In a prospective study,enhanced external counterpulsation (EECP) was performed for 1 hour each day for 35 days in 47 patients,mean age 61 6 8 years,with prior coronary revascularization who had chronic refractory angina pectoris despite antianginal drugs and who were not candidates for further coronary revascularization.Compared with baseline values,EECP significantly improved anginal symptoms,dyspnea on exertion,and quality of life after 35 days of treatment (p< 0.001) and at l-year follow up (p<0.001).Compared with the baseline value of 653 ± 249 feet,EECP significantly improved the 6-minute walking distance to 1025 ± 234 feet after 35 days of treatment (p<0.001) and to 1040 ± 221 feet at l-year follow up (p<0.001).However,EECP did not significantly affect left ventricular ejection fraction,left ventricular end-diastolic and end-systolic dimensions,left ventricular end-diastolic and end-systolic volumes,E/A ratio,isovolumic relaxation time,and deceleration time measured by two2-dimensional and Doppler echocardiography.