Coronary wave intensity and aortic root hemodynamics in hypertrophic obstructive cardiomyopathy

Abstract

Introduction: Hypertrophic Obstructive Cardiomyopathy (HOCM) is a genetic cardiomyopa- thy that causes heart failure and sudden death. One of its common features is the perturbed hemodynamics of the Aortic Root (AR) and the coronary arteries originating from the AR. In this study, we investigate coronary and AR hemodynamics, as well as their interaction in HOCM patients. For Coronary Hemodynamics: We developed a Wave Intensity Analysis Matlab program to investigate the hemodynamics of the Left Anterior Descending artery (LAD), originating from the Left Coronary Sinus (LCS). We then applied the Maximum Entropy Method to identify significant peaks in 10 HOCM patients and 11 Controls. Our results show that HOCM patients have perturbed dominant and secondary waves, which could act as supplementary predictor markers of the disease due to their absence in Controls. For AR Hemodynamics: We developed a Matlab program to study the hemodynamics of the AR and its 3 sinuses of Valsalva, using Cardiac Magnetic Resonance imaging in 10 HOCM patients and 13 Controls. Our results show that the AR jet in HOCM patients is asymmetric and skewed away from the LCS, with increased fractional area of backward flow in the LCS. For Coronary and AR Interaction: We investigate possible interactions between waves in the LAD and the perturbed hemodynamics of the AR, by studying various linear correlation tests within 10 HOCM patients. Our results show that the increased fractional area of backward flow in the LCS is the most significant variable that is linearly correlated with the appearance of waves only found in HOCM. Conclusion: Our results suggest the presence of an interaction between the LAD and LCS, which was not clearly demonstrated before. Such results do not demonstrate physical causes but suggest further investigations to elucidate the mechanisms involved in such complex interaction and pathobiology of HOCM