Relations between scars characteristics and genetic background in patients with arrhythmogenic right ventricular cardiomyopathy (ARVC) has not been investigated so far.

To investigate if genetic background change the scars characteristics in ARVC.

66 patients with ARVC (24 with culprit mutation) having undergone endocardial mapping have been retrospectively included. Every patient had a diagnosis of ARVC according to the task force criteria. Localisations, surfaces and perimeters of low votage areas (<1.5mV in bipolar and<5.5mV in unipolar) have been correlated to the existence of a culprit mutation, as well as volumes and ejection fraction of both ventricles by echocardiography, MRI or radionuclide.

Mutated patients more often had altered right ventricular ejection fraction (<0.05) and left ventricular late gadolinium enhancement (P=0.01). Right ventricle was more dilated (P=0.03), with larger scars in bi and unipolar voltage maps (P<0.05). Localisation of scars was linked to the genetic background, with more infero-lateral (P=0.01) or multiple scars (P=0.01) in mutated patients, while prevalence of outflow tract or apical scars did not differ.

In our ARVC population, culprit mutations increase size and number of intracardiac scars and degree of biventricular involvment, and localize scars in infero-lateral areas compared to patients without mutation.