Coronary flow reserve of normal left anterior descending artery in patients with ischemic heart disease: A transesophageal Doppler study

The aim of this study was to investigate the now reserve of a normal left a nterior descending coronary artery (LAD) in patients with coronary artery d isease (CAD) of other epicardial vessels by Doppler trans-esophageal echoca rdiography(TEE). Thirty-one consecutive patients (age 59 +/- 8 years; 23 me n) referred for TEE were considered. Eighteen patients had CAD and a 70% or greater LAD stenosis (group 1); 13 patients had right and/or circumflex CA D (greater than or equal to 70% stenosis) and normal or minimally diseased LAD (group 2). Ten patients (age 54 +/- 11 years) with normal coronary arte ries constituted group 3. Baseline and adenosine (0.160 mu g/kg per minute intravenously over 60 minutes) flow velocities in the LAD were measured by pulsed Doppler examination during TEE. Peak and mean systolic and diastolic flow velocities were calculated. Adenosine/baseline peak and mean velocity ratios were used for evaluating blood flow reserve In the LAD. Heart rate and arterial pressure values were similar in the 3 groups at baseline and d uring adenosine infusion. Baseline and adenosine-related now velocities wer e comparable in the 3 groups. Peak and mean diastolic velocity ratios were lower in groups 1 and 2 compared with group 3 (peak velocity ratio 1.68 +/- 0.81 and 1.93 +/- 0.35 vs 2.62 +/- 0.32, P < .05; mean velocity ratio 1.71 +/- 0.86 and 2.01 +/- 0.41 vs 2.84 +/- 0.74, P < .05), whereas no differen ces were found between groups 1 and 2. No significant differences were foun d in systolic how velocity ratios among the 3 groups. Patients with ischemi c heart disease have a reduced diastolic how velocity reserve in the LAD in dependent from the presence of significant LAD stenosis. Thus the adenosine TEE-Doppler study should be considered a screening test for CAD rather tha n for LAD disease.