Echocardiographic Characteristics Including Tissue Doppler Imaging After Enhanced External Counterpulsation Therapy

The aim of this study was to echocardiographically assess the effects of EECP (Enhanced External Counterpulsation Therapy) therapy on systolic and diastolic cardiac function. LVEF (left ventricular ejection fraction), ESV (end-systolic volume), EDV (end-diastolic volume), Sm (myocardial systolic wave), Ea (myocardial early diastolic wave), Vp (propagation velocity), E/Ea (peak early diastolic transmitral flow velocity/Ea), E/Vp and diastolic function grade were studied in twenty-five patients before and after 35 hours of EECP. EECP reduced ESV and EDV and increased EF significantly (p=0.018, 0.013, 0.002, respectively) in patients with baseline LVEF≤50%, but not in patients with baseline LVEF>50%. Patients with E/Ea≥14 had a significant reduction in EDV and ESV (p=0.038 and 0.32, respectively) and an increase in LVEF (p=0.007) after EECP, whereas patients with baseline E/Ea<14 had no significant change in these parameters. Similarly, EECP significantly improved ESV, EDV and LVEF (p=0.014, 0.032, 0.027 respectively) in patients with grades II and III of diastolic dysfunction (decreased compliance) at baseline, but not in patients with normal diastolic function or grade I diastolic dysfunction (impaired relaxation). Patients with Ea<7 cm/sec prior to EECP showed significant improvement in EDV, ESV and LVEF after therapy (p=0.024, 0.015, 0.001), while patients with Ea ≥7cm/sec showed no significant change. Similarly, patients with Sm<7cm/sec prior to EECP showed significant improvement in EDV, ESV and LVEF after EECP (p=0.016, 0.017, 0.006), while patients with Sm ≥7cm/sec did not. These results provide new insight into the hemodynamic effectiveness and potential clinical applications of EECP.