Cardiopulmonary exercise testing in asthmatic patients

: In order to obtain objective information on physical fitness of asthmatic patients, mainly those with severe chronic airway obstruction, an incremental exercise test was carried out in 50 asthmatics. A control group of 48 healthy subjects had similar anthropometric characteristics. The 2 groups achieved similar maximal heart rates: 96.1 +/- 8 of predicted rate in the asthmatics as compared to 98.4 +/- 4 in the controls. Maximum oxygen consumption (VO2max), anaerobic threshold and oxygen pulse (VO2/hr) were significantly lower in the asthmatics. While in mild and moderate cases performance was limited by the cardiovascular system, in severe asthmatics the limitation was respiratory. There was no correlation between severity of airway obstruction and cardiac parameters such as oxygen pulse, anaerobic threshold and VO2max. On the other hand, there was good correlation between FEV1% and the dyspnea index (Ve/MVV%). The latter was less than 60% in all asthmatics when measured during exercise testing at 75% of maximal predicted heart rate. It is thus possible for an asthmatic to engage in physical activity of the intensity that can potentially improve his physical fitness. We assume that reduction in cardiac parameters is a result of poor physical fitness related to prolonged inactivity, quite common in asthmatics as a result of inappropriate physical education.