The Significance of Ventricular Interdependence in Patients with Right Ventricular Hypertrophy and Normal Left Ventricular Function

Abstract

The aim of the study is to quantify ventricular interactions by comparing tissue and spectral systolic echocardiographic parameters to allow the early identification of ventricular dysfunction. Clinical, paraclinical, electrocardiographic and echocardiographic evaluations were performed. Right ventricular hypertrophy was diagnosed in the M mode subcostal echocardiographic section. RV hypertrophy was defined by a right ventricular free wall thickness of ] 5 mm in diastole. We assessed the following RV and LV tissue and spectral systolic indices: apical systolic excursion of the lateral mitral ring (MAPSE), apical systolic excursion of the lateral tricuspid ring (TAPSE), left (Svs) and right (Svd) ventricular tissue systolic velocities, and RV and LV ejection times. We calculated the following to assess systolic ventricular interdependence: MAPSE/TAPSE, the normal value of which was considered as 0.66 � 0.14, and Svs/Svd, the normal value of which was considered as 0.76 � 0.21. The study group was compared to a control group with the same clinical features but without ventricular hypertrophy. Twenty-one patients were included in the study: 13 men (62%) and eight women (38%) with a mean age of 56 � 3.8 years. We compared the values between the study group and control group, with the following results: TAPSE = 20.4 � 0.9 vs. 24.1 � 0.76 and MAPSE/TAPSE = 0.74 � 0.06 vs. 0.75 � 0.04. MAPSE was comparable between the groups. Svs was comparable between the groups (0.09 � 0.01 vs. 0.12 � 0.02), whereas Svd was different between the groups (0.11 � 0.03 vs 0.16 � 0.03). Svs/Svd was 0.81 � 0.05 in the study group and 0.75 � 0.08 in the control group. LV ejection time was comparable between the two groups (299.8 � 23.6 ms vs. 303.3 � 28 ms), whereas, RV ejection time differed between the groups (275 � 17 ms vs. 245.5 � 28.5). Changes in TAPSE and MAPSE/TAPSE, in addition to Svd and Svs/Svd, are related to right ventricular dysfunction and suggest pathological changes in the interdependence mechanism of the ventricles in patients with RV hypertrophy. In addition, RV free wall thickness was strongly correlated with ventricular interdependence parameters, with the exception of MAPSE. Assessing these parameters and proportions in clinical practice will facilitate the early detection and appropriate treatment of right ventricular dysfunction.