In earlier work, we suggested that the start of the isovolumic contraction period could be detected in arterial pressure waveforms as the start of a temporary pre-systolic pressure perturbation (AICstart, start of the Arterially detected Isovolumic Contraction), and proposed the retrograde coronary blood volume flow in combination with a backwards traveling pressure wave as its most likely origin. In this study, we tested this hypothesis by means of a coronary artery occlusion protocol. In six Yorkshire × Landrace swine, we simultaneously occluded the left anterior descending (LAD) and left circumflex (LCx) artery for 5 s followed by a 20-s reperfusion period and repeated this sequence at least two more times. A similar procedure was used to occlude only the right coronary artery (RCA) and finally all three main coronary arteries simultaneously. None of the occlusion protocols caused a decrease in the arterial pressure perturbation in the aorta during occlusion (P > 0.20) nor an increase during reactive hyperemia (P > 0.22), despite a higher deceleration of coronary blood volume flow (P = 0.03) or increased coronary conductance (P = 0.04) during hyperemia. These results show that the pre-systolic aortic pressure perturbation does not originate from the coronary arteries.

Coronary occlusion, Coronary-aortic interaction, Isovolumic contraction, Pulse wave analysis,
Medical & Biological Engineering & Computing
Erasmus MC: University Medical Center Rotterdam

van Houwelingen, M.J, Merkus, D, te Lintel Hekkert, M, van Dijk, G, Hoeks, A.P.G, & Duncker, D.J.G.M. (2011). Coronary-aortic interaction during ventricular isovolumic contraction. Medical & Biological Engineering & Computing, 49(8), 917–924. doi:10.1007/s11517-011-0770-y