FREQUENCY OF ASYMPTOMATIC DISTURBANCES OF CARDIAC RHYTHM AND CONDUCTION IN MIDDLE-AGED MEN

A study of a random sample of 301 actively employed American men, of median age 55 years, employing cardiac recordings obtained during six-hour periods of ordinary activity indicates that asymptomatic periods of dysrhythmia and conduction disturbances occurred in 92.6 per cent of these men at some time during the recording period. Supraventricular premature contractions and other supraventricular dysrhythmias were found in 76.0 per cent of the recordings. These were not associated with present evidence of coronary heart disease or with subsequent death from coronary heart disease, except when supraventricular dysrhythmias were associated with other dysrhythmias or conduction defects. Ventricular premature contractions and complex ventricular dysrhythmias were found in 62.2 per cent of the recordings. These were significantly associated with the presence of coronary heart disease at the time of the examination. They were also associated with an enhanced risk of subsequent death from coronary heart disease. Defects of cardiac conduction, constant or transient, were found in 6.7 per cent of the men. These, too, were associated with an enhanced risk of subsequent death from coronary heart disease. © 1969.