Epsilon wave: A review of historical aspects

A Small Wave Missed in Wide Complex Tachycardia

This case report describes a patient in their 60s with intermittent palpitation, weakness, and irregular cardiac rhythm.

An Unusual Cause of ST-Segment Elevation in the Right Precordial Leads-A Clue From the Humble Waves

This case report describes a patient in their late teens who presented to the outpatient department stating that they had felt the implanted cardioverter defibrillator deliver a shock 3 times within the past 6 months.

Palpitations and Shortness of Breath-Just a "Bump in the Road" or Something More?

A previously healthy person in their 60s with progressive shortness of breath and fatigue for the past 6 months presented to the emergency department with palpitations and shortness of breath. What is your diagnosis?

Unexplained Syncope With Abnormal ECG Findings in the Emergency Department: Don't Miss the Epsilon Wave!

Arrhythmogenic cardiomyopathy (AC) is a genetic cardiac disorder associated with sudden cardiac death, specifically in young adults (D. Corrado, C. Basso, & D. Judge, 2017). AC is a disease of the heart muscle fibers and it is not usually diagnosed until its advanced stages. Typical AC presentation in the emergency department (ED) includes cardiac syncope, palpitations, ventricular arrhythmias, or resolved cardiac arrest. The epsilon wave is the hallmark and the major electrocardiographic (ECG) diagnostic criterion for AC in the later stages of the disease process (A. R. Perez-Riera et al., 2019). A definite diagnosis of AC is of high complexity and not typically made by emergency providers; however, many cases of advanced AC are discovered in the ED as a result of syncope. The purpose of this case review is to discuss the typical presentation, ECG findings, and emergency providers' role in the management of patients with suspected AC.

Desmoplakin cardiomyopathy and arrhythmogenic right ventricular cardiomyopathy: two distinct forms of cardiomyopathy?

The confirmation of a hypothesis that desmoplakin-related (DSP) cardiomyopathy could represent a distinct clinical entity from the classical, RV-dominant, form of arrhythmogenic cardiomyopathy (ACM), most frequently caused by PKP2 mutations, would without any shadow of doubt signify a turning point in the history of this disease. The concept of gene-specific diseases underneath the umbrella diagnosis of ACM would bring fundamental changes not only in the clinical, diagnostic and therapeutic approach, but also in terms of risk stratification, pushing the scientific community towards a more patient-centred view of the disease, similarly to what has already been done in other inherited arrhythmogenic disease (e.g., Long QT Syndrome; LQTS). We provide a state-of-the-art review, starting with a brief historical framework to give the necessary context and better focus the question. Then, we proceed with a novel, genotype-tophenotype-based comparison of the most important aspects of DSP-related cardiomyopathy with the classical, RV-dominant ACM: this allows us to ascertain not only that the differences between the forms exist, but are also clinically relevant and actionable, leading to the underrecognition of the atypical, DSP-related, LV-dominant forms when applying the current diagnostic criteria. These findings will usher an exciting era, in which the scientific community will try to answer a range of questions, starting from the reasons why different desmosomal mutations cause such different phenotypes.

Electrocardiograms Revealing Epsilon Waves Following Use of Hormone Supplements in Young Cardiac Arrest Patient

INTRODUCTION

An underlying cardiomyopathy should be suspected in young patients presenting with ventricular arrhythmias and sudden cardiac arrest. Electrocardiograms revealing epsilon waves are associated with many serious conditions such as arrhythmogenic right ventricular cardiomyopathy, posterior myocardial infarction, right ventricular infarction, infiltration disease, sarcoidosis, Brugada Syndrome, Tetralogy of Fallot, and hypothermia. This case report features epsilon waves in a young cardiac arrest patient suspected of having an unrecognized cardiomyopathy that resulted in a fatal arrhythmia in the setting of exogenous bovine thyroid hormone and steroid use.  Case presentation: A previously healthy 33-year-old male with a history of anabolic steroid use and bovine thyroid hormone use presented to the emergency department following witnessed cardiac arrest with bystander cardiopulmonary resuscitation (CPR). Upon emergency medical service (EMS) arrival, the patient was in ventricular fibrillation and received defibrillation with the return of spontaneous circulation. In the emergency department, he was unresponsive and required norepinephrine to maintain blood pressure. An epsilon wave and a prolonged QTc interval were noted on his electrocardiogram (ECG). CT angiogram of the chest and CT head were negative for acute abnormalities. Pertinent laboratory work-up included a lactate level of 12.0 mmol/L, thyroid-stimulating hormone of 0.02 ulU/L, and a free thyroxine level of 0.04 ng/dL. Cardiac ultrasound showed globally decreasedleft ventricular function with an ejection fraction of 25-30% and mild dilation of the right ventricle. A cardiac MRI was ordered but the patient had recurrent ventricular fibrillation and was too unstable to complete. He suffered anoxic brain injury with no improvements in neurologic function and was transitioned to comfort care. The patient died two months later in hospice care. The cause of cardiac arrest was attributed to the patient's steroid and bovine thyroid supplementation, but autopsy results revealed histologic evidence of possible arrhythmogenic right ventricular cardiomyopathy.  Discussion: Epsilon waves are widely known to be associated with structural abnormalities of the heart, most notably, arrhythmogenic right ventricular cardiomyopathies. Epsilon waves may be present in a variety of other medical conditions including posterior myocardial infarction, right ventricular infarction, infiltration disease, sarcoidosis, Brugada Syndrome, Tetralogy of Fallot, and hypothermia. This case report describes an epsilon wave found in a patient with suspected arrhythmogenic right ventricular cardiomyopathy that suffered a fatal arrhythmia triggered by bovine thyroid hormone and steroid use.