The influence of water-based training on arrhythmia in patients with stable coronary artery disease and preserved left ventricular function

Background: Water immersion may cause adverse cardiovascular events, including arrhythmias in patients with damaged cardiac muscle, e.g. with cardiac failure. So far, there have been rather few reports on arrhythmia induced by water training in patients with coronary artery disease (CAD). The aim of the study was to assess the influence of exercise training in moderately cold water (28–30°C) on arrhythmia and physical capacity in stable CAD patients with preserved left ventricular (LV) function. Methods: Sixty-two post-myocardial infarction male patients, mean age 50.9 ± 7.9 years, participated in 16 water-based trainings (WBT), which lasted 55-min, twice a week in water at 28–30°C. Each subject underwent 24 h Holter on-land monitoring (Holter-24) once during the study and twice in-water Holter monitoring (Holter-W) during WBT. Before and after WBT cardiopulmonary exercise test (CPET) was performed. The following parameters were analyzed: peak oxygen consumption (peak VO2), mean number of ventricular ectopic beats ( VEBs) and supraventricular ectopic beats (SVEBs) during Holter-24 and Holter-W, the percentage of men who developed arrhythmia during CPET vs. Holter-24 and vs. Holter-W. Results: WBT significantly improved patients’ physical capacity, and more often provoked arrhythmia, mainly SVEBs, than CPET or daily activity assessed during Holter-24. During WBT 58% men developed VEBs and 62% SVEBs. Conclusions: 1. WBT provoked arrhythmias significantly more often than did CPET and normal daily activity. 2. Owing to WBT patients improved their physical capacity which was still maintained at 1-year follow-up.