Clinical significance of dynamic left ventricular outflow tract obstruction during dobutamine stress echocardiography in women with suspected coronary artery disease

Background: Although dobutamine stress echocardiography (DSE) is frequently associated with dynamic left ventricular outflow tract obstruction (DLVOTO), little is known about its clinical significance in women with suspected coronary artery disease (CAD). Methods and Results: One hundred and two female patients (57±10 years) who underwent DSE as part of the Korean women’s chest pain registry study were included. Doppler echocardiography was performed during DSE to assess the presence of DLVOTO. Patients with DLVOTO (n=52) were older than those without DLVOTO (n=50; P=0.001). Hypertension was more prevalent in patients with DLVOTO (P=0.02). Patients with DLVOTO had smaller LV diameter, but higher LV mass index and relative wall thickness (P<0.05 for all). LV diastolic function (as reflected by late diastolic velocity, deceleration time of early diastolic velocity [E], and ratio of E velocity to early diastolic mitral annular velocity), was worse in patients with DLVOTO (P<0.05 for all). Patients with DLVOTO had shorter exercise time (P=0.02) and lower amount of work (P=0.04) than patients without DLVOTO. DSE-provoked DLVOTO was not related to the presence of CAD in these patients. Conclusions: In Korean women with suspected CAD, DSE-provoked DLVOTO is correlated with LV concentric remodeling and LV diastolic dysfunction, and may be associated with limited exercise tolerance and symptoms of chest pain.