Abstract 1833: Comprehensive Cardiac Magnetic Resonance Imaging in Family Members of Desmosomal Mutation-Associated Arrhythmogenic Right Ventricular Dysplasia/Cardiomyopathy Patients Reveals a Possible Early Sign of the Disease
Background: The ability of magnetic resonance imaging (MRI) to characterize right (RV) and left (LV) ventricular structure and function has made it an important tool for diagnosis of Arrhythmogenic RV Dysplasia/Cardiomyopathy (ARVD/C). The purpose of this study was to identify early morphologic variants of ARVD/C associated with mutations in genes encoding desmosomal proteins.
Methods: Twelve ARVD/C probands with a known desmosomal mutation were identified from our database. Thirty-eight family members of these probands underwent genotyping for desmosomal genes, and cardiac MRI using standard protocols. MRIs were evaluated by an investigator blinded to other clinical and genetic data.
Results: Of the 38 (age: 30 ± 17 years; 18 male) family members included in this study, 25 had one (n=21) or more (n=4) mutations in the PKP2, DSP, and/or DSG2 genes. Previously described RV (36% vs. 8%, P=0.11) and LV (17% vs. 0%, P=0.11) abnormalities did not differ significantly between individuals with and without a mutation. Interestingly, focal crinkling of the RV wall at the outflow tract and subtricuspid regions (“accordion sign” - figure⇓) was identified in 60% of the patients with a mutation and none of the patients without a mutation (P<0.001). The sign was present in 0%, 37%, 71%, and 75% of individuals who met 1, 2, 3, and 4+ criteria points (minor = 1 and major = 2 points) for ARVD/C diagnosis respectively (P<0.01). Isolated LV involvement was not present in any of the mutation carriers.
Conclusion: The “accordion sign” may be an early sign of ARVD/C associated with desmosomal mutations. Evaluation of large series of patients should be undertaken to define its role in the diagnosis of ARVD/C.