Bradycardia/Pacing Basics

Question 1

What are the eight major causes of abnormal bradycardia?

Answer 1

Sick sinus syndrome, cerebral hypofusion, drug effects, SA block, inferior MI, electrolyte disorder, sleep apnea, infections

Question 2

What are the six major causes of cerebral hypofusion?

Answer 2

Sinus brady, sinus arrest, SA block, carotid hypersensitivity, neurally mediated syncope, and tachy/brady syndrome

Question 3

What drugs can cause abnormal bradycardia?

Answer 3

Digitalis, beta blockers, calcium channel blockers, and amiodarone

Question 4

Who invented the EKG?

Answer 4

Willem Eintoven

Question 5

What is important to remember about Mobitz II block?

Answer 5

It is not necessarily 2:1. The PR interval is generally constant and a QRS is dropped either occasionally or in a pattern, such as 2:1, 3:1, etc.

Question 6

What is the difference between sinus arrest and sinus pause?

Answer 6

Sinus pause is interrupted by an ventricular escape beat, whereas sinus arrest is not.

Question 7

What are the three levels of evidence for for pacemaker indications?

Answer 7

Level A: generally accepted, large, randomized trials; Level B: smaller sample sizes, but well organized non-randomized trials; Level C: consensus among experts

Question 8

What are the four types of pacemaker indications?

Answer 8

Class I: PM is useful/beneficial, Class IIa: conflicting evidence favoring PM is useful/beneficial, Class IIb: conflicting evidence not favoring PM implant, Class III: PM is not considered useful/beneficial.

Question 9

What are the four main categories that pacemaker indications apply to?

Answer 9

Sinus node dysfunction, AV block, syncopes, and specific conditions

Question 10

What are the Class I indications for patients with sinus node dysfunction (4)?

Answer 10

Symptomatic bradycardia, medication induced bradycardia, symtomatic pause >3 seconds, chronotropic incompetence.

Question 11

What are the Class I indications for patients with third or second degree AV block?

Answer 11

W/ brady < 40 bpm (w/ or w/o symptoms), asystole > 3 seconds, post-ablation, post-operation, with neuromuscular disease, or intermittent BBB for 3rd degree or 2nd type 2 with BBB

Question 12

What are the Class IIa indications for patients with sinus node dysfunction?

Answer 12

Symptomatic brady < 40 bpm, syncope with no other cause

Question 13

What are the Class IIa indications for patients with third degree AV block?

Answer 13

Asymptomatic

Question 14

What are the Class IIa indications for patients with second degree AV block?

Answer 14

Asymptomatic Type II, Type I w/ narrow or wide QRS intra or infra His EP study, PM syndrome symptoms

Question 15

What are the Class I indications for patients with first degree heart block?

Answer 15

None.

Question 16

What are the Class IIa indications for patients with first degree heart block?

Answer 16

Atrial asystole with hemodynamic consequences or PM syndrome symptoms.

Question 17

What are the Class I indications for hypersensitive carotid syncope and neurocardiogenic syncope?

Answer 17

Asystole > 3 sec w/ no medications

Question 18

What are the Class IIa indications for hypersensitive CS and NCS?

Answer 18

Recurrent syncope or positive tilt test

Question 19

What specific conditions are Class I indications for a PM?

Answer 19

Acquired AV block, chronic bi/trifascicular block, AV block w/ acute MI, sinus node dysfunction, HSCS, NCS, children and adolescents with congenital heart disease, HCOM, idiopathic CM, cardiac transplant, complete AV block w/in 24 hours after valve surgery.

Question 20

What are the three areas of consideration for a management strategy for PM’s?

Answer 20

Rate support, AV synchrony and CoMorbidities

Question 21

What are the considerations for rate support?

Answer 21

Lower rate, Rate response, Upper rate and Rate Drop Response.