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

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 V1 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 V1 plus R-wave in V6 ≤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 V1, 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 V1 were common ECG signs in ALVC. A R-wave sum in I to II ≤8 mm and SV1+RV6 ≤12 mm were specific findings for ALVC phenotypes compared with controls.