Coronary-aortic interaction during ventricular isovolumic contraction

Med Biol Eng Comput. 2011 Aug;49(8):917-24. doi: 10.1007/s11517-011-0770-y. Epub 2011 Apr 13.

Abstract

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 (AIC(start), 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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Aorta / physiopathology*
  • Coronary Stenosis / physiopathology*
  • Coronary Vessels / physiopathology*
  • Electrocardiography
  • Female
  • Hemodynamics / physiology
  • Hyperemia / physiopathology
  • Myocardial Contraction / physiology*
  • Sus scrofa