Treatment of arrhythmias

Question 1

Bradyarrythmias of SA node

Answer 1

• sinus bradycardia * sinus arrest/pause
• tachy-brady syndrome * chronotropic incompetence- inability to
  mount age-appropriate HR with exercise
• sinus bradycardia * sinus arrest/pause
• tachy-brady syndrome * chronotropic incompetence- inability to
  mount age-appropriate HR with exercise

Question 2

Bradyarrhythmias of AV node

Answer 2

1st degree AV block, Mobitz I 2nd degree AV block (Wenkebach)

Question 3

Bradyarrhythmias below AV node

Answer 3

Mobitz II 2nd degree AB block, complete heart block

Question 4

Sinus bradycardia

Answer 4

SA node fires slow (<60BPM)

Question 5

Sinus arrest

Answer 5

a pause in the rate at which the SA node firesdue to failure of SA node discharge

Question 6

Bradycardia-tachycardia syndrome

Answer 6

SA node has alternating periods of firing too slowly (< 60 bpm) and too fast (> 100 bpm). Brady-tachy syndrome often manifests itself in periods of atrial tachycardia, flutter, or fibrillation

Question 7

Chronotropic incompetence

Answer 7

HR response to activity is unstable

Question 8

1st degreee AV block

Answer 8

delay in AV conduction, but each atrial signal is conducted to the ventricles

Question 9

2nd degree AV block- mobitz I and II

Answer 9

failure of atrial depolarizations to reach the ventricle. Mobitz I(Wenckebach): Progressive prolongation of the PR interval until a ventricular beat is dropped due to block of AV node. Mobitz II: intermittent dropped beats preceded by constant PR intervals due to block of bundle of His

Question 10

Mobitz I vs II

Answer 10

Mobitz1: difference in PR intervals before and after beat is >0.02seconds. MobitzII: difference in PR intervals before and after beat is <0.02 seconds

Question 11

What is advanced second degree block

Answer 11

block of two or more consecutive P waves

Question 12

3rd degree AV block

Answer 12

The QRS complexes are not caused by conduction of the P waves through the AV node to the ventricles, but rather the QRS is initiated at a site below the AV node (such as in the His bundle or the Purkinje fibers) as an escape rhythm

Question 13

Treatment for Bradyarrhythmias

Answer 13

1. treat reversible causes (ischemia, infarct, hypothyroidism). 2. Stop offending meds (antiarrhythmics, clonidine, lithium). 3. Acute treatment for unstable patient: beta-agonists (dopamine or isoproterenol), transcutaneous pacing, temporary transvenous pacing. 4. Long term: Permanent pacemaker

Question 14

Describe implantation of pacemaker

Answer 14

generator placed in shoulder with leads that are guided by venous system into heart (atria or ventricle) where sensing of heart rhythm occurs

Question 15

Two general categories of tachyarrhythmias

Answer 15

Supraventricular tachycardia or ventricular (tachycardia or fibrillation)

Question 16

Supraventricular tachycardia classifications

Answer 16

irregular: Atrial fibrillation, multifocal atrial tachycardia (3 or more p waves), atrial flutter. Regular: sinus tachycardia, AV nodal reentrant tachycardia, atrioventricular reentrant tachycardia, atrial flutter, atrial tachycardia, and junctional tachycardia

Question 17

Acute treatment of supraventricular tachycardia

Answer 17

Shock/cardiovert if unstable. If stable: irregular SVT treated with rate control, antiarrhythmics or cardioversion. Regular SVT treated with adenosine (blocks AV node)

Question 18

Treatment of Atrial fibrillation

Answer 18

reverse cause, control rate, anti-coag, control rhythm and possible cure with ablation

Question 19

Causes of atrial fibrillation

Answer 19

hypertension, mitral valve disease, alcohol, cariomyopathies, hyperthyroidism, lone AF

Question 20

List methods for rhythm control in Afib

Answer 20

drugs: class III agents, class IC agents. Electrical: DC shock has good success but requires sedation. Ablation is last resort

Question 21

Use of anti-coags in afib

Answer 21

risk of thromboembolism from clot in atrium

Question 22

Methods for rate control in Afib

Answer 22

meds: B blocerks, digoxin, verapamil (IV), Diltiazem (IV), amiodarone

Question 23

CHAD2 tool

Answer 23

risk assessment tool that weighs the risks and benefits of taking warfarin vs having an embolus. C: CHF, H: hypertension, A: Age>75, D: diabetes, 2: prior stroke/TIA

Question 24

Atrial flutter treatment

Answer 24

Catheter ablation has high success rate (better than Afib). Targets isthmus in RA btw tricuspid and IVC

Question 25

Treatment of ventricular tachyarrhythmias

Answer 25

if unstable: shock, treat underlying causes and meds. If stable: Meds (amiodarone, lidocaine, procainamide), treat underlying . If structural heart disease, may require defibrillator. If idiopathic, meds include B blockers, Ca channel blockers, Class IC and Class II agents and ablation.

Question 26

When does patient need a defibrillator

Answer 26

Secondary prevention: Patient has had sudden cardiac arrest without reversible cause. Primary prevention: No previous cardiac arrest by significant risk due to ischemic heart disease (low Ejection fraction<35% ), ischemic heart disease with EF 35-40% and inducible VT, or structural disease (hypertrophy, etc)