Electrical Alternans

Last Updated on September 19, 2022

Description

• Alternating QRS amplitude, seen in any or all leads on an ECG, with no additional changes to the conduction pathways of the heart

Pathophysiology

Alternating QRS amplitude is due to the effect of “swinging heart” from the fluid surrounding the heart

Significance

Typically associated with pericardial effusion / cardiac tamponade

Other causes of electrical alternans:
• Ventricular tachycardia
• Wolff-Parkinson-White
• Supraventricular tachycardia

Further Reading

1. https://www.ncbi.nlm.nih.gov/books/NBK534229/#:~:text=Electrical%20alternans%20is%20defined%20as%20alternating%20QRS%20amplitude%20that%20is,the%20fluid%20surrounding%20the%20heart.
2. https://emedicine.medscape.com/article/154706-overview