Effort angina, normal coronary angiogram, and dynamic left ventricular obstruction.

The development of dynamic left ventricular outflow tract (LVOT) obstruction (DLVOTO) during effort in patients without hypertrophic cardiomyopathy has been described only a few times and its clinical significance has not been established. This study was undertaken to determine DLVOTO during exercise in patients with angina and normal coronary arteries, and to analyze the potential mechanism involved. The study included 23 patients (60.7 +/- 7.2 years), with effort angina and normal coronary arteries who underwent exercise echocardiography. DLVOTO during exercise appeared in 7 patients (30.4%), with gradients ranging from 31.1 to 67.2 mm Hg (mean 41.3 +/- 12.6). These patients showed more symptoms (effort angina) during testing than the remaining patients (100% vs 47.3%; P = .014). LVOT size was the only predictive factor of DLVOTO (9.1 +/- 0.5 vs 10.3 +/- 1.2 mm/m(2); P = .017). In patients with angina and no epicardical coronary artery disease DLVOTO is associated with a lower LVOT size.