Atrial Fibrillation Lecture Powerpoint Flashcards
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A fib patients have a ___x rate of death compared to normal sinus rhythm and ___x increased risk of stroke. What population is highest prevalence of afib?
2x, 5x, elderly (>70 years)
A fib causes a loss of ____ that contributes up to 25% of cardiac output
Atrial kick
4 months of persistent Afib can result in…
….myolysis of cells, can make conversion to normal sinus rhythm much more difficult
3 clinical expressions of Afib
Paroxysmal - 1 hour to 48 hours
Persistent - 2 days to few weeks
Chronic - months to years
Most common arrhythmia responsible for Afib
-Reentry mechanism
Source of most afib origin foci can be found in the…
…pulmonary veins
Risk factors of Afib (7)
- lone atrial fibrillation in absence of structural heart disease
- holiday heart syndrome (excessive alcohol intake)
- HTN
- HF
- Post MI
- rheumatic valve disease (most common valvular disease to cause)
- Post CABG
A common sequellae in hypertrophic obstructive cardiomyiopathy (HOCM) is…
…ventricular tachycardia
Afib clinical symptoms (4)
- May be asymptomatic especially if chronic
- palpitations
- SOB
- syncope
Atrial fibrillation waves rate approx ____ bpm while atrial flutter has present ___ waves
100-160, p waves
Increased left atrial size on echocardiogram as result of chronic a fib impacts cardioversion how?
Makes it more difficult
Hemodynamically unstable patients with acute afib require this treatment (1)
direct cardioversion (synchronized)
Hemodynamically stable patients with acute afib require this treatment (4)
pharmacological approach by drugs including digoxin, IV dilitiazem or verapamil, and B blockers
3 principals of managing patient with Afib
- Rate control
- rhythm control
- anticoagulation
Pharmacological forms of rhythm control (4) and nonpharmacologic ones (2)
- amiodarone, sotalol, dofetilide, azemilide
- pulmonary vein catheter ablation or MAZE procedure (scarring of tissue to prevent abnormal signaling)
Highest risk of embolism is during the ____ of afib
First year
CHA2DS2VASc definition
A calculator to determine risk of stroke in afib patients where points are awarded to determine level of risk and justify indications for anticoagulation use (a score of 1 can indicate ASA, but 2 or more requires other anticoagulants)
Pradaxa (dabigatran) function
Direct thrombin (IIa) inhibitor that is used to prevent stroke in afib patients without need to check PT/INR
Xarelto (rivoraxaban) function
Factor Xa inhibitor used to prevent stroke in afib patients without needing PT/INR check
2 most popular anticoagulants used to prevent stroke in A fib patients
-Apixaban and rivoraxaban
After cardioversion, an Afib patient must be on anticoagulant agents for at least ____ weeks
4
2 pharmacologic cardioversion agents
- ibutilide
- dofetilide
The problem with antiarrhythmic agents
Afib is a bad condition, but some of the drugs increase life threatening arrhythmias and therefore are only given to patients if they have symptomatic afib despite adequate rate control
Amiodarone negative toxic side effects (5)
- pulmonary toxicity
- hyper//hypothyroidism
- pulmonary fibrosis (most common)
- liver toxicity
- proarrhythmias
Dronedarone function
Similar function to amiodarone but non iodinated and thus removes its bad side effects (decreases stroke, hospitalization, and death)
Dronedarone negative toxic side effects (4)
- GI nausea
- rash
- mild increase in serum creatinine
- decreased LV contraction (contraindicated in patients in heart failure)
What 2 parts of an EKG can you easily see flutter?
V1 or lead II
Atrial fib is a _____ _____ rhythm
irregularly irregular
Atrial fib can exist alongside _____.
Atrial flutter
4 classes of antiarrhythmic drugs
I (ABC) - Na+ Channel blockers
II - B blockers
III - K+ channel blockers
IV - Ca2+ channel blockers
Ashman’s phenomena
During atrial fib, a particularly wide QRS following a long RR interval then a short RR interval, often mistaken for a PVC that is benign in itself
2 EKG characteristics of pre-excitation syndrome (Wolff Parkinson white)
- short PR interval
- Delta waves
Anticoagulant required for use in valvular disease opposed to apixaban or rivoraxaban
Coumadin
Why are newer anticoagulants preferred in elderly patients? (3 reasons)
-simplified dosing, reduced drug to drug interactions, and reduced monitoring requirements
