Echocardiographic detection of right ventricular hypertrophy.

M-mode echocardiographic right ventricular wall thickness (RVW) and diastolic right ventricular internal diameter (RVID), when above the accepted normal range (RVW less than or equal to 5 mm, RVID less than or equal to 26 mm), are frequently used clinically to predict the presence of right ventricular hypertrophy. RVID was compared to anatomic right ventricular mass (RVM) in 27 patients and to RVW in 13 patients to determine their accuracy for predicting right ventricular hypertrophy (RVM greater than 65 gm). When increased, both measurements were specific for right ventricular hypertrophy. The specificity for RVW above 5 mm was 100% and for RVID greater than 26 mm was 79%. Neither was a sensitive indicator of hypertrophy. Only 36% of those with anatomic right ventricular hypertrophy had an echocardiographically dilated ventricle, and 67% had a thickened free wall. Neither measurement proved to be an accurate predictor of RVM, with a correlation for RVW of 0.56 and for diastolic RVID of 0.19.