PR Segment
PR Segment Introduction
PR segment is the isoelectric (flat line) segment representing the interval between the end of the P wave and the beginning of the QRS complex on the ECG tracing. The main conditions that cause PR segment abnormalities are Atrial Ischaemia and Pericarditis.
PR Segment ECG Changes
Changes in the PR segment, such as depression or elevation can be seen on an ECG
Atrial Ischaemia
In cases of atrial ischemia, changes in the PR segment on an electrocardiogram (ECG) might be observed. Atrial ischemia refers to insufficient blood supply to the atria, the upper chambers of the heart, which can result from reduced blood flow through the coronary arteries supplying the heart.
While changes in the PR segment are not as commonly associated with atrial ischemia compared to changes in other segments of the ECG (such as ST-segment or T-wave changes seen in myocardial ischemia), there can still be alterations in the PR segment.
Atrial ischemia might cause a depression or elevation of the PR segment in different leads. This deviation from the normal baseline might be subtle and might not always be easily identifiable. PR segment depression/elevation could suggest compromised atrial electrical activity due to insufficient blood flow.
Pericarditis
Pericarditis is inflammation of the pericardium, the thin sac-like membrane surrounding the heart. When evaluating an electrocardiogram (ECG) of a person with pericarditis, specific changes in the ECG, including alterations in the PR segment, can often be observed. Find out more about Pericarditis here.
The PR segment may appear depressed or flattened. This depression might be seen in multiple leads on the ECG. PR segment elevation will also be seen in reciprocal changes.
Learn more about ECG changes in Pericarditis here.
ECG Examples
Key Points
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PR segment is the isoelectric (flat line) segment representing the interval between the end of the P wave and the beginning of the QRS complex.
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Changes in the PR segment, such as depression, can indicate various cardiac conditions, including atrial ischemia and pericarditis.
Bibliography
Douedi, S., & Douedi, H. (2020). P wave. PubMed; StatPearls Publishing. https://www.ncbi.nlm.nih.gov/books/NBK551635/
Joint Royal Colleges Ambulance Liaison Committee and Association of Ambulance Chief Executives (2022). JRCALC Clinical Guidelines 2022. Class Professional Publishing
PR Segment Introduction
PR segment is the isoelectric (flat line) segment representing the interval between the end of the P wave and the beginning of the QRS complex on the ECG tracing. The main conditions that cause PR segment abnormalities are Atrial Ischaemia and Pericarditis.
PR Segment ECG Changes
Changes in the PR segment, such as depression or elevation can be seen on an ECG
Atrial Ischaemia
In cases of atrial ischemia, changes in the PR segment on an electrocardiogram (ECG) might be observed. Atrial ischemia refers to insufficient blood supply to the atria, the upper chambers of the heart, which can result from reduced blood flow through the coronary arteries supplying the heart.
While changes in the PR segment are not as commonly associated with atrial ischemia compared to changes in other segments of the ECG (such as ST-segment or T-wave changes seen in myocardial ischemia), there can still be alterations in the PR segment.
Atrial ischemia might cause a depression or elevation of the PR segment in different leads. This deviation from the normal baseline might be subtle and might not always be easily identifiable. PR segment depression/elevation could suggest compromised atrial electrical activity due to insufficient blood flow.
Pericarditis
Pericarditis is inflammation of the pericardium, the thin sac-like membrane surrounding the heart. When evaluating an electrocardiogram (ECG) of a person with pericarditis, specific changes in the ECG, including alterations in the PR segment, can often be observed. Find out more about Pericarditis here.
The PR segment may appear depressed or flattened. This depression might be seen in multiple leads on the ECG. PR segment elevation will also be seen in reciprocal changes.
Learn more about ECG changes in Pericarditis here.
ECG Examples
Key Points
-
PR segment is the isoelectric (flat line) segment representing the interval between the end of the P wave and the beginning of the QRS complex.
-
Changes in the PR segment, such as depression, can indicate various cardiac conditions, including atrial ischemia and pericarditis.
Bibliography
Douedi, S., & Douedi, H. (2020). P wave. PubMed; StatPearls Publishing. https://www.ncbi.nlm.nih.gov/books/NBK551635/
Joint Royal Colleges Ambulance Liaison Committee and Association of Ambulance Chief Executives (2022). JRCALC Clinical Guidelines 2022. Class Professional Publishing
