Reversible changes of electrocardiographic abnormalities after parathyroidectomy in patients with primary hyperparathyroidism.

BACKGROUND Several studies have reported that primary hyperparathyroidism is a risk factor of higher cardiovascular mortality, mainly because hyperparathyroidism is related to arterial hypertension, arrhythmias, structural heart abnormalities and activation of the renin-angiotensin- aldosterone system. However, very few studies have shown the electrocardiographic changes that occur after parathyroidectomy. That was the aim of this study. METHODS We studied 57 consecutive patients with primary hyperparathyroidism surgically treated. Electrocardiogram, serum electrolytes, parathyroid hormone, creatinine and albumin measures were obtained before and after surgery and were compared. RESULTS The most common basal electrocardiographic abnormalities were left ventricular hypertrophy (LVH, 24.6%), conduction disturbances (16.3%), and short QT and QTc intervals. After surgery, a QTc interval lengthening and a tendency of T wave shortening were observed, as well as an inverse association between QTc interval and serum levels of magnesium and corrected calcium. There were no differences in LVH and conduction disturbances after surgery. CONCLUSIONS Primary hyperparathyroidism is an important factor in the development of electrocardiographic abnormalities in this population, some of which are not corrected after parathyroidectomy. Further studies are required to demonstrate what factors are associated with persistence of electrocardiographic disturbances after surgery.