Epsilon Waves as an Extreme Form of Depolarization Delay: Focusing on the Arrhythmogenic Right Ventricular Cardiomyopathy/Dysplasia

Fig. (1). Progression of ventricular depolarization abnormality in a male patient with ARVC/D over ten years follow-up. It is first seen as a fractionation of the terminal part of the QRS-complex with prolonged TAD in the right precordial leads at age 43, when the patient was first diagnosed. Right ventricular structural abnormalities, which were present at the initial presentation, progressed rapidly to the right ventricular heart failure that ultimately led to heart transplantation (HTx) at the age of 52. The terminal depolarization abnormality observed at the initial presentation eventually developed into a very distinct epsilon wave observed in all chest leads with particularly high amplitude in leads V1-V3 and separated from the QRS complex by a low-amplitude signal segment. Note that the time from the onset of the QRS, which remains narrow in its appearance, to the end of the delayed ventricular depolarization signal observed in all 12 ECG leads gradually increases and reached 270 ms at the last ECG taken prior to HTx. ECGs are presented at 50 mm/s paper speed. (A higher resolution / colour version of this figure is available in the electronic copy of the article).

Fig. (2). An example of delayed depolarization potential in the right precordial leads, which met the definition of the epsilon wave that was observed in a patient with pulmonary embolism. Note the clear separation of the distinct spike from the end of the QRS complex in lead V2. In the lead V1, the delayed depolarization deflection is merged with the r’. (A higher resolution / colour version of this figure is available in the electronic copy of the article).