ECG features in Chronic Obstructive Pulmonary Disease
- The presence of hyperexpanded emphysematous lungs within the chest.
- The long-term effects of hypoxic pulmonary vasoconstriction upon the right side of the heart, causing pulmonary hypertension and subsequent right atrial and right ventricular hypertrophy (i.e. cor pulmonale).
Effects of Emphysema on the Heart
- Lung hyperexpansion causes external compression of the heart and lowering of the diaphragms, with consequent elongation and vertical orientation of the heart.
- Due to its fixed attachments to the great vessels, the heart undergoes clockwise rotation in the transverse plane, with movement of the right ventricle anteriorly and displacement of the left ventricle posteriorly.
- The presence of increased air between the heart and recording electrodes has a dampening effect, leading to reduced amplitude of the QRS complexes.
Effects on the pulmonary vasculature
- Chronic hypoxaemia causes reflex vasoconstriction in the pulmonary arterioles (“hypoxic pulmonary vasoconstriction”), with consequent elevation of pulmonary arterial pressures.
- Destruction of lung tissue with loss of pulmonary capillaries increases the resistance of the pulmonary vascular bed by reducing its effective surface area.
- Over time, this chronic elevation of pulmonary arterial pressures results in compensatory right atrial and right ventricular hypertrophy.
Typical ECG Findings in COPD
- Rightward shift of the P wave axis with prominent P waves in the inferior leads and flattened or inverted P waves in leads I and aVL.
- Rightward shift of the QRS axis towards +90 degrees (vertical axis) or beyond (right axis deviation).
- Exaggerated atrial depolarisation causing PR and ST segments that “sag” below the TP baseline.
- Low voltage QRS complexes, especially in the left precordial leads (V4-6).
- Clockwise rotation of the heart with delayed R/S transition point in the precordial leads +/- persistent S wave in V6. There may be complete absence of R waves in leads V1-3 (the “SV1-SV2-SV3” pattern).
2. With development of cor pulmonale, the following additional changes are seen:
3. Other ECG changes that may be seen include:
This ECG demonstrates many of the features of chronic pulmonary disease:
- Rightward QRS axis (+90 degrees).
- Peaked P waves in the inferior leads > 2.5 mm (P pulmonale) with a rightward P-wave axis (inverted in aVL)
- Clockwise rotation of the heart with a delayed R/S transition point (transitional lead = V5).
- Absent R waves in the right precordial leads (SV1-SV2-SV3 pattern).
- Low voltages in the left-sided leads (I, aVL, V5-6).
Sinus tachycardia may be due to breathlessness, hypoxia or bronchodilator therapy (e.g. salbutamol, theophylline).
Another good example of the pulmonary disease pattern:
- Rightward axis (+ 90 degrees).
- Peaked P waves.
- Low QRS voltages (most obvious in the limb leads).
- Clockwise rotation (transitional lead = V6).
- Virtually absent R waves in the right precordial leads (SV1-SV2-SV3 pattern).
This ECG shows multifocal atrial tachycardia with additional features of COPD:
- Rapid, irregular rhythm with multiple P-wave morphologies (best seen in the rhythm strip).
- Right axis deviation, dominant R wave in V1 and deep S wave in V6 suggest right ventricular hypertrophy due to cor pulmonale.
- 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. PMID: 12016190. 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.