AV blocks

Question 1

what causes AV blocks?

Answer 1

ischemia,

electrolyte abnromalities,

medications (BB, non dihydropyridine CCB - verapamil and diltiazem),

infiltrative dx (sarcoidosis),

age related fibrosis

Question 2

if pt has a 2:1 2nd degree AV symptomatic bradycardia, how do you treat them?

Answer 2

permanent pace maker.

Question 3

what do we do for a complete AV block if ptatinet is symptomatic and if there’s if there’s no medication side effect or ischemia?

Answer 3

permanent pace maker placement

note this applies regardless if patient is symptomatic or asymptomatic , with persistent or transient or occurs with rest or exercise.

Question 4

Difference between Mobitz Type 1 (wenkebach) and Mobitz type 2

Answer 4

Type 1 prolonging PR interval then dropped beat

Type 2 fixed prolonged PR interval and dropped beats

Question 5

Other indications for permanent pace maker placement

Answer 5

advanced second degree AV block (block with two consecutive P waves)

Mobitz Type 2 second degree AV (symptomatic or asymptomatic)

Mobitz type 1 second degree AV block (only if symptomatic)

Symptomatic sinus bradycardia (heart rate <40/min

Exercise chronotropic incompetence (inability to achieve 85% of age predicted maximum heart rate)

Question 6

AV node is supplied by which arter

Answer 6

right coronary artery and less commonly the left circumflex artery so a 70% stenosis of LAD won’t cause an AV block.

Question 7

what is this?

Answer 7

See P waves that have no relation to QRS complexes.

See dizziness, pre syncope, or syncope (stoke-adam attacks)

Question 8

if someone is acutely symptomatic what do you do with a complete heart block

Answer 8

give atropine but will need a pace maker

preferable a dual chamber pacing.