The association between myocardial ischemia and myocardial dysfunction in adult patients with systemic right ventricle - A single centre multimodality study.

Background: The exact interaction of factors leading to myocardial dysfunction and fibrosis of the systemic right ventricle (SRV) is not completely understood. Myocardial ischemia and injury associated with a supply-demand mismatch of the pressure overloaded SRV are thought to play an important role, however studies confirming this are lacking.

Methods: Adult SRV patients were included in this single centre cohort study. All patients underwent a comprehensive diagnostic and imaging workup. A two-day stress-rest SPECT was performed to assess myocardial perfusion. SRV ischemia was defined as decreased segmental tracer uptake during exercise with significant improvement at rest. Contrast enhanced cardiac magnetic resonance imaging (CMR) was also performed in a subgroup of patients without contraindication, to assess focal myocardial fibrosis. Differences between patients with and without SRV ischemia were assessed.

Results: Twenty-three SRV patients (15 with transposition of the great arteries after atrial switch procedure and 8 with congenitally corrected transposition of the great arteries; 5 (22%) females; mean age 38 ± 11 years) were included. Seven (30%) patients had SRV ischemia on SPECT. Late gadolinium enhancement on CMR was more common in patients with SRV ischemia (p = 0.002). However, there was no association between SRV ischemia and different echocardiographic or CMR parameters of SRV systolic function, laboratory markers (high-sensitivity troponin I and NT-proBNP) and exercise capacity.

Conclusions: Our multimodality study showed that SRV ischemia in adult SRV patients was associated with more focal myocardial fibrosis, but not with functional or imaging markers of SRV function.