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