Challenges in the diagnosis of arrhythmogenic right ventricular cardiomyopathy

Introduction. The diagnosis of arrhythmogenic right ventricular cardiomyopathy (ARVC) remains a challenging task. Despite the revised 2010 criteria of the ITF Task Force, most patients still face difficulties in establishing this diagnosis. Objective. To assess the clinical and genetic characteristics of patients with a preliminary diagnosis of “ARVC,” with a focus on the final diagnosis established after re-evaluation at the Republican Scientific and Practical Center of Cardiology (RSPC “Cardiology”). Material and methods. Twenty-eight patients (53.6% male, median age 35 [24; 43] years) with a preliminary diagnosis of ARVC referred to the RSPC “Cardiology” were examined. The clinical and instrumental evaluation included 12-lead ECG, 24-hour Holter monitoring, transthoracic echocardiography (TTE), and cardiac magnetic resonance imaging (MRI) with late gadolinium enhancement (LGE). The ARVC diagnosis was based on the 2010 ITF criteria and classified into definite, borderline, and possible categories. Genetic testing for mutations in genes associated with cardiomyopathies and inherited rhythm disorders was performed using next-generation sequencing (NGS). Results. Among the 28 patients with a preliminary diagnosis of ARVC, only 7 (25%) were diagnosed with definite ARVC according to the 2010 ITF criteria and confirmed by genotyping (mutations in the PKP2 and DSG genes in 5 patients, mutation in the non-desmosomal TMEM43 gene in 1 patient, and mutations in ILK and RBM20 genes in 1 patient). Eight (28.6%) patients were diagnosed with borderline ARVC, and 4 (14.3%) with possible ARVC. In 9 (32.1%) patients, the diagnosis of ARVC was ruled out due to misinterpretation of cardiac MRI. Genotyping revealed no ARVC-associated mutations in the borderline, possible, or excluded groups. A total of 7 (25%) patients received an ICD; of these, 6 were deemed appropriate, while 1 was considered inappropriate due to an unconfirmed ARVC diagnosis. Conclusions. A misdiagnosis of ARVC was found in 32.1% of patients suspected of having the condition. The most common reason for false suspicion was misinterpretation of cardiac MRI results, particularly regional dyskinesia/akinesia of the right ventricular wall due to factors such as pericardial constriction, right ventricular diverticulum, pectus excavatum, right ventricular enlargement in athletes, or frequent arrhythmias causing artifacts. Genotyping proved helpful in timely confirmation of the ARVC diagnosis in this patient cohort.