Ventricular extrasystoles and intracellular electrolytes in hypokalemic patients before and after correction of the hypokalemia.

Fifty-four initially hypokalemic patients, 43 of whom were on diuretic treatment, were given potassium supplementation until they showed a repeatedly normal serum potassium level. Muscle specimens obtained by percutaneous biopsy revealed that there were no concomitant increases in muscle potassium content, nor in intracellular potassium concentration, except in the very small group (6 patients) with a muscle magnesium content of greater than or equal to 3.95 mmol/100 g fat free dry solids (FFDS) and an initially lower muscle potassium content (less than or equal to 39.9 mmol/100 g FFDS). ECG, registered for 3 hours on a portable ECG tape recorder before and after correction of the serum potassium level, showed no change in the frequency of ventricular ectopic beats.