Water Hammer Shock in Coronary Arteries: A n Acoustic Analysis

Background   In coronary artery disease, the mechanisms underlying atherosclerosis initiation and progression remain incompletely understood. Our research conceptualizes the cardiovascular system as an integrated network of pumps and pipes.  Leveraging principles of fluid mechanics, we explore abnormal flow patterns that compromise endothelial integrity in vascular and pump-like components including the water hammer phenomenon. Consequently, our investigation focused on the pressure wave reflections arising from the water hammer event and their potential parallels in coronary flow dynamics.

Methods         This investigation is organized in a four-phase framework. The first phase establishes the fundamental principles of fluid mechanics, defining critical parameters for coronary flow dynamics. The second phase integrates acoustics concepts by analyzing in-vitro air particles movement in a tube. The third phase applies these acoustic insights to in vivo coronary flow. The final phase translates these insights into new coronary physiology standards. 

Results            The acoustic coronary flow investigations pinpointed pockets of high or moderate contrast concentrations, which might correspond to compression and rarefaction zones, respectively. Compression antinodes were correlated to severe stenotic lesions, most likely due to rapid shifts from low-pressure diastolic flow to high-pressure systolic surges, resulted in turbulence and intimal disruption. Rarefaction antinodes were possibly correlated with milder lesions, due to de-escalating transitions from high systolic pressure to lower diastolic pressure, resulting in less turbulence and milder injury. The areas of nodes remained avoided of lesion because of possibly no disorganized flow. Based on locations of these antinodes and nodes, a coronary acoustic action map was constructed, enabling the identification of existing lesions, forecasting the progression of current lesions, and predicting the development of future lesions.

Conclusion     The results suggested that intimal injury was induced by retrograde pressure waves from a water hammer event governed by acoustic principles. These preliminary findings represented the possible first evidence linking water hammer-induced pressure dynamics to coronary lesion development and progression.