Epsilon wave on an electronic loop in a case of arrhythmogenic right ventricular dysplasia with myocarditis: an updated definition of the Epsilon wave

Abstract

A young man presented with a history of myocarditis with palpitations and dizziness. He had implantation of a loop recorder that showed repetitive short episodes of VT. In addition, there were fragmented potentials immediately following the large and sharp electrograms (EGMs) before as well as after episodes of VT suggesting an Epsilon wave. This signal can be observed in multiple cardiac conditions including coronary artery disease. It was originally recorded on the epicardium as well as on the endocardium. However, in ARVD it can be defined as an electric signal observed after the end of the QRS complex in the right as opposed to the left precordial leads (difference ≥ 25 ms). It can also be an aid to the diagnosis of patients with ARVD who have other signs or symptoms suggesting ARVD including episodes of myocarditis. This potential consists of a slurring at the end of the QRS complex or an independent potential after the return to the isoelectric line. It can be better observed by increasing amplification of the ECG tracing as well as double speed using the Fontaine lead system. Epsilon wave too small to be recorded on the standard ECG can be extracted by Signal Averaging ECG SAECG).

The fragmented QRS and epsilon wave in arrhythmogenic right ventricular dysplasia: Does before‐and‐after the end of the QRS complex matter?

“…about the 16‐lead high‐definition electrocardiogram (ECG) in arrhythmogenic right ventricular dysplasia (ARVD) being more sensitive than 12‐lead electrocardiogram (ECG) to record electrocardiographic abnormalities such as epsilon wave and fragmented QRS. We want to address some points that merit more attention and would like to hear Dr. Fontaine's updated definition of the epsilon wave and fragmented QRS (f‐QRS) . In 1977, Guy Fontaine first described epsilon waves, which had been recorded at the time of epicardial surgery on patients who manifested sustained ventricular tachycardia .…”

“…Since both epsilon wave and f‐QRS waves are caused by zigzag conduction around the scarred myocardium and reflect the same pathophysiologic abnormality, the different definitions might be confusing in literature. We would like to hear Dr. Fontaine's opinion about the definition problem in literature for epsilon wave or f‐QRS.…”

Multichannel electrocardiogram diagnostics for the diagnosis of arrhythmogenic right ventricular dysplasia

“…As its name suggests, it was initially felt to be a disease of the right ventricle but there is now evidence of left ventricular and bi-ventricular forms [9][10][11] . Those affected are often asymptomatic and the first manifestation can be with a sudden, unexplained death.…”

“…De-noised time series were down-sampled from 1000 Hz to 100 Hz. Measure values for every channel were then calculated Furthermore, the performance of channels with greater ASWs was evaluated using theNearest Neighbor (k-NN) classification algorithm [11], in particular, using 1NN. The accuracy of the 1NN classifier based on the set of channels with greater ASW values was compared to the accuracies of nearest neighbor classifiers defined on sets of randomly selected channels.…”

Updated definition of epsilon waves

“…We do very much appreciate the letter to the editor on our article “Value of a novel 16‐lead high‐definition ECG machine to detect conduction abnormalities in structural heart disease.” The authors would like to hear Dr. Guy Fontaine's opinion about the definition problem for epsilon waves or f‐QRS in the literature. We are very sorry to tell you that Dr.…”