Hypocalcemic cardiomyopathy.

Two patients with cardiomegaly and congestive heart failure were found to be grossly hypocalcemic secondary to previously undiagnosed hypoparathyroidism. The cardiac failure was refractory to digitalis preparations and diuretics but responded dramatically when specific therapy restored the serum calcium to normal. The mechanism of congestive heart failure in hypocalcemia is discussed, and their association constitutes one form of reversible cardiomyopathy which should be kept in mind when a patient fails to respond to conventional antifailure therapy.