QT INTERVAL PROLONGATION IN THE PATIENTS RECEIVING MAINTENANCE HEMODIALYSIS

QT prolongation is associated with a poor prognosis in patients with v arious diseases. The pathogenesis of the long QT syndrome is not well understood and little is known about the QT interval in the patients r eceiving maintenance hemodialysis. We evaluated changes in the QTc int erval and investigated factors that contribute to its prolongation in 42 patients receiving maintenance hemodialysis. We also examined the a ssociation between the QTc interval and ventricular arrhythmias on 24- h ambulatory electrocardiograms. Comparison of standard 12-lead electr ocardiograms of 42 patients and of 30 healthy controls matched for age and sex showed that the QTc interval in the patients was significantl y prolonged (432.6 +/- 24.9 vs 402.0 +/- 21.0 ms, p <0.001). Multivari ate analysis using stepwise multiple regression identified diabetes me llitus and the ejection fraction measured by echocardiography as indep endent risk factors for QTc prolongation. The QTc interval was signifi cantly prolonged in patients with complex VPCs (couplers or salves) (n = 13, 447.9 +/- 14.4 ms) on 24 h ambulatory ECG compared with simple VPCs (none or occasional) (n = 29, 425.6 +/- 25.8 ms) (p = 0.03). In c onclusion, the QTc interval was prolonged in patients receiving mainte nance hemodialysis and QTc prolongation was associated with complex VP Cs. Decreased myocardial contractility and diabetes mellitus contribut ed to QTc prolongation.