[Value of an ergometric test for the assessment of cardiac failure]

Cardiac failure is usually defined according to clinical and haemodynamic criteria at rest although these patients are mainly symptomatic on effort. Is it possible to substitute or associate a more "objective" method to the NYHA functional classification such as exercise stress testing? If so, is there a correlation between these two types of classification and resting haemodynamic data; have they any predictive value of the patient's exercise capacity? Twenty two patients with severe cardiac failure (Class III or IV of the NYHA), 18 men and 4 women with a mean age of 58 years, underwent a triangular exercise stress test on a bicycle ergometer to 80 p. 100 or more of their theoretical maximal heart rate. The ergometric parameters chosen for the study were the maximal oxygen consumption or its value when limited by symptoms, the maximal work with respect to weight, the total duration of exercise and the percentage increase in systolic blood pressure. The haemodynamic parameters chosen were pulmonary capillary pressure, systolic index, ejection fraction and the velocity of circumferential fibre shortening. No correlation was found between the NYHA functional class and exercise capacity. A dissociated correlation was observed between exercise capacity and resting haemodynamic data. The best correlation was between systolic index and exercise capacity (work performed corrected for body weight, r = 0.70, p less than 0.01; oxygen consumption, r = 0.60, p less than 0.01). After one month of treatment with a vasodilator (Prazosin) in 10 patients, the duration of exercise increased by 2.2 +/- 0.5 min.(ABSTRACT TRUNCATED AT 250 WORDS)