Assessment of coronary flow reserve with transthoracic Doppler echocardiography: Comparison with intracoronary Doppler method

To evaluate the feasibility and usefulness of transthoracic Doppler echocar diography (TTDE) as a non-invasive method in recording distal anterior desc ending (LAD) coronary flow velocity, we compared coronary flow reserve (CFR ) measured by TTDE with measurements by intracoronary Doppler wire (ICDW). Twenty-one patients without LAD stenosis were studied. ICDW performed at ba seline and after intracoronary injection of 18 mu g adenosine. TTDE was per formed at baseline and after intravenous adenosine (140 mu g/kg/min for 2 m in). Adequate Doppler recordings of coronary flow velocities during systole were obtained in 14 of 21 study patients (67%) and during diastole in 17 ( 81%) patients. Baseline and hyperemic peak diastolic flow velocities measur ed by TTDE were significantly smaller than those obtained by ICDW (p<0.05). However, diminishing trends of diastolic and systolic velocity ratio after hyperemia were similarly observed in both methods. CFR obtained by TTDE (3 .0+/-0.5), was higher than the value calculated by ICDW (2.5+/-0.4). There were significant correlations between the values obtained by the two method s (r=0.72, p less than or equal to 0.01). It is concluded that TTDE is a fe asible method in measuring coronary flow velocity and appears to be a promi sing non-invasive method in evaluating CFR.