Aims: This study uses pulsed Doppler tissue imaging to analyse right ventricular myocardial function and its interaction with left ventricle in hypertrophic cardiomyopathy involving ventricular septum.
Methods and results: Thirty-four patients with septal hypertrophic cardiomyopathy and 30 normal subjects, comparable for sex, age, body mass index and heart rate, underwent complete standard Doppler echocardiography and pulsed Doppler tissue imaging of both posterior septum and right ventricular free wall, calculating myocardial velocities and both systolic and diastolic time intervals. Except for peak velocity A, the other Doppler tricuspid inflow measurements were significantly impaired in hypertrophic cardiomyopathy, without changes of tricuspid annular systolic excursion. Right ventricular Doppler tissue imaging showed longer right ventricular myocardial relaxation time in hypertrophic cardiomyopathy than in controls (P<0.00001), without a significant difference from other myocardial diastolic and systolic measurements. In the overall population, Doppler measurements of right and left ventricular inflow were not significantly associated, while (with the exception of myocardial deceleration time) all the other myocardial systolic and diastolic measurements derived by tissue imaging were directly related to the homologous septal myocardial indexes. In addition, a significant inverse relation was found between septal wall thickness and myocardial relaxation index (right-left myocardial relaxation time/right ventricular relaxation time x 100).
Conclusions: This study shows the usefulness of pulsed Doppler tissue imaging to detect impairment of right ventricular myocardial function and to provide evidence about ventricular interaction in forms of hypertrophic cardiomyopathy which involve interventricular septum.