Coronary wave intensity and aortic root hemodynamics in hypertrophic obstructive cardiomyopathy
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Author(s)
Francis, Nadine
Type
Thesis
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
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
Date Issued
2021-12
Date Awarded
2022-03
Copyright Statement
Creative Commons Attribution NonCommercial Licence
License URL
Advisor
Yacoub, Magdi
Parker, Kim
Sponsor
Al Alfi Foundation
Publisher Department
Bioengineering
Publisher Institution
Imperial College London
Qualification Level
Doctoral
Qualification Name
Doctor of Philosophy (PhD)