EFFECTS OF PARATHYROIDECTOMY ON LEFT-VENTRICULAR MASS IN PATIENTS WITH HYPERPARATHYROIDISM

The effects of parathyroidectomy on left ventricular muscle volume and mechanical performance were evaluated echocardiographically in 24 pat ients with secondary hyperparathyroidism due to chronic renal failure and in 7 with primary hyperparathyroidism. Intraventricular septum and posterior wall thickness, left ventricular end-diastolic diameters, l eft ventricular end-systolic diameters, shortening fraction, ejection fraction, and left ventricular mass index were measured by M mode reco rding by the parasternal short axis view prior to parathyroidectomy as baseline and repeated 12 months after parathyroidectomy. Serum basal carboxyterminal parathyroid hormone levels in patients with secondary hyperparathyroidism (34.4 +/- 13.7 ng/ml) were significantly higher th an in those with primary hyperparathyroidism (3.4 +/- 5.1 ng/ml; p < 0 .0001). At 12 months after parathyroidectomy, intraventricular septum and posterior wall thickness, left ventricular end-diastolic diameter and left ventricular mass index were reduced from 11.8 +/- 3.1 mm, 10. 9 +/- 1.7 mm, 53.8 +/- 6.3 mm, 200.8 +/- 57.1 g/m(2) to 10.0 +/- 2.1 m m (p<0.05), 9.8 +/- 1.9 mm (p<0.05), 50.7 +/- 7.2 mm (p<0.05), 149.6 /- 38.7 g/m(2) (p<0.0001), in patients with secondary hyperparathyroid ism. In patients with primary hyperparathyroidism, all echocardiograph ic parameters remained in the normal range and did not show any signif icant changes before or after parathyroidectomy. From this study, para thyroid hormone at extremely high concentrations as seen in secondary hyperparathyroidism appears to be a cardiotoxic substance. Therefore, all patients with secondary hyperparathyroidism should be examined by echocardiography and parathyroidectomy should be considered if myocard ial hypertrophy is present.