INDICATIONS AND LIMITS OF THE EXERCISE TEST IN CHRONIC HEART-FAILURE

Assessment of exercise capacity has been widely used in the evaluation of chronic heart failure (CHF), both to define the severity of the sy ndrome and to assess the changes induced by therapy. Various exercise tests and protocols can be used. The simple stress test using the exer cise bicycle or the treadmill can give useful indications only in pati ents with severe or lower functional reductions. Maximum exercise dura tion usually depends on the patient's and the physician's motivation. The addition of respiratory gas exchange measurements, maximum oxygen consumption (VO2) or anaerobic threshold, increases the exactness of t he assessment of the exercise limitation in CHF. VO2 maximum provides an objective marker of aerobic capacity and it is biased by neither th e patient nor the physician. This technique, however, requires the pat ient to exercise to exhaustion, and it is somewhat subjective and not indicative of normal daily exercise routine. The anaerobic threshold i s a useful way of evaluating adaptability to submaximal efforts and th e impact of the therapy on the daily performance. Nevertheless, it is significantly influenced by the fitness level and it has a reduced pro gnostic capability compared to VO2 maximum. Submaximal exercise tests discriminate particularly between patients with severe CHF. The major limits are the influence of the patient's motivation and its limited v alidation In terms of reproducibility and prediction in controlled sur veys. Copyright (C) 1996 Elsevier Science Ireland Ltd