Electrical alternans is associated with Massive Pericardial Effusion
Massive pericardial effusion produces a triad of:
- Low QRS voltage
- Electrical alternans
ECG findings with Electrical alternans
Electrical alternans occurs when
- consecutive, normally-conducted QRS complexes alternate in height.
- the heart swings backwards and forwards within a large fluid-filled pericardium.
Patients with this ECG pattern need to be immediately assessed for clinical and echocardiographic evidence of tamponade.
- Dr Smith’s ECG Blog: Differential diagnosis of low QRS voltage
- Mugmon, M. Electrical alternans vs. pseudoelectrical alternans. J Community Hosp Intern Med Perspect. 2012; 2(1) [PMC 3714094]
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
- Brady WJ, Truwit JD. Critical Decisions in Emergency and Acute Care Electrocardiography
- Surawicz B, Knilans T. Chou’s Electrocardiography in Clinical Practice: Adult and Pediatric
- Wagner GS. Marriott’s Practical Electrocardiography 12e
- Chan TC. ECG in Emergency Medicine and Acute Care
- Rawshani A. Clinical ECG Interpretation
- Mattu A. ECG’s for the Emergency Physician
- Hampton JR. The ECG In Practice, 6e