HEART IN HEATSTROKE

Evidence of cardiac damage was found in 17 out of 26 Bantu goldminers with heatstroke. Myocardial injury was diagnosed on the basis of serum lactic dehydrogenase (LDH) isoenzyme patterns and electrocardiographically. A significant increase in the percentage of LDH-1 was present in 69 per cent of the patients. Electrocardiographic tracings were abnormal in 58 per cent of the cases. The changes consisted mainly of sinus tachycardia and nonspecific S-T segment and T-wave abnormalities, which were reversible in those patients who were followed up. A good correlation (75 per cent) was found between the isoenzyme and the electrocardiographic evidence of cardiac damage. Pathological examination of the heart in the 2 patients who died in the acute stage showed interstitial edema and degeneration of the muscle fibers. Although myocardial damage occurred in the majority of the cases, in none was it severe enough to cause overt cardiac failure. © 1969.