Objective: The purpose of this study was to evaluate the potential of noninvasive measurement of coronary flow reserve (CFR) by transthoracic Doppler echocardiography (TTDE) for the assessment of myocardial ischemia in the left ventricular (LV) inferior regions.
Background: Although coronary flow assessment by TTDE has been determined for the assessment of perfusion abnormality in the LV anterior regions, the usefulness of this method has not been well investigated in the LV inferior regions.
Methods: We studied 50 patients (43 men; mean age 60 +/- 9 years) with suggested coronary artery disease. CFR in the posterodescending coronary artery (PDA) was calculated as a ratio of hyperemic to basal peak (peak CFR) and mean (mean CFR) flow velocities in the PDA, which were measured by TTDE. CFR values were compared with the results of exercise 201-thallium single photon emission computed tomography.
Results: CFR was successfully measured in 43 of 50 patients (86%). Mean and peak CFR < 2 were shown in 10 of 12 patients with abnormal perfusion in the LV inferior regions, whereas CFR > or = 2 were shown in 30 of 31 patients with normal perfusion. Thus, CFR < 2 in the PDA by TTDE had a sensitivity of 83% and a specificity of 97% for the assessment of perfusion abnormality in the LV inferior regions by 201-thallium single photon emission computed tomography.
Conclusions: CFR in the PDA measured by TTDE provides data equivalent to those obtained by 201-thallium single photon emission computed tomography for myocardial ischemia in the LV inferior regions.