The immediate hemodynamic effects of enhanced external counterpulsation on the left ventricular function

Objectives. Enhanced external counterpulsation (EECP) is a non-invasive therapy with long-term anti-anginal effects offered to patients with refractory angina pectoris. The purpose of the present study was to investigate the effect of EECP on myocardial contractility measured as global longitudinal strain (GLS) during EECP treatment. Design. Patients with known refractory angina were enrolled by invitation and underwent 1 h of EECP treatment. Two-dimensional echocardiography and Doppler echocardiography were performed before and during EECP treatment with 15-minute intervals. The peak diastolic/systolic blood pressure ratio (D/S ratio) was monitored with finger pletysmography. GLS was assessed offline with speckle-tracking software (EchoPAC GE Healthcare USA). Results. Twenty patients were included (mean age 65.0 +/- 8.2; 85% males). During EECP treatment, the systolic function of the left ventricle (LV) expressed in terms of an increasing GLS (-17.9 vs. -16.2% p < 0.05) and a rising cardiac output (5.5 vs. 4.6 l/min p < 0.05) were improved. D/S ratio during the EECP procedure was inversely correlated to LV filling pressure (E/Em ratio r = -0.5 p = 0.035). Conclusions. In conclusion, we demonstrated that EECP improved left ventricular GLS and systolic function in an acute setting. Future studies must explore whether these immediate hemodynamic changes are associated to the clinical effect of EECP treatment.