Evaluation of left ventricular systolic and diastolic regional function after enhanced external counter pulsation therapy using strain rate imaging

Abstract

Enhanced external counter pulsation (EECP) is a non-invasive and non-pharmacological therapy for patients with symptomatic coronary artery disease (CAD). There are, however, insufficient data to support the effectiveness of EECP in improving the myocardial mechanical properties of patients with refractory stable angina. We aimed to assess the effects of EECP on myocardial mechanical properties and cardiac functions in CAD patients not eligible for surgical or percutaneous revascularization procedures. Twenty patients in New York Heart Association (NYHA) functional Class III and IV angina were evaluated. The mean age of the patients was 63 +/- 9 years, and 65% were male. A comprehensive echocardiographic study including an evaluation of the tissue Doppler-based parameters of systolic and diastolic functions was performed before and after the termination of the protocol. EECP was carried out 1 h per day, 5 days per week, for 7 weeks. EECP resulted in a significant increase in peak late diastolic transmitral inflow velocity (0.75+/-0.14 vs. 0.83+/-0.20 m/s, P<0.05), propagation velocity (42.35+/-6.25 vs. 46.00+/-5.68 cm/s, P<0.05), peak early diastolic velocity of mitral annulus (5.35+/-1.79 vs. 5.95+/-1.10 cm/s, P<0.05), peak systolic velocity (2.51+/-0.28 vs. 2.67+/-0.26, P<0.05), and early diastolic velocity (3.24+/-0.18 vs. 3.52+/-0.26 cm/s, P<0.01) of all middle segments, peak late diastolic velocity of all basal (4.48+/-0.58 vs. 4.75+/-0.70 cm/s, P<0.05) and middle segments (2.82+/-0.66 vs. 3.25+/-0.46 cm/s, P<0.01), peak systolic strain rate of all basal (0.76+/-0.07 vs. 0.99+/-0.08 1/s, P=0.001) and middle segments (0.75+/-0.09 vs. 0.94+/-0.09 1/s, P<0.001), peak systolic strain of basal (11.64+/-1.51 vs. 13.97+/-1.52%, P<0.01) and middle segments (11.81+/-1.15 vs.13.73+/-1.57%, P<0.001), and left ventricular (LV) ejection fraction (40.25+/-12.72 vs. 46.25+/-12.97%, P<0.001).There was also a significant decrease in the ratios of transmitral E/A (0.92+/-0.41 vs. 1.08+/-0.46, P<0.05) and E/Ea (12.61+/-4.22 vs. 15.44+/-6.96, P<0.05) after EECP therapy. A significant reduction in NYHA angina class (>or=1 angina class) was seen in the patients, who completed treatment. EECP therapy seemed to improve both regional and global LV systolic and diastolic functions in patients with chronic angina pectoris.