Arrhythmias Flashcards
Arrhythmias are diagnosed by?
ECG
Normal resting Hr is ?
60-100
What are common complaints of arrhythmias?
palpitations, dizziness, lightheadedness, SOB, chest pain and fatigue
What is the sequence of normal sinus rhythm?
- SA node initiates electrical impluse
- impulse spreads through atria resulting in atrial contraction
- impulse goes to AV node and conduction is slowed
- impulse travels down to bundle of HIS and divides into bundle branch
- impulse spreads through ventricle via purkinje fiber
What is phase 0 of cardiac action potential?
rapid ventricular depolarization, influx of Na causing ventricular contraction (QRS wave)
What is phase 1 of cardiac action potential?
Early repolarization; Na channels close
What is phase 2 of cardiac action potential?
Plateau: influx of Ca and efflux of K
What is phase 3 of cardiac action potential?
Rapid ventricular repolarization in response to efflux of K (T wave)
What is phase 4 of cardiac action potential?
Resting membrane potential; atrial depolarization occurs (P wave)
At what phase do Class Ia, Ib, Ic work at?
phase 0
At what phase do class III work at?
phase 3
Etiology of arrhythmias?
MI, infarction, electrolyte imbalances, elevated sympathetic states, drugs
Supraventricular arrhythmias example
sinus tachycardia, A. fib, atrial flutter
Ventricular arrhythmia example?
premature ventricular contractions, ventricular tachycardia, ventricular fibrillation
When to worry when QT interval is?
> 500 msec
what can increase risk of QT prolongation?
hypokalemia, hypomagnesemia
Drugs that increase QT interval?
Class 1 antiarrhythmics, antibiotics, azole antifungals, antidepressants, antiemetics, antipsychotics, oncology agents, HIV agents
Class I
Ia: disopyramide, quinidine, procainamide
Ib: lidocaine, mexiletine
Ic: flecainide, propafenone
Class II
beta blockers
Class III
dronedarone, dofetilide, sotalol, ibutilide, amiodarone
Class IV
verapamil, diltiazem
What is goal resting HR?
< 80 BPM
Preferred for rate control?
BB and Non-DHP CCB
What is rhythm control consist of?
methods for conversion to NSR and maintenance of NSR
What drugs are used for rhythm control?
dofetilide, dronedarone, flecainide, propafenone, sotalol
MOA of Ia antiarrhythmics?
block Na and K
Which Ia have strong anticholinergic effects?
disopyramide and quinidine
Norpace, norpace CR
disopyramide
MOA of Ib antiarrhythmics?
pure sodium channel blockers
Rythmol
propfenone
Nexterone, pacerone
amiodarone
Multaq
dronedarone
Betapace, sotylize, sorine
sotalol
Corvert
ibutilide
Tikosyn
dofetilide
Therapeutic range of digoxin for Afib ?
0.8-2
