Background The temporal behavior of the coronary microcirculation in acute myocardial infarction may affect outcome. Diastolic deceleration time and early systolic flow reversal derived from coronary artery blood flow velocity patterns reflect microcirculatory function.
Objectives To assess left anterior descending coronary artery flow velocity patterns using Doppler transthoracic echocardiography after primary percutaneous coronary intervention, in patients with anterior AMI.
Methods Patterns of flow velocity patterns of the LAD were obtained using transthoracic echocardiography-Doppler in 31 consecutive patients who presented with anterior AMI. Measurements were done at 6 hours, 36–48 hours, and 5 days after successful PPCI. Measurements of DDT and pressure half times (Pt½), as well as observation for ESFR were performed.
Results In the first 2 days following PPCI, the average DDT, 600 ± 340 msec, were shorter than on day 5, 807 ± 332 msec (P < 0.012). FVP in the first 2 days were dynamic and bidirectional: from short DDT (< 600 msec) to long DDT (> 600 msec) and vice versa. On day 5 most DDTs became longer. Pt½ at 6 hours was not different than at day 2 (174 ± 96 vs. 193 ± 99 msec, P = NS) and became longer on day 5 (235 ± 98 msec, p = 0.012). Bidirectional patterns were also observed in the ESFR in 6 patients (19%) at baseline, in 4 (13%) at 36 hours, and in 2 (6.5%) on day 5 after PPCI.