Second degree AV block causes: Difference between revisions
No edit summary |
No edit summary |
||
| Line 1: | Line 1: | ||
__NOTOC__ | __NOTOC__ | ||
{{Second degree AV block}} | {{Second degree AV block}} | ||
{{CMG}}; {{AE}} {{CZ}} {{MS}} | {{CMG}}; {{AE}} {{CZ}}; {{MS}} | ||
==Overview== | ==Overview== | ||
Atrioventricular (AV) block is defined as an interruption in the transmission of an impulse, either transient or permanent, from the atria to the | Atrioventricular (AV) block is defined as an interruption in the transmission of an impulse, either transient or permanent, from the [[atria]] to the [[ventricle]]s due to an anatomic or functional impairment in the conduction system. In second degree AV block, some atrial impulses fail to reach the ventricles. Wenckebach described progressive delay between atrial and ventricular contraction and the eventual failure of an atrial beat to reach the ventricles. Mobitz subsequently divided second degree AV block into two subtypes, as determined by the findings on the [[electrocardiogram]]. In Mobitz type I AV block, progressive [[PR interval]] prolongation precedes a non-conducted [[P wave]]. While in Mobitz type II AV block, the PR interval remains unchanged prior to a P wave that suddenly fails to conduct to the ventricles. | ||
==Causes== | ==Causes== | ||
| Line 183: | Line 183: | ||
* [[Emery-Dreifuss muscular dystrophy]], [[sex linkage|x-linked]] | * [[Emery-Dreifuss muscular dystrophy]], [[sex linkage|x-linked]] | ||
* [[Endocarditis]] | * [[Endocarditis]] | ||
* [[vagus nerve| | * [[vagus nerve|Enhanced vagal tone in athletes]] | ||
* [[Eslicarbazepine acetate]] | * [[Eslicarbazepine acetate]] | ||
{{col-break|width=33%}} | {{col-break|width=33%}} | ||
| Line 191: | Line 191: | ||
* [[Glycogenosis type 2b]] | * [[Glycogenosis type 2b]] | ||
* [[HCM]] | * [[HCM]] | ||
* [[Neuromuscular disease| | * [[Neuromuscular disease|Hereditary neuromuscular disease]] | ||
* [[Hodgkin lymphoma]] | * [[Hodgkin lymphoma]] | ||
* [[Hyperkalaemia]] | * [[Hyperkalaemia]] | ||
| Line 214: | Line 214: | ||
* [[Myotonic dystrophy]] | * [[Myotonic dystrophy]] | ||
* [[Myxedema]] | * [[Myxedema]] | ||
* [[ | * [[Neonatal lupus erythematosus]] | ||
* [[prolonged PR interval|Normal variants of PR prolongation]] | * [[prolonged PR interval|Normal variants of PR prolongation]] | ||
* [[Pain]] | * [[Pain]] | ||
Revision as of 17:54, 6 September 2013
|
Second degree AV block Microchapters |
|
Diagnosis |
|---|
|
Treatment |
|
Case Studies |
|
Second degree AV block causes On the Web |
|
American Roentgen Ray Society Images of Second degree AV block causes |
|
Risk calculators and risk factors for Second degree AV block causes |
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Cafer Zorkun, M.D., Ph.D. [2]; Mahmoud Sakr, M.D. [3]
Overview
Atrioventricular (AV) block is defined as an interruption in the transmission of an impulse, either transient or permanent, from the atria to the ventricles due to an anatomic or functional impairment in the conduction system. In second degree AV block, some atrial impulses fail to reach the ventricles. Wenckebach described progressive delay between atrial and ventricular contraction and the eventual failure of an atrial beat to reach the ventricles. Mobitz subsequently divided second degree AV block into two subtypes, as determined by the findings on the electrocardiogram. In Mobitz type I AV block, progressive PR interval prolongation precedes a non-conducted P wave. While in Mobitz type II AV block, the PR interval remains unchanged prior to a P wave that suddenly fails to conduct to the ventricles.
Causes
Life Threatening Causes
Life-threatening conditions can result in death or permanent disability within 24 hours if left untreated.
- Acute myocardial infarction
- Acute rheumatic fever
- Bacterial endocarditis
- Myocarditis
- Severe hypothermia
Common Causes
- Acute rheumatic fever
- Bacterial endocarditis
- Calcific aortic stenosis
- Degenerative disease
- Digoxin
- Dilated cardiomyopathy
- Diltiazem
- Enhanced vagal tone
- HCM
- Hypertension
- Iatrogenic after surgical correction of VSD, tetralogy of Fallot, and endocardial cushion defect
- Inferior ST elevation MI
- Massive calcification of the mitral annulus
- Myocarditis
- Normal variants
- Penetrating and non-penetrating trauma of the chest
- Sclerodegenerative disease of the electrical conduction system
- Verapamil
- β blockers