Electrocardiogram abnormalities and heart rate variability in predicting mortality and cardiovascular events among hemodialyzed patients.

PURPOSE

The aim of the study was to evaluate the correlation between electrocardiographic parameters and heart rate variability with cardiovascular events and mortality among chronic hemodialysis patients.

METHODS

In this prospective study, we enrolled 116 asymptomatic patients in whom we performed ambulatory 24-h electrocardiographic Holter monitoring and before and after hemodialysis electrocardiographs. We measured the interval (PR, QRS, QTc, QTc dispersion) differences on the surface electrocardiographs and obtained frequency-domain measures from Holter monitoring (VLF, LF, HF and the LF/HF ratio).

RESULTS

During the follow-up period, 13 participants died (11.2 %) and 16 (13.8 %) patients experienced a cardiovascular event. The pre-post-dialysis difference in QTc interval was the best predictor for cardiovascular events (95 % CI 0.453-0.786), while pre-dialysis QRS interval was the predictor for all-cause mortality (95 % CI 1.134-3.136). Also, both outcomes were predicted by pre-post-dialysis difference in PR interval and VLF.

CONCLUSIONS

Interval changes during hemodialysis are predictive for cardiovascular events and mortality. Autonomic dysfunction and changes in PR should be monitored routinely, particularly in patients with suspected coronary artery disease.