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Update in Atrial Fibrillation
พญ. กนกศรี� อัศวสันติ อัายุ�รีแพทยุ�โรีคหัวใจและหัลอัดเล�อัด
กล��มงานอัายุ�รีกรีรีม โรีงพยุาบาลเพชรีบ#รีณ์�
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