NONINVASIVE ASSESSMENT OF CORONARY FLOW DYNAMICS BEFORE AND AFTER CORONARY ANGIOPLASTY USING TRANSESOPHAGEAL DOPPLER

Recent invasive studies using intracoronary Doppler catheters or guide wires reported improved coronary flow dynamics after successful percutaneous transluminal coronary angioplasty. Transesophageal Doppler enables the measurement of coronary flow velocities within the left anterior descending artery. The present study as designed to test: (1) whether transesophageal Doppler may detect coronary flow velocity changes in patients undergoing angioplasty for left anterior descending artery stenosis, and (2) whether this technique may help to evaluate non-invasively the results of the procedure. Twenty-three patients undergoing angioplasty if the left anterior descending artery were studied by transesophageal Doppler before and <24 hours after the interventional procedure. Coronary flow velocities were measured in the proximal part of the left anterior descending artery with thd use of pulsed Doppler guided by color flow imaging. The degree of stenosis was measured by computerized quantitative coronary arteriography. Coronary flow velocity signals were successfully obtained in 19 of 23 patients (83%). In 16 successful angioplasty procedures, peak diastolic velocity increased from 37 +/- 14 cm/s before angioplasty to 51 +/- 16 cm/s after (p = 0.0001). In the 3 patients in whom angioplasty was unsuccessful transesophageal Doppler showed no significant increase in peak diastolic coronary flow velocity. In a total of 19 angioplasty procedures, a good linear relation was found between the percent changes in coronary flow diastolic velocity and the reduction in the degree of stenosis (r = 0.85; p = 0.0001). All patients with >20% increase in peak diastolic velocity had >40% stenosis reduction. Thus, in patients with stenosis of the left anterior descending artery, transesophageal Doppler shows improvement in coronary flow pattern after successful angioplasty. This method may be useful for noninvasive evaluation of angioplasty results in these patients.