EVALUATION OF INTRAMYOCARDIAL CORONARY BLOOD-FLOW WAVE-FORM DURING INTRAAORTIC BALLOON PUMPING IN THE ABSENCE OR PRESENCE OF CORONARY STENOSIS

Our aim was to evaluate the effects of intraaortic balloon pumping (IA BP) on the blood velocity waveform in the absence or presence of coron ary artery stenosis, Using anesthetized open-chest dogs, the septal ar terial blood flow velocities were measured with a 20 MHz 80-channel ul trasound pulsed Doppler velocimeter in the absence (n = 5) or presence (n = 3) of left main coronary artery stenosis. The blood velocity wav eform was analyzed by calculating the systolic retrograde velocity int egral (SR) and the diastolic antegrade velocity integral (DA). A slosh ratio was defined as SR/DA. The left anterior descending arterial flo w (CBF), aortic pressure (AoP), and poststenotic distal coronary press ure (DIP) were also measured simultaneously. We compared the effect of IABP on the velocity waveforms in the absence and in the presence of coronary artery stenosis. In the absence of stenosis, IABP increased D iP during diastole and augmented DA while it also increased SR. IABP a ugmented the net CBF because of the greater increase in DA than SR. In the presence of stenosis, however, IABP did not increase DiP and resu lted in no significant effect on the net CBF.