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ATRIAL FIBRILLATION MANAGEMENT. MINI-LECTURE. OBJECTIVES. REVIEW INITIAL MANAGEMENT OF AFIB; MEDICAL VS CARDIOVERTING MEDICAL MANAGEMENT: RATE VS RHYTHM CONTROL ROLE OF ANTICOAGULATION. CASE VIGNETTE.
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ATRIAL FIBRILLATIONMANAGEMENT MINI-LECTURE
OBJECTIVES • REVIEW INITIAL MANAGEMENT OF AFIB; MEDICAL VS CARDIOVERTING • MEDICAL MANAGEMENT: RATE VS RHYTHM CONTROL • ROLE OF ANTICOAGULATION
CASE VIGNETTE • This is a 65 y/o M who presents to the ED with dizziness, shortness of breath, and palpitations which began approximately two hours ago when he was playing catch with his grandson. No syncope or chest pain. • On exam: He is afebrile with a BP=110/55, HR=110-162 bpm, and respiratory rate of 25. A&Ox4 w/ NAD. Cardiac exam reveals tachycardia with an irregularly irregular rhythm. • How would you approach the initial management of this patient?
Demographics • Common; 2.2 million people in U.S. • Male>Female • Prevalence increases with age • Leading cause of embolic strokes • Associated with increased risk for heart failure and all cause mortality
WORK-UP • H and P • CXR • EKG • Echo • TFTs • CMP • Trop and EKG
MANAGEMENT The first step in management is to determine whether the patient is stable or not… -Look for any hemodynamic instability such as hypotension -Is the patient responsive? -Are there any mental status changes? -are symptoms persistent and unbearable?
INITIAL MANAGEMENT DECISION afib Urgent Cardiovert Unstable Ss Stable Anticoagulate** Rate vs rhythm Control
RATE VS RHYTHM CONTROL • Rate Control vs Rhythm Control • **no clear survival benefit in rate vs rhythm control**
RATE CONTROL • Agents: • Beta Blocker: Metoprolol and Propranolol (ICU=esmololgtt) • Non-dihydropyridine CA blockers: verapamil & Diltiazem(ICU=diltiazemgtt) • Digoxin Goal: Rest 60-80 bpmand Activity 80-110
RATE CONTROL; Which Agent to choose? AFIB SBP 100 to 120 SBP >120 SBP 90-110 DIGOXIN Load: 0.5mg IV6 hrs later; 0.25mg IV6 hrs later; 0.25 mg IV Maintenance: 0.125 mg daily B-Blocker Initial: Metoprolol 5mg IVP q5min x3doses Prn: metoprolol 5mg IV q6hr prn Maintenance: Metoprolol 25 mg po BID (max 100mg BID) Ca2+ Blockers Initial and prn: Diltiazem 10mg IVP q6hrs Maintenance: Diltiazem 30mg PO q6hs
Rhythm Control • AGENT: • III: Amiodarone, Ibutilide, Dofetilide, Sotalol • IC: Flecainide, Propafenone • IA: Procainamide
ANTICOAGULATION • Risk of stroke increases with valvular afib • Risk of CVA=4.5% per year in nonvalvular afib • Risk of CVA in recurrent paroxysmal afib=persistent afib=permanent afib • Agents: ASA vs Coumadin vs Dabigatran vs Rivaroxaban
ANTICOAGULATION; Which Agent to Choose? • CHADS2 SCORE • CHF: 1 point • HTN: 1 point • AGE >75: 1 point • DM: 1 point • Stroke or prior TIA: 2 points Score: 0=ASA alone 1= either warfarin or ASA 2 or more= warfarin
ASPRIRIN • CHADS2=0 or 1 • 81 mg to 325mg PO daily • Lower risk for bleeding than warfarin • No need to check INRs etc • Lower risk of major bleeds in patients who are a fall risk
Coumadin • For CHADS2 score 2 or greater and also 1 depending on patient and physician preference • Goal INR= 2 to 3 • Must monitor INRs regularly • Can be dangerous if fall risk or bleeding risk high
ASA + Clopidogrel • If not a candidate for warfarin; this can reduce stroke risk greater than ASA alone • Risk for major bleeding increased
Dabigatran • Direct Thrombin Inhibitor • Alternative to warfarin for CHADS2=1 or greater in those without valvular afib • RE-LY Trial showed superior to warfarin in preventing ischemic and hemorrhagic CVAs with reduced risk of life threatening bleeding but higher risk of GI bleeds • No lab monitoring* • No reversal agent available for major bleeding events
Rivaroxaban • Oral factor Xa inhibitor • Seems to be equivalent in efficacy to warfarin for CVA prevention and no difference in major bleeding events • Demonstrates a reduction in intracranial hemorrhage • Note: risk of thrombotic events increased for 28 days after stopping drug so may need to bridge with another anticoagulant during this time.
SUMMARY • AFIB: very common arrhythmia and leading cause of embolic CVAs • Initial Workup: H and P, trop, EKG, TSH, Echo, CXR, CMP • Management: First must determine if stable vs unstable (medically manage vscardiovert immediately) • For stable Afib: rate vs rhythm control (equal in efficacy). Start with rate control and if that fails try rhythm. • Always remember to calculate CHADS2 score and anticoagulate for CVA ppx.
References • Uptodate.com; Topics: SVT, atrial fibrillation management, afib overview • Sabatine, Marc S. Ed.; Pocket Medicine The Mass General Hospital Handbook of Internal Medicine 4th edition Lippincott Williams and Wilkins Philadelphia, PA 2008. • MKSAP 16; Cardiology ACP 2012 • Maxine A. Papadakis, Stephen J. McPhee, Eds; CURRENT Diagnosis and Treatment; McGraw Hill Education 2012. • Dan L. Longo, Anthony S. Fauci, Dennis L. Kasper, Stephen L. Hauser, J. Larry Jameson, Joseph Loscalzo, Eds. Harrison's Principles of Internal Medicine, Online. 18th ed.McGraw Hill 2012