New electrocardiographic criteria for diagnosing right ventricular hypertrophy in mitral stenosis. Comparison with Bonner's and Mortara's criteria.

New criteria for the diagnosis of right ventricular hypertrophy (RVH) using a point scoring system were developed after analyzing standard 12-lead ECGs in 155 patients with mitral stenosis verified by cardiac catheterization and 155 age and sex-matched apparently normal healthy subjects. ECGs were evaluated to identify criteria that provided maximum sensitivity and at least a 95% specificity: (1) the R wave magnitude in V1 had to be greater than 0.7 mV; (2) the S wave magnitude in V6 had to be greater than 0.3 mV; (3) the S wave magnitude in V1 less than 0.5 mV; (4) the R wave magnitude in V1 plus the S wave magnitude in V6 minus the S wave magnitude in V1 must be greater than 0 mV; and (5) the degree of frontal QRS axis had to be greater than 90 degrees. Application of these criteria achieved 25% (39 of 155) sensitivity in patients with RVH, significantly better (p less than 0.01) than the 17% sensitivity (17 of 155) of Bonner's criteria for the automated ECG. The specificity of the proposed criteria was 98% (152 of 155), significantly better (p less than 0.01) than the 90% specificity (139 of 155) of Mortara's criteria. Thus, it was evident that the accuracy of the proposed criteria was the highest among those criteria used in a point scoring system including the currently used automated ECG criteria for the diagnosis of RVH.