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Explain
Reading File
analyse_media
Finding Sources
Searching PubMed
COPD AND electrocardiography
Searching the Web
COPD ECG vertical heart axis lead I sign ECG reference
Finding Sources
Reading Web Page
https://litfl.com/ecg-in-chronic-obstructive-pulmonary-disea…
The image explains the ECG axis change in COPD, especially emphysema.
Mechanism
COPD/emphysema
→ lungs become hyperinflated
→ the diaphragm is pushed downward and flattened
→ the heart becomes more vertical in the chest
→ the mean QRS electrical axis shifts toward about +90°. This is called a vertical QRS axis. With more marked shift, it may become right-axis deviation.
→ lungs become hyperinflated
→ the diaphragm is pushed downward and flattened
→ the heart becomes more vertical in the chest
→ the mean QRS electrical axis shifts toward about +90°. This is called a vertical QRS axis. With more marked shift, it may become right-axis deviation.
What this looks like on ECG
- Lead I becomes very small or nearly isoelectric because lead I looks horizontally from right arm to left arm, while the QRS vector is pointing mainly downward.
- This is sometimes called the Lead I sign in emphysema.
- Leads II, III, and aVF show more prominent positive QRS complexes, because these inferior leads look downward and align with the vertical/downward QRS vector.
- The circled complexes in the diagram show that:
- QRS is relatively small in lead I/aVL
- QRS is more positive/prominent in II, III, aVF
Important correction
The diagram says “axis shifts to 90°.” This is best understood as verticalization of the electrical axis. It is not necessarily pathologic right-axis deviation by itself. At approximately +90°, lead I is often nearly isoelectric. If the axis moves beyond +90°, there is right-axis deviation, which may also reflect pulmonary hypertension or right-ventricular hypertrophy in advanced COPD.
Other possible ECG findings in COPD include low-voltage limb-lead complexes, clockwise rotation/poor R-wave progression in chest leads, and right atrial or right ventricular strain features in advanced disease. The vertical axis finding is supportive only, not diagnostic of COPD. A COPD ECG reference describes this typical rightward/vertical QRS-axis shift.
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