Update in Atrial Fibrillation

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1-2% of general population Average age 75 – 85 years 5 fold risk of stroke 3 fold risk of CHF Higher mortality

Causes of AFCardiovascular

VHD

- rheumatic MS

- prosthetic heart valve

- MV repair

Myocardial disease

Coronary artery disease ( CAD )

Congenital heart disease ( e.g. ASD )

HT

Non cardiovascular Aging DM Obesity, sleep apnea Hyperthyroid / Hypothyroid COPD Sepsis CKD Post surgery

Mechanisms of AF

Extracardiac Factors:

HypertensionObesity

Sleep apneaHyperthyroidism

Alcohol/drugs

Atrial Structural Abnormalities:

FibrosisDilation

IschemiaInfiltration

Hypertrophy

InflammationOxidative stress

Atrial tachycardia remodeling

Genetic Variants:ChannelopathyCardiomyopathy

RAAS activation

Autonomic nervous system

activation

Atrial Electrical Abnormalities:↑Heterogeneity

↓Conduction↓Action potential duration/refractoriness

↑AutomaticityAbnormal intracellular Ca++ handling

AF

Clinical presentations of AF Asymptomatic Dyspnea on exertion, exercise intolerant Palpitation Syncope Heart failure Systemic thromboembolism ( stroke, acute arterial occlusion )

Physical examination

irregulary irregular pulse rate signs of associated diseases

Screening for AF

Pulse palpation in patient age > 65

If irregular ECG

Investigations in AF

Blood chemistry ( e.g. CBC, serum Cr ) TFT CXR Echocardiogram Holter monitoring

Definitions of AF: A Simplified Scheme

Term Definition

Paroxysmal AF  

AF that terminates spontaneously or with intervention within 7 d of onset. Episodes may recur with variable frequency.

Persistent AF Continuous AF that is sustained >7 d.

Long-standing persistent AF

Continuous AF >12 mo in duration.

Permanent AF The term “permanent AF” is used when the patient and clinician make a joint decision to stop further attempts to restore and/or maintain sinus rhythm.

Acceptance of AF represents a therapeutic attitude on the part of the patient and clinician rather than an inherent pathophysiological attribute of AF.

Acceptance of AF may change as symptoms, efficacy of therapeutic interventions, and patient and clinician preferences evolve.

Nonvalvular AF AF in the absence of rheumatic mitral stenosis, a mechanical or bioprosthetic heart valve, or mitral valve repair.

Valvular AF1. Rheumatic mitral stenosis2. Prosthetic heart valve3. Mitral valve repair

Nonvalvular AF

Lone AF1. Nonvalvular AF2. Age < 65 year

Management of AF

Rhythm control : restoration and maintenance of sinus rhythm Rate control : ventricular rate Clot control : prevention of thromboembolic event

Rhythm control ( recent-onset AF < 48 hrs )

Medical cardioversion Electrical cardioversion Pill in pocket : paroxysmal AF

Strategies for Rhythm Control in Patients with Paroxysmal* and persistent AF†

Direct current cardioversion Informed- consent : indication and complication Adequate sedation AP electrode placement more effective than anterolateral placement Biphasic waveform : 150-200 J If PPM or ICD : electrode paddle at least 8 cm from generator

Factor predispose to AF recurrence

Age AF duration before cardioversion Number of previous recurrence Increase LA size Reduced LV function Presence of CAD or pulmonary or mitral valve disease Atrial ectopic beat with long – short sequence Faster HR Variation in atrial contraction

Rhythm control AF > 48 hrs

Rate control Stable : BB / non dihydrpyridine CCB Severely compromised : iv Verapamil/ Metoprolol / Digoxin Severe Depressed LV function : Amiodarone AF with slow ventricular response : Atropine

if symptomatic bradycardia TPM

**** After acute control follow with long term rate control

Approach to Selecting Drug Therapy for Ventricular Rate Control*

Atrial Fibrillation

No Other CV Disease

Hypertensionor HFpEF

LV Dysfunction

or HFCOPD

Beta blockerDiltiazemVerapamil

Beta blockerDiltiazemVerapamil

Beta blockerDiltiazemVerapamil

Beta blocker†Digoxin‡

Amiodarone§

Asymptomatic Preserved LVEF

< 110 bpm

Symptom evaluation : EHRA score

Clot control : Anticoagulant prevention of systemic thromboembolism

Valvular AF VKA for all

Antithrombotic Therapy to Prevent Stroke in Patients who Have Nonvalvular AF (Meta-Analysis)

Adapted with permission from Hart et al.

 

  

   

   

 

      

 

 

    

 

 

  

 

 

Adjusted-dose warfarin compared with placebo or control

Antiplatelet agents compared with placebo or control

Adjusted-dose warfarin compared with antiplatelet agents

Recommendations COR LOE

For patients with nonvalvular AF with prior stroke, transient ischemic attack, or a CHA2DS2-VASc score of 2 or greater, oral anticoagulants are recommended. Options include:

• warfarin (INR 2.0 TO 3.0), or I A

• dabigatran, or I B

• rivaroxaban, or I B

• apixaban. I B

Recommendations COR LOE

For patients with nonvalvular AF and a CHA2DS2-VASc score of 0, it is reasonable to omit antithrombotic therapy. IIa B

For patients with nonvalvular AF and a CHA2DS2-VASc score of 1, no antithrombotic therapy or treatment with an oral anticoagulant or aspirin may be considered. IIb C

Risk of bleeding : HASBLED Hypertension : SBP> 160 mmHg

Abnormal renal and liver function - Chronic dialysis, renal transplant, serum creatinine ≥ 200 mmol/L ( 2.26 mg/dL ) - Chronic hepatic disease ( cirrhosis ) , bil > 2 x UNL , AST, ALT > 3 x UNL

Stroke

Bleeding - Previous bleeding Hx and /or predisposition to bleeding – bleeding diathesis, anemia

Labile INRs - Unstable / High INR or poor time in therapeutic range < 60%

Elderly : >65 yr

Drug or alcohol - Use antiplatelet, NSAID, alcohol abuse

High risk Point ≥ 3

Optimal INR INR 2.0 – 3.0 for prevent systemic emboli in Nonvalvular AF INR 1.8 – 2.5 in elderly ( not based on any large trial evidence ) CYP2C9 and VKORC1 genotypes

– influence warfarin dose requirement and asso with bleeding event

Specific patient groups and AF ACS

- DC if unstable situation ( hypotension or shock, HF, persistent angina)

- VKA with CHA2DS2-VASc score

Hypertrophic cardiomyopathy

- VKA independent of CHA2DS2-VASc score Hyperthyroidism

- VKA with CHA2DS2-VASc score

- BB for rate control

Specific patient groups and AF COPD- VKA with CHA2DS2-VASc score

- Nondihydropyridine CCB for rate control

HFpEF- BB or Nondihydropyridine CCB for rate control

- caution needed in patients with overt congestion, hypotension, or HFrEF

HFrEFDigoxin or Amiodarone for rate control

Postoperative AF

AF with WPW and Pre-excitation syndrome

WPW ( Wolf-Parkinson-White syndrome)

Short PR interval <120 msecs. QRS > 100 msecs. Delta wave = slurred upstroke at beginning of QRS.

Type APositive QRS

in V1

Type BNegative QRS

in V1

Recommendations COR LOE

Prompt direct-current cardioversion is recommended for patients with AF, WPW syndrome, and rapid ventricular response who are hemodynamically compromised.

I C

Administration of intravenous amiodarone, adenosine, digoxin (oral or intravenous), or nondihydropyridine calcium channel antagonists (oral or intravenous) in patients with WPW syndrome who have pre-excited AF is potentially harmful because these drugs accelerate the ventricular rate.

III: Harm B