aetiology
Last reviewed 01/2018
Acute atrioventricular block is caused by:
- myocardial infarction:
- complicates 15% of inferior myocardial infarcts because of transient AVN ischaemia
- permanent block is unusual and the escape rhthym originates high in the conducting system
- occasionally an anterior infarct interupts both bundle branches resulting in a slow unstable heart beat with bad prognosis
- digitalis poisoning
- diphtheria
- virus infection
Chronic atrioventricular block is caused by:
- idiopathic bundle branch fibrosis - accounts for 50% of cases in the elderly
- chronic coronary disease
- calcification of the aortic valve or mitral annulus infiltrating the conducting system
- sarcoid
- Chagas' disease
- gumma