Dysrhythmias

Question 1

What part of the electrical system of the heart is usually diseased in Mobitz type 1 second degree block?

Answer 1

Usually disease of AV node - normal in some athletes esp during sleep

• if acute, inferior wall ischemia likely
• inferior wall supplied by RCA, which also supplies AV node

Question 2

What part of the electrical system of the heart is usually diseased in Mobitz type 2 second degree block?

Answer 2

Usually a disease of the distal conduction system, below the AV node (his-purkinje system)

Question 3

What is the treatment for Mobitz type 2 second degree block?

Answer 3

Permanent pacemaker

Question 4

What can cause third degree AV block and how do you tell them apart on EKG?

Answer 4

• inferior MI –> escape rhythm originates at or near AV junction, so it appears narrow complex
• anterior MI –> escape rhythm is from ventricles and is wide complex

Question 5

Treatment of third degree AV block

Answer 5

permanent pacemaker

Question 6

What part of the electrical system could be affected by the following?

• Anterior MI (LAD)
• Inferior MI (RCA)

Answer 6

• Anterior MI (LAD) –> distal conducting system

- Inferior MI (RCA) –> AV node

Question 7

Management of acute SVT?

Answer 7

vagal maneuvers –> Adenosine –> slow AV conduction with BBlocker / Diltiazem / verapamil

Question 8

Long term therapy of SVT

Answer 8

• pill in the pocket for PRN use: diltiazem + propranolol/flecanide
• use the medication that converted the rhythm
• catheter ablation

Question 9

What is the most common etiology of multifocal atrial tachycardia? What is the treatment?

Answer 9

almost invariably associated with severe pulmonary disease. Tx: verapamil, diltiazem, choose cardioselective BB like metoprolol

Question 10

Initial medications to consider for rate control in A fib

Answer 10

Beta blockers (metoprolol, carvedilol, bisoprolol) - careful with COPD
Non-dihydropyridine CCB (diltiazem) - safe in COPD. Careful in HF

Question 11

What do you do with the following CHA2DS2-VASc score?

Woman with score of 1

Answer 11

no anticoagulation

Question 12

What do you do with the following CHA2DS2-VASc score?

Woman with score of 2

Answer 12

Gray zone, aspirin vs oral anticoagulation

Question 13

What do you do with the following CHA2DS2-VASc score?

Woman with score of 3

Answer 13

Anticoagulate

Question 14

What do you do with the following CHA2DS2-VASc score?

Man with score of 0

Answer 14

no anticoagulation

Question 15

What do you do with the following CHA2DS2-VASc score?

Man with score of 1

Answer 15

Gray zone, aspirin vs anticoagulation

Question 16

What do you do with the following CHA2DS2-VASc score?

Man with score of 2

Answer 16

anticoagulate

Question 17

What are two situations in which you would select warfarin over a DOAC in treatment of A fib

Answer 17

• mechanical heart valve

- severe mitral stenosis

Question 18

What is the best predictor of long term success in catheter ablation?

Answer 18

size of the left atrium

Question 19

How to achieve rhythm control in wolff-parkinson-white syndrome with rapid rate?

Answer 19

• do not use AV nodal blocking agents (amio, dig, Bblocker, adenosine, verapamil, diltiazem) –> may force conduction down accessory pathway
• follow usual approach for SVT
• us ibutilide or procainamide

Question 20

Treatment of pts with symptomatic sick sinus syndrome

Answer 20

Pacemaker therapy

Question 21

Definition of the following

• non-sustained V tach
• sustained V tach

Answer 21

> 3 beats in a row from ventricle at rate of > 100 bpm

• nonsustained: self termination within 30 seconds
• sustained: duration > 30 seconds

Question 22

Treatment of torsades do pointes

Answer 22

IV magnesium

Question 23

Treatment of the following genetic prolonged QT

• long QTc > 470 msec
• long QTc > 500 msec

Answer 23

• long QTc > 470 msec –> beta blocker

- long QTc > 500 msec –> may need ICD

Question 24

Causes of acquired prolonged QT syndrome

Answer 24

• medications
• hypokalemia
• hypomagnesemia
• hypocalcemia