Epsilon Wave Definition

  • Small deflection (“blip” or “wiggle”) buried in the end of the QRS complex
  • On Standard 12-lead ECG (S-ECG), best seen in ST segment of V1 and V2, they are usually present in leads V1 through V4
  • Caused by post-excitation of myocytes in the right ventricle
  • Characteristic finding in patients with arrhythmogenic right ventricular dysplasia (ARVD)
Epsilon Waves
Epsilon wave in V1 due to RV conduction delay

Epsilon waves are the most specific and characteristic finding in arrhythmogenic right ventricular dysplasia (ARVD). In ARVD, myocytes are replaced by fat, producing islands of viable myocytes in a sea of fat. This causes a delay in excitation of some of the myocytes of the right ventricle, producing a small “blip” seen during the ST segment of the ECG.

Epsilon waves have also been described in patients with:

  • Posterior myocardial infarction
  • Right ventricular infarction
  • Infiltrative disease
  • Sarcoidosis

ECG Examples of Epsilon Waves
epsilon-wave-IIb-590x250 2
epsilon-V1b-590x182 2
ARVD Epsilon
Epsilon Waves

Fontaine lead

epsilon waves regular lead placement versus Fontaine lead placement
Comparison of S-ECG versus F-ECG in the ability to detect epsilon waves (arrows). Gottschalk et al 2014

The Fontaine lead placement increases sensitivity of detecting epsilon waves so that they are detected in three leads (FI, FII, FIII) rather than one lead in the regular placement.

History of the Epsilon Wave

Guy Hugues Fontaine (1936-2018) was a French cardiologist and electrophysiologist. In 1977 he defined and named arrhythmogenic right ventricular dysplasia ARVD; the epsilon wave; and the Fontaine lead placement to best amplify the waves on an ECG

The term “epsilon” was nice, because it occurs in the Greek alphabet after delta; thus, delta represents the pre-excitation and epsilon the post-excitation phenomenon. In addition, epsilon is also used in mathematics to express a very small phenomenon

Fontaine 1997

Fontaine bipolar precordial leads (F-ECG) can be used to increase the sensitivity of epsilon wave detection. Leads are placed as shown:

  • Right Arm (RA) over the manubrium;
  • Left Arm (LA) over the xiphoid process;
  • and Left Leg (LL) in the standard V4 position (5th ICS MCL).

Instead of regular leads I, II, and III there are now three bipolar chest leads that are termed FI, FII, and FIII which record the potentials developed in the right ventricle, from the infundibulum to the diaphragm.

The vertical bipolar lead FI, (similar to aVF) magnifies the atrial potentials and can be used to record:

  • epsilon waves;
  • search for AV dissociation in ventricular tachycardia;
  • and to study abnormal atrial rhythms when the P waves are too small on regular leads.
Fontaine lead placement FI F II F III with heart and vectors
Fontaine bipolar precordial leads (F-ECG)

Clinical studies

In 2010, Wang et al published their study on Epsilon waves detected by various electrocardiographic recording methods: in patients with arrhythmogenic right ventricular cardiomyopathy. In particular they compared the three ECG methods of S-ECG, R-ECG and F-ECG in known ARVD/C patients.

They identified 3 patterns of epsilon waves:

  • (A) wiggle waves
  • (B) small spike waves [B1 – spike upward; B2 – spike downward]
  • (C) smooth potential waves with the QRS duration in V1 exceeding the QRS duration in V3 by at least 25ms.
Patterns of epsilon waves wang et al 2010 2
Patterns of epsilon waves. Wang et al 2010

They found that

  • The duration and amplitude of epsilon waves detected by F-ECG were longer and larger than those detected by the other 2 ECG recording methods.
  • Epsilon waves are relatively low in sensitivity, manifesting themselves during S-ECG in only 20% to 25% of ARVC patients; and those waves are usually seen in leads V1 through V3.
  • Epsilon waves were found in 38% of all patients using S-ECG and increased that to 50% by using F-ECG.
  • The detection rate of epsilon waves using combined methods of ECG recording was significantly higher than that of S-ECG alone (S-ECG 38%; SF-ECG 56%; and SRF-ECG 66%, P=0.0039).

Arrhythmogenic Right Ventricular Dysplasia (ARVD)

The ECG changes in Arrhythmogenic Right Ventricular Dysplasia include:

  • Epsilon wave (most specific finding, seen in 50% of patients)
  • T wave inversions in V1-3 (85% of patients)
  • Prolonged S-wave upstroke of 55ms in V1-3 (95% of patients)
  • Localised QRS widening of 110ms in V1-3
  • Paroxysmal episodes of ventricular tachycardia with a LBBB morphology (RVOT tachycardia)

ECG Examples
Example 1
  • 12-lead ECG is a typical example of ARVD.

Prolonged S-wave upstroke in ARVD
Prolonged S-wave upstroke in ARVD

Example 2

26 year old male presents to emergency with palpitations, dizziness and diaphoresis., No complaints of chest pain or shortness of breath.

ECG on arrival:

sustained VT with LBBB pattern 1

ECG diagnosis: sustained VT with LBBB pattern, heart rate = 125 bpm and right superior QRS axis (only aVR lead with positive QRS complexes). This atypical axis is a hallmark of VT with focus in apex of right ventricle.

ECG Post cardioversion

sustained VT with LBBB pattern post cardioversion 2

Universal low voltage of QRS complexes. Epsilon wave V2 and lead II. T wave inversion in all precordial leads


Fontaine leads showing epsilon waves in ARVD C 2019
Typical example of arrhythmogenic cardiomyopathy with LV involvement. ε wave (arrows).
Pérez-Riera AR. 2019

Example 3
Arrhythmogenic Right Ventricular Dysplasia (ARVD) 002
VT with LBBB morphology due to ARVD

  • Corrado D, Biffi A, Basso C, Pelliccia A, Thiene G. Twelve-lead ECG in the athlete: physiological versus pathological abnormalities. Br J Sports Med 2009; 43: 669-676. [PMID: 19734501]
  • Perez Diez D, Brugada J. Diagnosis and Management of Arrhythmogenic Right Ventricular Dysplasia: An article from the E-Journal of the ESC Council for Cardiology Practice, European Society of Cardiology 2008.
  • Fontaine G et al. Stimulation studies and epicardial mapping in ventricular tachycardia: study of mechanisms and selection for surgery. In: Kulbertus HE, ed. Re-entrant Arrhythmias: Mechanisms and Treatment. 1977: 334 –350.
  • B. Gottschalk et al. The use of Fontaine leads in the diagnosis of arrhythmogenic right ventricular dysplasia. Ann Noninvasive Electrocardiol, 2014; 19(3): 279-284

ECG Library Basics

Advanced Reading



LITFL Further Reading



BA MA (Oxon) MBChB (Edin) FACEM FFSEM. Emergency physician, Sir Charles Gairdner Hospital.  Passion for rugby; medical history; medical education; and asynchronous learning #FOAMed evangelist. Co-founder and CTO of Life in the Fast lane | Eponyms | Books | Twitter |

MBBS (UWA) CCPU (RCE, Biliary, DVT, E-FAST, AAA) Adult/Paediatric Emergency Medicine Advanced Trainee in Melbourne, Australia. Special interests in diagnostic and procedural ultrasound, medical education, and ECG interpretation. Editor-in-chief of the LITFL ECG Library. Twitter: @rob_buttner


Leave a Reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.