Dysrhythmias Flashcards
What part of the electrical system of the heart is usually diseased in Mobitz type 1 second degree block?
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
What part of the electrical system of the heart is usually diseased in Mobitz type 2 second degree block?
Usually a disease of the distal conduction system, below the AV node (his-purkinje system)
What is the treatment for Mobitz type 2 second degree block?
Permanent pacemaker
What can cause third degree AV block and how do you tell them apart on EKG?
- 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
Treatment of third degree AV block
permanent pacemaker
What part of the electrical system could be affected by the following?
- Anterior MI (LAD)
- Inferior MI (RCA)
- Anterior MI (LAD) –> distal conducting system
- Inferior MI (RCA) –> AV node
Management of acute SVT?
vagal maneuvers –> Adenosine –> slow AV conduction with BBlocker / Diltiazem / verapamil
Long term therapy of SVT
- pill in the pocket for PRN use: diltiazem + propranolol/flecanide
- use the medication that converted the rhythm
- catheter ablation
What is the most common etiology of multifocal atrial tachycardia? What is the treatment?
almost invariably associated with severe pulmonary disease. Tx: verapamil, diltiazem, choose cardioselective BB like metoprolol
Initial medications to consider for rate control in A fib
Beta blockers (metoprolol, carvedilol, bisoprolol) - careful with COPD Non-dihydropyridine CCB (diltiazem) - safe in COPD. Careful in HF
What do you do with the following CHA2DS2-VASc score?
Woman with score of 1
no anticoagulation
What do you do with the following CHA2DS2-VASc score?
Woman with score of 2
Gray zone, aspirin vs oral anticoagulation
What do you do with the following CHA2DS2-VASc score?
Woman with score of 3
Anticoagulate
What do you do with the following CHA2DS2-VASc score?
Man with score of 0
no anticoagulation
What do you do with the following CHA2DS2-VASc score?
Man with score of 1
Gray zone, aspirin vs anticoagulation
What do you do with the following CHA2DS2-VASc score?
Man with score of 2
anticoagulate
What are two situations in which you would select warfarin over a DOAC in treatment of A fib
- mechanical heart valve
- severe mitral stenosis
What is the best predictor of long term success in catheter ablation?
size of the left atrium
How to achieve rhythm control in wolff-parkinson-white syndrome with rapid rate?
- 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
Treatment of pts with symptomatic sick sinus syndrome
Pacemaker therapy
Definition of the following
- non-sustained V tach
- sustained V tach
> 3 beats in a row from ventricle at rate of > 100 bpm
- nonsustained: self termination within 30 seconds
- sustained: duration > 30 seconds
Treatment of torsades do pointes
IV magnesium
Treatment of the following genetic prolonged QT
- long QTc > 470 msec
- long QTc > 500 msec
- long QTc > 470 msec –> beta blocker
- long QTc > 500 msec –> may need ICD
Causes of acquired prolonged QT syndrome
- medications
- hypokalemia
- hypomagnesemia
- hypocalcemia
