Atrial Fibrillation Treatment & Complications Flashcards
What is Atrial Fibrillation?
A supraventricular tachyarrhythmia wth uncoordinated atrial activation and consequently ineffective atrial contraction
What characteristics can be observed on an ECG during atrial fibrillation?
- Irregular R-R interval
- Absence of distinct repeating P waves
- Irregular atrial Activity
** if very fast, (greater than 200 bpm) the R-R will already be very fast so it may be difficult to see that it is irregular, so you may have to slow down the pulse before you can diagnose it
What is the cause of the irregular rhythm seen in atrial fibrillation?
Everything in the atria is in a circus rhythm, which is where the irregularity comes in & when you have a depolarization touch the AV node, it sends it to the ventricle, causing the irregularity of ventricular contraction
What are the major steps to atrial fibrillation diagnosis?
- Pulse palpation (can help you identify irregularity)
- 12 lead ECG
- Holter monitoring
- Others
- Echocariogram (can see that they are not having normal atrial contractions)
- Labs
- Thyroid function test (TFT), electorlytes, clotting, Liver function test (LFT), CBC
How could you identify this ECG as atrial fibrillation?
- Rate
- not identifiable because they are variable (R-R)
- irregular
- P waves?
- no distinct P waves
What is the criteria for an ECG diagnosis of atrial fibrillation?
- P waves are absent adn R-R interval is variabl
- f-waves (atrial rate - 350-600 beats/min)
- Ventricular response in grossly irregular at 100-160 beats/min
- Rate: no. of R waves x 6 (10 sec strip)
- also, notice the R waves may have different amplitudes reflecting the different amount of time for preload & repolarization
What percent of individuals aged 40 and older will develop atrial fibrillation?
25%
Is the prevalence of atrial fibrilation higher in males or females?
males
How does the addition of atrial fibrillation affect the occurrence of the following situations
Death
Stroke
Hospitalization
Quality of life & Exercise capacity
LV function
- Death rate is doubled
- Stroke risk increases 5x
- Hospitalization is more frequent
- Quality of life & Exercise capacity can be markedly decreased
- LV function - tachycardia myopathy / heart failure
Fill out the indicated spaces in the provided table
Far right column is preferred treatment
- have to document the initial event (when they first felt palpitations)
What are the cardiac etiologies of atrial fibrillation?
- hypertensive heart disease
- valvular heart disease
- ischaemic heart disease
- cardiomyopathy
- pericarditis
- congenital heart disease
- post cardiac surgery
What are the non-cardiac etiologies of atrial fibrillation?
- Pulmonary: pneumonia, COPD, PE
- hyperthyroidism
- excess catecholamine / sympathetic activity
- drugs and alcohol (meth)
- significant electrolyte imbalance (K+, Ca2+)
- thyrotoxicosis
What are the characteristics of long atrial fibrillation?
- Purely an electrical diagnosis
- younger patients <60
- no underlying cause
- usually not much symptoms
- normal heart structure
- no associated co-morbidities
What is the pneumonic for precipitants of atrial fibrillation?
- P: pulmonary embolism
- I: ischemia (cardiac)
- R: respiratory disease
- A: atrial enlargement or myxoma
- T: thyroid disease (check 1st episode TSH)
- E: EtOH withrawl (“holiday heart”)
- S: sleep anea / sepsis
also consider chronic hypertension & myocarditis
Why is atrial fibrillation management important?
Extremely common & can lead to symptoms
- Potentiall serious consequences
- embolism
- impaired cardiac output
- increased mortality
Non-dihydropyridine calcium channel blockers are contraindicated in patients with what conditions?
patients with left ventricular systolic dysfunction & decompensatd heart failure b/c of their negative inotropic effects
Fill out the treatment diagram based on the indicated conditions
What time frame indicates acute atrial fibrillation & how is it managed?
- Hemodynamically unstable
- hypotension/acute heart failure/chest pain (MI)/syncope/Altered mental status
- use DC cardioversion - ACLS algorithm
- synchronized shock, b/c they do have a pulse
- Hemodynamicallly stable
- rate control: if significant tachycardia
- rhythm control: flecainide, propafenone (cl-l), amiodarone, sotalol (cl-III)
- anticoagulant: LMWH, UFH
Describe the management of permanent atrial fibrillation
- heart rate control
- minimize symptoms associated with excessive heart rates
- prevent tachycardis-associated cardiomyopathy
- anticoagulation
In which scenarios is rhythm control the preferred therapy?
- first epidose
- reversible cause (alcohol)
- symptomatic patient despite rate control
- patient unable to take anticoagulant (falls, bleeding, noncompliance)
- CHF precipitated or worsened by afib
- young afib patient (to avoid chronic electrical & anatomic remodeling that occurs with afib)
In which scenarios is rate control the preferred therapy?
- age > 65, less symptomatic hypertension
- recurrent afib
- previous antiarrhythmic drug failure
- unlikely to maiintain sinus rhythm (enlarged LA)
Why is cardioversion performed & what are the two types?
What other drug needs to be administered during a cardioversion? Why?
- Cardioverstion is performed as part ofa rhythm-control treatment strategy
- Types
- electrica (ECV)
- pharmacological (PCV)
- Cardioversion of AF is associated with increased risk of stroke in the absence of antithrombotic therapy
What are the uniqe risks associated with rhythm control drugs as compared to rate control in the Affirm study?
- 80% needed to hospitalized (opposed to 73% with rate control)
- chance of survival from entering bradycardia or pulseless electrical activity (PEA) - common with rhythm control - is less than chance of survive after entering vfib or vtach caused by rate conrol drugs
- higher change of entering torsades de pointes
- No difference: death, disabling stroke, majore bleed or cardiac arrest
- Sinus rhytm maintained only 63% of rhythm contorl group
What are the major rate control drug options?
- Beta blocker
- calcium channel blocker
- digoxin
- AV junction ablation pluc pacemaker
How is stroke risk affected by atrial fibrillation?
include percentages for both below 60 & above 80
- without AF
- < 60 yrs: 0.5%
- > 80 yrs: 3%
- with AF
- < 60 yrs: 3% (5x higher)
- > 80 yrs: 30% (10x higher)
What are the clinical factors accociated with risk of stroke in patients with atrial fibrillation?
- mitral stenosis
- previous stroke
- increasing age
- hypertension
- CCF
- diabetes
- CHD
- Hyperthyroidism
What are the echo factors accociated with risk of stroke in patients with atrial fibrillation?
- mitral stenosis
- LV dysfunction
- Left atrial spontaneous contrast (left atrial enlargment)
How do you calculate someone’s CHA2DS2VASc?
** very likely will be on exam
What is the percent stroke risk associated wtih each level of
CHA2DS2VASc?
What criteria can lead to increase risk of a major bleed on an anticoagulant on anticoagulation for atrial fibrillation?
What is indicated “high risk”?
> 3 = high risk
major bleed: intracranial, HB drop > 2gm, transfusion, hospitilization
What is themost common anticoagulant we use with atrial fibrillation?
warfarin
With atrial fibrillation, what is the target INR?
2-3
?? I don’t really know what this means
What patients should remain on warfarin?
- patients already receiving warfarin and stable whose INR is easy to control
- If dabigatran, rivaroxaban, apixaban are not available
- Cost
- if patient is not likely to comply with twice daily dosing (Dabigatran, Apixaban)
- Chronic kidney disease (GFR < 30 ml/min)
What is RF ablation therapy?
rhythm control strategy
electrophysiology
can ablate around the pulmonary veins, where a lot of afib originates
When should you consider ablation therapy?
antiarrhythmic therapy ineffective
antiarrhythmic therapy not tolerated
symptomatic afib
Ablation should be considered as a first strategy for individuals with what characteristics?
- patients very symptomatic in AF and refuses antiarrhythmic drug therapy
- young patients whose only effective antiarrhythmic drug is amiodarone
- patient with significant bradycardia for whome antiarrhythmic drug therapy will require pacemaker
