Abstract
Electrocardiogram (ECG) may play a crucial role in the diagnosis of left-sided variants of desmosomal arrhythmogenic cardiomyopathies. This article discusses the most common ECG changes, such as T-wave inversion and low QRS voltages, and new ECG signs such as Q-waves, low voltages in specific leads, posterior fascicle block, and R/S ratio ≥ 0.5 in V1. In addition, ventricular arrhythmias have peculiar features in these patients. Electrocardiogram may be an early marker of this insidious cardiomyopathy and allow to avoid sudden cardiac death often in young people. Electrocardiogram abnormalities may also be indicators of disease evolution over time.