Effects of enhanced external counterpulsation on Renin-Angiotensin System in experimental AMI

The effects of enhanced external counterpulsation (EECP) on Renin-Angiotensin System (RAS) activity in acute MT (AMI) were studied in 18 dogs divided into three groups: Control (N=6), AMI (N=6) and AMI+EECP (N=6). The LAD in AMI groups was occluded, with EECP performed 60-180 minutes post occlusion in the AMI+EECP group. Plasma renin activity, angiotensin II, angiotensin converting enzyme were measured at baseline, 60, 120, and 180 minutes. Baseline values were similar. AMI significantly increased RAS activity and this activity increased with occlusion time. However, EECP reversed RAS changes towards control values. EECP decreases in RAS activity may be mediated by hemodynamic effects and shear stress induced increase in nitric oxide, and may potentially alter cardiovascular remodeling post AMI.