Usefulness of total 12-lead qrs voltage compared with other criteria for determining left ventricular hypertrophy in hypertrophic cardiomyopathy: analysis of 57 patients studied at necropsy

Abstract

The sensitivity of electrocardiographic indicators of left ventricular (LV) hypertrophy is known to be rather poor. To date, no study has undertaken a comparison of the various electrocardiographic criteria for LV hypertrophy among patients with hypertrophic cardiomyopathy (HC). In this study, we compared the sensitivity of the total 12-lead QRS amplitude with the sensitivity of certain standard electrocardiographic criteria for LV hypertrophy in necropsy patients with HC. A total of 57 hearts were studied. The last technically satisfactory electrocardiogram available from each necropsy patient was used. Electrocardiographic criteria employed to diagnose LV hypertrophy included the Sokolow and Lyon index, the Romhilt-Estes voltage criteria, the Romhilt-Estes point score, the ratio of RV6:RV5 greater than 1 proposed by Holt and Spodick, and a method utilizing the sum of the amplitudes of the QRS complexes of all 12 leads. The total 12-lead QRS amplitude ranged from 66 to 339 mm (mean: 197 mm) (10 mm = 1 mV). Using 175 mm as the upper limit of normal, this technique yielded a sensitivity of 53%, which was the highest sensitivity of any criteria tested. The Sokolow-Lyon index had a sensitivity of 39%; the Romhilt-Estes voltage criteria, 37%; the Romhilt-Estes point score system, 49%; and the criterion of RV6 more than RV5, 39%. No correlation was found between total 12-lead QRS voltage and heart weight, LV free wall thickness, LV peak systolic and end-diastolic pressures, or LV outflow tract peak systolic pressure gradient. The 10 patients (18%) with transmural LV scars had significantly lower total 12-lead QRS voltage than did the 48 patients (78%) without such scars (155 mm versus 205 mm, p = 0.02). Total 12-lead QRS amplitude more than 175 mm is a useful indicator of LV hypertrophy and, among patients with HC, it is more sensitive than other more commonly employed criteria.