"Passive exercise" using whole body periodic acceleration: Effects on coronary microcirculation

Background The whole body periodic acceleration (WBPA) system has recently been developed as a "passive exercise" device by providing increased pulsatile shear stress for improvement of endothelial function. This study aimed to investigate the short-term effect of WBPA on coronary flow reserve (CFR) through transthoracic Doppler echocardiography (TTDE) in healthy subjects and patients with coronary artery disease (CAD). Methods This study consisted of 15 healthy subjects and 20 patients with CAD who underwent CFR examination before and immediately after WBPA. The flow velocity in the distal portion of the left anterior descending coronary artery (LAD) was measured with TTDE at baseline and during adenosine infusion. Coronary flow reserve was calculated as the ratio of hyperemic to basal mean diastolic flow velocity. Results The WBPA treatment was completed in all 35 subjects without complications. There were no significant differences in heart rate and systolic blood pressure before and after WBPA. Whole body periodic acceleration increased CFR from 3.3 +/- 1.0 to 3.7 +/- 1.1 in the 35 subjects (P < .001). Coronary angiography showed significant LAD narrowing in 8 of the 20 CAD patients, but WBPA increased CFR from 2.4 +/- 0.4 to 2.7 +/- 0.5 in them as well (P < .01). Conclusions This study demonstrates that WBPA improves CFR in healthy subjects and patients with CAD. (Am Heart J 2010; 159: 620-6.)