QT Dispersion Before and After Hemodialysis

Abstract

Abstract. Sudden cardiac death is common in patients on hemodialysis, and may occur in the immediate postdialysis period, when ventricular premature complexes are common. Elevated QT dispersion (Maximum — Minimum QT interval on standard 12-lead electrocardiogram) is associated with increased risk of ventricular arrhythmias following myocardial infarction, but has not previously been assessed in patients with chronic renal failure. We studied electrocardiograms recorded in 50 patients before and after a single hemodialysis session, and in 20 control subjects. QT dispersion was significantly higher in patients (63.1 ± 20.6 ms) compared with control subjects (36.0 ± 13.7 ms; P < 0.001) and rose significantly after hemodialysis to levels comparable to those seen following myocardial infarction (76.6 ± 27.0 ms; P < 0.01). Because QT dispersion reflects nonhomogeneous recovery of ventricular excitability, hemodialysis patients may be at significantly greater risk of reentrant arrhythmias and sudden death in the postdialysis period.

Clinical Associations between Serial Electrocardiography Measurements and Sudden Cardiac Death in Patients with End-Stage Renal Disease Undergoing Hemodialysis

“…However, in our study, the QTc interval was not prolonged compared to its normal value before or after HD [ 35 ]. QT dispersion, as in other studies, was >50 ms both before and after HD; hence, it was higher than normal [ 14 , 15 ] but was not different between the SCD and survivor groups. It may be conjectured that previous studies focused on cardiovascular mortality rather than SCD, potentially explaining the difference with our results.…”

“…Among non-invasive methods, electrocardiography (ECG) reflects myocardial changes such as the prolongation of QT interval, QTc interval, QTc dispersion, and QT peak-to-end (QTpe) interval [ 11 , 12 , 13 , 14 , 15 ]. As mentioned in many previous reports, several risk factors of SCD cause ventricular remodeling and myocardial fibrosis, leading to ventricular dysfunction and dys-synchronization [ 5 , 6 , 7 ], changes which are known to affect SCD risk [ 11 , 12 , 13 ].…”

QT Prolongation in Dialysis Patients: An Epidemiological Study with a Focus on Malnutrition

“…It is noteworthy that significant and lethal organic changes have been demonstrated in only 30% of these cases of sudden cardiac death at autopsy [10]. Dialysis therapy itself may cause undesirable effects on the cardiovascular system by inducing rapid changes in both electrolytes and plasma volume and by fast correction of metabolic acidosis [11][12][13][14][15][16]. These changes are considered arrythmogenic, so autonomic nervous system disorder, especially in diabetic patients, should also be considered in relation to provoking arrhythmias [17][18][19][20].…”

Electrolyte concentration during haemodialysis and QT interval prolongation in uraemic patients

“…In patients undergoing haemodialysis (HD), electrocardiographic changes are frequently observed. 1 A prolongation of the QT interval, [2][3][4] an increase of QT dispersion, [5][6][7] and an alteration of the capability to adapt QT interval to heart rate changes 8 have been reported during HD sessions. These alterations of ventricular repolarization represent a potential arrhythmic risk in HD patients.…”