Evaluation of a Heart Rate Controlled Cycle Ergometer for use in Cardiac Rehabilitation

Abstract

The purpose of this study was to evaluate a stationary cycle ergometer that was designed for controlling the heart rate (HR) of cardiac patients during an exercise training program. The cycle has the capability of maintaining a prescribed training HR (±5 beats/min) by adjusting power output. Twenty healthy subjects (44 ± 7 years) and 25 cardiac patients (59 ± 8 years) volunteered as participants. The patients had documented myocardial infarction, coronary artery bypass graft surgery, or percutaneous transluminal coronary angioplasty. Exercise protocols included a 5-minute warm-up function followed by either a continuous or an interval training program (12 minutes) and concluded with a 3-minute active recovery. Data were collected at 1-minute intervals at rest, during exercise, and at recovery. Evaluation of the cycle was based upon: continuous HR recordings of the cycle compared to a Quinton 2000 electrocardiographic (ECG) system, the cycle's capability of maintaining the appropriate target HR; and the effect of arrhythmias on the cycle's HR monitoring device and its capability of maintaining the prescribed HR. Validity coefficients between the HR from the cycle compared with the ECG system for all exercise phases were high (r = 0.97 to 0.99). Observed HRs were not significantly different (P > 0.05) from the target HR. Adjustments in the power output were not affected by arrhythmias. These data indicated that the cycle is a valid, safe instrument and is acceptable for home use by selected cardiac patients and in cardiac rehabilitation centers.