Prognostic significance of right ventricular function during exercise in asymptomatic/minimally symptomatic patients with nonobstructive hypertrophic cardiomyopathy

The Role of Right Ventriculo-Arterial Coupling in Symptoms Presentation of Patients with Hypertrophic Cardiomyopathy

BACKGROUND

Hypertrophic cardiomyopathy (HCM) is the most common inherited cardiomyopathy. The hallmark of HCM is myocardial fibrosis which contributes to heart failure, arrhythmias, and sudden cardiac death (SCD).

OBJECTIVE

To identify the factors implicated in heart failure symptoms and functional capacity of patients with HCM.

METHODS

In this cohort study, 43 patients with HCM were recruited. According to functional capacity and symptoms presentation, patients were categorized according to New York Heart Association (NYHA) classification, and echocardiographic measurements of left ventricle systolic and diastolic function were conducted. The echocardiographic assessment of right ventriculo-arterial coupling (RVAC) was made by calculating the tricuspid annular peak systolic tissue Doppler velocity (TASV)/estimated RV systolic pressure (RVSP) ratio.

RESULTS

Almost half (51%) of our study population present symptoms of heart failure and were categorized as the symptomatic group-NYHA 2 or higher. Maximum LVOT gradient, RVSP, and the ratio of E/e' were higher in the symptomatic group compared with the asymptomatic group. TASV was lower in the symptomatic group compared with the asymptomatic group (11 ± 1 cm/s vs. 13 ± 2 cm/s, p = 0.04). However, there was no difference in other potentially influential factors, such as heart rate or systemic blood pressure. The SCD risk score does not differ between the two studied groups. The RVAC (estimated with the TASV/RVSP ratio) was lower in the symptomatic group compared with the asymptomatic group (0.32 ± 0.09 vs. 0.46 ± 0.11, p < 0.001).

CONCLUSION

A low RVAC (as estimated with TASV/RVSP ratio) value could represent an echocardiographic marker of right ventricular-arterial uncoupling in patients with HCM and impaired functional status.

Clinical Usefulness of Right Ventricle-Pulmonary Artery Coupling in Cardiovascular Disease

Right ventricular-pulmonary artery coupling (RV-PA coupling) refers to the relationship between RV contractility and RV afterload. Normal RV-PA coupling is maintained only when RV function and pulmonary vascular resistance are appropriately matched. RV-PA uncoupling occurs when RV contractility cannot increase to match RV afterload, resulting in RV dysfunction and right heart failure. RV-PA coupling plays an important role in the pathophysiology and progression of cardiovascular diseases. Therefore, early and accurate evaluation of RV-PA coupling is of great significance for a patient's condition assessment, clinical decision making, risk stratification, and prognosis judgment. RV-PA coupling can be assessed by using invasive or noninvasive approaches. The aim of this review was to summarize the pathological mechanism and evaluation methods of RV-PA coupling, the advantages and disadvantages of each method, and the application value of RV-PA coupling in various cardiovascular diseases.

Color tissue doppler imaging of tricuspid annular plane systolic and diastolic excursion in children: A comparison of normal, volume-overloaded and pressure overloaded right ventricles

BACKGROUND

Tricuspid annular plane (TAP) systolic excursion (TAPSE) is a reproducible M-mode parameter for the measurement of longitudinal shortening of the right ventricle (RV). To date, all attention has been focused on the systolic excursion of TAP and the diastolic excursion of the annular plane back to the base has been ignored. This study aims to compare the quantitative (excursion, slope, and duration) and qualitative (velocity, acceleration, and indentation) characteristics of TAP systolic and diastolic excursion, using color tissue Doppler imaging, in three groups of children with normal RV (NORV), volume overloaded RV (VORV), and pressure overloaded RV (PORV) and normal pulmonary arterial pressure.

SUBJECTS AND METHODS

A prospective case-control study was performed in three groups of children with normal heart, VORV and PORV. TAPSE and tricuspid annular plane diastolic excursion (TAPDE) were quantitatively and qualitatively analyzed and compared between the three groups. Statistical analysis was performed using IBM SPSS Statistics for Windows.

RESULTS

TAPSE, TAPDE, TAPSE slope, TAPSE slope/TAPDE slope, TAPDE duration and TAPDE duration/RR interval were lower in PORV (TAPSE: PORV: 14.45 ± 4.30, NORV: 20.45 ± 5.46, P = .003, TAPDE:PORV: 14.39 ± 4.61, NORV: 20.28 ± 5.65, P = .004, TAPSE slope:PORV: 4.79 ± 1.40, NORV: 7.15 ± 1.98, P = .001, .001, TAPDE duration:PORV: 201.1 ± 87.9 ms, NORV: 292.1 ± 97.9, P = .006, TAPDE duration/RR interval: PORV: .37 ± .09, NORV: .48 ± .08, P = .0002).

CONCLUSION

Pressure-overload on RV produced more impairment of TAPSE and TAPDE patterns than volume overload. Values of TAPSE and TAPDE in patients with VORV and PORV stay in two ends of the normal spectrum. The harmful impact of pre-tricuspid volume overload seems to be less than the post-tricuspid volume overload.