external 3-lead ECG registration was continuously performed. Danicamtiv was administered intravenously at a dose of 2 mg/kg according to a protocol approved by the local Animal Care Committee (4-1/2019/DEMÁB).iv.), dissolved in its special solvent ) at a dose of 2 mg/kg. Danicamtiv dose was chosen according to a previously published pharmacokinetic study [Chemicals were obtained from Sigma-Aldrich Co. . Danicamtiv was purchased from MedChemExpress . Stock solutions for in vitro experiments were prepared in DMSO as solvent and stored at 4 °C. Appropriate amounts of concentrated stock solutions were dissolved in the bathing medium to obtain final danicamtiv concentrations of 0.01, 0.1, 0.3, 0.5, 1, and 2 μM for in vitro experiments. These concentrations were reached by cumulative dosing during the experiments. The concentration of DMSO in these solutions was 0.1%. The control (danicamtiv-free) vehicle contained the same amount of DMSO. With regard to in vivo experiments, danicamtiv was administered intravenously  for 5 min, followed by 30 min-long perfusions with Joklik solution containing 1 mg/mL collagenase  and 0.2% bovine serum albumin  added 50 µM Ca2+. Then cells were grounded, and normal Ca2+ concentration was restored progressively. Cells were stored at 15 °C until the measurements.Canine cardiomyocytes obtained from adult mongrel dogs were studied, since their physiological properties are very similar to those of humans. Cardiomyocytes were isolated from the midmyocardial region of the LV, as was described previously ,34. Brie2+-sensitive ratiometric fluorescent dye for 30 min in the presence of Pluronic F-127 (25 mg/mL) to avoid early elimination of the dye from the intracellular space. A total of 25 mg Pluronic F-127 was dissolved in 1 mL DMSO and this solvent was used to make a Fura-2 AM stock solution. Cells were then incubated for 30 min to allow the intracellular esterases to release Fura-2. Cardiomyocytes were placed in a chamber on the stage of an inverted microscope (Nikon TS-100). The final volume of the chamber was filled with 1 mL Tyrode solution . After sedimentation, a rod-shaped cardiomyocyte with clear striation, and acceptable contraction upon field-stimulation was selected for further experiments. Field stimulation was performed at 0.5 Hz . Alternating excitation wavelengths of 340 nm and 380 nm were used to monitor the fluorescence signals of Ca2+-bound and Ca2+-free Fura-2 dye, respectively. Fluorescent emission was detected above 510 nm in the case of both wavelengths, and traces were digitized at 120 Hz using the FeliX Software  [Cardiomyocytes were loaded with 5 μM Fura-2 AM CaNJ, USA) .2+ transients were assessed. Cardiomyocyte SL was measured in µm by a high-speed camera. Duration of contraction was defined as the time in seconds from the beginning until the end of cardiomyocyte contractions and time to peak interval was assessed from the beginning to the peak of shortenings, also in seconds. Rates of contraction and relaxation were determined at the linear phases of contractions and relaxations, respectively, and expressed in µm/s. The resting Ca2+ level was estimated by Fura-2 ratio (fluorescent intensity ratio at 340 and 380 nm excitation) at baseline (before cardiomyocyte stimulation). The Ca2+ transient duration was determined as the time interval measured between the 50% of ascending and descending slope of Ca2+ transient. The amplitude of Ca2+ transients was defined as the difference between the peak of Ca2+ transients and the resting Ca2+ levels (340 nm/380 nm ratio). Ca2+ transient increase kinetics was determined as the slope of a linear regression line fitted to the ascending Ca2+ transient (340/380*s−1).The experimental protocol was the following: cardiomyocytes were paced at 0.5 Hz for at least 2–3 min to achieve a steady state at the beginning of each experiment. Da-nicamtiv was added in a cumulative manner  followed by a 4–7-min incubation period, then contractility was measured upon 0.5 Hz pacing. Multiple parameters of cardiomyocyte contraction and intracellular CaEchocardiography was carried out using the Vevo 3100 Imaging System including Vevo Imaging Station  equipped with high-frequency transducer . Anesthetized rats  were shaved and placed onto a heated platform  equipped with ultra-low noise, high-resolution ECG electronics. The ECG was continuously monitored and recorded (2 min) during echocardiographic examinations. Echocardiographic imaging was started 5 min after danicamtiv i.v. injection and lasted maximum 15 min. Data acquisition was performed in B-, 2D-, M-, and Doppler modes, from parasternal long- and short axis , as well as suprasternal and apical 4 chamber views . Cardiac function was assessed in accordance with the guidelines of American Society of Echocardiography . The manDiastolic function was assessed by pulsed-wave Doppler (PWD) and tissue Doppler imaging (TDI) from apical 4 chamber views at the levels of the mitral valve (MV) and the septal annulus, respectively. Transmitral early  and late atrial  peak flow velocities, MV E/A ratio, and deceleration time  of the E wave were determined. Isovolumic contraction time , systolic ejection time , and isovolumic relaxation time  were determined in the left ventricular cavity, where both mitral inflow and left ventricular outflow could be visualized. Myocardial performance index (MPI) was calculated as the Tei-index (IVRT+IVCT/LVET(SET)). The length of a cardiac cycle  was determined from R-R distance. Duration of systole  was considered as ET+IVCT, while duration of systole  was calculated as CL-SystDur. The ratio of the DiastDur/SystDur was also calculated. The PW Doppler mode was also used to determine aortic flow (Ao) parameters from a modified suprasternal (aortic arch) view. Aortic velocity time integral , mean and peak velocity , mean and peak pressure gradient  were calculated by the software after automatically tracing the borders of the Doppler jet. Similarly, the flow parameters of the pulmonary artery (PA) were determined as PA velocity time integral , mean and peak velocity , mean and peak pressure gradient . The pulmonary vein was visualized by using a modified PSLAX view . Pulmona® software equipped with the VevoStrain® extension . The software displays acquired videos in configurable slow-motion loops, allowing for suitable analysis even when the HR is high. Grayscale B-mode pictures were used to measure strain and strain rate parameters. Images were carefully selected to provide adequate visualization of myocardial borders; endo- and epicardial borders were traced semi-automatically, with manual adjustment where needed, to achieve proper quality tracking of each loop. Borders were traced from the mid-basal level. Longitudinal and radial strain parameters were generated from PLAX view, while circumferential strain parameters and fractional area change  were assessed from SAX view images, with papillary muscles excluded from tracing. Ventricular borders were defined, and the speckle-tracking system assigned circumjacent areas adjacent to the outlined chamber. The software algorithm estimated velocity , displacement , strain , and strain rate  for each site on the designated line by following the defined border region . Speckle-tracking data were visualized in a color-coded map representing diastolic and systolic deformations, and reconstructed in a 3D image to provide a better spatio-temporal perception of wall motion. Time-to-peak analysis (TPk) was also performed to assess local wall motion synchronism, as TPk slope analysis delivers further information about regional motion and deformation development. For this method, the myocardium was divided into six anatomic segments, in agreement with the definition of the American Heart Association. Peak and average radial systolic velocity values (cm/s), global longitudinal strain , global circumferential strain , and fractional area change  after i.v. danicamtiv administration were analyzed and compared to baseline values of each animal [Strain echocardiographic analysis was carried out offline. According to the Lagrangian and Eulerian strain tensors of finite deformation theory, the strain (S) of a soft tissue in each direction is described as the difference between the segment’s initial length and its changed length, whereas strain rate (SR) is the rate of deformation change over a given time period. During the conventional echocardiographic imaging, high-frame rate (>200 fps) traces were recorded from both the parasternal long- and short axis views , by a trained investigator. Images were evaluated in slow motion (1/8) before data storage, to ensure reproducibility. A single observer performed all strain analysis using the VevoLABh animal ,39,40,41Three lead ECG recording was performed in parallel with the echocardiographic examinations. After anesthesia, animals were placed in a dorsal position and leads were positioned subcutaneously. LabChart Reader v8.1.14 software was used to evaluate ECG recordings. The following parameters were considered for the evaluation: heart rate, PQ interval, QRS duration, QT time, corrected QT interval, T-wave amplitude. For the evaluation, 6 consecutive cardiac cycles were averaged for each parameter, and data are presented as mean ± SEM.p < 0.05; exact p values are indicated in the results section .Results were evaluated and graphs were created in the GraphPad Prism 9.0 software . As for cellular measurements the number of experiments in each group varied between 9 and 14 from 6 different hearts. Background fluorescence intensity levels were obtained at the end of the measurements on a region without cardiomyocytes and manually subtracted the fluorescence intensities for background correction. Fourteen rats were measured before and after iv. treatment of da-nicamtiv. For all experiments, values were evaluated for normality  and were then evaluated by paired t-tests, ordinary one-way ANOVA, or Kruskal–Wallis test with multiple comparisons as appropriate. Group descriptions are given as mean ± SEM values. Statistical significance was accepted at 2+ transient. Although the administration of danicamtiv inherently affects LV diastolic function, this effect may be less prominent for danicamtiv than for OM. To some degree, this difference may relate to danicamtiv’s evoked augmentation in atrial contractility. Moreover, limitations in diastolic function appear as a class-effect during the application of direct myosin activators. Accordingly, considerable attention should be paid to the stratification the of LV diastolic function in patients treated with danicamtiv.Danicamtiv has the potential to augment LV systolic function in the absence of an increase in the amplitude of the intracellular Ca


Multivariate logistic regression analysis showed that basal ECV  and LDH1 level  were two independent risk factors for CA. Further study demonstrated that basal ECV in the heart failure group was significantly higher than that of the nonheart failure group (p < 0.01). Notably, ROC curve showed that basal ECV had a good predictive value for CA and heart failure, with AUC of 0.911 and 0.893 , and the best cutoff values of 38.35 and 37.45, respectively. Taken together, basal ECV is a good predictor of CA and heart failure for MM patients.Multiple myeloma (MM) is a hematological malignancy of plasma cell origin. Cardiac amyloidosis (CA) is a common form of heart damage caused by MM and is associated with a poor prognosis. This study was a prospective cohort study and was aimed at evaluating the clinical predictive value of extracellular volume fraction (ECV) based on cardiovascular magnetic resonance (CMR) T1 mapping for cardiac amyloidosis and cardiac dysfunction in MM patients. Fifty-one newly diagnosed MM patients in Zhongnan Hospital of Wuhan University were enrolled in the study. A total of 19 patients  developed CA. The basal ECV of CA group was significantly higher than that of the non-CA group ( Symptomatic light chain (AL) amyloidosis occurs in 15%~30% of multiple myeloma (MM) patients and becomes more severe when the disease progresses. Cardiac amyloidosis (CA) is a condition in which primary or secondary factors cause the deposition of amyloid protein in the heart muscle, causing abnormalities in the structure and function of the heart [Endomyocardial biopsy (EMB) is the gold standard for the diagnosis of CA. However, it is invasive and needs advanced technical skills to obtain cardiac tissues . BNP, prCardiac magnetic resonance (CMR) can comprehensively evaluate the size of the heart cavity, the thickness of the atrioventricular wall, myocardial movement, and the state of cardiac function. Although late gadolinium enhancement (LGE) is useful in the early detection of CA , it is nNCT05034146).In the present study, a total of 51 newly diagnosed multiple myeloma (MM) patients were enrolled in the Department of Hematology, Zhongnan Hospital of Wuhan University, during the period from May 2019 to June 2021. Exclusion criteria are as follows: (1) patients with chronic kidney disease, kidney transplantation, or single kidney and (2) patients with a history of coronary heart disease, anemic heart disease, cardiac dysfunction, or cardiac amyloidosis due to other diseases. This study was approved by the Ethics Committee of Zhongnan Hospital of Wuhan University  the patient has corresponding clinical symptoms, (2) abnormal light chain examination, (3) amyloid deposits confirmed by bone marrow biopsy, and (4) CMR results which support amyloidosis . Accordiβ2-MG, LDH1, hypersensitive TNI, pro-BNP, and LVEF were measured from the blood sample of patients with multiple myeloma.Bone marrow biopsy was conducted and viewed in fluorescence microscope to confirm amyloid deposits. Biomarkers for detecting myocardial injury such as All participants underwent standard CMR examinations on a 3.0 T MR scanner  equipped with an 18-channel phased-array body coil combined with 12 channels in the supine position. Pre- and postcontrast T1 mapping was acquired using a modified Look-Locker inversion recovery (MOLLI) sequence with 5(3)3 and 4(1)3(1)2 schemes, respectively. T1 mapping images were collected at the base, midventricle, and apex on the short-axis left ventricle (LV). LGE imaging was performed by using a phase-sensitive inversion-recovery (PSIR) gradient-echo pulse sequence. LGE images were acquired 10 to 15 min after administration of contrast agent , covering three long-axis planes (2-3-4 chamber) and short-axis slices from the atrioventricular ring to the LV apex.All CMR image analyses were performed with an offline commercial software . Native T1 and post-T1 values were measured by drawing a region of interest on the septum myocardium of the basal, midventricle, and apex short-axis slice images (this was done blinded to the LGE images). ECV was calculated by the following equation: ECV = (1/T1myo post − 1/T1 myo pre) × (1 − Hct)/(1/T1blood post − 1/T1 blood pre). Hematocrit was obtained on the same day of the CMR scans. The LGE pattern was classified into characteristic for CA and negative for CA. According to the nomenclature and segmentation of the left ventricular myocardium (the cardiac segmentation model) of the American Heart Association (AHA), in the long axis, the left ventricle is divided into equal thirds named the basal, mid, and apical thirds. The tip of the apex forms a separate final segment. When these thirds are viewed in short axis, they form rings that are numbered counterclockwise which can be further divided into equal sectors: the basal third with six 60° sectors, the mid third with six 60° sectors, and the apical third with four 90° sectors. The average ECV of the equal thirds are named basal ECV, mid ECV, and apical ECV.T test was used for intergroup comparison. The ones that do not fit the normal distribution are represented by M . The Wilcoxon rank sum test was used for comparison between groups. The counting data are expressed in percentage numbers. χ2 or Fisher's exact test was used for comparison between groups. Multivariate logistic regression analysis was performed to find independent risk factors for cardiac amyloidosis and neofunctional dysfunction after excluding indicators that caused significant collinearity. The Spearman method was used to analyze data correlation. The receiver operating characteristic (ROC) curve was plotted, and the area under curve (AUC) was calculated to evaluate the predictive effectiveness of ECV. All tests were bilateral tests, and p < 0.05 was considered statistically significant.SPSS 26.0 statistical software was used for data analysis. The measurement data are normally distributed by using the Shapiro-Wilk test. Those conforming to the normal distribution are represented by mean ± SD. Independent sample β2-MG, LDH1, hypersensitive TNI, pro-BNP, basal ECV, apical ECV, and mid ECV were significantly higher in the CA group than those in the non-CA group , while LVEF value was lower than that in the non-CA group (p < 0.05). There was no significant difference in Durie-Salmon (DS) staging and International Staging System (ISS) staging between the two groups  , ESV (CF/BSA), myocardial mass (CF/BSA), basal ECV, apical ECV, and mid ECV . ALB and CK-MB were lower than that of the nonheart failure group (p < 0.05) (p > 0.05)  . There wβ2-MG, LDH1, hypersensitive TNI, pro-BNP, and LVEF as independent variables to construct the regression model. Multivariate logistic regression analysis showed that basal ECV  and LDH1  were independent risk factors for CA , β2-MG , hs-TNI , and LDH1  but was negatively correlated with ALB   .p = 0.007) was an independent risk factor for heart failure , and ESV (CF/BSA) were used as independent variables. Multivariate logistic regression analysis showed that basal ECV  > myocardial mass (CF/BSA) (0.668) > hs-TNI (0.647)  alone in the prediction of the risk of CA. As shown in β2-MG (0.817) > hs-TNI (0.8) > myocardial mass (CF/BSA) (0.708) > EDV (CF/BSA) (0.696) = ESV (CF/BSA) (0.696) , impaired calcium homeostasis, cellular dysfunction, and death of adult cardiomyocytes .The sensitivity and negative predictive values of basal ECV on CMR T1 mapping for the diagnosis of CA in AL were both 100%, while the specificity and positive predictive values were 80% and 81%, respectively . LGE of ECV showed a promise in noninvasive diagnosis of CA . ECV hasThe Mayo Clinic presented two prognostic models for AL amyloidosis in 2004 and 2012, respectively. In addition, there is a European model. The European and Mayo 2012 models have shown good predictive performance in recent validation studies . HoweverTo our knowledge, this study was the first to evaluate the predictive value of basal ECV for CA and heart failure in MM patients. The results indicate that basal ECV is a good predictor of CA and heart failure in patients with MM. Basal ECV can effectively identify patients with cardiac dysfunction caused by AL amyloidosis, which is helpful for the selection of chemotherapy regimens. The advantage of the clinical application of basal ECV can avoid invasive heart biopsy.


Point-of-care ultrasonography (POCUS) represents a goal-directed ultrasound examination performed by clinicians directly involved in patient healthcare. POCUS has been widely used in emergency departments, where US exams allow physicians to make quick diagnoses and to recognize early life-threatening conditions which require prompt interventions. Although initially meant for the real-time evaluation of cardiovascular and respiratory pathologies, its use has been extended to a wide range of clinical applications, such as screening for deep-vein thrombosis and trauma, abdominal ultrasonography of the right upper quadrant and appendix, and guidance for invasive procedures. Moreover, recently, bedside ultrasounds have been used to evaluate the fluid balance and to guide decongestive therapy in acutely decompensated heart failure. The aim of the present review was to discuss the most common applications of POCUS in the emergency setting. In 2001, the American College of Emergency Physicians (ACEP) published the first Emergency Ultrasound Guidelines with the aim to describe the principal point-of-care ultrasonography (POCUS) applications and to underline the importance of continuing education and training in the use of emergency ultrasounds. These guidelines then expanded together with the growing use of focused ultrasounds ,4. The aLung ultrasound (LUS) examinations can be performed with the use of probes of different frequencies based on the lung region to be explored. A high-frequency 7.5–10 MHz) linear probe, thanks to it having a greater spatial resolution than its depth of penetration, is useful for performing a detailed exam of the chest wall and pleurae. Conversely, a low-frequency (3.5–5 MHz) curvilinear probe has a greater depth of penetration and is suitable for examining the parenchymal structures below the pleurae. Lichtenstein et al. –10 MHz l. The proLUS examinations allow for the detection of trapped air within the pleural space. Three signs are suggestive of a pneumothorax (PNX) diagnosis.(A) Abolition of lung slidingLung sliding is represented by the physiological movement of the parietal pleura against the visceral pleura during the respiratory cycle, which is visualized in B-mode images . The abo(B) A-linesA-lines are horizontal hyperechoic lines localized below the pleural line and repeated at equal intervals . They re(C) Lung pointIn the M-mode view, the “seashore sign” is defined as the presence of straight lines above the pleural line with an associated granular patter below it. This sign confirms lung ventilation and sliding  and coulPleural effusion is defined as a hypoechoic/anechoic structure without the presence of air inside which presents during expiration and inspiration  18]. Th. Th18]. B-lines are vertical hyperechoic lines derived from the pleural line , obliterLung consolidation corresponds to a complete loss of lung tissue aeration, which favors ultrasound transmission and is a common finding in various clinical conditions: pneumonia, atelectasis, and pulmonary embolisms . In LUS For pulmonary embolisms, LUS exams can show the pulmonary infarction area, defined as triangular or rounded, hypoechoic, homogeneous subpleural consolidation . A meta-The principal role of POCUS in the emergency department is the rapid assessment of patients with hemodynamic instabilities  through Cardiac POCUS is done by using a low-frequency phased array probe (3.5–5 MHz) pointed at four main views: the parasternal long-axis, parasternal short-axis, apical four-chamber, and subcostal/subxiphoid views.2 caused by cardiocirculatory failure and tissue hypoperfusion. This condition is defined by the coexistence of hypotension (systolic BP < 90 mmHg and mean BP < 65 mmHg), tachycardia (HR > 100), and signs of peripheral and central hypoperfusion . Ec. Ec55]. The patient in cardiac arrest requires a prompt-initiation cardiopulmonary resuscitation (CRP) and Advanced Cardiac Life Support (ACLS) treatment algorithms. In this setting, POCUS could be a useful tool for guiding lifesaving bedside procedures , for assessing the quality of chest compressions, for confirming the clinical suspect of a reversible cause of CA, and for differentiating true pulseless electrical activity (PEA) from pseudo-PEA . The mosThe most common POCUS applications of abdominal ultrasounds include the evaluation of patients with abdominal pain or trauma ,63. MoreAcute abdominal pain represents one of the most common causes of referrals to an emergency department, and POCUS provides help in differentiating patients who require additional diagnostic tests or hospitalization ,66. In t(A) Intraperitoneal free fluidAbdominal ultrasounds allow for the detection of pathological intraperitoneal free fluid (IPF) accumulation, although it cannot differentiate the type of liquid. IPF may result from a ruptured ectopic pregnancy, a urine leak, bile, or ascites. IPF appears anechoic and is most often localized in the perihepatic (in Morrison’s pouch) or perisplenic region, while, in the pelvis, it is usually seen in the pouch of Douglas. Therefore, it is important for evaluating the right upper quadrant (RUQ), left upper quadrant (LUQ), periphery of the abdomen (left and right) in the paracolic gutters, and pelvis. Once the fluid is localized, ultrasonographic guidance can increase success and decrease the complications of common procedures such as paracentesis . Most of(B) Appendicitis and CholecystitisUSs of the right upper quadrant in people suspected to have biliary colic can reveal cholecystitis with a great accuracy ,70. Its Several studies have demonstrated that the sensitivity and specificity of POCUS in detecting appendicitis are nearly 84% and 90%, respectively ,75. When(C) Abdominal aortic aneurysmPOCUS represents an important tool for the diagnosis of abdominal aortic aneurysms in patients admitted into the emergency room for abdominal pain . An AAA An acute kidney injury is a common finding among patients admitted to the emergency department, but it portends a bad prognosis and a high mortality rate (about 50%) . BedsideA hemodynamic AKI is due to kidney hypoperfusion, and it may be due to volume depletion; cardiac disfunction; severe abdominal congestion; or vasoplegia, such as in sepsis. A comprehensive assessment of the heart, lung water, and venous congestion  is essenPOCUS may quickly identify acute urinary retention and detect obstructive nephropathy requiring procedural drainage . NephrolRenal vascular studies also give useful information through the assessment of the renal resistive index (RRI). The RRI evaluates the macrovascular perfusion into the kidney  and is cood flow . The RRIood flow . Moreoveood flow ,93.Renal ultrasonography provides information on the chronicity of medical renal disease through the evaluation of the renal length, the cortical thickness, and its echogenicity . Hence, An elevated right atrial pressure portends bad clinical outcomes in selected patients . Venous Although the IVC is a good indicator of the central venous pressure (CVP) , it is nThe blood flow patterns in the hepatic veins (HVs) are pulsatile with two retrograde “A” and “V” waves and two anterograde “S” (systolic) and “D” (diastolic) waves. The S wave is larger than the D wave, and they represent the systolic movement of the anulus towards the apex and the diastolic ventricular filling, respectively. When the RAP increases, the amplitude of the S wave decreases when compared to that of the D wave (S < D pattern). As congestion worsens, the S wave becomes blunted until it is reversed . DespiteThe portal vein (PV) is isolated from the central veins; therefore, its normal flow pattern appears continuous or mildly pulsatile. The main alteration in the PV waveform is the progressive pulsatility with an increasing RAP, which can be quantified using the pulsatility fraction .PF: [ is like that of the portal vein with a continuous flow and a brief interruption during atrial systole . This paAcute lower-extremity proximal deep-vein thrombosis (DVT) represents the third leading vascular disease after acute myocardial infarction and stroke . AlthougRegarding the instrumentation, the ultrasound machines used range from pocket-sized handset devices to advanced and more sophisticated devices . It is aAcute: the thrombus itself may not be visible. If detected, it is deformable with the force applied on the probe and with a regular surface; it is a distended vein.Subacute thrombus: (before six months and after clot formation) intermediate morphological changes that cannot be included in the chronic phase.Chronic post-thrombotic change: not compressible nor deformable with an irregular surface; the vein caliber may be normal or reduced.The natural history of deep-vein thrombosis goes through several stages: an initial phase (1–6 days) which is characterized by a mobile hypoechoic clot at high risk for embolism; a second stage (within two weeks) that involves a nonhomogeneous structure with mixed echogenicity ; and a tAssessing the presence or absence of a pulse is a key moment in the management of cardiac arrest. Doppler ultrasounds provide an alternative to the manual pulse check. Sanchez et al.  conducteIn the clinical setting of suspected stroke or TIA in the emergency department, the POCUS method appears to have a poor correlation with CT for the diagnosis of significant stenosis . Even thPOCUS is currently used in various neurological settings, such as intracranial pressure (ICP) estimation, especially after a traumatic brain injury . Even thPOCUS also allows one to verify the correct placement of the central venous catheter (CVC) through a saline flush test with evidence of a rapid atrial vortex within 2 s of starting the saline infusion from one of the CVC lumens . ComparePOCUS is also acquiring an emerging role in chest traumatology. In particular, rib fractures are frequent complications of blunt chest trauma . An earlThe implementation of artificial intelligence (AI) software in POCUS is undoubtedly fascinating and carries a great potential improvement to this methodology. The field of the application of machine learning and of deep learning software in echography could be directed at the training of resident physician ; nonethePOCUS represents a goal-directed ultrasound examination which allows clinicians to rapidly evaluate patients in the emergency setting through a limited and focused number of standard echographic views. POCUS helps to make quick diagnoses and to identify early life-threatening conditions which require prompt interventions. The aim of our review was to summarize the various POCUS applications with a focus on the emergency setting as discussed below. Indeed, even if initially meant for cardiac and lung disease evaluations, US exams have been extended to many medical conditions with great clinical benefits both in the emergency setting and in critically ill patients. These considerations make ultrasonography an integral part of emergency medicine.