Left ventricular (LV) involvement in the advanced stage of arrhythmogenic right ventricular cardiomyopathy (ARVC) is a well recognized phenomenon. T wave inversion in the lateral leads has been reported to be an electrocardiographic marker of LV involvement. Variants of ARVC that preferentially affect the left ventricle (left-dominant subtype of arrhythmogenic cardiomyopathy) have recently been recognized. We herein report a case in which an initial electrocardiogram that was similar to the left-dominant subtype of arrhythmogenic cardiomyopathy progressed to definitive ARVC over a period of 7 years. This case supports the hypothesis that LV involvement in ARVC may precede the evident onset of significant RV dysfunction.