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Management of Atrial Fibrillation 03.01.2014

Presenter - Dr. Amish Bhutani Moderator - Dr. Barun Kumar

Atrial FibrillationIntroductionCauses, Consequences, Classification & Epidemiology of AFPresentationAF: Acute ManagementRhythm ControlRate ControlRate Vs RhythmPrevention of Thromboembolism: AnticoagulationNewer OACsSummary

Atrial Fibrillation

Atrial fibrillation (AF) is a supraventricular arrhythmia characterized electrocardiographically by low-amplitude baseline oscillations (fibrillatory or f waves) and an irregularly irregular ventricular rhythm

Uncoordinated atrial activation

The f waves have a rate of 300 to 600 beats/min and are variable in amplitude, shape, and timing.

Hypertension (usually with left ventricular hypertrophy)Ischemic heart disease,Dilated cardiomyopathyRestrictive cardiomyopathies such as amyloidosis, constrictive pericarditis Cardiac tumorsSevere pulmonary hypertension Obesity and obstructive sleep Excessive alcohol intake (holiday heart),Open heart or thoracic surgery,Myocarditis Pulmonary embolism.Hyperthyroidism Tachycardia induced. Patients with tachycardia-induced AF most often have AV nodal reentrant tachycardia or a tachycardia related to the Wolff-Parkinson-White syndrome that degenerates into AFCauses of AF

Reversible causes of AFAlcohol intake (holiday heart syndrome),Surgery, Electrocution,MI, pericarditis, myocarditis, Pulmonary embolism or other pulmonary diseases, Hyperthyroidism, Pheochromocytoma and other metabolic disorders.Drugs , CaffeineSubarachnoid hemorrhage, Nonhemorrhagic, major stroke

The Consequences of AFThromboembolismStroke: 4.5 increased riskMicroemboli: reduced cognitive functionProthrombotic stateMortality2 increased risk independent of comorbid CV diseaseSudden death in HF and HCMHospitalizationsMost common arrhythmia requiring hospitalization2-3 increased risk for hospitalizationImpaired HemodynamicsLoss of atrial kickIrregular ventricular contractionsHFTachycardia-induced cardiomyopathyReduced QoLPalpitations, dyspnea, fatigue, reduced exercise toleranceHCM=hypertrophic cardiomyopathy; QoL=quality-of-life.Van Gelder IC, et al. Europace. 2006;8:943-949; Narayan SM, et al. Lancet. 1997;350:943-950; Wattigney WA, et al. Circulation. 2003;108:711-716; Wyse DG, et al. Circulation. 2004;109:3089-3095; Favale S, et al. PACE. 2003;26:637-639. AF is an enormous contributor to the growing cost of medical care

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Classification of AFParoxysmal AF - that terminates spontaneously within 7 days

Persistent AF - present continuously for more than 7 days

Longstanding AF - persistent for more than 1 year

Permanent AF - longstanding AF refractory to cardioversion is termed permanent. Lone AF - AF in patients younger than 60 years who do not have hypertension or any evidence of structural heart disease First episode - Symptomatic or asymptomatic Self limited or persistent Recurrent AF - 2 or more episodes lasting > 30 seconds

Guideline-BasedAF Treatment OptionsCCB = calcium channel blocker; SR = sinus rhythm; ACE-I = angiotensin-converting enzyme inhibitor; ARB = angiotensin II receptor blocker; LA = left atrial.Fuster V, et al. J Am Coll Cardiol. 2006;48(4):854-906.Maintenance of SR

PharmacologicClass IA Class ICClass III-blockers

NonpharmacologicCatheter ablationPacingSurgery Implantabledevices

Stroke preventionPharmacologicWarfarinAspirin +/- clopidogrelDabigatranFactor Xa inhibitorsNonpharmacologicRemoval/isolationLA appendage

Rate controlPreventremodelingCCBsACE-Is, ARBsStatinsFish oilPharmacologicCCBs-blockersDigitalisAmiodaroneDronedaroneNonpharmacologicAblate and pace

8There are 3 strategies for the management of patients with AF: rate control, maintenance of SR, and stroke prevention. A combination of strategies may be appropriate in some patients. Rate control is usually easier to achieve than SR maintenance, but the disadvantage is persistence of an irregular ventricular response that does not allow for symptomatic relief for many patients. Although hemodynamic function is improved with rate control, maintenance of SR frequently leads to better results. The drugs (Ca2+ blockers, -blockers, and digitalis) used to maintain ventricular response may cause very slow heart rates in some patients. These patients may require implantation of a permanent pacemaker.Maintenance of SR has 2 proven advantages, relief of symptoms and improved hemodynamics. In addition, there is the theoretical (but not proven) possibility that maintenance of SR leads to a decrease in thromboembolic events and electrical atrial remodeling. The disadvantage of choosing maintenance of SR as a treatment option is the drug (class IA, IC, and III, -blockers) side effects, which are usually only an annoyance, but can be life-threatening in a small percentage of patients. Nonpharmacologic approaches to maintaining SR (MAZE, pulmonary vein isolation) are important adjunctive therapies to consider for patients who are already undergoing cardiac surgery, but are rarely required as first-line therapy. Implantable atrial defibrillators are another nonpharmacologic approach, but substantial patient discomfort and a narrow indication are 2 major disadvantages. Catheter ablation is also an option, and several approaches to this therapy have been reported. Stroke prevention is important for AF patients with a high risk for stroke. Such patients require warfarin alone or in combination with aspirin as anticoagulation therapy. The nonpharmacologic approach to stroke prevention is LA appendectomy. This can be used as adjunctive or stand-alone therapy and could markedly reduce the risk of embolic stroke and possibly avoid long-term warfarin therapy.

Atrial Fibrillation: EpidemiologyPrevalence - 3.8% 60 Yrs - 9% >80 Yrs ( JAMA 2001;285:2370)Stroke Rate in AF- 5-9.6% (JACC 2004, 43: 929-35) (JAMA 2001,285, 2864-70) (Stroke rate is similar in Paroxysmal and persistent AF)Relative risk of death 1.3- 2 times

1.Lloyd-Jones DM, et al. Circulation 2004;110:104210462. Go et al. JAMA 2001;285:2370-5Prevalence of Atrial Fibrillation

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Atrial Fibrillation: PresentationDyspnoeaPalpitationSyncopeDizzinessMyocardial IschemiaAsymptomatic

AF: Acute Mx & Rhythm Control

Atrial Fibrillation: Ac MxAssess the hemodynamic Status If unstable: DC ShockIf stable: Assess risk factor Start Anticoagulation Rate controlling drugs Decide Rate vs Rhythm Control Pharmacological vs DC cardioversion

Anticoagulation and CardioversionAfib < 48 hours: Cardioversion (CV)No anticoagulation indicatedAfib > 48 hours: Anticoagulate for 3-4 weeks before CVOR get TEE

Anticoagulate for 1 month after CV

Atrial Fibrillation: DC CardioversionAdvantage- More effectiveDisadvantage- Risk of Thrombo-embolism Requires conscious sedation Arrhythmia

Atrial Fibrillation: DC CardioversionMethod Synchronized DC shock- External - Internal (COPD, obese)Biphasic preferred ( high success- 79-84%) [ Mittal et al, Circ 2000, 101:1282] [ Page et al , JACC 2002,39:1956]Monophasic- 100 J- 14% success 200 J- 39% success 360 J- 95% successInitial 200 J is recommended with monophasic 100 J with biphasic [ Jogler et al, AJC 2000, 86: 348]

Atrial Fibrillation: DC CardioversionComplicationThromboembolism- 1-7% sed by prior anticoagulation [ Arnold et al, JACC 1992;19:851]Arrhythmia- Sinus Arrest , Bradycardia - VF, VT (Risk factor- Hypokalemia, Dig intoxication, improper synchronization)

Atrial Fibrillation: DC CardioversionRecurrenceComplete shock failure and immediate recurrence 25%Subacute recurrence in 2 wk 25%70% in NSR at 24 hour after cardioversionHigh chance of recurrences- old age, long duration of AF [ van Gelder et al, AJC 1991;68: 41]

Pharmacological Cardioversion of AFAMIODARONE [ IIa]Efficacy - 18-80% IV 3-7 mg/kg bolus 1.2 -1.8 gm/day 300 mg iv in 1 hr f/b 20 mg/ kg infusion in 24 hr with Tab Amiodarone 200 mg TDS x 1 wk 200 mg BD x 3 wkEfficacy 48.5% at 30 days vs placebo 0% - 82% if LA size < 45 mm - 76 % if AF duration < 1 month [ Kochiadakis et al AJC 1999, 83: 58]

Pharmacological CardioversionAmiodarone side effects- Hypotension ( 5-15%)- t/t- iv fluidPhlebitis (10-33%)TDP ( 0-5%)QT prolongationPulmonary toxicity

Phlebitis, QTHypotensionotherTDP

Pharmacological Cardioversion of AFIBUTILIDE [CORVERT]Efficacy- 45-60%If f/b DC Cardioversion 100%Only IV 1 mg bolus [ 0.01 mg/kg]Risk- TDP [1.7-4%]

DOFETILIDE [TIKOSYN]Efficacy- 30%Only oral 500 microgm BDRisk- TDP

Pharmacological Cardioversion FLECAINIDE [ TOMBOCOR]Efficacy- 75-91% for recent onset AFShould be avoided in patients with underlying organic heart disease with LV dysfunctionDose 200-300 mg PO - 1.5 -3 mg/kg over 10-20 minSide effects- TDP, Reduce LV contractility, exacerbation of sinus node dysfunction

Pharmacological Cardioversion PROPAFENONE [ RYTHMOL]Useful for recent onset AFEfficacy- 56-83% Dose- 600 mg PO - 1.5 2 mg/kg over 10-20 minShould be used cautiously or not at all in patients with HF or severe COPD.Side effects- Atrial Flutter, VT, Hypotesion, Bradycardia, Intraventricular conduction defects.

Pharmacological Cardioversion: PILL IN THE POCKET APPROACHA single oral bolus do

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