Exercise and Cardiac Measures in Dialysis Patients

Background: The impact of the known non-invasive cardiac indices for identification of hemodialysis (HD) patients at high-risk for sudden cardiac death (SCD) has not been evaluated. Patients: Fifty-nine HD patients were randomized into 2 groups. Thirty of them (group A-aged 54.6±8.9 years) participated in a supervised training program with stationary bicycles during their HD sessions (3/weekly) for 10 months, while the rest (group B-aged 53.2±6.1 years) remained untrained and were used as controls. Study hypothesis: Exercise training will affect most of the non-invasive cardiac markers of SCD and the total score positively. Method: At entry, as well as at the end of the study all subjects underwent a cardiopulmonary exercise testing (estimation of aerobic capacity-VO2peak), an echocardiographic study (LV ejection fraction -LVEF evaluation), an ambulatory 24-hour Holter monitoring for cardiac autonomic nervous system activity evaluation by time- and frequency- domain heart rate variability (HRV) calculation (measurement of SDNN, mean RR and low to high frequency ratio-LF/HF), a signal-averaged ECG (late potentials-LP documentation) and a submaximal exercise test for microvolt-T-wave alternans (TWA) detection.