Exercise testing in patients with valvular diseases.
Sixty-eight patients with valvular diseases (VD) were subjected to maximal, symptoms limited, exercise testing (ET) using a cycloergometer. The exercise was limited in 82% of the valvular patients by dyspnea attributed to pulmonary capillary pressure rising, even if in the 20 patients with mitral stenosis the relation between the effort intensity and mitral valve area (MVA) (echo) was absent (r = 0.26). Myocardial aerobic impairment (MAI) was absent in 17%, mild in 41%, moderate in 39% and severe in 3% of the patients with VD. It was considered overestimated, the effort being stopped, in 2/3 of the patients, before a heart rate of 85% of maximal heart rate (MxHR) was reached. This suggests that the patients with VD unlike coronary patients, still have a reserve of increasing MVO2 when exercise is stopped. Even in the above condition, the average difference between functional aerobic impairment (FAI) and MAI was 6% for NYHA I, 10.6% for NYHA II and 17% for NYHA III showing a physical deterioration in patients above the limit imposed by the valvular disease itself. ST segment depression of 1 mm or more at 0.08 s after J point was registered in 30% of the patients. Due to the insufficient rise of the heart rate (HR) in the majority (2/3) of the patients with VD, these data probably underestimate the myocardial ischemia. Consequently other stress testings whose main action is not the increase of HR and MVO2 i.e., dypiridamole and adenosine, are preferred in the investigation of myocardial ischemia in the patients with VD.