Sudden cardiac deaths and ventricular extrasystoles on days with four levels of geomagnetic activity.

Four hundred and eighty sudden deaths were studied on 4009 consecutive days from 1976-1986, according to each of 4 levels of geomagnetic activity. Ventricular extrasystoles (VPCs) recorded by 24-hour Holter monitoring were studied on 364 days. 211 cardiac outpatients were studied. It was shown that both sudden deaths and VPCs were significantly more frequent on days with the lowest/quiet level of geomagnetic activity.