Abstract 2756: Fat Deposition within the RV Myocardium in Asymptomatic Young Patients is a Common Incidental Finding
Background: A characteristic pathologic finding in patients (pts) with arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C) is microscopic fibro- fatty replacement (MFD) of ventricular myocardium. Accurate non-invasive diagnosis of ARVD/C relies upon confirming the presence or absence of MFD within the myocardium yet the prevalence of this finding in patients without ventricular arrhythmias (VA), is unknown.
Methods: Consecutive noncontrast cardiac computed tomography (CT) images were assessed for the presence of MFD in young asymptomatic patients (pts) undergoing cardiac CT for coronary artery calcium scoring. All images were reviewed independently by 2 cardiac radiologists and consensus achieved where a discrepancy occurred. Specific observations were the presence or absence of MFD in the RV by location (free wall, RV outflow tract, and junction with moderator band) and visually estimated RV size (defined as dilated or normal).
Results: A total of 584 pts (448 (73%) male;) were included (age 36.2 ± 4.2 years; range 12– 40 years). Of these, 28 were excluded. Of these, 71 pts (12%) had evidence of macroscopic fatty deposition within the RV myocardium which was most frequent along the wall of the RV outflow tract (33 patients, 46%), moderator band (28 patients, 39%), free wall of the RV (23 patients, 32%). Less commonly MFD was found in the apical inferoseptal segment of the RV (1 pt). Increased body mass index was not associated with increased likelihood of MFD in the RV (p=0.23). None of the patients had dilatation of the right ventricle by visual inspection.
Conclusion: Macroscopic fatty deposition of the RV wall is a common incidental imaging finding in young patients without a history of VA and may lead to increased likelihood of false positive cardiac CT findings in patients undergoing evaluation for other reasons.