Blood velocity profile in poststenotic region and velocity waveform of coronary arterial inflow into intramyocardium during coronary artery stenosis in dogs

In anesthetized, open chest dogs, velocity profiles across a vessel were investigated in poststenotic regions of the canine left coronary artery by our 80-channel 20 MHz ultrasound velocimeter. The phasic inflow pattern into myocardium was measured in the septal artery for different severity of stenosis with and without intracoronary adenosine administration. The poststenotic velocity profiles were characterized by a constricted high velocity with diastolic reverse flow near the wall, which may dissipate energy. The velocity waveform of intramyocardial inflow following stenosis exhibited increased systolic retrograde flow with decreased diastolic forward flow, resulting in a remarkable reduction of coronary inflow into the myocardium. Adenosine administration did not improve the stenotic flow reduction by stenosis.