Arrhythmias Flashcards
______ arrhythmias result from disturbances in impulse discharge and impulse _______ from the sinus node
Sinus; conduction
List the 5 sinus arrhythmias
Sinus bradycardia
Sinus tachycardia
Sinus arrhythmia
Sinus arrest
Sinus exit block
Normal sinus rhythm
Sinus tachycardia
Can be caused by anything that stimulates the sympathetic nervous system or inhibits the parasympathetic nervous system
Sinus tachycardia
Drugs such as epinephrine, norepinephrine, dopamine, dobutamine, tricyclic antidepressants, isuprel, cocaine, and nitroprusside _______ sympathetic tone causing ______ HR
Increased, increased
Drugs such as atropine _____ parasympathetic tone resulting in _____ HR
Decrease, decreased
Sinus bradycardia
The sympathetic nervous system works as a cardiac ______
Accelerator
The autonomic nervous system works as a cardiac ______
Inhibitor
Sinus tachycardia begins and ends ______ in contrast to other tachycardias that begin and end ______
Gradually; suddenly
Marked bradyarrhythmias alternating with episodes of tachyarrhythmias that is accompanied by symptoms of hemodynamic compromise (dizziness, syncope, CP, HF)
Tachy-Brady syndrome
Treatment of choice for persistent sinus bradycardia
Atropine
Max dose: 3 mg
Sinus arrhythmia
Sinus pause (arrest and exit block)
Differentiator for sinus pauses
Sinus block on time
Sinus arrest not on time
A pacemaker other than the sinus node
Ectopic pacemaker
Can be atrial junctional or ventricular
Abnormal condition in which myocardial cells may depolarize more than once after stimulation by a single electrical impulse
Triggered automaticity
Common causes of triggered automaticity
MI
hypoxia
hypomagnesemia
Long QT
Slow HR
meds that prolong repolarization
Circular movement of an impulse commonly resulting in rapid heart rates
Reentry
Wandering atrial pacemaker
Common causes of reentry
MI
Hyperkalemia
Accessory pathway
The pacemaker site shifts back and forth between the sinus node, other atrial sites, and sometimes the AV node
Wandering atrial pacemaker
Common cause of WAP
Increased vagal effect on the SA node
(Altered automaticity)
Variant of WAP with rates > 100 bpm
Common in persons with COPD
MAT
multifocal atrial tachycardia
PACs
PACs associated with a wide QRS complex
Aberrantly conducted PACs
Due to impulse reaching the bundle branches before repolarization is complete. Causes sequential depolarization of ventricles
T/F
The pause associated with PACs is usually non compensatory
True
Measurement from r wave before PAC to r wave after PAC is less than the sum of two R-R intervals of underlying rhythm
Common causes of PACs
Stress
Alcohol, caffeine, nicotine
Hypoxia
MI
Chronic lung disease
When PACs occurs in consecutive runs of three or more (at a rate of 140-250 bpm)
______ is considered to be present
Atrial tachycardia
Nonconducted PAC
Most common cause of unexpected pauses in a regular sinus rhythm
Nonconducted PACs
How to differentiate between Nonconducted PAC and sinus pauses
Compare T wave contours
PAC will alter T wave
Atrial Tachycardia
Paroxysmal atrial tachycardia is commonly initiated by a ____
PAC
Initial treatment of choice in patients with PAT who are hemodynamically unstable
Cardioversion
Treatment options for patients with PAT who are hemodynamically stable
1st: Sedation
Next: vagal maneuvers
Adenosine 6mg
Rate control drugs (CCB, BB)
Ablation
Atrial flutter
Consists of a negative component followed by a positive component producing v shaped waveforms
Sawtooth appearance
Flutter waves in atrial flutter
In atrial flutter _____ ratios are more common than _____ ratios
Even; odd
If the conduction ratio varies, the ventricular rhythm will be irregular and the rhythm described as atrial flutter with ______\\
Variable AV conduction
Clots in the atria
Mural thrombi
If atrial flutter has been present less than ______ it is safe to convert the rhythm with cardioversion or amiodarone
48 hours
atrial fibrillation
_____ is the most common rhythm next to sinus rhythm
Atrial fibrillation
AF with a V rate <100 bpm
Controlled atrial fibrillation
AF with a V rate >100 bpm
Uncontrolled AF or AF with rapid ventricular response (RVR)
Commonly caused by valvular heart disease, particularly mitral valve disease
Chronic AF
List the 6 atrial arrhythmias
Wandering atrial pacemaker
Premature atrial contraction
Nonconducted PAC
Paroxysmal atrial tachycardia
Atrial flutter
Atrial fibrillation
