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Electrocardiography of Atrioventricular Block
Bradley A Clark1, Eric N Prystowsky2
1St.Vincent Hospital, 10590 North Meridian Street, Suite 200, Indianapolis, IN 46290, USA.
Cardiac Electrophysiology Clinics
|October 25, 2021
Summary
Delayed atrioventricular (AV) conduction, often due to AV nodal issues, can be diagnosed using electrocardiogram findings. Differentiating between AV nodal and infranodal disease is crucial for understanding heart block causes.
Area of Science:
- Cardiology
- Electrophysiology
Background:
- Delayed atrioventricular (AV) conduction typically originates in the AV node.
- This is characterized by AH prolongation on intracardiac ECG and PR prolongation on surface ECG.
Purpose of the Study:
- To differentiate between AV nodal and infranodal disease based on ECG characteristics.
- To understand the diagnostic criteria for various types of AV conduction blocks.
Main Methods:
- Analysis of surface and intracardiac electrocardiogram (ECG) findings.
- Correlation of PR interval, QRS duration, and AV block patterns (e.g., 2:1 block).
Main Results:
- A normal PR interval with wide QRS in 2:1 block suggests infranodal disease.
- A prolonged PR interval with narrow QRS suggests AV nodal disease.
- Block within the His bundle is indicated by 2:1 AV block with normal PR and QRS intervals.
Conclusions:
- ECG parameters like PR interval and QRS duration are key to localizing AV conduction delays.
- Understanding these patterns aids in diagnosing the specific site of heart block, from the AV node to the His bundle.
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