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

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

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.

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.

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.