Changes in QT intervals in patients with end-stage renal disease before and after hemodialysis

• Published in: Saudi journal of kidney diseases and transplantation Vol. 21; no. 3; pp. 460 - 465
• Main Authors: Malhas, Mahmud, Farhud, Salih, Zayyat, Khayr Al-Din, al-Bitar, Sami
• Format: Journal Article
• Language: English
• Published: Riyadh, Saudi Arabia Saudi Center for Organ Transplantation 01.05.2010; Medknow Publications and Media Pvt. Ltd; Wolters Kluwer Medknow Publications
• Subjects: Adult; Arrhythmias, Cardiac - etiology; Arrhythmias, Cardiac - physiopathology; Care and treatment; Chronic kidney failure; Chronic renal failure; Diseases; Electrocardiogram; Electrocardiography; Female; Health aspects; Heart Conduction System - physiopathology; Hemodialysis; Humans; Kidney Failure, Chronic - complications; Kidney Failure, Chronic - physiopathology; Kidney Failure, Chronic - therapy; Kidneys; Male; Middle Aged; Patient outcomes; Renal Dialysis; Risk factors; Time Factors; Treatment Outcome; الأمراض; الأمراض المزمنة; الدم; الفشل الكلوي; الكلى; المرضى; تخطيط القلب; غسيل الكلى; Saudi Arabia
• ISSN: 1319-2442; 2320-3838

Increased dispersion of QT intervals is known to predispose to ventricular arrhyth­mias and sudden cardiac death. To assess the effect of hemodialysis (HD) on QT and corrected QT (QTc) intervals and their dispersions in chronic hemodialyzed patients we studied 85 patients (male/female = 48/37; mean age 44 ± 17 year) on chronic hemodialysis. Simultaneous 12-lead ECG was recorded before and after HD in a standard setting. The QT intervals for each lead were measured manually by one observer using calipers. Each QT interval was corrected for heart rate: QTc= QT ? R-R/ (in milliseconds [ms]). ECG parameters, body weight, blood pressure, heart rate, electrolytes (Na + , K + , Ca ++ , phosphate), urea, and creatinine were measured before and after HD. The mean of pre and post dialysis cycle intervals was 828 ± 132 ms and 798 ± 122 ms respec­tively; the difference was not significant. The mean of QT max intervals changed significantly from 446 ± 47 to 465 ± 72 ms (P< 0.05). The mean of corrected QT cmax intervals increased significantly from 472 ± 38 to 492 ± 58 ms (P< 0.05). The mean of QT dispersions and the corrected QT interval dispersions changed from 60 ± 29 to 76 ± 32 ms (P< 0.05) from 72 ± 46 to 98 ± 56 ms (P< 0.05), respectively. During HD, the serum potassium and phosphate levels decreased whereas the calcium levels increased. We conclude that QT and QTc interval and dispersion increase in HD patients.