Ch 6 Arrhythmias & Cardiac Arrest Flashcards
(27 cards)
Management of A-fib
Rate control v rhythm conversion
Chronic A-fib: thrombus at L atrium / L atrial appendage. NEVER want to convert unless you confirm via TEE there is no thrombus present
Medications: Amiodarone (safer for pt with rEF) / BB / CCB -diltiazem ( caution with rEF) / Digoxin / Anticoagulation if sustained A-fib
Amiodarone
Indications: atrial or ventricular arrhythmias
Effects: K+ channels in myocardial cells
Adverse Effects: Monitor QTc prolongation, bradycardia, hypotension
Long Term: toxicity, pulmonary fibrosis, neuro or hepatic injury, thyroid dysfunction
Long Half Life- 58 days b n
Digoxin effects & uses
Increases myocardial contractility, slows conduction impulse through the AV node
Control ventricular rate in A-fib / a-flutter
Best suited for patients with HF / A-fib
Digoxin can cause almost any ____?
Arrhythmia
_____ increases risk of digoxin toxicity
Hypokalemia
Meds that increase or decrease the effects of digoxin
Increases Dig levels : Amiodarone (reduce digoxin dose by 1/2 when amiodarone started) & PPIs
Decrease: Antacids - decreases bioavailability of Dig
Signs of Digoxin Toxicity
Bradycardia
Prolonged PR Interval - 1st degree AV block
ST segmented depression
Prolong QT interval
Vision changes, see yellow halos
N/V
Dizziness
Stable vs Unstable SVT
Stable - VAD
V - Vagal Manuevers
A - Adenosine 6 / 12 x2 every 1-2 minutes
D - Diltiazem or BB
Unstable - synchronized cardioversion
Adenosine effects
Depresses AV node conduction & SA node activity for SVT
Adenosine half life
<10 seconds
Adenosine adverse effects
Momentary asystole or AV block, facial flushing, hypotension, nausea
Adenosine Contraindications
Heart blocks / WPW with wide QRS, asthma/bronchospasms
Which leads best for differentiating SVT vs ventricular origin?
V1 & V6 - positive concordance in the precordial leads shows more likely VT than SVT
Drug of choice for monomorphic wide complex tachycardia?
Lidocaine
*** Since 2010 guidelines - adenosine 6 mg IV may repeat dose
What uses abnormal conduction pathway between the atria & ventricles often using the Bundle of Kent accessory pathway? Accessory pathways conduct faster than the AV node?
Wolfe-Parkinson-White
What has a delta wave - slurred upstroke in the QRS and a short PR interval <0.12 sec?
WPW
What is the treatment for WPW?
Antiarrhythmic medications to slow conduction
- BB often used
- Flecainide, propafenone, sotalol, or amiodarone
What medications are avoided in WPW?
Digoxin, calcium channel blockers & adenosine. These AV nodal blocking agents may cause VT
Short term treatment of WPW?
Cardiovert if unstable
Long term treatment of WPW?
EP consult for ablation of the accessory pathway
IA Prolongs repolarization - used in atrial / ventricular dysrhythmias. QT prolongation
Quinidine (Cardioquin)
Procainamide
1B Shortens action potential duration for ventricular dysrhythmias
Lidocaine (xylocaine)
Tocainamide (Tonocard)
Mexiletin (Mexitil)
1C Blocks Na+ Channels for ventricular dysrhythmias
Flecainamide (tambocor)
Propafenone (Rhythmol)
II Decreases HR & SA node automaticity beta blocker for atrial dysrhythmias & SVT
Propanolol (Inderal)
Esmolol (Brevibloc)
