Atrial Fibrillation Flashcards

(43 cards)

1
Q

AFib is the? Explain the types of Afib?

A

• THE most common sustained arrhythmia • Can be paroxysmal, persistent or permanent • Paroxysmal (PAF) – Start/stop spontaneously – Duration < 24 hours; usually minutes to few hours • Persistent – Duration < 7 days, or – Requires chemical or electrical termination • Permanent (Chronic) – Does not respond to therapy

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2
Q

Valvular Afib? Non-valvular?

A

Valvular stenosis (MS) Prosthetic valve Non-valvular: Garden variety AF (HTN, diabetes, heart disease)

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3
Q

Explain the risk of stroke in AFL and AFib?

A

• Risk of stroke is higher in both AF and AFL • There may be a continuum of increasing risk with increasing disorganization of atrial activity • Thrombus formation in LAA: > 95% – LAA has tremendous anatomical variation • Mechanism of thrombus formation – Mechanical dysfunction with stasis of blood – Pro-inflammatory state – Pro-coagulant state

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4
Q

The clinical decision for anticoagulants with afib/AFL?

A

• AF = AFL in terms of stroke risk – Rx the same • PAF = Persistent = Permanent in stroke risk • So, clinical decision regarding anticoagulation is NOT based on the arrhythmia but on the risk factors – CHADS2 or CHADS2-VA2 Score

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5
Q

AF medical statistics?

A

AF is important Common Prevalence is increasing Disability and Death Stroke – risk is 5 x  Symptoms  QOL Associated with 2x mortality Expensive PH issue Medicare $20B

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6
Q

ABC’s of Afib?

A

Treatment Imperatives A: Anticoagulate / ASA / Appendage closure B: Best Rhythm ? SR or is rate control adequate? If SR, attempt FIRST o/w, it may be too late C: Control rate ?

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7
Q

What is the leading cause of hospitalizations for Arrhythmia?

A

AF Is the Leading Cause of Hospitalizations for Arrhythmia

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8
Q

80% of patients with MS who develop embolism, have?

A

AF

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9
Q

Stroke incidence? 90% of strokes are? AF is the most______?

A

800,000 – 900,000 per year in the U.S. 90% of all strokes are ischemic strokes > 30% are unexplained = cryptogenic (> 200,000 per year) AF is the most common underlying cause of cryptogenic strokes (30-40%)

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10
Q

Afib can cause? Onset? effects on HF?

A

• Palpitations, SOB, dizziness, not feeling well • Exercise intolerance • Onset may be gradual… – may be hard for some patients to recognize – often attributed to “age” • Worsens HF – Tachycardia-induced cardiomyopathy – LVH / HCM (hypertrophic cardiomyopathy) – loss of AV synchrony

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11
Q

AF increases stroke risk by?

A

AF: Stroke risk by 3-5 fold • Strokes – ischemic (90%) or hemorrhagic (10%) • 30-40% of ischemic strokes are cryptogenic; i.e. 1/3 of ALL strokes • AF is the most common cause of cryptogenic strokes • AF-strokes are WORSE than “non-AF” strokes – because of larger infarctions • Since AF is increasing, we WILL see more strokes in the future

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12
Q

AF and mortality?

A

AF is associated with increased Mortality • Association may not be causal – but AF is a bad sign! • Patients with HF – AF is associated with 2x increased mortality • Patients with ICD – AF is associated with 2x increased mortality

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13
Q

AF expenses?

A

• 80% of AF patients are > 65 years age1 • Medicare is the primary payer for AF care in the US:2 – Hospital inpatient 78.4% – Hospital outpatient 56.4% – Emergency department 61.4% – Physician office 69.4% • Medicare spends > 16 Billion annually3 • 60-70% of health care costs due to hospitalizations They are at the hospital more often and use more resources?

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14
Q

3 reasons to treat AF?

A

C: Common; most prevalent arrhythmmia D: Disability and Death E: Expensive for health care systems AND – AF gets worse with time

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15
Q

Outcomes of AF?

A
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16
Q

Explain the fibrosis in Afib? Indicator of? What scorring is used?

A
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17
Q

CHADS2 scores are composed of what areas?

A
  • Congetive Heart Failure or EF < 35% = 1 • Hypertension = 1 • Age > 75 = 1 • Diabetes = 1 • Stroke or prior TIA = 2
  • Possible scores = 0 - 6
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18
Q

CHADS2 stroke risk with score

A

CHADS2 Score, stroke risk and prevention

0 1.9% Low ASA or nothing

1 2.8% Moderate ASA or anticoagulation

2 4.0% “ anticoagulation

3 5.9% High “

4 8.5% “ “

5 12.5% “

6 18.2%

19
Q

Explain the CDA2DS2-VASc scoring system?

A

C = Congestive Heart Failure

H = Hypertension

A = Age > 75 = 2 points

D = Diabetes

S = Stroke (TIA) = 2 points

V = Vascular Disease (MI, PAD, Aortic atherosclerosis)

A = Age 65 -74 = 1 point

Sc = Sex category (Females = 1)

MAXIMUM = 9 points
0 = ASA; 1 = ASA or anticoagulation; ≥2 = anticoagulation
20
Q

Management imperatives of Afib?

A

Management Imperatives: A, B, C
A = Anticoagulate or ASA? B = Best rhythm? C = Controlled rate?

21
Q

Anticoagulants in Afib?

A

• Warfarin (Coumadin) • Dabigatran (Pradaxa) • Rivaroxaban (Xeralto) • Apixaban (Elequis)

22
Q

Mechanism of action of Apixaban Rivaroxaban? Dabigatran? these are examples of?

A

Examples of novel oral anticoagulants

23
Q

Novel oral anticoagulants as effective as?

A
  • Risk of stroke in AF has nothing to do with whether AF is paroxysmal, persistent or permanent
  • Risk of stroke is the same in patients with AF and AFL
  • NOACs ≈ warfarin
24
Q

Aspirin, Plavix, or Anticoagulation ?

A

Aspirin, Plavix, or Anticoagulation ?
Anticoagulation > ASA

Anticoagulation > ASA + Plavix AND, bleeding risk is

the same
New Anticoagulants ≈ warfarin

25
How do we get Rhythm control?
– AAD therapy – Catheter ablation – Surgical ablation
26
How do we et rate control?
– with medications – AVN ablation + PPM
27
Why do we want to get patients back in NSR quickly? how?
Duration of AF predicts likelihood of maintaining NSR postcardioversion – TEE(transesophageal Echocardiogram)/Cardioversion (CV) – CV if duration \< 48 hours
28
Why are results worse for Afib the longer we wait to get to NSR?
Remodeling
29
Explain remodeling?
Ionic Remodeling – minutes  L-type Ca2+ current, Ito, IK(ur), sus Electrical Remodeling = Δ change in electrical properties - hours Shortening of atrial APD, shortening of AF wavelength, shortening of atrial refractoriness Structural Remodeling = Fibrosis - days to weeks Light and electron microscopic changes in the atria – similar to chronic ischemic hybernation in the ventricle – (dedifferentiation of cells towards fetal stage; apoptosis)
30
Remodeling reversibilty?
• After restoring sinus rhythm – electrical remodeling may be reversible – structural remodeling (fibrosis) – not reversible
31
How to choose which to control first rate or rhythm?
32
If in doubt about which to control first (rate or rhythm) do what? why?
* IF IN DOUBT: Try rhythm control first – if it fails, go to rate control * If you try rate control first and symptoms persist, it may be too late to restore or maintain sinus rhythm – because of irreversibility of atrial fibrosis
33
Antiarrhythmic drugs to suppress AF?
• Class I agents (patients without SHD) – IC: flecainide, propafenone • Class III agents – amiodarone, sotalol, dofetalide, dronedarone
34
Advantages to antiarrhythmic treatment for AF?
• Advantages – Efficacy for some patients, at least initially (\< 50% of all patients) – Acceptance – Noninvasive – You can do easily
35
Disadvantages to antiarrhythmic drugs for AF?
Disadvantages – High recurrence rate – High long-term cost – Noncurative – Adverse effects – Potential proarrhythmia
36
How do we choose an Antiarrhythmic drug?
* Efficacy – about 40-50% at 1 year; amiodarone - higher * Admission to hospital for initiation or outpatient initiation? * Side effects – GI, fatigue, toxicity * Metabolism – Hepatic: amiodarone, dronedarone – Renal: sotalol, dofetalide * Tolerance * Comorbidities: LVH – amiodarone, (dronedarone) CHF – amiodarone, dofetalide, sotalol, QT prolongation – amiodarone, dronedarone
37
Some cardiomyopathies are due to? When rate control is achieved what often happens?
Some cardiomyopathies are due to atrial fibrillation with rapid ventricular response. RVR  CM When rate control is achieved, LV function often improves dramatically. Tachycardia can also cause cardiomyopathy
38
How do we control the ventricular rate in Afib?
• Digoxin • Calcium channel blockers Verapamil, diltiazem • Beta blockers
39
Explain tachycardia induced Cardiomyopathy in AF?
* Very common * Rate control target in AF – Resting \< 80 bpm – Moderate Exercise \< 110 bpm * How do you assess rate control? – 24 Hour Holter – 6 Minute Hall Walk Test
40
Should we shoot for lenient or strict rate control in AF?
• CONCLUSION: Lenient rate control is as effective as strict rate control and is easier to achieve.
41
Ectopic foci in catheter ablation?
42
Types of catheter ablation?
AV Junction Ablation ectopic sites
43
Explain the catheter ablation strategies for Paoxysmal AF and Persistent AF?
* Paroxysmal AF –Pulmonary vein isolation (PVI) –If recurrence, redo PVI ± linear lesions –If left AFL – map AFL and ablate * Persistent or Permanent AF –Do PVI ± linear lesions ± focal drivers