Abstract:
Introduction: Paediatric cardiomyopathies are clinically heterogeneous heart muscle disorders responsible for a significant morbidity and mortality. Phenotypes include hypertrophic, dilated, restrictive and arrhythmogenic right ventricular cardiomyopathy. The aetiology is diverse and includes genetic and non-genetic causes. Restrictive cardiomyopathy (RCM) is uncommon in children, accounts for 5% of all cardiomyopathies and has the worst prognosis. Case Report: An eight-year-old girl with a history of syncopal attacks over one year, developed acute dyspnoea. She had a cardiac arrest on admission and died despite resuscitation. Her past clinical records showed an echocardiogram report revealing biventricular diastolic dysfunction, good ventricular systolic function, biatrial dilatation and biventricular hypertrophy. Myocardial biopsy showed mild interstitial fibrosis. She had been diagnosed as having RCM. At autopsy the heart weighted 210g with biatrial dilatation, symmetrical biventricular wall thickening (both right and left ventricular wall thickness 18mm) and subendocardial fibrosis. The histology of the myocardium revealed hypertrophy and mild disarray of myocytes and interstitial fibrosis. There was no amyloid or iron deposits, granulomas or tissue eosinophilia. Cause of death was ascertained as acute cardiac failure following cardiomyopathy. Discussion and Conclusion: RCM is a disease characterized by a primary decrease in ventricular compliance resulting in diastolic failure. This patient had classic functional and structural features of RCM which include biventricular diastolic dysfunction, good ventricular systolic function and biatrial dilatation. An increased biventricular wall thickness which is a classic feature of hypertrophic cardiomyopathy (HCM) suggests clinical overlap with HCM. Mixed phenotype of RCM/HCM has shown significant transplant free survival compared to pure RCM. Relatively less symptoms and longer survival in this child could be explained by mixed RCM/HCM phenotype.
