Delta Wave Overview
The Delta wave is a slurred upstroke in the QRS complex often associated with a short PR interval. It is most commonly associated with pre-excitation syndrome such as WPW.
The characteristic ECG findings in the Wolff-Parkinson-White syndrome are:
- Short PR interval (< 120ms)
- Broad QRS (> 100ms)
- A slurred upstroke to the QRS complex (the delta wave)
In 1930, Wolff, Parkinson, and White erroneously thought that the wide QRS complex was caused by a type of bundle-branch block. This was corrected in 1933 by Wolferth and Wood.
in 1944 Segers PM, Lequime J and Denolin proposed the symbol Δ to represent the triangle shape at the base of the upsloping QRS complex. They described the ‘… deformation of the PQ segment is the result of a supplementary electrical deflection that we propose to call Δ‘ . This became more commonly described as the ‘delta wave‘
ECG examples of Delta Waves
Negative delta waves (e.g. seen in lead aVR)
- Wolff-Parkinson-White syndrome
- Who’s Afraid Of The Big Bad Wolff?
- VT versus SVT with aberrancy
- Puzzling Paroxysmal Palpitations
- Hurst JW. Naming of the waves in the ECG, with a brief account of their genesis. Circulation. 1998 Nov 3;98(18):1937-42
- Wolferth CC, Wood FC. The mechanism of production of short P-R intervals and prolonged QRS complexes in patients with presumably undamaged hearts: hypothesis of an accessory pathway of auriculoventricular conduction (bundle of Kent). American Heart Journal. 1933; 8: 297-311.
- Segers PM, Lequime J, Denolin H. L’activation ventriculaire précoce de certains cœurs hyperexeitables. Étude de I’onde Δ de I’électrocardiogramme. Cardiologia. 1944; 8(3-4):113-167.
ECG Library Basics
- Wiesbauer F, Kühn P. ECG Yellow Belt online course: Become an ECG expert. Medmastery
- Wiesbauer F, Kühn P. ECG Blue Belt online course: Learn to diagnose any rhythm problem. Medmastery
- Rawshani A. Clinical ECG Interpretation ECG Waves
- Smith SW. Dr Smith’s ECG blog.
- Mattu A, Tabas JA, Brady WJ. Electrocardiography in Emergency, Acute, and Critical Care. 2e, 2019
- Brady WJ, Lipinski MJ et al. Electrocardiogram in Clinical Medicine. 1e, 2020
- Straus DG, Schocken DD. Marriott’s Practical Electrocardiography 13e, 2021
- Hampton J. The ECG Made Practical 7e, 2019
- Grauer K. ECG Pocket Brain (Expanded) 6e, 2014
- Brady WJ, Truwit JD. Critical Decisions in Emergency and Acute Care Electrocardiography 1e, 2009
- Surawicz B, Knilans T. Chou’s Electrocardiography in Clinical Practice: Adult and Pediatric 6e, 2008
- Mattu A, Brady W. ECG’s for the Emergency Physician Part I 1e, 2003 and Part II
- Chan TC. ECG in Emergency Medicine and Acute Care 1e, 2004
LITFL Further Reading
- ECG Library Basics – Waves, Intervals, Segments and Clinical Interpretation
- ECG A to Z by diagnosis – ECG interpretation in clinical context
- ECG Exigency and Cardiovascular Curveball – ECG Clinical Cases
- 100 ECG Quiz – Self-assessment tool for examination practice
- ECG Reference SITES and BOOKS – the best of the rest