Background: Obesity may limit sensitivity of ECG voltage criteria for left ventricular hypertrophy (LVH) because of increased distance of exploring electrodes from the left ventricle. So we aimed to evaluate the influence of obesity on the diagnostic value of electrocardiographic criterions for detecting LVH.
Methods: From June 2003 to march 2004, 159 consecutive patients who visited the department of cardiology of one university hospital, were enrolled in this study, Echocardiographic LVH used as gold standard was defined by left ventricular mass indexed to body surface area and height2.7. The accuracy of the Sokolow-Lyon voltage criteria, Romhilt-Estes point scoring criteria, and Cornell criteria were examined and compared according to obesity.
Results: The amplitude of Sokolow-Lyon voltage in obese group was significantly lower than that in non-obese group and less correlated to left ventricular mass index than Cornell voltage or Romhilt-Estes point score. Compared with the sensitivity in normal-weight patients, the sensitivity of Sokolow-Lyon voltage criteria in obese patients was markedly decreased (non-obese: 50.0%, obese: 17.6%). The sensitivity of Cornell voltage in obese was not lower than that in non-obese group (non-obese: 26.9%, obese: 32.4%).
Conclusion: Using Sokolow-Lyon voltage criteria can underestimate the presence of the left ventricular hypertrophy in obese patients, whereas Cornell criteria appears less dependent on body status. These findings have important clinical and epidemiologic implications for detecting left ventricular hypertrophy in obese person.

Keywords: Obesity, Electrocardiography, Left ventricular hypertrophy