Right ventricular hypertrophy and diastolic dysfunction in arterial switch patients without pulmonary artery stenosis

OBJECTIVE: To assess pulmonary flow dynamics and right ventricular (RV) function in patients without significant anatomical narrowing of the pulmonary arteries late after the arterial switch operation (ASO) by using magnetic resonance imaging (MRI). METHODS: 17 patients (mean (SD), 16.5 (3.6) years after ASO) and 17 matched healthy subjects were included. MRI was used to assess flow across the pulmonary trunk, RV systolic and diastolic function, and RV mass. RESULTS: Increased peak flow velocity (>1.5 m/s) was found across the pulmonary trunk in 14 of 17 patients. Increased RV mass was found in ASO patients: 14.9 (3.4) vs 10.0 (2.6) g/m2 in normal subjects (p