AFib

Supraventricular arrythmia

• originate from above bundle of His

• not as detrimental, more common

• atrial fibrillation, atrial flutter, paroxysmal supraventricular tachycardia, and autonomic atrial tachycardia

Ventricular arrythmia

• originate from below bundle of His

• premature ventricular complexes, ventricular tachycardia, and ventricular fibrillation

Atrial fibrillation

• supraventricular arrhythmia

• uncoordinated atrial activation → ineffective atrial contraction

• chaotic, rapid (300-500 bpm), and irregular atrial rhythm

• often from electrical activity from ectopic action potentials from pulmonary veins of LA or re-entry due to interstitial fibrosis

Epidemiology of AFib

• most common

• increased incidence and prevalence due to aging pop, obesity (causes LA stretch), increasing detection, and increasing survival

AFib Related Outcomes

• death

• stroke

• LV dysfunction/HF

• Cognitive decline/Vascular dementia

• Depression (QoL, tx)

• Impaired QoL

• Hospitalizations

Risk Factors for AFib

• conditions:

  • age

  • smoking

  • physical activity

  • alcohol

  • obesity

  • height

  • HTN

  • resting HR

  • diabetes

  • CKD

  • OSA

  • thyroid disease

  • sepsis

• CVD

  • HF

  • CAD

  • VHD

  • cardiac surgery

• SDOH

  • education

  • income

  • socioeconomic status

• Others

  • EKG markers

  • biomarkers

  • genetics

AFib Causes

• most commonly bc of structural heart disease

• most common associations; HTN, VHD, PAH, CAD, inflammatory causes, drugs, alcohol, caffeine

• can have acute causes → thyrotoxicosis, surgery, alcohol withdrawal, sepsis, excessive physical exertion

  • treat underlying cause!

AFib Classification

• progressive disease

• Stages 1-4

Stage 1 AFib

• at risk

• presence of AFib risk factors

• treat modifiable risk factors

Stage 2 AFib

• Pre-AF

• structural or electrical findings

  • atrial enlargement

  • frequent atrial ectopy

  • short bursts of atrial tachycardia

  • atrial flutter

• treat modifiable risk factors, consider heightened surveillance

Stage 3 AF

• different substages: paroxysmal, persistent, long-standing persistent, successful AF ablation

• treat modifiable risk factors

• ongoing monitoring

• stroke risk assessment and therapy if appropriate

• treat symptoms

Stage 3A

• Paroxysmal AF

• intermittent, terminates within ≤7 days of onset

Stage 3B

• persistent AF

• continuous, sustains for ≥ 7 days and requires intervention

Stage 3C

• long-standing persistent AF

• continuous for ≥ 12 months

Stage 3D

• successful AF ablation

• freedom from AF after percutaneous or surgical intervention to eliminate AF

Stage 4

• permanent AF

• no further attempts at rhythm control

• stroke risk assessment and therapy if appropriate

• treat symptoms

AFib diagnosis

• gold standard: 12 lead ECG

• for paroxysmal: holter/event monitor (captures rhythm over 2 week span)

• other options: single and multiple lead devices that provide ECG

Atrial flutter

• “sawtooth” pattern ECG

• managed same as AFib

• rapid but REGULAR beating of atria

Clinical Evaluation of AFib

• med history: AF pattern, family history/comorbidities, risk factors (bleeding, thromboembolism)

• assess Sx, functional impairment

• BMP, Mg, LFT, CBC, HbA1c, Thyroid tests

  • hyperthyroidism can predispose to AFib

• TTE

Clinical Characteristics of AFib

• asymptomatic (90%) or symptomatic

  • either way, still at risk for stroke, systemic embolism, mortality

• palpitations, exertional fatigue, lightheadedness, exercise intolerance, dyspnea

• syncope

• complications: stroke, tachycardia-induced cardiomyopathy

Stroke and AFib

• irregular atrial contraction may not eject all blood into ventricles, allowing blood to pool and clot by left atrial appendage

• clot can be ejected and block blood flow in brain

• pts in AFib for 48H → clot risk

Tachycardia-Induced Cardiomyopathy

• heart walls will thicken and sitffen overtime as they are beating too rapidly

• progress to heart failure

ACC/AHA AFib General Management

• 4 A’s: Access to All Aspects of Care for All

• SOS: Stroke Risk, Optimize modifiable risk factors, Symptom management (rate vs rhythm control)

• HEAD 2 TOES: risk factor screening → HF, Exercise, Arterial HTN, Diabetes, Tobacco, Obesity, Ethanol, Sleep

ESC AFib Management

• AF-CARE

• C: Comorbidity and risk factor management

• A: Avoid stroke and thromboembolism

• R: Reduce symptoms by rate and rhythm control

• E: Evaluation and dynamic reassessment

AFib Primary Prevention

• lifestyle modification

• target obesity, physical inactivity, unhealthy alcohol consumption, smoking, diabetes, and HTN

AFib Secondary Prevention

• weight loss (if BMI > 27, at least 10% loss)

• physical fitness (moderate to vigorous exercise 210 min/week)

• smoking cessation

• minimize alcohol

• optimize HTN control

• Screen for OSA

Stroke Risk Assessment

• CHA₂DS₂-VAS_c preferred, 

• based on risk for stroke, NOT AF pattern

GARDFIELD-AF

• Glocal Anticoagulant Registry in the Field - Atrial Fibrillation

• includes mortality and bleeding risk, smoking, renal disease, and dementia

CHA₂DS₂-VAS₂

• C: CHF → 1 pt

• H: HTN → 1 pt

• A₂: Age 75 or older → 2 pts

• D: DM → 1 pt

• S₂: prior stroke/TIA → 2 pts

• V: Vascular disease (ACS, PVD) → 1 pt

• A: age 65-74 → 1 pt

• S_c: Female

Stroke risk recommendations

• 0: none

• Male 1 or Female 2: consider oral anticoag

• Male 2 or Female 3: recommend oral anticoag

Additional Risk factors for stroke

• higher AF burgen/longer duration

• persistent/permanent AF vs paroxysmal

• obesity (BMI 30+)

• hypertrophic cardiomyopathy

• poorly contr

Bleeding Risk

• must be evaluated for pts on anticoag

• HAS-BLED → most validated, most often used risk score

• concerns regarding risk discrimation and inclusion of nonspecific factors that increase stroke risk AND bleeding

  • renal disease, stroke history

• limitations in clinical decision making

• should be continually reassessed

HAS-BLED

• H: HTN (SBP >160) → 1 pt

• A: abnormal renal or liver fx (Scr ≥ 2.3, cirrhosis, bilirubin > 2x ULN w ALT/AST 2x ULN) → 1 pt each

• S: stroke → 1 pt

• B: bleeding → 1 pt

• L: labile INR (< 60% in therapeutic range) → 1 pt

• E: Elderly (65+) → 1 pt

• D: Drugs (not NSAIDS/anti-platelet) or alcohol (≥ 8 drinks/week) → 1 pt each

HAS-BLED score evaluation

• 0: low bleed risk

• 1-2: moderate bleed risk

• 3: high bleed risk

Oral Anticoags for AFib

• DOACs preferred over warfarin

• consider: efficacy, safety, insurance, renal/hepatic fx, drug interactionsmadherence, and pt preference

DOACs

• factor Xa inhibitors (apixaban, rivaroxaban, edoxaban) and direct thrombin inhibitor (dabigatran)

• dosing based on age, renal fx, weight

• consider concomitant meds and hepatic fx

Warfarin

• need for higher time in therapeutic range (70+%)

• consider concomitant meds, vitamin K intake, pt education on adherence

Rate vs Rhythm Control

• limit symptoms or improve outcomes by controlling HR, reverting to sinus rhythm, or maintaining sinus rhythm

• most pts require combination approach

• shared decision making recommended

Factors favoring rate control

• patient preference

• older patient

• longer history of AF

• fewer symptoms

Factors favoring rhythm control

• patient preferrence

• younger pt

• shorter history of AF

• more symptoms

Rate Control Agents

• beta blockers

• non-DHP CCBs (avoid in HFrEF)

• digoxin, amiodarone

• cardioversion (acute setting)

• long-term: AV nodal ablation with pacemaker insertion

AFib goal HR

< 100-110

Rhythm Control

• trial recommended for those w reduced LV function and persistent/high burden AF to evaluate if AF is contributing to reduced LV function

• dofetilide (Class 3), dronedarone (Class 3), flecainide (Class 1c), propafenone (Class 1c), sotalol (Class 2, 3)

• cardioversion (electrical and/or pharmacological), catheter ablation

Pharmacological cardioversion

• variable success rate

• no need for general anesthesia

• concerns with SE/toxicity

• reasonable if hemodynamically stable

• indicated for new-onset or persistent AF

• agents:

  • ibutilide: if LVEF 40% or lower → class 3

  • amiodarone IV: longer to convert → class 3

  • flecainide, propafenone: pill in the pocket → class 1c

  • IV procainamide (alt) → class 1a

Direct Current Cardioversion

• higher success rates

• treatment for hemodynamic instability

• need general anesthesia

• can cause burns

Anticoagulation during Cardioversion

• need to be anticoagulated with unfractionated heparin or LMWH

• 3 weeks of therapeutic anticoag before cardioversion

• may have TTE to confirm no clot before cardioversion

  • if detected, anticoag for at least 3-6 weeks

• 4 weeks of therapeutic anticoag after cardioversion

Maintenance of Sinus Rhythm

• reasonable for long-term therapy if antiarrhythmics pref over catheter ablation

• agents:

  • dofetilide, amiodarone (LVEF 40% or lower) → Class 3

  • flecainide, propafenone (if no previous MI, known structural heart disease, or ventricular scar/fibrosis) → class 1c

  • dronedarone (if no recent decompensated HF or severe LV dysfunction) → Class 3

  • alt. sotalol

Amiodarone

• can be initiated outpatient

• loading and maintenance dosing

• LOTS of AE

Dofetilide

• in-hospital initiation

• hold previous antiarrhythmic at least 3 half lives before initiation

• wait at least 3 days to 12 hours after conversion (5 doses)

• indicated to maintain normal sinus rhythm in highly symptomatic afib

• used to have REMS

Catheter ablation

• early rhythm control procedure

• peel tissue off of foci in atria

Torsades de Pointes

• polymorphic ventricular tachycardia that can lead to sudden cardiac death

• treatment: magnesium sulfate 1-2 g IV over 1-2 min

  • long-term: beta blockers, permanent pacing, implan

  • table cardioverter-defibrillator

Drugs that Prolong QT

• antiarrhythmics (esp 1a, 3)

• antibiotics (quinolones, macrolides)

• azole antifungals

• antidepressants (TCAs, SSRIs, SNRIs, mirtazapine, trazodone)

• Antiemetics (5-HT3 receptor antagonist, droperidol, phenothiazides)

• Antipsycotics (aripiprazole, chlorpromazine, clozapine, haloperidol, olanzapine, paliperidoe, quetiapine, risperidone, ziprasidone)