ABSTRACT
In the 1970s, cardiac rehabilitation was accepted as beneficial for the patient following a myocardial infarction or coronary bypass surgery (1, 2). Patients with significant left ventricular dysfunction were usually excluded based on the concern of excess risk (3, 4). In 1979, Lee et al. (5) and in 1982, Conn et al. (6) reported that exercise training was safe in patients with impaired ventricular function and demonstrated significantly improved work capacity after training. Both investigators noted no improvements in ventricular function but no deterioration either. Weber and Janicki classified patients with chronic heart failure according to the maximum VO2 achieved as well as by the anaerobic (ventilatory) threshold (7). This classification is presented in Table 1.
