Relations between voltage mapping and diagnosis or genetic background in patients with arrhythmogenic right ventricular cardiomyopathy (ARVC) have not been investigated so far.

We investigate if diagnosis or genetic background were linked to voltage mapping in ARVC.

Seventy patients with proved or suspected ARVC undergoing 3D endocardial voltage mapping and genetic testing have been retrospectively included. Localisation and extension of bipolar low voltage areas were correlated to ARVC diagnosis and presence of a culprit mutation.

Forty-four over seventy fulfilled ARVC Task Force criteria and 25/70 had culprit mutations. Endocardial (38/44 vs. 16/26, P=0.02) and especially infero-lateral scars (31/44 vs. 9/26, P=0.003) were more often present in patients fulfilling Task force criteria vs. suspected ARVC, with larger scars (area 23±27 vs. 8±11 cm², P=0.04, perimeter 17±10 vs. 11±7cm, P=0.03) (sensitivity 86%). Mutated patients had more infero-lateral (19/25 vs. 21/45, P=0.01), multiple (12/20 vs. 11/34, P=0.04) and larger scars (perimeter 21±10 vs. 12±7cm, P=0.01) vs. non-mutated patients. In patients with ARVC diagnosed according to the Task Force criteria, there was a trend toward more infero-lateral (P=0.09) and larger scars (P=0.08) in mutated cases. PKP2-mutated cases tended to have less ourflow tract (P=0.08) and less multiple scars (P=0.09) vs. other mutations (Fig. 1).

3D endocardial mapping could have an important role for ARVC diagnosis and may be able to detect minor forms with otherwise insufficient criteria for diagnosis. More frequent and larger infero-lateral scars are present in mutated patients with borderline differences according to the mutated genes.