Left Ventricular Non-Compaction in Congenital and Inherited Heart Disease – Structural and Functional Correlations.

Abstract

This thesis examines the structural and functional correlations of LVNC in congenital and inherited cardiac disease. LVNC is an architectural abnormality associated with heart failure, thromboembolism and arrhythmia. Current understanding is confounded by its rarity, lack of consensus on diagnostic criteria and the vast spectrum of associated abnormalities. Cardiac magnetic resonance imaging (CMR) is the gold standard for imaging myocardial architecture and function. Patients with congenital heart disease (CHD) have abnormal haemodynamics that may affect myocardial structure, both due to the initial lesions as well as effects of childhood interventions. In Chapter 3, the survival rates of adults with coarctation of the aorta (CoA) were assessed. We reported significantly improved survival rates in the contemporary era however, there was persistent morbidity due to hypertension, surgical sequelae and associated CHD. In Chapter 4, CMRs in patients with CoA were reviewed from three CHD centres, to assess the effects of LVNC on cardiac function. Chapter 5 explores the effect of LVNC on ventricular function in adults with single ventricle heart disease, where a constellation of lesions leads to a single systemic ventricle. CMR data was reviewed from three CHD centres and demonstrated a high prevalence of LVNC and adverse effects on systolic function. Chapter 6 reports clinical, genetic and imaging data in asymptomatic myotonic dystrophy patients, compared to age and gender matched controls. Abnormalities on CMR including LVNC, myocardial scar and LV dysfunction were prevalent and did not correlate with the genetic abnormality. LVNC also correlated with repolarisation abnormalities. In Chapter 7, a semi-automated quantification technique was developed to measure non-compacted mass from base to apex. This was utilised to compare extent and correlation with function in patients with isolated LVNC. The systolic non-compacted to compacted thickness ratio had the strongest correlation with systolic function, with low inter-observer variability. This body of work reports the lesion-specific variation in prevalence and consequences of LVNC in patients with CHD and inherited cardiac disease. We develop an objective, semi-automated, CMR based quantification technique that will hopefully, inform clinical risk stratification.