[Severe hyperkalemia in cardiac patients]

Hyperkalaemia with severe myocardial consequence may complicate the treatment of heart failure. In five patients who developed kalaemia ranging from 6.5. to 8.6. mEq/l, the ECG showed altered auriculogram and/or widened QRS, the latter change being associated with ST segment elevation and very large T wave in one case. Such hyperkalaemia cannot be termed iatrogenic, although it is promoted by diuretic-induced hyponatraemia and dehydration. The essential part is played by an aggravation of the haemodynamic status, responsible for acute renal insufficiency with oligoanuria, and by the attendant metabolic acidosis. The correction of this metabolic acidosis promotes diuresis, causing potassium depletion and the rapid regression of electrocardiographic abnormalities. Parenteral alkalinization with sodium bicarbonate, associated with furosemid to prevent sodium overload, instituted in emergency, is the only way to prevent asystole or ventricular fibrillation when kalaemia exceeds 8 mEq/l.