Usefulness of exercise stress echocardiography for predicting cardiovascular events and atrial fibrillation in hypertrophic cardiomyopathy

BACKGROUND

In hypertrophic cardiomyopathy (HCM), the determinants of exercise tolerance and the usefulness of exercise stress echocardiography (ESE) for predicting hard endpoints have not been fully investigated. We aimed to assess the key parameters of ESE for exercise tolerance and the factors predictive of cardiovascular events and new-onset atrial fibrillation (AF) in patients with HCM.

METHODS

Seventy-four consecutive patients with HCM who underwent ESE and with an ejection fraction ≥50 % were enrolled. The primary endpoint was a composite of cardiovascular death, heart failure hospitalization, ventricular fibrillation or tachycardia, and ventricular assist device implantation. The secondary endpoint was new-onset AF.

RESULTS

The primary endpoint occurred in 13 patients. The left and right ventricular functions during exercise were responsible for decreased exercise tolerance. Peak exercise e' and tricuspid annular plane systolic excursion (TAPSE) significantly predicted increased primary outcome risk (hazard ratio 1.35, 95 % confidence interval 1.10-1.76, p = 0.003; hazard ratio 1.19, 95 % confidence interval 1.07-1.32, p = 0.002, respectively), and the results were consistent even after adjustment by maximum workload. These ESE parameters improved the prognostic model containing estimated glomerular filtration rate (eGFR) and left atrial (LA) volume index. In AF-naive patients (n = 58), LA volume, peak exercise LA reservoir strain, and left ventricular outflow tract (LVOT) pressure gradient predicted new-onset AF.

CONCLUSIONS

In patients with HCM, ESE parameters related to left and right ventricular function were responsible for low exercise tolerance. Furthermore, e' and TAPSE at peak workload could be useful for predicting cardiovascular events in addition to eGFR and LA volume index. LVOT pressure gradient and LA function during exercise predicted new-onset AF.

Right ventricular diastolic function predicts clinical atrial fibrillation after coronary artery bypass graft

Background

Patients with moderate-severe left ventricular systolic dysfunction undergoing coronary artery bypass graft (CABG) surgery are at high risk of mortality and morbidity. Our aim is to evaluate the right ventricular (RV) diastolic function in these patients, and monitor its effects on postoperation outcomes.

Materials and Methods

In a cohort study, patients with moderate-severe left ventricular systolic dysfunction (ejection fraction ≤35%) who were candidate for CABG were included. Baseline transthoracic echocardiography (TTE) was performed, and RV diastolic function measures were obtained. After CABG, the length of intubation, inotrope dependency, hospital stay in intensive care unit and ward, in-hospital and after discharge mortality, postoperative atrial fibrillation (POAF) were evaluated in all patients.

Results

Sixty-seven patients were prospectively included in the study. The mean ± standard deviation age of our patients was 61.4 ± 9.3. There was no difference between grades of RV diastolic function and postoperative outcomes. However, we found significant difference between grades of RV diastolic function and onset of in hospital, and total POAF (P-value = 0.017). Multivariate analysis demonstrated that preoperative tricuspidEt/E't (ratio of peak early-diastolic flow rate across the tricuspid valve orifice to peak early-diastolic velocity at the lateral tricuspid annulus), left atrial volume and "high risk" Euroscore II were independent predictors for POAF during hospitalization and total POAF in patients with moderate to severely impaired left ventricular systolic function (P-values were 0.04, 0.003 and 0.001, respectively).

Conclusion

We believe that patients with increased tricuspid Et/E't are high risk for POAF; therefore, any risk score for POAF should include a comprehensive TTE including evaluation of RV diastolic function before surgery.

Echocardiography in the Evaluation of the Right Heart

The significance of the right ventricle (RV) as a predictor of outcomes in a series of cardiac conditions has recently been recognized. Consequently, more studies are now focusing on improving the assessment of the RV. Its primary function is to support adequate pulmonary perfusion pressure in different circulatory and loading situations and to ensure that there is a low systemic venous pressure. Echocardiography is the first-line method of choice due to its accuracy when assessing RV structure and function, as well as its wide availability. The geometry of the RV is complex and its evaluation can be difficult. Integrating and combining multiple parameters may be a more reliable way to determine normal or abnormal function. Novel techniques are increasingly being performed more routinely in clinical practice and are facilitating diagnosis and treatment choices.

Deciphering hypertrophic cardiomyopathy with electrocardiography

The comprehensive assessment of patients with hypertrophic cardiomyopathy is a complex process, with each step concurrently focusing on confirmation of the diagnosis, differentiation between sarcomeric and non-sarcomeric disease (phenocopy), and prognostication. Novel modalities such as genetic testing and advanced imaging have allowed for substantial advancements in the understanding of this condition and facilitate patient management. However, their availability is at present not universal, and interpretation requires a high level of expertise. In this setting, electrocardiography, a fast and widely available method, still retains a significant role in everyday clinical assessment of this population. In our review, we follow a stepwise approach for the interpretation of each electrocardiographic segment, discussing clinical implications of electrocardiographic patterns in sarcomeric disease, their value in the differential diagnosis from phenocopies, and impact on patient management. Outlining the substantial amount of information to be obtained from a simple tracing, we exhibit how electrocardiography is likely to remain an integral diagnostic tool in the future as well.

Right ventricular involvement in hypertrophic cardiomyopathy: evidence and implications from current literature

Objectives. In current guidelines, hypertrophic cardiomyopathy (HCM) is defined by hypertrophy of the left ventricle (LV). Less attention has been given to the right ventricle (RV) in patients with HCM. We wanted to provide an overview of current literature on RV involvement in HCM. Design. We performed a systematic search in PubMed and added additional articles by manual screening of references. The quality of the articles was assessed according to the GRADE system. Results. We identified 35 original articles on RV involvement in HCM. Based on these publications, RV hypertrophy occurs in 28-44% of HCM patients, depending on the cut-off value for hypertrophy and the method for assessment. Histological studies show the same structural changes in RV as are typically described in the LV cardiomyocyte hypertrophy and disarray, as well as fibrosis. These changes are similar, but less pronounced in the RV than in the LV. We discuss how HCM can impact the RV, either through a primary involvement similar to the LV or secondary to hemodynamic effects resulting from LV dysfunction. RV dysfunction in HCM is associated with higher mortality, partly due to an increased risk of ventricular tachycardia and sudden cardiac death. Conclusions. The evidence for RV involvement in HCM is limited. Multimodal imaging assessment of the RV should be included in the work-up of patients with HCM, and the added value of including RV function in the risk stratification algorithm should be further explored.

Presence and prognostic value of ventricular diastolic function in arrhythmogenic right ventricular cardiomyopathy

INTRODUCTION

Limited data exist regarding the presence and importance of diastolic parameters in patients with arrhythmogenic right ventricular cardiomyopathy (ARVC). We sought to evaluate RV diastolic parameters and echo-based diastolic predictors of major adverse cardiovascular events (MACE).

METHOD

48 patients with a definitive diagnosis of ARVC were included and followed for 6-18 months. A comprehensive standard two-dimensional (2D) transthoracic echocardiography (TTE) with precise evaluation of systolic and diastolic indices of both ventricles was done. RV isovolumetric relaxation time (IVRT), RV myocardial performance index (MPI), and right atrial (RA) volume were evaluated.

RESULTS

48 patients (mean age = 38.5 ± 14 years; 79.2% male) were enrolled. 27.3% had grade I, 68.2% had grade II, and 4.5% had grade III RV diastolic dysfunction. In 12-month follow-up, 12 patients (25%, with mean RV3DEF = 24.8 ± 9%) experienced MACE and required hospitalization: ventricular tachyarrhythmia in 7 patients (14.6%), RV clot in 2 subjects (4.2%), and right-sided failure in 3 cases (6.3%). In logistic regression analysis, tissue Doppler velocity of tricuspid annulus (e' TV) (P = .02, OR = 0.581, CI = 0.368-0.917), peak E mitral valve (P = .043, OR = 0.95, CI = 0.913-0.999), tissue Doppler velocity of septal e' (P = .052, OR = 0.733, CI = 0.536-1.003), and MPI (P = .009, OR = 95, CI = 3.083-2942) were powerful predictors of MACE.

CONCLUSION

In our study, RV diastolic function parameters including e' TV and e' MV, RA volume and area, and RV MPI were powerful predictors of MACE and may be considered during the baseline and follow-up of the ARVC patients.

Echocardiographic assessment of the right heart in adults: a practical guideline from the British Society of Echocardiography

The structure and function of the right side of the heart is influenced by a wide range of physiological and pathological conditions. Quantification of right heart parameters is important in a variety of clinical scenarios including diagnosis, prognostication, and monitoring response to therapy. Although echocardiography remains the first-line imaging investigation for right heart assessment, published guidance is relatively sparse in comparison to that for the left ventricle. This guideline document from the British Society of Echocardiography describes the principles and practical aspects of right heart assessment by echocardiography, including quantification of chamber dimensions and function, as well as assessment of valvular function. While cut-off values for normality are included, a disease-oriented approach is advocated due to the considerable heterogeneity of structural and functional changes seen across the spectrum of diseases affecting the right heart. The complex anatomy of the right ventricle requires special considerations and echocardiographic techniques, which are set out in this document. The clinical relevance of right ventricular diastolic function is introduced, with practical guidance for its assessment. Finally, the relatively novel techniques of three-dimensional right ventricular echocardiography and right ventricular speckle tracking imaging are described. Despite these techniques holding considerable promise, issues relating to reproducibility and inter-vendor variation have limited their clinical utility to date.

Prevalence and Prognostic Implications of Right Ventricular Dysfunction in Patients With Hypertrophic Cardiomyopathy

Right ventricular (RV) dysfunction is a well-known prognostic factor in several cardiac diseases. However, the prevalence of RV dysfunction in hypertrophic cardiomyopathy (HC) is unclear and its prognostic value is unknown. This study aims at addressing these issues assessing RV function with speckle tracking echocardiography. In 267 HC patients (52 ± 15 years, 68% male), standard and advanced echocardiographic measurements of RV function were performed including RV 4-chamber longitudinal strain (RV4CLS) and RV free wall longitudinal strain (RVFWLS). The primary end point was all-cause mortality and heart failure development. RV dysfunction was observed in 9% of patients based on tricuspid annular plane systolic excursion (≤17 mm), 5% based on fractional area change (<35%), 23% based on RVFWLS ≥-19%, 39% based on RVFWLS ≥-23%, and 55% based on RV4CLS ≥-20%. In total 59 (22%) patients reached the primary end point during a median follow-up of 6.7 (interquartile range 4.2 to 9.8) years. Kaplan-Meier survival curve showed a significant worse survival free of the end point for patients with impaired RV4CLS ≥-20% versus patients with preserved RV4CLS <-20% (log-rank 7.0, p = 0.008) and for patients with impaired RVFWLS ≥-19% versus patients with preserved RVFWLS <-19% (log-rank 4.4, p = 0.037). Multivariable Cox regression analysis showed that E/E' (hazards ratio [HR] 2.26 [1.30 to 3.92], p = 0.004), left ventricular global longitudinal strain LV GLS (HR 1.08 (1.01 to 1.17), p = 0.034) and RV4CLS (HR 1.08 (1.02 to 1.15), p = 0.007) were independently associated with the primary end point. In conclusion, RV dysfunction as measured by longitudinal strain is relatively frequent in HC patients. Impaired RV4CLS is - together with LV GLS and E/E' - associated with adverse outcome, which may indicate a more severe form of HC.

The prognostic value of biventricular long axis strain using standard cardiovascular magnetic resonance imaging in patients with hypertrophic cardiomyopathy

BACKGROUND

Long axis strain (LAS) is a parameter derived from standard cardiovascular magnetic resonance imaging. However, the prognostic value of biventricular LAS in hypertrophic cardiomyopathy (HCM) is unknown.

METHODS

Patients with HCM (n = 384) and healthy volunteers (n = 150) were included in the study. Left ventricular (LV)-LAS was defined as the percentage change in the length measured from the epicardial border of the LV apex to the midpoint of a line connecting the mitral annulus at end-systole and end-diastole. Right ventricular (RV)-LAS represented the percentage change of length between epicardial border of the LV apex to the midpoint of a line connecting the tricuspid annulus at end-systole and end-diastole. The primary endpoint was a combination of all-cause death and sudden cardiac death aborted by appropriate implantable cardioverter-defibrillator discharge and cardiopulmonary resuscitation after syncope. The secondary endpoint was a combination of the primary endpoint and hospitalization for congestive heart failure.

RESULTS

Twenty-nine patients (7.6%) achieved the primary endpoint, and the secondary endpoint occurred in 66 (17.2%) patients. In multivariate Cox regression analysis, RV-LAS was an independent prognostic factor for the primary (hazard ratio (HR), 1.13) and secondary (HR, 1.11) endpoints. In the subgroup of patients with a normal RV ejection fraction (EF) (>45.0%, n = 345), impaired RV-LAS was associated with adverse outcomes and might add incremental prognostic value to RVEF and tricuspid annular plane systolic excursion (TAPSE) (p < 0.01).

CONCLUSIONS

RV-LAS is an independent predictor of adverse prognosis in HCM in addition to RVEF and TAPSE.

Impaired Right Ventricular Mechanics at Rest and During Exercise Are Associated With Exercise Capacity in Patients With Hypertrophic Cardiomyopathy

Background Impaired right ventricular ( RV ) function indicates RV involvement in patients with hypertrophic cardiomyopathy ( HCM ). We aimed to assess RV function at rest and during exercise in HCM patients and to examine the association between impaired RV mechanics and exercise capacity. Methods and Results A total of 76 HCM patients (48 without and 28 with RV hypertrophy) and 30 age- and sex-matched controls were prospectively recruited. RV function was evaluated at rest and during semisupine bicycle exercise by conventional echocardiography and 2-dimensional speckle-tracking imaging. Exercise capacity was measured by metabolic equivalents. RV functional reserve was calculated as the difference of functional parameters between peak exercise and rest. Compared with controls, HCM patients had significantly higher RV free wall thickness, lower RV global longitudinal strain and RV free wall longitudinal strain at rest and during exercise, and reduced RV systolic functional reserve. Compared with those with HCM without RV hypertrophy, patients with HCM with RV hypertrophy had lower metabolic equivalents. Among HCM patients, an effective correlation was seen between exercise capacity and peak exercise RV global longitudinal strain and peak exercise RV free wall longitudinal strain. A binary logistic regression model revealed several independent predictors of exercise intolerance in HCM patients, but receiver operating characteristic curve analysis indicated exercise RV global longitudinal strain had the highest area under the curve for the prediction of exercise intolerance in HCM patients. Conclusions HCM patients have RV dysfunction and reduced contractile reserve. Exercise RV global longitudinal strain correlates with exercise capacity and can independently predict exercise intolerance. In addition, patients with HCM with RV hypertrophy exhibit more reduced exercise capacity, suggesting more severe disease and poorer prognosis.

Preparticipation Cardiovascular Screening of Student-Athletes with Echocardiography: Ethical, Clinical, Economic, and Legal Considerations

PURPOSE OF REVIEW

To identify whether the use of echocardiography is a viable approach for the screening of athletes for the prevention of sudden cardiac death when considering ethical, clinical, economic, and legal issues.

RECENT FINDINGS

Ethical musings, echocardiographic findings, economic calculations, and legal analysis suggest that echocardiographic screening may reduce sudden cardiac death on the athletic field. Ethical, clinical, economic, and legal considerations suggest echocardiographic screening is a viable option to meet the societal goal to prevent athletic field sudden death.

Decreased biventricular mechanics and functional reserve in nonobstructive hypertrophic cardiomyopathy patients: implications for exercise capacity

The present study investigated the changes of biventricular mechanics at rest and during exercise and examined the association between exercise capacity and biventricular mechanics and functional reserve in nonobstructive hypertrophic cardiomyopathy (NHCM) patients. A total of 50 NHCM patients and 25 controls were consecutively recruited for this study. Using echocardiography and two-dimensional speckle-tracking imaging, an experienced echocardiographer determined the following indices: RV free wall longitudinal strain (RVFWLS), LV global longitudinal strain (LVGLS), strain rate (SR), and functional reserve of strain values. We also investigated the relationships between biventricular mechanics and exercise capacity using metabolic equivalents (METs). NHCM patients had lower RVFWLS, LVGLS, systolic SR, early diastolic SR, and systolic and diastolic reserve during exercise compared to controls. An association of biventricular mechanics (LVGLS, RVFWLS) with exercise capacity at rest and during exercise was established. Multivariable logistic regression revealed that RVFWLS and LVE/e' during exercise (RVFWLS-exe, E/e'-exe) were independent predictors of exercise intolerance. Receiver operating characteristic curve analysis indicated that LVE/e'-exe had a higher area under the curve for predicting exercise intolerance in NHCM patients. In hierarchical analysis, RVFWLS-exe provided an incremental predictive value of exercise intolerance over LVGLS during exercise (LVGLS-exe) and LVE/e'-exe. LVE/e'-exe also changed incrementally compared to LVGLS-exe and RVFWLS-exe. NHCM patients have decreased biventricular mechanics at rest and during exercise and impaired biventricular functional reserve, and biventricular mechanics are associated with functional capacity. We propose that simultaneous evaluation of biventricular function should provide incremental predictive value for exercise intolerance.

Prevalence and Prognostic Significance of Right Ventricular Dysfunction in Patients With Hypertrophic Cardiomyopathy

Few data are available regarding the prevalence and clinical significance of right ventricular systolic dysfunction (RVSD) in hypertrophic cardiomyopathy (HC) patients. This study aimed to evaluate right ventricular (RV) systolic function by cardiovascular magnetic resonance and explore the prevalence and prognostic significance of RVSD in HC patients. A total of 226 patients with HC assessed by cardiovascular magnetic resonance were included in this retrospective study. RVSD was defined by RV ejection fraction (RVEF) ≤45% and was present in 26 (11.5%) patients. Association between RVSD, clinical characteristics, and outcomes were analyzed. RVEF was significantly lower in patients with RVSD than without RVSD (36.2 ± 7.0% vs 60.5 ± 7.4%, p < 0.001). There was a positive correlation between RVEF and left ventricular ejection fraction (r = 0.45; p < 0.001). During a mean follow-up of 30.5 ± 23.9 months, there were 22 (9.7 %) all-cause mortality, including 12 (5.3%) cardiovascular death. Kaplan-Meier analysis showed a significantly higher risk for cardiovascular mortality in patients with RVSD (p = 0.026), but no significant difference in all-cause mortality (p = 0.118) and heart failure related rehospitalization (p = 0.485). On multivariate Cox regression analysis, RVSD (hazard ratio 5.36; confidence interval 1.39 to 20.77; p = 0.015) and RVEF (hazard ratio 0.94; confidence interval 0.89 to 0.98; p = 0.011) were independent predictors of cardiovascular mortality. In conclusion, RVSD is a common phenotype and a strong independent predictor of cardiovascular mortality in HC patients.

Right ventricular involvement in hypertrophic cardiomyopathy: Patterns and implications

Although hypertrophic cardiomyopathy (HCM) is the most common inherited cardiomyopathy worldwide, the criteria for its definition and most of the literature concern the left ventricle, thus confirming the theory that the right ventricle is the neglected one. Right ventricular (RV) involvement includes structural and functional changes with significant impact on clinical presentation and prognosis. The pattern of RV hypertrophy can be variable with possible dynamic obstruction. Histological findings suggest similar pathogenetic changes in both ventricles supporting the common myopathic process with sarcomeric mutations. Systolic dysfunction of the RV is subtle, and the classical echocardiographic indices are usually within normal limits, while global longitudinal strain is significantly impaired. Diastolic dysfunction of the RV is also evident in patients with HCM possibly due to fibrosis of the RV free wall and/or the obstruction of the RV filling with significant prognostic implications. RV involvement in HCM is associated with increased incidence of supraventricular and ventricular arrhythmias, severe dyspnea, pulmonary thromboembolism, progressive heart failure, and increased risk of sudden cardiac death. Therefore, the RV should be routinely included in the detailed assessment of patients with HCM.

Right ventricle myectomy

Right ventricular (RV) hypertrophy is common in patients with hypertrophic cardiomyopathy (HCM), and is associated with more severe disease. Conventional surgical strategies such as the traditional Morrow procedure pose a particularly high risk to patients with severe hypertrophy and RV obstruction, for whom the most appropriate therapeutic approach has not yet been established. We have proposed a new technique for surgical correction in patients with hypertrophic obstructive cardiomyopathy and severe hypertrophy, which involves approaching the area of obstruction by entering through the conal part of the RV. This novel technique provides effective elimination of biventricular obstruction and the precise removal of the areas of septal fibrosis in patients with hypertrophic obstructive cardiomyopathy. The current literature review analyzes the indications and various techniques for performing a RV myectomy, and presents the results of follow-up assessments in patients with biventricular obstruction and severe hypertrophy.

The clinical features, outcomes and genetic characteristics of hypertrophic cardiomyopathy patients with severe right ventricular hypertrophy

Introduction

Severe right ventricular hypertrophy (SRVH) is a rare phenotype in hypertrophic cardiomyopathy (HCM) for which limited information is available. This study was undertaken to investigate the clinical, prognostic and genetic characteristics of HCM patients with SRVH.

Methods

HCM with SRVH was defined as HCM with a maximum right ventricular wall thickness ≥10 mm. Whole-genome sequencing (WGS) was performed in HCM patients with SRVH. Multivariate Cox proportional hazards regression models were used to identify risk factors for cardiac death and events in HCM with SRVH. Patients with apical hypertrophic cardiomyopathy (ApHCM) were selected as a comparison group. The clinical features and outcomes of 34 HCM patients with SRVH and 273 ApHCM patients were compared.

Results

Compared with the ApHCM group, the HCM with SRVH group included younger patients and a higher proportion of female patients and also displayed higher cardiovascular morbidity and mortality. The multivariate Cox proportional hazards regression models identified 2 independent predictors of cardiovascular death in HCM patients with SRVH, a New York Heart Association class ≥III (hazard ratio [HR] = 8.7, 95% confidence interval (CI): 1.43-52.87, p = 0.019) and an age at the time of HCM diagnosis ≤18 (HR = 5.5, 95% CI: 1.24-28.36, p = 0.026). Among the 11 HCM patients with SRVH who underwent WGS, 10 (90.9%) were identified as carriers of at least one specific sarcomere gene mutation. MYH7 and TTN mutations were the most common sarcomere mutations noted in this study. Two or more HCM-related gene mutations were observed in 9 (82%) patients, and mutations in either other cardiomyopathy-related genes or ion-channel disease-related genes were found in 8 (73%) patients.

Conclusions

HCM patients with SRVH were characterized by poor clinical outcomes and the presentation of multiple gene mutations.

Assessing hemodynamics noninvasively in patients with heart failure

PURPOSE OF REVIEW

Describe the contemporary assessment of cardiac hemodynamics using a comprehensive echo-Doppler examination in the heart failure (HF) patient.

RECENT FINDINGS

Cardiac flow and filling pressures, on both the left and right sides of the heart, are fundamental to the accurate assessment of the HF patient. Accurate assessment of left ventricular (LV) and right ventricular (RV) systolic and diastolic function is necessary to establish, or exclude, HF as a cause or component of dyspnea in a given patient and to help determine causes of hemodynamic instability in HF patients. Variables such as spectral Doppler (mitral and tricuspid inflow, pulmonary and hepatic venous flow, and pulmonary valve regurgitation signal), tissue Doppler imaging, and speckle tracking, applied to the left and right heart, can help to accurately estimate cardiac hemodynamics.

SUMMARY

A comprehensive echocardiogram with Doppler can provide an accurate assessment of left and right heart hemodynamics that is fundamental to the assessment and management of the HF patient.

The Prevalence and Long-Term Outcomes of Extreme Right versus Extreme Left Ventricular Hypertrophic Cardiomyopathy

OBJECTIVES

Extreme left ventricular hypertrophy (LVH) is a known risk factor for sudden cardiac death in hypertrophic cardiomyopathy (HCM). Extreme right ventricular hypertrophy (RVH) is rare, and whether it is linked to a poor outcome is unknown. This study was designed to investigate differences between HCM patients with extreme RVH and those with extreme LVH.

METHODS

Among 2,413 HCM patients, 31 with extreme RVH (maximum right ventricular wall thickness ≥ 10 mm) and 194 with extreme LVH (maximum left ventricular wall thickness ≥ 30 mm) were investigated. The main clinical features and natural history were compared between the 2 groups.

RESULTS

The prevalence of extreme RVH and extreme LVH was 1.3 and 8.0%, respectively. Patients with extreme RVH tended to be younger and female (p < 0.01). Cardiovascular-related mortality and morbidity within 10 years were significantly greater in the extreme RVH group (p < 0.05). Multivariate analysis demonstrated 3 independent predictors for cardiovascular mortality - extreme RVH, left ventricular end-diastolic dimension ≥ 50 mm, and age ≤ 18 years at baseline - and 2 for morbidity - extreme RVH and presyncope.

CONCLUSIONS

Compared with extreme LVH, extreme RVH was quite uncommon in HCM and had a worse prognosis. A right ventricle examination should be performed in routine HCM evaluation.

Assessing right ventricular function in patients with hypertrophic cardiomyopathy with cardiac MRI: correlation with the New York Heart Function Assessment (NYHA) classification

Purpose

To determine whether 3.0-T magnetic resonance imaging (MRI) could assess right ventricular (RV) function in patients with hypertrophic cardiomyopathy (HCM), and if this assessment is correlated with the New York Heart Function Assessment (NYHA) classification.

Materials and Methods

Forty-six patients with HCM and 23 normal individuals were recruited. Left and right ventricular function parameters including end-diastolic and end-systolic volumes (EDV, ESV), stroke volume (SV) and ejection fraction (EF) and dimensions were measured and compared using 3.0-T MRI. RV function parameters between HCM patients and controls were compared using independent sample t tests. A one way ANOVA test with Bonferroni correction was used to determine significant differences among different NYHA groups. Receiver operating characteristic analyses calculated the sensitivity and specificity of RV dysfunction on MRI for the prediction of HCM severity.

Results

Statistical analysis revealed significant differences of left ventricular (LV) and RV volumetric values and masses between the HCM patients and controls (all p<0.05). Within the HCM group, the simultaneously decreased maximum RVEDD correlated well with the LVEDD (r = 0.53; p<0.001). The function and dimension parameters among Class I to III were not determined to be significantly different (all p>0.05). However, significant differences between the Class IV and I-III groups (all P<0.0167) indicated that the diastolic and systolic function in both the RV and LV were impaired in Class IV patients. ROC analyses identified the EDV, ESV and EDD of both the LV and RV with a high sensitivity cutoff value to predict the HCM patients with severe heart failure (Class IV) with high sensitivity and specificity.

Conclusions

RV involvements were comparable to those of LV global function impairments in patients with HCM. The presence of RV dysfunction and decreased dimension on the MRI helped to predict the severe symptomatic HCM with high sensitivity and specificity.

Prevalence and clinical correlates of right ventricular dysfunction in patients with hypertrophic cardiomyopathy

Hypertrophic cardiomyopathy (HC) is a disease that mainly affects the left ventricle (LV), however recent studies have suggested that it can also be associated with right ventricular (RV) dysfunction. The objective of this study was to determine the prevalence of RV dysfunction in patients with HC and its relation with LV function and outcome. A total of 324 consecutive patients with HC who received care at Stanford Hospital from 1999 to 2012 were included in the study. A group of 99 prospectively recruited age- and gender-matched healthy volunteers were used as controls. RV function was quantified using the RV fractional area change, tricuspid annular plane systolic excursion (TAPSE), and RV myocardial performance index (RVMPI). Compared with the controls, the patients with HC had a higher RVMPI (0.51 ± 0.18 vs 0.25 ± 0.06, p <0.001) and lower TAPSE (20 ± 3 vs 24 ± 4, p <0.001). RV dysfunction based on an RVMPI >0.4 and TAPSE <16 mm was found in 71% and 11% of the HC and control groups, respectively. Worst LV function and greater pulmonary pressures were independent correlates of RV dysfunction. At an average follow-up of 3.7 ± 2.3 years, 17 patients had died and 4 had undergone heart transplantation. LV ejection fraction <50% and TAPSE <16 mm were independent correlates of outcome (hazard ratio 3.98, 95% confidence interval 1.22 to 13.04, p = 0.02; and hazard ratio 3.66, 95% confidence interval 1.38 to 9.69, p = 0.009, respectively). In conclusion, RV dysfunction based on the RVMPI is common in patients with HC and more frequently observed in patients with LV dysfunction and pulmonary hypertension. RV dysfunction based on the TAPSE was independently associated with an increased likelihood of death or transplantation.