Insensitivity to Digoxin Associated with Hypocalcemia

Abstract

Hypercalcemia increases the effect of digitalis and its derivatives on the heart. Hypocalcemia, on the other hand, is not a recognized inhibitor of the action of digitalis, although resistance to the action of digitalis is known to occur in a variety of conditions such as anemia, hyperthyroidism, rheumatic carditis or subacute bacterial endocarditis.1 , 2 In the hypocalcemic patient described below, atrial fibrillation associated with a rapid ventricular response failed to respond to therapeutic levels of digoxin until the serum calcium had risen toward the normal range.Case ReportAn 85-year-old man was admitted to the hospital complaining of shortness of breath. . . .