What is the significance of a wide S wave on an electrocardiogram (ECG)?

Medical Advisory BoardAll articles are reviewed for accuracy by our Medical Advisory Board
Educational purpose only • Exercise caution as content is pending human review
Article Review Status
Submitted
Under Review
Approved

Last updated: April 25, 2025View editorial policy

Personalize

Help us tailor your experience

Which best describes you? Your choice helps us use language that's most understandable for you.

From the Guidelines

A wide S wave on an electrocardiogram (ECG) is a significant finding that may indicate right ventricular hypertrophy (RVH), particularly when combined with other ECG criteria such as right axis deviation, tall biphasic R/S complexes, and signs of right atrial abnormality, as suggested by the American Heart Association electrocardiography and arrhythmias committee 1. When evaluating a wide S wave, it's crucial to consider it in the context of other ECG findings and the patient's clinical presentation. The presence of prominent S waves in leads V5 or V6, in addition to ECG criteria for left ventricular hypertrophy (LVH), may suggest biventricular hypertrophy, which has important implications for patient management and prognosis 1. Some key points to consider when interpreting a wide S wave include:

  • The width of the S wave reflects the time taken for ventricular depolarization to spread through the myocardium, and prolongation suggests delayed conduction through certain parts of the heart.
  • Combined tall R waves and deep S waves in leads V2 to V6, with a combined amplitude greater than 60 mm, may indicate LVH in patients with congenital heart defects and RVH 1.
  • Further cardiac evaluation, such as echocardiography, stress testing, or cardiac MRI, may be necessary to determine the underlying cause of the wide S wave and to guide management decisions.
  • The clinical significance of a wide S wave depends on the patient's symptoms and overall clinical context, with asymptomatic patients potentially requiring only monitoring, while symptomatic patients may require more urgent evaluation and treatment.

From the Research

Wide S Wave

  • A wide S wave in leads I and/or V6 can be an indicator of various cardiac conditions, including right ventricular overload and myocardial disease 2.
  • The presence of a prominent S wave in leads I and/or V6 is more frequent in patients with cardiopulmonary diseases than in those without these conditions 2.
  • However, this ECG sign is not highly specific for any particular disease, and can be found in conditions such as myocardial hypertrophy and pulmonary diseases 2.
  • The relationship between ECG criteria, including S wave patterns, and left ventricular hypertrophy (LVH) has been studied, with findings suggesting that ECG criteria for LVH have low sensitivity for diagnosis confirmed by echocardiography 3.
  • Other studies have explored the role of ECG in diagnosing and managing cardiac conditions, including acute coronary syndromes and left ventricular hypertrophy, highlighting the importance of considering clinical context and multiple diagnostic tools 4, 5.

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

Electro- and echocardiographic features of left ventricle hypertrophy in patients with hypertrophic cardiomyopathy.

Annals of noninvasive electrocardiology : the official journal of the International Society for Holter and Noninvasive Electrocardiology, Inc, 2022

Research

The role of the ECG in diagnosis, risk estimation, and catheterization laboratory activation in patients with acute coronary syndromes: a consensus document.

Annals of noninvasive electrocardiology : the official journal of the International Society for Holter and Noninvasive Electrocardiology, Inc, 2014

Research

Left ventricular hypertrophy: The relationship between the electrocardiogram and cardiovascular magnetic resonance imaging.

Annals of noninvasive electrocardiology : the official journal of the International Society for Holter and Noninvasive Electrocardiology, Inc, 2014

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

Have a follow-up question?

Our Medical A.I. is used by practicing medical doctors at top research institutions around the world. Ask any follow up question and get world-class guideline-backed answers instantly.