Background: Cardiac magnetic resonance (CMR) evaluation of athletes for arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC/D) is complicated by overlapping features such as right ventricular (RV) volume increase. The revised ARVC/D diagnostic Task Force Criteria (TFC) incorporate cut-off values for RV ejection fraction (EF) and RV end-diastolic volume (EDV) on CMR.
Design: To distinguish ARVC/D patients from athletes we compared CMR ventricular volumes, function, TFC cut-off values, and LV/RV ratios since athletes show proportionate, and ARVC/D patients disproportionate, changes in LV and RV.
Methods: Quantitative CMR parameters of 33 ARVC/D patients (64% male, mean age 45.4 years, diagnosed by revised TFC), 66 healthy athletes and 66 healthy non-athletes (sex and age matched) were compared using revised TFC and new cut-off values representing LV/RV balance.
Results and conclusions: Absolute values for ARVC/D patients/athletes/non-athletes were: in males, RV EDV 149/133/106 ml/m(2), ratio EDV LV/RV 0.70/0.91/0.93, RV EF 34/52/54%, LV EF 48/57/58%, ratio EF LV/RV 1.49/1.10/1.09; and in females, RV EDV 115/115/91 ml/m(2), ratio EDV LV/RV 0.86/0.94/0.97, RV EF 43/54/58%, LV EF 52/57/61%, ratio EF LV/RV 1.23/1.08/1.04 (p-values < 0.05). Areas under the ROC-curve are 0.68 (RV EDV index), 0.84 (LV/RV EDV ratio) and 0.93 (RV EF), demonstrating significantly (p < 0.001) better performance of RV EF and LV/RV EDV ratio. If a wall motion abnormality is present (observed in 30 ARVC/D patients and not in healthy subjects), RV EF can help distinguish ARVC/D from physiological cardiac adaptation in athletes on CMR whereas RV EDV index cannot. A good alternative in athletes is the LV/RV EDV ratio, representing normal proportionate adaptation of both ventricles.