Transthoracic Doppler echocardiographic assessment of coronary flow velocity pattern in patient with acute myocardial infarction implies progression of myocardial damage.

Background: Coronary flow velocity (CFV) pattern with a rapid deceleration time of diastolic flow velocity and small average systolic peak velocity immediately after reperfusion implies poor wall-motion recovery in patients with acute myocardial infarction. Microvascular injury has been demonstrated to progress after coronary reperfusion. The purpose of this study was to assess whether CFV 1 day after reperfusion (day 1) may reflect accurately the degree of myocardial damage.

Methods: In the left anterior descending coronary artery in 29 patients with anterior acute myocardial infarction, CFV was measured immediately and 1 day after recanalization using transthoracic Doppler echocardiography, respectively. Regional wall motion was estimated as anterior wall-motion score index (AWMSI) by echocardiography before recanalization and 1 month after the onset of acute myocardial infarction.

Results: Although significant correlation was observed among deceleration time of diastolic flow velocity, average systolic peak velocity, and average peak velocity immediately after reperfusion and 1-month AWMSI (r = -0.62, P < .001; r = -0.61, P < .001; and r = -0.55, P < .01, respectively), much better correlation was demonstrated between those at day 1 and 1-month AWMSI (r = -0.72, P < .0001; r = -0.68, P < .0001; and r = -0.60, P < .001, respectively). Deceleration time of diastolic flow velocity, average systolic peak velocity, and average peak velocity in poor wall-motion recovery group (1-month AWMSI > 2.0, n = 14) were significantly smaller (P < .01, P < .05, and P < .05, respectively) at day 1 compared with those immediately after reperfusion.

Conclusions: CFV pattern assessed by transthoracic Doppler echocardiography at day 1 provides the degree of myocardial damage much more accurately than that immediately after reperfusion. These results may suggest that myocardial damage progresses after reperfusion.