Diastolic disfunction in systemic right ventricle: a cardiac magnetic resonance study on atrial function in congenital corrected transposition of great arteries patients

Abstract

Abstract Background congenital corrected transposition of great arteries (ccTGA) leads to systemic position of the right ventricle (sRV). Patients with ccTGA are usually asymptomatic in the first decades of life but over time sRV will fail to support elevated systemic pressure, possibly leading to systolic heart failure (HF) in adulthood. Several factors have been associated with sRV failure and worse prognosis such as tricuspid valve dysfunction, conduction abnormalities, previous surgery due to associated lesions. However, little is known about diastolic function in sRV. We hypothesize that diastolic dysfunction characterizes sRV pathophysiology, therefore an accurate evaluation of diastolic function would allow a better assessment and risk stratification of patients. The present study aims to investigate the diastolic function in patients with ccTGA by assessing left atrial (LA) morpho-functional parameters. Methods we retrospectively examined Cardiac Magnetic Resonance (CMR) imaging of 33 ccTGA patients clinically referred to our Center between April 2014 and December 2022. ccTGA patients were matched based on sex and age with a healthy volunteer population (control group) and a group of patients with Hypertrophic Cardiomyopathy (HCM) diagnosed with HFpEF according to HF guidelines criteria. LA morpho-functional parameters were compared among the three groups: LA volumes (obtained by the length-area method), ejection fraction (EF) and, by means of feature tracking analysis, strain reservoir (εs), conduit (εe) and booster pump (εa). All patients were in sinus rhythm at the time of CMR. Results In comparison with the control group, ccTGA patients had a significant impairment in LA function (LA EF: 41,6 ± 15,1 vs 63,9 ± 7,8, p < 0,001, εs: 19,0 ± 8,3 vs 38,0 ± 10,3, p < 0,001, εe: 11,7 ± 5,9 vs 21,1 ± 8,3 p < 0,001, εa: 7,6 ± 4,1 vs 16,8 ± 6,1, p < 0,001). Conversely, no significant difference was found between ccTGA and HCM group regarding LA function (EF: 41,6 ± 15,1 vs 42,0 ± 10,1, εs: 19,0 ± 8,3 vs 22,6 ± 8,8, εe: 11,7 ± 5,9 vs 12,6 ± 7,0, εa: 7,6 ± 4,1 vs 10 ± 3,7). As for morphological parameters, ccTGA patients had an increase of LA volumes compared to both the control group and HCM patients. Conclusion ccTGA patients present an impaired LA function and a significative increase in LA volume consistent with the presence of diastolic disfunction. Further studies are needed to assess the clinical impact of morpho-functional LA impairment in ccTGA patients.