[The coincidence of rapidly progressing dilated cardiomyopathy and primary hyperparathyroidism. The course before and after the removal of a parathyroid adenoma].

Severe cardiac arrhythmias (Lown class IVa), rapid loss of physical capacity and dyspnoea on the slightest exertion occurred in a 55-year-old man with idiopathic dilated cardiomyopathy. In the preceding year he had recurrent diarrhoea and lost 23 kg in weight. He was found to have hypercalcaemia (3-3.2 mmol/l). The heart failure significantly improved under treatment with twice daily 12.5 mg captopril, 100 mg spironolactone daily, furosemide 40 mg twice daily, and digitoxin 0.07 mg daily. The arrhythmia responded to verapamil 80 mg and quinidine 160 mg, both drugs three times daily. Primary hyperparathyroidism was found to be the cause of the hypercalcaemia (parathormone 84 pmol/l). After the parathyroid adenoma had been removed the patient's condition again improved markedly. There were only rare monotopic extrasystoles, cardiac size regressed, and diuretics were no longer necessary. His medication at present is verapamil (80 mg three times daily), captopril (12.5 mg three times daily) and digitoxin (0.07 mg daily). It is concluded that the hypercalcaemia influenced the severity of the cardiomyopathy. It would seem that both intra- and extracellular calcium homoeostasis is of great importance in dilated cardiomyopathy.