Aneurysmal dilation of the right ventricular outflow tract complicates assessment of right ventricular function in patients with repaired tetralogy of Fallot. Tricuspid annular plane systolic excursion is commonly used to estimate ejection fraction. We hypothesised that tricuspid annular plane systolic excursion measured by cardiac MRI approximates global and segmental right ventricular function, specifically right ventricular sinus ejection fraction, in children with repaired tetralogy of Fallot.

Tricuspid annular plane systolic excursion was measured retrospectively on cardiac MRIs in 54 patients with repaired tetralogy of Fallot. Values were compared with right ventricular global, sinus, and infundibular ejection fractions. Tricuspid annular plane systolic excursion was indexed to body surface area, converted into a fractional value, and converted into published paediatric Z-scores.

Tricuspid annular plane systolic excursion measurements had good agreement between observers. Right ventricular ejection fraction did not correlate with the absolute or indexed tricuspid annular plane systolic excursion and correlated weakly with fractional tricuspid annular plane systolic excursion (r=0.41 and p=0.002). Segmental right ventricular function did not appreciably improve correlation with any of the tricuspid annular plane systolic excursion measures. Paediatric Z-scores were unable to differentiate patients with normal and abnormal right ventricular function.

Tricuspid annular plane systolic excursion measured by cardiac MRI correlates poorly with global and segmental right ventricular ejection fraction in children with repaired tetralogy of Fallot. Tricuspid annular plane systolic excursion is an unreliable approximation of right ventricular function in this patient population.

The prevalence of right ventricular dysfunction in idiopathic dilated cardiomyopathy is incompletely studied in children. Furthermore, right ventricular function may signal worse outcomes. We evaluated recently published right ventricular function echocardiographic indices in identifying dysfunction in children with idiopathic dilated cardiomyopathy and the impact of right ventricular dysfunction on long-term prognosis.

A retrospective database review of right ventricular function indices in 30 patients with idiopathic dilated cardiomyopathy was compared with 60 age- and sex-matched controls from January, 2001 until December, 2010. Right ventricular function was assessed by Doppler tissue peak systolic S′, early and late diastolic E′ and A′ waves and isovolumic acceleration at the tricuspid valve annulus; pulsed wave Doppler tricuspid valve inflow E and A waves; right ventricular myocardial performance index; tricuspid annular plane systolic excursion; right ventricular fractional area change.

Right ventricular systolic and diastolic function in idiopathic dilated cardiomyopathy was significantly impaired. All measured indices except for isovolumic acceleration and fractional area change were significantly reduced, with a p-value less than 0.05. There was no right ventricular index predictive of death or transplantation. Patients with poor outcome were significantly more likely to need inotropic support (p-value equal to 0.018), be placed on a ventricular assist device (p equal to 0.005), and have a worse left ventricular ejection fraction z-score (p-value equal to 0.002).

Right ventricular dysfunction is under-recognised in children presenting with idiopathic dilated cardiomyopathy. The need for clinical circulatory support and left ventricular ejection fraction z-score less than minus 8 were primary determinants of outcome, independent of the degree of derangement in right ventricular function.