Coronary arterial wave form relates to compression of intramural vasculature controlled by left ventricular end diastolic pressure (1079.11)

Abstract

The aim of this study was to test the hypothesis that left ventricular, LV, end diastolic pressure, LVEDP, contributes to coronary arterial flow waveform since it reflects venous pressure determining microvascular intramural blood volume, MIBV.In 12 patients undergoing coronary catheterization, coronary flow velocity and pressure were measured simultaneously in undiseased vessels with a 0.014‐in dual‐sensor guidewire and LV pressure with an open ended catheter. Measurements were performed under intact autoregulation. The signals were analyzed with wave intensity analysis that allows separating the contribution to the net coronary energy coming from the aorta and from the microcirculation.Both the microcirculatory‐originating waves, generated during contraction (backward compression wave, BCW) and relaxation (backward expansion wave, BEW), were linearly related to LVEDP (p<0.04 for both waves) while both the aortic‐generating waves during contraction and relaxation were not.It is known that LVEDP relates well to coronary venous pressure hence, an increase in LVEDP reduces the pressure head over the microcirculation. Its effect on flow can be compensated by autoregulation but also by increasing MIBV due to increasing microvascular pressure pressure. Increased MIBV results in an enhanced BCW by the elastance effect when the myocardium is contracting and consequently it results also in a higher BEW because of restoration forces due to compliance of the microcirculation. By increasing the energy of the BCW and BEW, LVEDP has an influence on the coronary flow waveform.