Electrocardiographic diagnosis of left ventricular hypertrophy in the presence of right bundle branch block in cases with essential hypertension.

Right bundle branch block was diagnosed in electrocardiograms of 37 of 1085 patients with essential hypertension. Echocardiographically left ventricular hypertrophy was diagnosed in 14 of these 37 patients. Eighteen electrocardiographic (ECG) criteria, which were previously recommended, were determined in these 37 patients. The sensitivities of five criteria were found to be better than 50%. These are SV1 > or = 2 mm; RV6 > RV5; S III + (R+S) maximum precordial lead > or = 30 mm; P/PR > or = 1.6; R aVL > or = 11 mm. However, their specificities ranged from 56.5% to 95.6%. When the combination of RV6 > RV5 and S III + (R+S) maximum precordial lead > or = 30 mm was used, sensitivity was 57.1 and specificity was 100%. It is concluded that the presence of right bundle branch block these ECG criteria can be used for the diagnosis of left ventricular hypertrophy.