Arrythmias 2

Question 1

AV nodal blocks explanation

Answer 1

delays are a normal function of the AV node however prolonged delay and conduction block of electrical fibres causes heart block

Question 2

First degree heart block

Answer 2

every QRS impulse is delayed slightly
PR intervals over 0.2seconds
Regular
‘If the R is far from P, then you have a first degree’

Question 3

Second degree heart block Mobitz type 1

Answer 3

Gradually increasing PR interval per complex followed by a skipped QRS complex
Regular rhythm and rate of 60-100
‘Longer, longer, longer drop - then you have a Wenckebach’

Question 4

Second degree heart block mobitz type 2

Answer 4

consistent PR intervals
regular rhythm except for one dropped beat
‘if the message cant get through, then you have type 2 type 2’

Question 5

Third degree heart block

Answer 5

P waves and QRS complex present but out of sync
Both atrial and ventricular rhythms are independently regular but disassociated
generally bradycardic

Question 6

third degree mechanism

Answer 6

due to progressive fatigue of AV node or conduction failure in His-perkinje system due to septal infarction. Ventricles develop and escape rhythm which is bradycardic and out of sync.

Question 7

Mobitz type 1 mechanism

Answer 7

reversible condition of conduction block at AV node causing progressive fatigue and eventual inability to conduct an impulse.

Question 8

Mobitz type 2 mechanism

Answer 8

failure of conduction as the His-purkinje level of the system. More likely due to structural damage while type 1 is functional error. Normally alongside known LBBB