Prediction rule for diagnosis of arrhythmogenic right ventricular dysplasia based on wall thickness measured on MR imaging.

MRI is seeing an increasing role in the evaluation of suspected arrhythmogenic right ventricular dysplasia (ARVD). Our aims were to establish wall thickness criteria for diagnosis of ARVD based on MR imaging measurements. A cross-sectional case-control retrospective study of 21 cardiac MR exams over a 3 year period identified five patients (two men, three women) of average age 43 years (range 36-48) who were diagnosed with ARVD and 16 patients (nine men, seven women) of average age 52 years (range 25-78) who were diagnosed with normal right ventricular wall motion. Patient demographic characteristics (age, sex) and right ventricular free wall thickness (RVFWT) were evaluated for predictive ability. Calculated RVFWT was (mean+/-SD, in mm); (4.4+/-1.4) for ARVD, and (7.8+/-2.9), controls with P<0.001. Logistic regression analysis indicated that sex and age were not significant independent predictors (P>0.05). RVFWT allowed for a prediction rule with Area under the receiver operator curve of 0.94 to be generated. In our study, measurement of the thickness of the right ventricular free wall using cardiac-gated MRI proved to be a statistically significant predictor of ARVD.