Mechanisms of Myocardial Ischemia in Hypertrophic Cardiomyopathy : Insights From Wave Intensity Analysis and Magnetic Resonance

Raphael, Claire E., Cooper, Robert, Parker, Kim H., Collinson, Julian, Vassiliou, Vassilis, Pennell, Dudley J., de Silva, Ranil, Hsu, Li Yueh, Greve, Anders M., Nijjer, Sukh, Broyd, Chris, Ali, Aamir, Keegan, Jennifer, Francis, Darrel P., Davies, Justin E., Hughes, Alun D., Arai, Andrew, Frenneaux, Michael, Stables, Rod H., Di Mario, Carlo and Prasad, Sanjay K. (2016) Mechanisms of Myocardial Ischemia in Hypertrophic Cardiomyopathy : Insights From Wave Intensity Analysis and Magnetic Resonance. Journal of the American College of Cardiology, 68 (15). 1651–1660. ISSN 0735-1097

[img]
Preview
PDF (Published manuscript) - Published Version
Available under License Creative Commons Attribution.

Download (1MB) | Preview

Abstract

Background: Angina is common in hypertrophic cardiomyopathy (HCM) and is associated with abnormal myocardial perfusion. Wave intensity analysis improves the understanding of the mechanics of myocardial ischemia. Objectives: Wave intensity analysis was used to describe the mechanisms underlying perfusion abnormalities in patients with HCM. Methods: Simultaneous pressure and flow were measured in the proximal left anterior descending artery in 33 patients with HCM and 20 control patients at rest and during hyperemia, allowing calculation of wave intensity. Patients also underwent quantitative first-pass perfusion cardiac magnetic resonance to measure myocardial perfusion reserve. Results: Patients with HCM had a lower coronary flow reserve than control subjects (1.9 ± 0.8 vs. 2.7 ± 0.9; p = 0.01). Coronary hemodynamics in HCM were characterized by a very large backward compression wave during systole (38 ± 11% vs. 21 ± 6%; p < 0.001) and a proportionately smaller backward expansion wave (27% ± 8% vs. 33 ± 6%; p = 0.006) compared with control subjects. Patients with severe left ventricular outflow tract obstruction had a bisferiens pressure waveform resulting in an additional proximally originating deceleration wave during systole. The proportion of waves acting to accelerate coronary flow increased with hyperemia, and the magnitude of change was proportional to the myocardial perfusion reserve (rho = 0.53; p < 0.01). Conclusions: Coronary flow in patients with HCM is deranged. Distally, compressive deformation of intramyocardial blood vessels during systole results in an abnormally large backward compression wave, whereas proximally, severe left ventricular outflow tract obstruction is associated with an additional deceleration wave. Perfusion abnormalities in HCM are not simply a consequence of supply/demand mismatch or remodeling of the intramyocardial blood vessels; they represent a dynamic interaction with the mechanics of myocardial ischemia that may be amenable to treatment.

Item Type: Article
Additional Information: Open Access under a Creative Commons Attribution 4.0 International (CC BY 4.0) licence.
Uncontrolled Keywords: angina,cardiovascular magnetic resonance,cmr,left ventricular outflow tract obstruction,perfusion
Faculty \ School: Faculty of Medicine and Health Sciences > Norwich Medical School
Depositing User: Pure Connector
Date Deposited: 07 Oct 2016 16:00
Last Modified: 30 Sep 2019 06:30
URI: https://ueaeprints.uea.ac.uk/id/eprint/60788
DOI: 10.1016/j.jacc.2016.07.751

Actions (login required)

View Item View Item