Bradyarrhythmias, Pacing, ICDs

Question 1

Use of atropine cautioned in what three conditions?

Answer 1

-AMI, may increase infarct size
-Heart transplant. Lack of, or paradoxical, response.
-2nd degree type 2 block, or 3rd degree block. Block is below AV node, and will not be effective.

Question 2

Medication used for CCB or BB overdose?

Answer 2

Glucagon

Question 3

Isoproterenol - use? Side effect? Pharmacology?

Answer 3

Used to treat bradycardia. May cause hypotension. Non-selective beta agonist. May increase or decrease BP, as also causes vasodilation.

Question 4

Types of second degree heart block?

Answer 4

Type 1 (Wenkebach): Progressive lenghtening of PR interval until dropped.
-Type 2: Fixed PR & PP interval, Random dropped beats.

Question 5

Which heart blocks are at/above and which are below the AV node?

Answer 5

-At/Above AV Node: 1st degree, 2nd degree (type 1)
-Blow AV node: 2nd degree (type 2), 3rd degree.

Question 6

Indications to treat bradycardia after MI?

Answer 6

-Symptoms
-Sinus pause > 3 seconds
-HR < 40 w/ hypotension

Question 7

Indications for pacing for sinus bradycardia after MI?

Answer 7

-Asystole
-Alternating RBBB/LBBB (identifies dz below AV node)
-2nd degree block, type 2, with new BBB or trifasicular block.

Question 8

Pacer codes? (5 positions)

Answer 8

1. Pacing
2. Sensing
3. Response
4. Programability
5. Multisite pacing

Question 9

Pacer code: AAI.
What is it used for?

Answer 9

Sinus node dysfunction. Requires intact AV node. Good for AV synchrony.

Question 10

Pacer code: VVI.
What is it used for?

Answer 10

Used when AV conduction not intact. Useful backup pacing for atrial arrhythmias. Does not maintain AV synchrony.

Question 11

Pacer code: DDD.
What is it used for?

Answer 11

Used for all heart blocks. Maintains AV synchrony. Most physiologic mode. Must have wires in A & V.

Question 12

Percentage of cardiac output dependent on AV synchrony?

Answer 12

25%

Question 13

What does magnet mode do for a pacer?

Answer 13

Turns off sensing, results in asynchronous pacing at fixed rate. I.e., AOO, VOO, DOO. (Pacing/Sensing/Response).
Can be useful to stop inappropriate pacing from electrical nose such as Bovie, or to stop PPM-induced tachycardia.

Question 14

What does magnet mode do for an ICD?

Answer 14

Stops ICD shocks, but does not alter pacing mode.

Question 15

What is T-wave over-sensing regarding PPMs?

Answer 15

AKA Double-Counting, it is a form of inappropriate pacing.

Question 16

Antibiotics that prolong QTc?

Answer 16

Erythromycin, bactrim, pentamadine

Question 17

GI drug that prolongs QTc?

Answer 17

Cisapride

Question 18

Antifungal that prolongs QTc?

Answer 18

Ketoconazole

Question 19

Opiate that prolongs QTc?

Answer 19

Methadone

Question 20

Stimulant that prolongs QTc?

Answer 20

Ephedrine, pseudoephredine

Question 21

EKG findings in brugada syndrome?

Answer 21

ST elevations in V1, V2, no reciprocal changes in opposing leads. RBBB.

Question 22

Risk of brugada syndrome?

Answer 22

Ventricular arrhythmias, sudden death.

Question 23

Acute Tx for brugada syndrome?

Answer 23

Quinidine or amio

Question 24

Chronic Tx for Brugada syndrome?

Answer 24

Quinidine, ICD, catheter ablation

Question 25

Doe sepsis-induced AF need AC?

Answer 25

If lasting longer than 48 hours.