Intermittent failure of atrial impulses to be conducted through AV node and His bundle, subdivided into Mobitz type 1 (Wenckebach) or Mobitz type 2
Mobitz type 1: delay in AV conduction progressively increases until an impulse is not conducted, on the ECG the PR interval gets longer and longer until there is a dropped beat
Mobitz type 2: intermittent failure of conduction of the atrial impulse to the ventricles usually in a 2:1 ratio, the PR interval does not lengthen
Mobitz type 1 can be due to increased vagal tone and often occurs during sleep
Mobitz type 2 is pathological and has a similar aetiology to 1st degree AV block
Bradycardia, hypotension
Can be asymptomatic, SOB, chest pain, pre-syncope/syncope
ECG: To assess rhythm; may require a Holter monitor
Echo: if LV function impaired the patient may benefit from CRT
Stop offending medications
A temporary pacing wire may be required
Mobitz type 2 always requires a permanent pacemaker
Complications: Death, injuries from syncope
Both Mobitz type 1 and 2 can progress to complete heart block
Prognosis is good following PPM implantation
Death, injuries from syncope
