Biatrial Enlargement Definition
- Biatrial enlargement is diagnosed when criteria for both right and left atrial enlargement are present on the same ECG.
- The diagnosis of biatrial enlargement requires criteria for LAE and RAE to be met in either lead II, lead V1 or a combination of leads.
ECG Criteria for Biatrial Enlargement
In lead II
Bifid P wave with:
- Amplitude ≥ 2.5mm
- Duration ≥ 120 ms
Biphasic P waves with:
- Initial positive deflection ≥ 1.5mm tall
- Terminal negative deflection ≥ 1mm deep
- Terminal negative deflection ≥ 40 ms duration
- P wave positive deflection ≥ 1.5 mm in leads V1 or V2
- Notched P waves with duration >120 ms in limb leads, V5 or V6
Causes of Biatrial Enlargement
Combination of both left and right atrial enlargement.
- Pulmonary hypertension due to:
- Chronic lung disease (cor pulmonale)
- Tricuspid stenosis
- Congenital heart disease (pulmonary stenosis, Tetralogy of Fallot)
- Primary pulmonary hypertension
- Mitral valve disease
- Aortic valve disease
- Aortic stenosis
- Mitral incompetence
- Hypertrophic cardiomyopathy (HOCM)
Biatrial enlargement due to idiopathic cardiomyopathy:
- Biphasic P waves in V1 with a very tall positive deflection (almost 3 mm in height!) and a negative deflection that is both deep (> 1 mm) and wide (> 40 ms).
- P waves in lead II are tall (> 2.5mm) and wide (> 120 ms).
- P waves in V2 are tall (> 1.5 mm), while the terminal negative portion of V1 is deep (> 1mm) and wide (> 40 ms).
- Chung DC, Nelson HM. ECG – A Pictorial Primer [internet]. Accessed 12/12/2011.
- Edhouse J, Thakur RK, Khalil JM. ABC of clinical electrocardiography. Conditions affecting the left side of the heart. BMJ. 2002 May 25;324(7348):1264-7. Review. PubMed PMID: 12028984; PubMed Central PMCID: PMC1123219 [Full Text].
- Harrigan RA, Jones K. ABC of clinical electrocardiography. Conditions affecting the right side of the heart. BMJ. 2002 May 18;324(7347):1201-4. Review. PubMed PMID: 12016190; PubMed Central PMCID: PMC1123164 [Full Text].
- Brady WJ, Truwit JD. Critical Decisions in Emergency and Acute Care Electrocardiography
- Hampton, JR. The ECG In Practice, 6e
- Surawicz B, Knilans T. Chou’s Electrocardiography in Clinical Practice: Adult and Pediatric, 6e
- Wagner, GS. Marriott’s Practical Electrocardiography 12e
- Chan, TC. ECG in Emergency Medicine and Acute Care
- Mattu, A. ECG’s for the Emergency Physician
LITFL Further Reading
- ECG BASICS — Waves, Intervals, Segments and Clinical Interpretation
- ECG A to Z by diagnosis –alphabetical diagnostic approach to the ECG
- ECG CLINICAL CASES — ECG’s placed in clinical context with a challenging Q&A approach
- 100 ECG Quiz — Self-assessment tool for examination practice
- ECG Reference SITES and BOOKS — the best of the rest
- LITFL ECG IMAGE Database — Searchable database of LITFL ECG’s
- ECG and Cardiology Eponymous Syndromes — Cheats guide to eponymous emancipation
- ECG Exam Template — a framework for answering ECG exam questions.