Magnesium and potassium interrelationships in cardiac arrhythmias.

Depletion of K and Mg appears to play a significant role in the ventricular tachyarrhythmias seen in alcoholic patients, patients treated with diuretics and/or patients with digitalis toxicity. A therapeutic strategy is suggested by the observation that hypokalemic patients have a 38-42% incidence of concurrent hypomagnesemia: that Mg as well as K should be replenished in all hypokalemic patients who suffer from alcoholism or who are receiving diuretics and/or digitalis because of the ventricular tachyarrhythmias which accompany these clinical states. Routine serum Mg determination will contribute significantly towards identifying patients at risk for cardiac arrhythmias due to Mg depletion.