Abstract 1744: Left Anterior Descending Coronary Artery Flow Dynamics in Anterior Myocardial Infarction and Primary Angioplasty: Reduced in Early Phase and Hyperemic Pre-Discharge
Microcirculatory function in patients with acute myocardial infarction (MI) and primary angioplasty (PCI) is dynamic and affects coronary flow. Although, TIMI and myocardial blush grades provide semi-quantitative flow evaluation after primary PCI, serial and quantitative flow evaluation is still lacking.
Aim: Serial assessment of left anterior descending coronary artery (LAD) flow in patients with anterior MI, immediately after primary PCI and pre-discharge, relation to microcirculatory function and comparison to normal subjects.
Methods: Velocities in the LAD were recorded within 6 hours after PCI and 1 week later in 36 patients presenting with acute anterior MI. A control group of 96 normal subjects was used as a reference of normal LAD flow. Sampling of LAD velocity was obtained from trans-thoracic Doppler. Diastolic deceleration time< 600 msec, indicating impaired microcirculation was found in 16 subjects. Flow in the LAD was estimated using heart rates, Doppler time velocity integrals and LAD color Doppler diameters.
Results: Diastolic LAD flow immediately after PCI in subjects with microcirculatory impairment, 29 ± 21 ml/min was lower than in those without, 35 ± 11ml/min, p < 0.05, and lower than normal 36 ± 22, p < 0.05. One week after PCI, diastolic flow in the LAD increased to 59 ± 38 ml/min in patients with microcirculatory impairment, p < 0.03, and to 50 ± 13 ml/min in those without, p < 0.04. Diastolic LAD flow pre-discharge in both post-MI groups, were higher than normal, p < 0.05.
After primary-PCI, flow in the LAD is dynamic.
In the presence of microcirculatory impairment, early LAD flow is reduced.
Pre-discharge, LAD flow increases and is higher than normal, indicating hyperemic state.