Aim. This study was designed to investigate if electrical stimulation of skeletal muscles may represent an alternative or a complementary way of rehabilitation in congestive heart failure (CHF).
Methods. 26 patients with chronic stable CHF, NYHA functional class III, were randomly assigned to a rehabilitation program using either a classical bicycle training program, or an electrical stimulation of inferior limb muscles. Patients in the bicycle group (Bi, n = 13) underwent 25 sessions of 20min bicycle exercise at 100% of their anaerobic threshold (AT). Patients in the electrical stimulation group (ES, n = 13) had 25 sessions of low-frequency (10Hz) electrical stimulation applied simultaneously to quadriceps and calf muscle of both legs during 30min. A 6-min walk-test and maximal bicycle exercise testing with VO2 measurements were performed before and after the training program.
Results. All the exercise parameters increased significantly after rehabilitation in both groups: distance walked in 6min, peak VO2 and VO2 at anaerobic threshold (AT), exercise duration and maximal achieved workload. When we looked at the relationship between improvement of peak VO2 and increase in maximal heart rate, there is a close correlation in the Bi group (r = 0.85, P < 0.01) but not in the ES group: similarly, improvement of exercise time and maximal workload was closely correlated with the increase in maximal HR in the Bi group (r = 0.87, P < 0.01) and not in the ES group.
Conclusions. These results show that an improvement of exercise capacities can be achieved either by classical bicycle training or by electrical stimulation.
Support by grant IGA Ministry of Health CZ, NS 10096-4.