Polarcardiographic criteria for myocardial infarction in Chinese men.

Polarcardiograms (PCG) derived from xyz leads of the Frank electrocardiogram (ECG) were recorded in the supine position in 1264 initially healthy middle-aged Chinese men who had been under continuing medical surveillance and were re-examined seven years later. Polarcardiographic criteria for myocardial infarction (MI) were demonstrated in 97 men (7.7%), but only 15 of them showed diagnostic Q waves in the electrocardiogram (ECG). Polarcardiographic criteria for MI were independent of age, but ranged from 4.3% in 464 apparently normal men to 38% in 21 men with manifestations of ischemic heart disease. The possible association of polarcardiographic criteria and a history of smoking was limited to those with clinical evidence of heart disease. The "false positive" rate of 4.3% in clinically normal men was similar to that reported in younger Canadians and in Cretan population samples.