First-degree atrioventricular block
First-degree AV block | |
---|---|
Other names | First degree heart block, PR prolongation |
third degree AV block | |
Causes | Fibrosis in AV node, medication, vagal tone, electrolyte disturbances |
Diagnostic method | Electrocardiogram |
Treatment | Avoidance of AV-nodal-blocking medication |
First-degree atrioventricular block (AV block) is a disease of the
Causes
The most common causes of first-degree heart block are AV nodal disease, enhanced
Diagnosis
In normal individuals, the AV node slows the conduction of electrical impulses through the heart. This is manifest on a surface
In first-degree heart block, the AV node conducts the electrical activity more slowly. This is seen as a PR interval greater than 200 ms in length on the surface ECG. It is usually an incidental finding on a routine ECG.[4]
First-degree heart block does not require any particular investigations except for electrolyte and drug screens, especially if an overdose is suspected.[5]
Treatment
The management includes identifying and correcting electrolyte imbalances and withholding any offending medications. This condition does not require admission unless there is an associated myocardial infarction. Even though it usually does not progress to higher forms of heart block, it may require outpatient follow-up and monitoring of the ECG, especially if there is a comorbid bundle branch block. If there is a need for treatment of an unrelated condition, care should be taken not to introduce any medication that may slow AV conduction. If this is not feasible, clinicians should be very cautious when introducing any drug that may slow conduction; and regular monitoring of the ECG is indicated.[6]
Prognosis
Isolated first-degree heart block has no direct clinical consequences. There are no symptoms or signs associated with it. It was originally thought of as having a benign prognosis. In the
A subset of individuals with the triad of first-degree heart block,
Controversy
In October 2022 the
See also
References
- ^ "Lesson VI - ECG Conduction Abnormalities". Retrieved 2009-01-07.
- PMID 28846254. Retrieved 3 July 2021.
- PMID 28846254. Retrieved 3 July 2021.
- PMID 28846254. Retrieved 3 July 2021.
- PMID 28846254. Retrieved 3 July 2021.
- PMID 28846254. Retrieved 3 July 2021.
- PMID 19549974.
- ^ "Atrioventricular Block". The Lecturio Medical Concept Library. Retrieved 3 July 2021.
- ^ "Guide for Aviation Examiners, Archives and Updates" (PDF). FAA Guide for Aviation Medical Examiners. faa.gov. Archived from the original on 31 October 2022. Retrieved 31 October 2022.
- ^ "The FAA has very quietly tacitly admitted that the EKGs of pilots are no longer normal". Substack. substack.com. 17 January 2023. Archived from the original on 31 March 2023. Retrieved 31 March 2023.
- PMID 28846254. Retrieved 31 March 2023.
- ^ "New FAA cardiac health rules not prompted by COVID-19 shots". Associated Press. 20 January 2023. Retrieved 12 May 2023.