Absence of ECG Task Force Criteria does not rule out structural changes in genotype positive ARVC patients

Area of Science:

• Cardiology
• Genetics
• Medical Imaging

Background:

• Arrhythmogenic Right Ventricular Cardiomyopathy (ARVC) is characterized by progressive replacement of right ventricular myocardium with fibrofatty tissue.
• Electrophysiological abnormalities are often considered primary in ARVC, preceding morphological and functional changes.
• The relationship between ECG findings and cardiac imaging in ARVC requires further clarification.

Purpose of the Study:

• To determine the prevalence of ARVC patients with imaging evidence of structural disease but without fulfilling ECG Task Force Criteria (TFC).
• To investigate the utility of ECG TFC in ruling out structural abnormalities in genotype-positive ARVC individuals.

Main Methods:

• Cross-sectional analysis of 182 probands and family members with ARVC-associated mutations from the Nordic ARVC Registry.
• Echocardiography and cardiac MRI (CMR) were used to assess structural and functional abnormalities, differentiating between Task Force Criteria (TFC) and broader "abnormalities".
• ECG TFC were applied as defined, with multivariate analysis to assess associations with arrhythmic events.

Main Results:

• Only 4% of ARVC patients met echocardiographic TFC without any ECG TFC.
• A significant 38% of patients exhibited imaging abnormalities (echocardiography) without fulfilling ECG TFC.
• CMR data showed 16% met CMR TFC without ECG TFC, and 24% had CMR abnormalities without ECG TFC.

Conclusions:

• Over one-third of ARVC genotype-positive patients present with subtle imaging abnormalities despite not meeting ECG TFC.
• The absence of ECG TFC does not exclude the presence of structural abnormalities in ARVC genotype-positive individuals.
• These findings emphasize the importance of integrating imaging data with genetic and ECG findings for comprehensive ARVC diagnosis.