Atrial Dysrhythmias Flashcards
Name the 4 types of Atrial Dysrhythmias
Premature Atrial Contraction (PAC)
Atrial Fibrillation
Atrial flutter
Paroxysmal supraventricular tachycardia (PSVT)
Define Premature Atrial Contractions
Ectopic pacemaker in atrium discharges before SA node fires
What causes Premature Atrial Contractions?
Usually, benign
Check electrolytes (If you notice new onset of PAC’s/ increased in frequency check for electrolyte imbalance)
Increase in frequency may be indicated patient is about to convert to a-fib
Stress
Cardiac stimulants (caffeine)
May indicate Atrial pathology
Define Atrial Fibrillation
Total disorganization of serial electrical activity due to multiple ectopic foci,resulting in loss of effective Atrial Contraction (kick)
Atrial rate >400bpm Ventricular rate >100-175bpm
R to R intervals are Irregularly Irregular
Most common dysrhythmia
Prevalence increases with age
What causes Atrial Fibrillation?
Usually occurs with some underlying heart disease (all of them)
Electrolyte imbalance
Hypoxia
Cardiac surgery
Atrial Fibrillation equation
Atrial Fibrillation=fibrillating atria=pooling of blood=clot information=risk for embolus
Note: If in LA (left atria) can cause a stroke
What will the patient with Atrial Fibrillation look like?
Depends on Ventricular rate, how long rhythm has been present, and the patient’s CV status.
Typically, Onset is FAST rate-so s/s are those of tachydysrhythmia
Define Atrial flutter
Identified by recurring, regular, saw-toothed-shaped flutter waves
Originates from a single ectopic focus; reentry impulse is repetitive & cyclic (one irritable cardiac cell in the atria that wants to be in charge)
R to R interval is regular or irregular
Atrial rate may be >250bpm; Ventricular rate slower
What causes Atrial flutter?
Rarely occurs in a healthy heart; underlying heart condition (any of them)
Electrolyte imbalance
What does the patient with atrial flutter look like?
Depends on Ventricular rate, how long the rhythm has been present, and the patient’s CV status
Typically, onset is FAST rate- so s/s are those of tachydysrhythmia
And-Yes at risk for emboli.
Atrial Fibrillation/Flutter goals
Ventricular rate control
Rhythm control
Prevent embolic stroke
How do we treat Atrial Fibrillation/Flutter?
Drugs for RATE control: B-adrenergic Blockers(metoprolol),calcium channel Blockers(diltiazem, verapamil)-initially IV route
Drugs for RHYTHM control: amiodarone & doFETilide-initially IV route
Drugs to prevent clots: warfarin
How do we treat Atrial Fibrillation/Flutter?
If stable, but symptomatic?
Slow Ventricular rate with IV either calcium channel blocker, beta blocker, digitalis, amiodarone
May be “bolus” & start a drip…
If unstable/hemodynamically compromised?
Synchronized cardioversion
Define Synchronized cardioversion
Choice of therapy for hemodynamically unstable supraventricular tachydysrhythmia
Synchronized circuit delivers a countershock on the R wave of the QRS complex of the ECG (need to have a R wave before cardioverting a patient)
Synchronizer switch must be turned ON
If the synchronized cardioversion is non-emergency the patient is sedated before the procedure (True/False)
True
What is the initial energy for synchronized cardioversion?
50 to 100 Joules (increase if needed)
Make sure all personnel are “ALL CLEAR” before discharging the device during a synchronized cardioversion (True or False)
True
What do you do if a patient becomes pulseless during a synchronized cardioversion?
Turn the synchronizer switch OFF & perform defibrillation
Synchronized cardioversion nursing care
Maintain patent airway
Administer oxygen
Assess VS & LOC
Monitor for dysrhythmias
Provide emotional support
Document results of cardioversion
How to treat Atrial Fibrillation if has a-fib for >48 hours
Anticoagulation therapy with warfarin (Coumadin) is recommended for 3 to 4 weeks before cardioversion and 3 to 4 weeks after successful cardioversion
What procedure is performed before a Cardioversion (to make sure no clots in atrium)
TEE (Transesophageal Echocardiogram)
What medication will be administered if emergent cardioversion performed?
Low-molecular weight heparin or heparin drip will be initiated.
If treatment for atrial Fibrillation/Flutter doesn’t work, what’s next?
Long term anticoagulation therapy.
Drug of choice is typically warfarin (Coumadin)
Disadvantage-have to monitor INR regularly
Alternative anti-coag drugs
dabigatran (Pradaxa), apixaban (eliquis) Twice daily
Rivaroxaban (Xarelto), eboxaban (Savaysa) once daily
Advantage: (no routine lab testing)
Disadvantage: Cost, more than once daily dosing & contraindicated with impaired renal function
What limits atrial Fibrillation/Flutter pharmacy therapy for dysrhythmias?
High failure rates
Potential for drug toxicity
Non-pharmacology treatment for atrial Fibrillation/flutter.
Catheter ablation
Radio-frequency or cryothermal therapy
Maze procedure
What is a Catheter ablation?
Invasive procedure that destroys an irritable focus causing the dysrhythmia
Must undergo EP studies & mapping procedures to locate the focus.
What is a Maze procedure?
Surgical procedure consists of creating a number of incisions in atrium to disrupt the re-entrant circuits. Looks schematically like a children’s Maze with only one path from the SA node to the AV node.
Define Paroxymal Supraventricular tachycardia (PSVT)
Originates in ectopic focus anywhere above bifurcation of Bundle of His
Run repeated premature beats is initiated and it usually starts with a PAC
Paroxysmal refers to an abrupt onset and termination (without warning).
What causes PSVT?
In normal heart
Overexertion
Emotional stress
Stimulants
Digitalis toxicity
Various forms of heart disease
What does the patient look like with PSVT?
Depends on how long it lasts & how FAST Ventricular rate
(See Key Features slide) Tachydysrhythmias
How do we treat PSVT?
Vagal maneuvers (should be on monitor)
Valsalva (most effective)- Hold breath 10-15 seconds (should see neck distention), then resume breathing.
Coughing
Carotid sinus massage (CSM) MD ONLY
Diving reflex/cold water immersion- submerge face in cold water (triggers vagal response)-Due to complexities, rarely used in modern clinical medicine
How to treat PSVT if vagal maneuvers fail?
Adenosine IV push
VERY short half life (follow with rapid NS flush)
May cause a pause on rhythm strip, patient may be aware
Onset=10-40 seconds/duration 1-2 minutes
How do we treat PSVT if vagal maneuvers and/or drug therapy is ineffective and/or patient becomes hemodynamically unstable?
Cardioversion
