Abstract
Myocardial fibrosis is associated with ventricular arrhythmia. Late gadolinium enhancement cardiac magnetic resonance (LGE-CMR) has been the standard approach to visualise regional myocardial fibrosis. T1 mapping is a novel CMR technique that overcomes the inherent limitation of conventional LGE imaging to assess diffuse fibrosis.The incidence of arrhythmia and sudden death continues to be high despite the benefits of cardiac resynchronisation therapy (CRT) in terms of symptomatic improvement and overall mortality. As myocardial scar can have a structural and functional impact on remodeling, there is a need to further elucidate the effect of CRT on electrophysiology and to better select patients for CRT.
Prospective clinical studies were conducted to assess the ability of CMR scar quantification to
1. predict the risk of ventricular arrhythmia in both ischaemic and non-ischaemic cardiomyopathy (ICM, NICM) patients;
2. predict reverse remodeling following CRT in dyssynchronous heart failure patients.
Investigative studies were also carried out to
1. explore CMR scar characterisation using high-resolution 3-dimensional scar image acquisition in heart failure patients;
2. explore clinical utilisation of T1 mapping for myocardial fibrosis quantification;
3. understand the relationship between scar heterogeneity and substrate for ventricular arrhythmia;
4. explore electrical remodeling effect of CRT in dyssynchronous heart failure patients
The present study is the first to demonstrate that non-contrast native T1 is an independent predictor of ventricular arrhythmia in patients with ICM or NICM. It provides confirmation that the extents of scar and grey zone derived from LGE-CMR are independently associated with ventricular arrhythmia. With regards to prediction of CRT remodeling, focal scar burden detected by LGE-CMR is associated with a poor response to CRT, whereas markers of diffuse interstitial fibrosis were not however predictive of CRT response.
These findings have important clinical implications, lending support for the use of quantitative myocardial scar quantification in selecting patients for complex device therapy.
| Date of Award | 2016 |
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| Original language | English |
| Awarding Institution |
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| Supervisor | Reza Razavi (Supervisor) |