Identification of electrocardiographic criteria for diagnosis of right ventricular hypertrophy due to mitral stenosis.

Current electrocardiographic (ECG) criteria for diagnosing right ventricular hypertrophy (RVH) have low sensitivity. In this study maximally specific and sensitive ECG criteria for RVH due to mitral stenosis (MS) were developed that incorporated the principles derived from spatial changes in the QRS complex observed on the vectorcardiogram and any existent ECG criteria that supplement the diagnostic capability of the criteria derived from the vectorcardiogram. The standard 12-lead electrocardiograms of a control group of 500 consecutively selected subjects with 50 women and 50 men in each decade between ages 20 and 69 years were compared with the electrocardiograms of a study population of 50 patients with RVH due to MS. Inclusion criteria were a diagnosis of MS by catheterization, normal coronary arteriographic and left ventriculographic findings and no other valvular abnormalities. It was hypothesized that patients with RVH resulting from MS would have QRS forces that are maximally anterior (A) and rightward (R) and minimally posterolateral (PL); thus, the A + R - PL value in the study group would be greater than that in the control group. The subsequently derived formula criterion (A + R - PL greater than or equal to 0.7 mV) and 2 additional criteria, R less than or equal to 0.2 mV in lead I and P less than 0.25 mV in leads II, III, aVF, V1 or V2, were tested in both groups. The specificity and sensitivity of each individual criterion was determined; when combined, the criteria yielded 94% specificity and 64% sensitivity. Moderate to severe RVH due to MS was detected in two-thirds of the patients using the proposed criteria.