Atrial Fibrillation Flashcards
A fib is a common cardiac arrhythmia with EKG characteristics of?
- no repetitive pattern of R-R intervals
irregularly irregular - no distinct p waves
problems with having a-fib?
decreased cardiac output
increased risk for thrombus formation
increased risk for arrhythmias
pathogenesis of A-fib.
usually some underlying heart disease causes multiple wavelet formation in the atria
as AF becomes established, the refractory period of atrial muscle shortens so these electrophysiologic changes predispose to further AF
long standing hypertension causes ___
hypertrophy
prevalence and incidence of A- fib increase with ___ and with presence of ____disease
age
presence of CV disease
do men or women have higher risk of a-fib?
men
potential risk factors for a-fib
hyperthyroidism surgery: cardiac as well as non-cardiac family hx or genetics low birth wt inflammation and infection pericardial fat PACs other SVTs low Mg ETOH consumption medications- anything that can affect HR can cause arrhythmia
chronic disease associations with a-fib
two most common:
- hypertension
- coronary heart disease
common in undeveloped countries: rheumatic heart disease
other associations: valvular heart disease HF hypertrophic cardiomyopathy congenital heart disease COPD OSA UTE diseases DM metabolic syndrome CKD
Acute AF etiology
PIRATES
P: Pulmonary disease I: ischemia R: rheumatic heart disease A: anemia/ atrial myixema T: thyrotoxicosis E: ethanol S: sepsis
Chronic AF etiology
HTN
CHF
what is A-fib with RVR
Atrial fibrillation with rapid ventricular rate, over 100
what is Paroxysmal AF
a-fib terminates spontaneously or with intervention within 7 days of onset
what is persistent AF
A-fib that fails to self terminate within 7 days
often requires drug or electrical cardioversion
what is long standing persistent AF?
A-fib that lasts more than 12 months
What is permanent AF?
persistent AF where joint decision is made to no longer pursue a rhythm control strategy
in ______ AF, myocytes are still relatively healthy and can revert back to sinus rhythm within 7 days
paroxysmal
Prevention of AF
Physical activity and weight loss
Mediterranean diet
Symptoms of patient with AF
not all are symptomatic could be presenting with embolus-stroke typical features: -fatigue -SOB - Palpitations/ tachycardia - weakness -lightheardedness - generalized malaise
more severe symptoms:
- dyspnea at rest
- angina
- presyncope/syncope
precipating causes that could cause AF
alcohol
emotion
exercise
potentially reversible causes of AF
hyperthyroidism
alcohol excess
diagnostic tests for AF
ekg blood tests echo holder monitor stress test chest x ray
what lab tests would you do in pt with AF?
TSH, T4 CBC BMP/CMP Urine for protein glucose for A1C troponin magnesium phosphorus BNP PT/INR, aPTT
two types of echo that can be done on pt with AF
- transthoracic echo (TTE)
- evaluate size of atria
- size/function of ventricles
- detect valvular disease, LVH, pericardial disease - transesophageal echo (TEE)
- select patients to assess for thrombi in Left atrium of left atrial appendage
- clots can move in cardioversion- so need to check risk for thrombus already formed
what test must you get if you suspect AF
EKG
for a patient with AF that you may suspect has CAD, what additional test would you do?
stress test
hemodynamic instability present with what symptoms?
BP is low or high patient in distress tachypnea oxygen is low cyanotic syncopal
all this means they aren’t getting enough perfusion to the tissues
goals of AF therapy
control symptoms if present
prevent thromboembolism
example circumstances where urgent/emergent cardioversion may be needed
- acute ischemia
- evidence of organ hypo perfusion (cool clammy skin, confusion, acute kidney injury)
- severe manifestations of HF (pulmonary edema)
- hemodynamic instability
reasons to admit for AF
management of HF or hypotension after control of rate or rhythm
initiation of antiarrythmic drug
treat associated medical problems- HTN, thyroid storm, infection, COPD, PE, cardiac ischemia, etc.
in rate control, drugs are used to slow conduction through ____.
AV node
for most patients who are with new onset AF and who are in the AF at the time of presentation, ______ control will precede any attempt to restore sinus rhythm.
rate control
if a patient is hemodynamically unstable, would you use rate or rhythm control?
rhythm
need to cardiovert
most patients with AF will require slowing of _______ to improve symptoms
ventricular rate
rate control medications
- beta blockers
- calcium channel blockers - verapamil or diltiazem
- digoxin: only used in HF patients
rhythm control options
- anti arrhythmic drug therapy
- percutaneous catheter ablation
- surgical procedures
____ control us more often used in patients with asymptomatic or mildly symptomatic AF and are older than 65 yrs old
rate control
____ control us typically used in symptomatic patients younger than 65
rhythm
when selecting a beta blocker for AF, would you use propranolol?
no, it is not cardioselective
potential indications of cardiversion
hemodynamic instability first episode long term rhythm control symptomatic or persistant AF infrequent symptomatic episodes potentially reversible cause
when not to cardiovert
minimal to no symptoms
low likelihood of success:
- AF continuously for more than 1 year
- left atrium markedly enlarged
- AF recurrence while taking antiarrhytmic drug
- when underlying precipitant has not been corrected- pericarditis, thyrotoxicosis, etc.
the most serious, common complication of AF is ___
arterial thromboembolism
the most clinically evident TE event is ____.
ischemic stroke
risk factors for TE event
rheumatic mitral stenosis, prosthetic heart valves
Age older 65
prior stroke/TA
DM
HTN
method to evaluate need for antithrombotic therapy?
CHA2DS2-VASc score
CHA2DS2-VASc score
what is each category?
C- congestive HF or LV dysfunction H- HTN A2- age over 75 D- DM S2- prior Stroke or TIA or TE V- vascular disease A- age- 64-75 yrs Sc- sex category (female)
anyone with a CHA2DS2-VASc score of ___ needs to be treated on antithrombotic therapy
2
patients who require antithrombotic therapy
- anyone considered for cardioversion
2. those who meet criteria for long term anticoagulation
what does the CHA2DS2-VASc score of 2 mean?
strongly reccomend that non valvular AF patients receive oral anticoagulation
benefit exceeds risk for almost all patients
What does the CHA2DS2-VASc score of 1 mean
more variability than with score of 2 or more
age is more significant risk factor, can use to determine therapy
clinical judgment will play important role in helping patient choose between anticoagulation and no anticoagulation
what does a CHA2DS2-VASc score of 0 mean
no anticoagulation is recommended for majority of patients
For an AF patient that has had it more than 48 hours, what should anticoagulation protocol be?
give oral anticoagulation at least 3 weeks prior to cardioversion and use for 4 weeks of oral anticoagulation after
For an AF patient that has had it less than 48 hours, what should anticoagulation protocol be?
can depend on whether anticoagulation is used, use clinical judgement
reasons to anticoagulate before and after cardioversion
most embolic events occur within ten days of cardioversion
patients undergoing cardioversion of AF more than 48 hours duration are a high risk group for embolic event
types of anticoagulants used for AF
- direct thrombin inhibitor
- factor Xa inhibitor
- vitamin K antagonist
which anticoagulant is indicated for A-fib with valvular disease
vitamin K antagonist- warfarin
_____ have shown similar or lower risk of ischemic stroke and major bleeding events vs warfarin in nonvalvular AF
DOACs
advantages of DOACs
convenience- no routine INR testing
high relative reduction in ICH
lack of susceptibility to dietary interactions
reduced susceptibility to DDI
disadvantages of DOACs
lack of efficacy and safety in CKD
lack of easy monitoring of blood levels and compliance
higher cost
unknown potential ADRs with continued long term use
situations in which you may prefer warfarin
already on warfarin
prosthetic heart valves, rheumatic mitral valve disease, mitral stenosis, and other valve diseases
not likely to comply with dosing of DOACs
cost
CKD with GFR less than 30
if DOAC is CI, especially due to DDIs
what DOAC should you use for ESRD
apixaban
could you use ASA alone as an anticoagulant
no
what can you use in patients that can’t be treated with anticoagulant
aspirin and clopidogrel
most patients will not need bridging with IV ____ heparin
unfractionated
if bridging is needed, what heparin should you use?
LMWH
when should you consider bridging anticoagulant in an AF patient?
if deemed high risk for TE event but low risk for hemorrhage
do you bridge a patient with nonvalvular AF with acute stroke?
no, ischemic stroke could turn into hemorrhagic stroke
for first episode of AF, is electrical or pharm cardioversion preferred?
electrical
for paroxysmal AF, is drug or electrical therapy preferred?
drug
possible indications for hospitalizations with patients with AF
ablation is considered- especially in symptomatic and associated with hemodynamic collapse and RVR
bradycardia after cardioversion
treatment of associated medical problems
elderly patients
further management of HF or hypotension after control of rate to rhythm
imitation of antiarrythmic drug therapy
follow up appointments in patients with AF should usually be seen again in ___.
1 week
