EFFECTS OF SECONDARY HYPERPARATHYROIDISM ON CARDIAC-FUNCTION IN PEDIATRIC-PATIENTS ON HEMODIALYSIS

Cardiovascular complications are an important cause of morbidity and m ortality in chronic hemodialysis patients. In order to examine the eff ect of parathyroid hormone (PTH) and vitamin D on left ventricular fun ctions, 11 patients between the ages of 13 and 18 years on regular hem odialysis were investigated using M-mode echocardiography and systolic time intervals. The ratio of the pre-ejection period to the left vent ricular ejection time was found to be 0.38 +/- 0.02 (range 0.25 +/- 0. 50) and was elevated above normal in five of the 11 patients examined. Four of these patients had hypertension and one had severe anemia. Th e left ventricular ejection fraction was 55 +/- 2.54% and fractional f iber shortening was 31.55 +/- 2.26%, both of which were within normal limits for age. Although the velocity of circumferential fiber shorten ing was within normal limits in the majority of cases, the mean value was 1.437 +/- 0.11 circ/s, which is above normal for this age period. PM levels were between one and 4.70 ng/ml. All of the hemodialysis pat ients had been receiving 1 alpha hydroxycholecalciferol and had normal calcium levels. Although they had high PM levels, most of these patie nts displayed normal myocardial contractility. No significant correlat ion was obtained between Increment in PM levels and myocardial functio n indices. These results imply that PTH is not the only factor affecti ng myocardial functions. Since all of these patients have received vit amin D therapy for long periods, we suggest that vitamin D may have pr evented the deleterious effect of PM on myocardial function.