The Diagnostic Value of the 12-Lead ECG in Arrhythmogenic Left Ventricular Cardiomyopathy

background: electrocardiographic (ECG) findings in arrhythmogenic left ventricular cardiomyopathy (ALVC) are limited to small case series. objectives: this study aimed to analyze the ECG characteristics of ALVC patients and to correlate ECG with cardiac magnetic resonance and genotype data. methods: we reviewed data of 54 consecutive ALVC patients (32 men, age 39 +/- 15 years) and compared them with 84 healthy controls with normal cardiac magnetic resonance. results: T-wave inversion was often noted (57.4%), particularly in the inferior and lateral leads. Low QRS voltages in limb leads were observed in 22.2% of patients. the following novel ECG findings were identified: left posterior fascicular block (LPFB) (20.4%), pathological Q waves (33.3%), and a prominent R-wave in V-1 with a R/S ratio >= 0.5 (24.1%). the QRS voltages were lower in ALVC compared with controls, particularly in lead I and II. at receiver-operating characteristic analysis, the sum of the R-wave in I to II <= 8 mm (AUC: 0.909; P < 0.0001) and S-wave in V-1 plus R-wave in V-6 <= 12 mm (AUC: 0.784; P < 0.0001) effectively discriminated ALVC patients from controls. It is noteworthy that 4 of the 8 patients with an apparently normal ECG were recognized by these new signs. transmural late gadolinium enhancement was associated to LPFB, a R/S ratio >= 0.5 in V-1, and inferolateral T-wave inversion, and a ringlike pattern correlated to fragmented QRS, SV1+RV6 <= 12 mm, low QRS voltage, and desmoplakin alterations. conclusions: pathological Q waves, LPFB, and a prominent R-wave in V-1 were common ECG signs in ALVC. An R-wave sum in I to II <= 8 mm and SV1+RV6 <= 12 mm were specific findings for ALVC phenotypes compared with controls.