Right ventricular fat infiltration in asymptomatic subjects: observations from ECG-gated 16-slice multidetector CT

OBJECTIVE: To analyze the computed tomography (CT) findings of fatty replacement in the right ventricle (RV) of asymptomatic subjects and to correlate the CT findings with electrocardiogram (ECG) abnormalities. METHODS: This prospective study included 996 subjects who underwent ECG-gated 16-slice CT for determination of coronary calcium scores. The CT findings were analyzed in terms of location, pattern, and degree of RV fat infiltration, along with the shape and dimension of RV. The RV fat was regarded present when a region showed less than or equal to -30 Hounsfield units as revealed by CT. RESULTS: Computed tomography features suggestive of RV fat were found in 169 subjects (17%; 136 men and 33 women; mean age, 56.3 years). The most frequent location of fat was the basal superior wall (93%); next was the middle superior wall (72%); and then, the RV outflow tract (44%). Subjects with moderate to severe involvement were older than those with mild involvement (P = 0.012). In 3 subjects, the RV wall thickening with fat was more than 5 mm. Angular deformity and undulating appearance of the RV also occurred in 25 (15%) and 20 subjects (12%), respectively. However, these were not patients with ECG findings positive for arrhythmogenic RV dysplasia. CONCLUSIONS: Asymptomatic subjects may have fat in RV on CT. However, these subjects show no RV dysfunction or significant ECG-abnormalities consistent with the diagnosis of arrhythmogenic RV dysplasia.