Estimation of right ventricular contractility by continuous-wave Doppler echocardiography

The right ventricular dP/dt(max) and relatively load-independent index, dP/dt(max)/IP (IP: instantaneous pressure difference between the right ventricle and right atrium) can be measured from the tricuspid regurgitant velocity by continuous-wave Doppler echocardiography. The present study investigated these indices as measures of right ventricular contractility. Thirty-one patients were classified into three groups: 11 patients without right ventricular disease (control group), 9 with dilated cardiomyopathy and 1 with hypertrophic cardiomyopathy in the dilated phase (DCM group), and 10 with pulmonary hypertension (PH group). Right ventricular contractility was impaired in both the PH group and DCM group, but dP/dt(max) was significantly larger in the PH group compared with the control group and DCM group (519±113 vs 249±66 and 234±78 mmHg/sec, p<0.01). There was no significant difference between dP/dt(max) in the control group and DCM group. dP/dt(max)/IP in the PH group was smaller than the control group (31±8 vs 39±7/sec, p<0.05) and larger than the DCM group (22±12/see, p<0.05). Mean New York Heart Association grading was 1.0 in the control group. 3.1 in the DCM group, and 2.8 in the PH group, respectively. Thus, dP/dt(max)/IP, noninvasively obtained by continuous-wave Doppler echocardiography, may be a better index for evaluating right ventricular contractility than dP/dt(max).