[Cardiopulmonary responses to exercise in patients with hypertrophic obstructive cardiomyopathy].

Objective: The aim of this study was to observe the cardiopulmonary responses to exercise in patients with hypertrophic obstructive cardiomyopathy (HOCM) and to evaluate the effectiveness of percutaneous transluminal septal myocardial ablation (PTSMA).

Methods: Eighty-five patients with HOCM received cardiopulmonary exercise test using a cycle ergometer. Twenty sedentary volunteers served as controls. All patients underwent maximal cardiopulmonary exercise test without severe complication. Among them 20 patients received PTSMA, and the cardiopulmonary exercise test was repeated 1 - 3 months and 6 - 12 months after the intervention.

Results: The peak oxygen uptake attained on the test, maximum oxygen pulse and anaerobic threshold were reduced in patients with HOCM compared with the control group (P < 0.01). Patients in New York Heart Association class I had higher cardiopulmonary indexes than those in classes II and III. For those with PTSMA there was a significant increase in peak oxygen uptake, maximum oxygen pulse and anaerobic threshold 1 - 3 months after PTSMA (P < 0.05), but there was no further change after 6 - 12 months.

Conclusion: The results show that cardiopulmonary exercise testing for patients with HOCM is safe. There are severe abnormalities in exercise responses during incremental upright exercise in HOCM patients. PTSMA is a promising nonsurgical procedure for subjective exercise limitation in patients with HOCM. Long-term observations for the patients with this procedure are necessary.