Stress perfusion CMR in hypertrophic cardiomyopathy: comparison with late gadolinium enhancement

Villa, Adriana; Bettencourt, Nuno; Zarinabad, Niloufar; Baydes, R Hinojar; Nagel, Eike; Chiribiri, Amedeo

doi:10.1186/1532-429x-16-s1-p324

Cited by 3 publications

(3 citation statements)

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“…Modelling ischaemia as septal is reinforced by the evidence that septal ischaemia in HCM is particularly common in previous works. 39–41 Specifically, visual examples of large perfusion defects involving the septum of HCM patients can be seen in these other studies. 40 , 42 Perfusion impairment is associated with hypertrophy, 4 further motivating the inclusion of ischaemia in the region of septal hypertrophy in our reconstruction of human HCM ventricles.…”

Section: Resultsmentioning

confidence: 85%

Mechanisms of ischaemia-induced arrhythmias in hypertrophic cardiomyopathy: a large-scale computational study

Coleman,

Doste,

Ashkir

et al. 2024

Cardiovascular Research

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Aims Lethal arrhythmias in hypertrophic cardiomyopathy (HCM) are widely attributed to myocardial ischaemia and fibrosis. How these factors modulate arrhythmic risk remains largely unknown, especially as invasive mapping protocols are not routinely used in these patients. By leveraging multiscale digital-twin technologies, we aim to investigate ischaemic mechanisms of increased arrhythmic risk in HCM. Methods and Results Computational models of human HCM cardiomyocytes, tissue and ventricles were used to simulate outcomes of phase 1A acute myocardial ischaemia. Cellular response predictions were validated with patch-clamp studies of human HCM cardiomyocytes (n=12 cells, N=5 patients). Ventricular simulations were informed by typical distributions of subendocardial/transmural ischaemia as analysed in perfusion scans (N=28 patients). S1-S2 pacing protocols were used to quantify arrhythmic risk for scenarios in which regions of septal obstructive hypertrophy were affected by (i) ischaemia, (ii) ischaemia and impaired repolarisation, and (iii) ischaemia, impaired repolarisation, and diffuse fibrosis. HCM cardiomyocytes exhibited enhanced action potential and abnormal effective refractory period shortening to ischaemic insults. Analysis of c.a. 75,000 re-entry induction cases revealed that the abnormal HCM cellular response enabled establishment of arrhythmia at milder ischaemia than otherwise possible in healthy myocardium, due to larger refractoriness gradients that promoted conduction block. Arrhythmias were more easily sustained in transmural than subendocardial ischaemia. Mechanisms of ischaemia-fibrosis interaction were strongly electrophysiology dependent. Fibrosis enabled asymmetric re-entry patterns and break-up into sustained ventricular tachycardia. Conclusions HCM ventricles exhibited an increased risk to non-sustained and sustained re-entry, largely dominated by an impaired cellular response and deleterious interactions with the diffuse fibrotic substrate.

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Section: Resultsmentioning

confidence: 85%

Mechanisms of ischaemia-induced arrhythmias in hypertrophic cardiomyopathy: a large-scale computational study

Coleman,

Doste,

Ashkir

et al. 2024

Cardiovascular Research

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“…Two studies reported perfusion defects [ 30 ] and exercise wall motion abnormalities (WMAs) [ 32 ] to be most frequently septal, which is consistent with the septum and anterior LV wall being the most frequently hypertrophied regions in HCM [ 64 ]. In another cohort, the septum and inferior segments were most affected by perfusion defects [ 101 ].…”

Section: Relationships Between Markers Of Disease Severity and Ischae...mentioning

confidence: 88%

Mechanisms and prognostic impact of myocardial ischaemia in hypertrophic cardiomyopathy

Coleman

Ashkir

Raman

et al. 2023

Int J Cardiovasc Imaging

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Despite the progress made in risk stratification, sudden cardiac death and heart failure remain dreaded complications for hypertrophic cardiomyopathy (HCM) patients. Myocardial ischaemia is widely acknowledged as a contributor to cardiovascular events, but the assessment of ischaemia is not yet included in HCM clinical guidelines. This review aims to evaluate the HCM-specific pro-ischaemic mechanisms and the potential prognostic value of imaging for myocardial ischaemia in HCM. A literature review was performed using PubMed to identify studies with non-invasive imaging of ischaemia (cardiovascular magnetic resonance, echocardiography, and nuclear imaging) in HCM, prioritising studies published after the last major review in 2009. Other studies, including invasive ischaemia assessment and post-mortem histology, were also considered for mechanistic or prognostic relevance. Pro-ischaemic mechanisms in HCM reviewed included the effects of sarcomeric mutations, microvascular remodelling, hypertrophy, extravascular compressive forces and left ventricular outflow tract obstruction. The relationship between ischaemia and fibrosis was re-appraised by considering segment-wise analyses in multimodal imaging studies. The prognostic significance of myocardial ischaemia in HCM was evaluated using longitudinal studies with composite endpoints, and reports of ischaemia-arrhythmia associations were further considered. The high prevalence of ischaemia in HCM is explained by several micro- and macrostructural pathological features, alongside mutation-associated energetic impairment. Ischaemia on imaging identifies a subgroup of HCM patients at higher risk of adverse cardiovascular outcomes. Ischaemic HCM phenotypes are a high-risk subgroup associated with more advanced left ventricular remodelling, but further studies are required to evaluate the independent prognostic value of non-invasive imaging for ischaemia.

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“…A number of potential mechanisms have been suggested for microvascular dysfunction in HCM including decreased arteriolar density, fibrosis, myofibril disarray and elevated LV end-diastolic pressure (LVEDP) [38,39]. Reduced diastolic compliance secondary to progressive hypertrophy and disarray increasing stiffness may lead to reduced coronary micro-circulation filling [40].…”

Section: Coronary Artery Diseasementioning

confidence: 99%

Sleep Disordered Breathing in Hypertrophic Cardiomyopathy—Current State and Future Directions

Venkataraman

Karim

Rajendran

et al. 2020

JCM

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Hypertrophic cardiomyopathy (HCM) is the most common inherited cardiomyopathy and sleep disordered breathing (SDB) is a treatable risk factor that has been seen to occur concurrently, and is known to propagate mortality and morbidity in a number of cardiovascular disease states including heart failure, and indeed hypertrophic cardiomyopathy. In this review, we summarize past studies that explored the simultaneous occurrence of HCM and SDB, and the pathophysiology of SDB in relation to heart failure, arrhythmias, cardiac ischemia and pulmonary hypertension in HCM. The current therapeutic modalities, with the effect of obstructive sleep apnea (OSA) treatment on HCM, are then discussed along with potential future directions.

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Stress perfusion CMR in hypertrophic cardiomyopathy: comparison with late gadolinium enhancement

Cited by 3 publications

References 0 publications

Mechanisms of ischaemia-induced arrhythmias in hypertrophic cardiomyopathy: a large-scale computational study

Mechanisms of ischaemia-induced arrhythmias in hypertrophic cardiomyopathy: a large-scale computational study

Mechanisms and prognostic impact of myocardial ischaemia in hypertrophic cardiomyopathy

Sleep Disordered Breathing in Hypertrophic Cardiomyopathy—Current State and Future Directions

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