Related Experiment Video

Updated: Jun 2, 2026

Cardiac Loading using Passive Left Atrial Pressurization and Passive Afterload for Graft Assessment
08:49

Cardiac Loading using Passive Left Atrial Pressurization and Passive Afterload for Graft Assessment

Published on: August 2, 2024

Coronary-aortic interaction during ventricular isovolumic contraction

Marc J van Houwelingen1, Daphne Merkus, Maaike Te Lintel Hekkert

  • 1Experimental Cardiology, Thoraxcenter, Cardiovascular Research Institute COEUR, Erasmus MC, University Medical Center Rotterdam, Dr Molewaterplein 50, P.O. Box 2040, 3000 CA, Rotterdam, The Netherlands. m.vanhouwelingen@erasmusmc.nl

Medical & Biological Engineering & Computing
|April 14, 2011
PubMed

Insights

The pre-systolic aortic pressure perturbation, previously thought to originate from coronary arteries, is not caused by them. Coronary artery occlusion did not affect this pressure wave, refuting the initial hypothesis.

Area of Science:

  • Cardiovascular Physiology
  • Hemodynamics
  • Coronary Circulation

Background:

  • The start of isovolumic contraction is potentially detectable in arterial pressure waveforms as a pre-systolic pressure perturbation (AICstart).
  • Previous hypotheses suggested retrograde coronary blood flow and pressure waves as the origin of AICstart.

Purpose of the Study:

  • To test the hypothesis that AICstart originates from the coronary arteries.
  • To investigate the relationship between coronary blood flow dynamics and aortic pressure perturbations.

Main Methods:

  • Performed coronary artery occlusion protocols in six swine (LAD, LCx, RCA, and all three simultaneously).
  • Measured simultaneous aortic pressure waveforms and coronary blood flow.
  • Analyzed pressure perturbations during occlusion and reactive hyperemia.

Main Results:

  • Coronary artery occlusions did not alter the aortic pressure perturbation during occlusion or reactive hyperemia.
  • Despite significant changes in coronary blood flow deceleration and conductance, the AICstart remained unaffected.
  • Statistical analysis showed no significant changes in pressure perturbation (P > 0.20 for occlusion, P > 0.22 for hyperemia).

Conclusions:

  • The pre-systolic aortic pressure perturbation (AICstart) does not originate from the coronary arteries.
  • The proposed mechanism involving retrograde coronary blood flow is refuted by these findings.
  • Further research is needed to identify the true origin of the AICstart.

More Related Videos

Cardiac Response to β-Adrenergic Stimulation Determined by Pressure-Volume Loop Analysis08:05

Cardiac Response to β-Adrenergic Stimulation Determined by Pressure-Volume Loop Analysis

Published on: May 19, 2021

Related Concept Videos

Cardiac Cycle01:29

Cardiac Cycle

The cardiac cycle refers to the sequence of events that occur in the heart from the beginning of one heartbeat to the next. It's characterized by alternating periods of contraction (systole) and relaxation (diastole) of the heart muscles.
During the cardiac cycle, blood flow through the heart is regulated entirely by changing pressure gradients. This sequence of events begins with the heart in a state of total relaxation, known as mid-to-late diastole, during which blood passively flows from...
Physiology of the Heart: The Cardiac Cycle01:18

Physiology of the Heart: The Cardiac Cycle

The cardiac cycle describes the events from one heartbeat to the next. It includes three main phases: diastole, atrial systole, and ventricular systole, all driven by changes in chamber pressures and the function of heart valves.
Diastole: The Relaxation Phase
During diastole, all four heart chambers relax. The atrioventricular (AV) valves open, and the semilunar valves close. This phase sees the lowest chamber pressures, promoting ventricular filling. Venous blood enters the heart through the...
The Cardiac Cycle01:13

The Cardiac Cycle

The heart beats rhythmically in a sequence called the cardiac cycle—a rapid coordination of contraction (systole) and relaxation (diastole).
The Process
Electrical signals—sent from the sinoatrial (SA) node in the right atrial wall to the atrioventricular (AV) node between the right atrium and right ventricle—cause both atria to simultaneously contract. When the signal reaches the AV node, it pauses for approximately a tenth of a second, allowing the atria to contract and empty blood into the...
Aortic Regurgitation I: Introduction01:15

Aortic Regurgitation I: Introduction

IntroductionAortic regurgitation is characterized by the backward flow of blood from the aorta into the left ventricle during diastole and arises from the improper closure of the aortic valve. This condition results in left ventricular volume overload and can stem from both acute and chronic etiologies, each contributing uniquely to the disease's progression and symptomatology.Acute and Chronic CausesAcute aortic regurgitation often results from events that suddenly impair the integrity of the...
Coronary Circulation01:21

Coronary Circulation

The heart, an organ critical to survival, gets nourishment not from the blood it pumps but from a separate circulation system known as coronary circulation. This is the shortest circulation in the body and is responsible for supplying the heart with the nutrients it needs to function effectively.
Coronary circulation begins at the base of the aorta, where two main arteries arise—the left and right coronary arteries. These arteries encircle the heart in the coronary sulcus and supply the...
Cardiac Output II: Effect of Stroke Volume on Cardiac Output01:22

Cardiac Output II: Effect of Stroke Volume on Cardiac Output

Cardiac output (CO), the amount of blood the heart pumps per minute, is a parameter in cardiovascular physiology determined by stroke volume and heart rate. Stroke volume, the amount of blood pushed from one of the ventricles per heartbeat, is influenced by preload, afterload, and contractility.
Preload
Preload refers to the initial elongation of the cardiac myocytes before contraction and is related to the volume of blood filling the heart at the end of diastole, or end-diastolic volume. The...