Arrhythmias

Question 1

What is AFib with RVR?

Answer 1

RVR = rapid ventricular rate

AFib with tachycardia over 100 bpm

Question 2

Presenting symptoms for AFib

Answer 2

Dizziness, syncope
Palpitations
Dyspnea on exertion
Chest pain - esp if also have underlying structural disease

Question 3

5 disease risk factors that predispose you to higher risk of developing AFib

Answer 3

1. Mitral valve stenosis or prolapse
   - Atria narrow as result of increased pressures
2. CAD
3. HF - dilated heart causes increased pressures in LA –> stretch
4. Hyperthyroidism
5. HTN

Question 4

When is the risk of stroke highest for AFib pts?

Answer 4

Right after you put them back into normal rhythm

Stagnant blood from AFib is now being moved with rhythm

Question 5

What is the difference between valvular and non-valvular AFib?

Answer 5

Valvular - with mitral valve disease (stenosis or regurgitation)
Non-valvular - AFib without those

Question 6

Why is CO reduced in AFib?

Answer 6

Answer = no atrial kick

+ fast HR (decreased filling time, lower SV with increased HR)

Question 7

How much does atrial kick contribute to LV filling?

Answer 7

20%

Question 8

What are the 2 therapeutic objectives you must do before restoring normal sinus rhythm in an AFib pt?

Answer 8

1st ALWAYS = anti-coag - warfarin, plavix, aspirin
2. Ventricular rate control
1st choice is BBs or Ca CBs

Question 9

What is the goal HR for AFib pts?

Answer 9

110bpm

Studies show no benefit to lowering this further below

Question 10

BB mechanism

Answer 10

B1 receptors blocked in heart

Trying to control the electrical activity through AV node

Question 11

Ca channel blocker

Answer 11

Control rate at nodes b/c Ca channels are larger part of nodal AP

Question 12

Non-DHP vs DHP use

Answer 12

Non = rate control
DHP = HTN control

Question 13

Goal for warfarin pts vs normal INR

Answer 13

Warfarin: 2=3
Normal: 1

Question 14

Is there a difference between pharm methods of rate control

Answer 14

Chose based on structural heart disease vs no and what other drugs they’ve tried in the past and failed

• Prolonged QT
• Structural
• HF

Question 15

Pharm methods to control rate

Answer 15

Look up on answer key!

Question 16

Meds for long term AFib prevention

Answer 16

Propanolol = BBer 
Flecanide = class 1c, Na CB w/ no change AP
Sotalol - class 3 (K CB)
Amioderone - class 3 (K CB)

Question 17

AFib pathophys

Answer 17

Multiple nodes of electrical impulse firing all at once

Question 18

AFlutter pathophys

Answer 18

Looping re-entry

Question 19

What is the CHADS scoring system to determine should you be on anti-coag therapy?

Answer 19

CHADS score
Risk for stroke
C - CHF
H- HTN
A - AGE
D - diabetes
Stroke (+2)

Question 20

Triggers for AVNRT

Answer 20

Caffeine 
Exercise
Smoking 
Stress 
Alcohol 
Increases the amt of pre-mature atrial contractions you can have -> the extra beat you need to set off AVNRT

Question 21

Non-pharm, non-electrical acute treatment for AVNRT

Answer 21

Vagal stim:
Valsalva
Carotid massage
Face in cold water
Press eyeballs = pain stim for vagus

Question 22

If you give adenosine and the arrhythmia terminates, what were the 2 possible causes of tachycardia?

Answer 22

Adenosine blocks excess tracts and lowers AV node rate
Adenosine stops AVNRT or AVRT
No rate conversion = AFib or flutter as cause of tachycardia

Question 23

What would an AVRT pt have a totally normal EKG?

Answer 23

Ventricle to atria bypass tract

Only see AVRT when tachycardia - wide complex

Question 24

Why don’t you give Ca CB or digoxin to WPW pts?

Answer 24

Both can enhance bypass tract conduction by shortening bypass refractory time
Increased rate of arrhythmias
Chose BBs or procainamide (class 1a)

Question 25

Chronically treat AVNRT or AVRT pts with meds

Answer 25

Block AV node
BBs
Ca CBs

Question 26

Pt with wide complex, regular tachycardia - p waves not consistently visible, QRS > 160 ms. What is the arrhythmia?

Answer 26

VT

Question 27

1st line treatment for sustained VT + back up

Answer 27

Amioderone
2nd lidocaine
3rd procainamide

Question 28

Cardioaversion vs defibrilation

Answer 28

Cardio - shocks pt on the QRS
Defrib - asynchronous, shock as soon as you press button regardless of where they are on their cardiac cycle, risk of putting them into a more unstable rhythm

Question 29

Rapid, irregular rhythm + wide QRS complex with continuously changing amplitude - what is the arrhythmia

Answer 29

Torsades

Question 30

Drugs for Torsades

Answer 30

Magnesium

Increase HR - isoproteronol

Question 31

Torsades pathophys

Answer 31

EAD on T wave

“R on T phenomenon”