In-vitro study of the role of anomalous origin of coronary artery in sudden cardiac death

Gianluca Zitti
Università Politecnica delle Marche


Abstract

Sudden cardiac death (SCD) in athletes is often related to anomalies in coronary-arteries origin, which involves the first part of the coronary path and may affect the coronary perfusion. However, these anomalies have not been associated to the processes that induces the SCD. This because coronary perfusion is governed by both the aortic pressure and by the coronary autoregulation, and no symptoms are observed even during intense physical activities. To independently analyze the role of anomalous coronary artery origins, we propose an experimental setup, reproducing the human ascending aorta, aortic sinuses of Valsalva, left, and right coronary arteries, and including a first-hand trileaflet bioprosthetic aortic valve. The physiological flow is generated using a custom designed pulse-duplicator system, simulating cardiac rest and light-exercise conditions. Water has been used in the experiments, modifying accordingly the pump rate, to satisfy the dynamic similarity accordingly to the different viscosity. A specific procedure mimicking the cardiac system autoregulation has been employed to ensure consistent experimental conditions. The experimental setup has been used with two different models, which differ only in the anomalous origin of the left coronary artery from the right sinuses of Valsalva, featuring an intramural course inside the aortic root wall. To understand the accurately the hydrodynamic processes, aortic pressures, coronary pressures, and coronary flows have been measured. These simultaneous measurements allowed us to compare the coronary flow with the driving pressure, to evaluate coronary resistance and to perform the wave-intensity analysis, which revealed destructive phenomena that could be favored by anomalous origin of left coronary.