Systemic right ventricles rarely show myocardial scars in cardiac magnetic resonance delayed-enhancement imaging.

Objectives: To test the hypothesis that myocardial scars cause systolic dysfunction in patients with transposition of the great arteries and a systemic right ventricle.

Methods: We retrospectively analyzed 20 consecutive patients (10 male, mean age 27.3 years) with a systemic right ventricle who underwent cardiac magnetic resonance imaging with 1.5 T. Cine steady-state free-precession sequences were performed to obtain volumes and function. Phase-sensitive inversion-recovery (PSIR) delayed-enhancement imaging was performed to detect myocardial scars. Tricuspid insufficiency was detected with echocardiography. Furthermore, the presence of arrhythmias and New York Heart Association (NYHA) class were assessed.

Results: Mean ejection fraction of systemic right ventricles was 43 ± 11 %, mean end-diastolic volume index was 111 ± 37 ml/m(2). Delayed-enhancement imaging revealed only one myocardial scar in the wall of a right ventricular aneurysm. All patients but one (95 %) presented with tricuspid insufficiency. Clinically relevant arrhythmias were present in 13/20 patients (65 %). The majority of patients (90 %) were NYHA class I or II. Arrhythmias, tricuspid insufficiency and NYHA class were not associated with right ventricular ejection fraction.

Conclusions: Although right ventricular function was clearly impaired in our patient cohort, there was only one myocardial scar. Our results show that myocardial scarring assessed by PSIR delayed-enhancement imaging is not the underlying pathology of systemic right ventricular failure.