Simultaneous analysis of wall motion and coronary flow reserve of the left anterior descending coronary artery by transthoracic doppler echocardiography during dipyridamole stress echocardiography.

BACKGROUND

Coronary flow reserve (CFR) can be measured in the left anterior descending artery (LAD) by dipyridamole transthoracic Doppler echocardiography (DTTDE). This information may critically improve the diagnostic accuracy of dipyridamole stress echocardiography, which is limited by moderate sensitivity.

OBJECTIVE

We sought to assess the feasibility and accuracy of value of DTTDE.

METHODS

We evaluated 752 consecutive patients (478 men; mean age, 64.7 years) referred for dipyridamole stress echocardiography. The diastolic velocity in the LAD was continuously monitored with pulsed Doppler at baseline and during hyperemia induced by the infusion of 0.84 mg/kg of dipyridamole. CFR was calculated as the ratio of maximal and basal diastolic velocity; a value < 2 was considered to indicate decreased CFR. Wall motion was assessed semiquantitatively. Coronary angiography was performed in 132 patients the week after DTTDE.

RESULTS

Adequate tracings were obtained in 95% of patients studied (715 of 752). In the subset of 132 patients undergoing coronary angiography, 71 patients (group A) showed a nonsignificant (<70%) and 61 patients (group B) a significant stenosis of the LAD. In group A, 65 had a normal wall-motion response (91.5% specificity) and 19 patients showed a decreased CFR (73.2% specificity; P =.1). In group B, new wall-motion abnormalities were seen in 42 patients (68.8% sensitivity), whereas CFR was decreased in 52 patients (86.8% sensitivity; P <.02).

CONCLUSION

Simultaneous assessment of wall motion and CFR of the LAD with DTTDE was highly feasible and safe. The information about CFR had a significantly higher sensitivity than the analysis of wall motion during dipyridamole stress echocardiography.