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54 Cards in this Set
- Front
- Back
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AF defn |
an irregularly, irregular supraventricular arrhythmia w atrial rates of 350-450 bpm |
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AF EKG |
no p waves, irregular, narrow QRS |
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classification of AF |
-first episode -paroxysmal -persistent -permanent the longer you have the disease, it progresses to permanent |
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paroxysmal AF |
AF alternates w NSR, pt reverts spontaneously |
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persistent AF |
AF alternates w NSR, pt requires tx (electrical or pharmacological) to convert to NSR |
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permanent AF |
inability to convert to NSR w therapy |
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sx of AF |
-reduced exercise tolerance -weakness -fatigue -dizziness -lightheadedness -palpitations -chest pain -SOB -syncope may be asymptomatic! |
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morbidity of AF |
-reduced EF, CO, CHF, hypotension -valvular and non-valvular AF both increase stroke risk -overall stroke rate is 4.5%/year -higher in elderly (18%/yr), lower in "lone" AF (1%/yr) |
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mortality of AF |
independent risk factor post-stroke, post-MI, CHF |
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outcome goals for AF |
direct therapy to: 1. reduce sx 2. reduce morbidity -improve heart fxn -reduce incidence of stroke -reduce emergency department visits -reduce hospitalization rates 3. improve QOL no trial w primary endpoint to: -reduce mortality -promote cost-effective therapy |
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specific therapeutic goals for AF |
1. control or cure precipitating causes 2. control rapid ventricular rate 3. prevent thromboembolic complications 4. convert AF to NSR 5. reduce recurrences of AF by attempting to maintain NSR |
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approach to acute AF if: unstable, serious sn/sx |
-check oxygen sats, IV line, intubation equipment ready -> pre-medicate -> electrical conversion |
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approach to acute AF: no unstable, serious sn/sx |
atrial fibrillation, atrial flutter -> consider: -cardiac status? -duration of AF? -rate control -anticoagulation -conversion |
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acute ventricular rate control |
-slower HR allows ventricles to fill better, improving cardiac hemodynamics -may reduce AF sx, reduce ED tx time, prevent hospitalization -drugs MUST work to BLOCK AV Node (beta-blockers, CCB, digoxin, amiodarone) -"target" acute HR control controversial -IV agents used if pt is symptomatic |
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target acute HR control |
controversial -traditionally < 100 bpm -critically-ill < 120 bpm -depends on sx and comorbid diagnosis |
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rate control drugs |
beta blockers calcium blockers digoxin amiodarone (miropenem, carbapenem) |
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tx of AF if cardiac fxn normal |
-IV beta blocker -IV CCB (verapamil or diltiazam) |
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tx of AF if EF < 40% or HF |
-IV digoxin -IV amiodarone |
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acute antithrombotic prophylaxis |
-blood stasis in fibrillating atria leads to clot formation inside atrial chambers -electrical, pharm, or spontaneous cardioversion to NSR may restore atrial contraction and eject clot (eg stroke) -acute antithrombotic prophylaxis choice based on duration of AF episode, hx of recurrence |
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risk of stroke during active cardioversion w/o antithrombotic therapy |
0.8% in AF _< 58 hours duration 5% in AF > 58 hours duration |
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acute antithrombotic prophylaxis if AF _< 48h |
-no antithrombotic therapy reqd |
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acute antithrombotic prophylaxis if AF > 48h or unknown |
conventional approach vs TEE-guided approach conventional approach: -warfarin x 3 wk (INR 2-3) --> if transesophageal echo (TEE) clot then repeat, if no clot, then cardioversion (electrical or rx) --> warfarin x 4wk (INR 2-3) TEE-guided approach -IV heparin/LMWH ->if TEE clot, then warfarin x 3wks (INR 2-3) -if no clot, cardioversion (electrical or rx) -> warfarin x 4 wk (INR 2-3) |
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acute conversion to NSR |
-electrical cardioversion or antiarrhythmic drugs -conversion may reduce sx and improve cardiac hemodynamics by restoring atrial "kick" and eliminating rapid ventricular response -may reduce ED tx time, and prevent hospitalization drugs MUST act on ATRIAL TISSUE -prolong atrial refractory period to convert AF to NSR -Class IA, IC, III antiarrhythmic drugs |
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antiarrhythmics |
Class IA Class IC Class III make refractory period longer |
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class IA antiarrhythmic drugs |
Quinidine Procainamide |
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class IC antiarrhythmic drugs |
propafenone flecainide |
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class III antiarrhythmic drugs |
sotalol amiodarone ibutilide |
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pts where more difficult to actively convert to NSR |
-longer duration of AF -larger left atrium -low ejection fraction/clinical CHF -mitral valve regurgitation |
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consider acute conversion for what pts |
-acute AF episode duration for _<48h -first episode/paroxysmal AF, NOT persistent/permanent -pts who remain symptomatic despite HR control |
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when to consider TEE-guided strategy or delayed cardioversion |
if AF episode > 48h |
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ibutilide dose |
1mg IV over 10 min, repeat x 1 prn |
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ibutilide CI |
hx of Torsades de pointes unstable angina CHF MI or CABG in past 6mth |
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procainamide dose |
1g IV over 30 min, then 2mg/min |
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procainamide CI |
hx of hypersensitivity Torsades de pointes |
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propafenone dose |
600mg po single dose |
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propafenone CI |
> 80y/o unstable angina MI in past 6mth CHF _> NYHA class II sick sinus syndrome |
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flecainide dose |
300mg po single dose |
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flecainide CI |
> 80y/o unstable angina MI in past 6mth CHF _> NYHA class II sick sinus syndrome |
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rate control vs rhythm control |
much more ADRs for rhythm (amiodarone) control vs rate (diltiazem) -rhythm had no better outcomes than rate rhythm had no benefit in all-cause mortality or ischemic stroke |
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when to use rate control |
should be the preferred initial long-term strategy |
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when to use rhythm control |
consider trial for the following: -pts who remian symptomatic w frequent and/or severe episodes despite rate control therapy rhythm control did not improve outcomes in heart failure pts, and should not be initial strategy |
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drugs for chronic ventricular rate control |
beta blockers calcium channel blockers digoxin amiodarone -digoxin, BB, CCB all control resting HR -BB and CCB control resting and exercise HR -CCB or digoxin may improve exercise tolerance, BB may worsen exercise tolerance choose agent based on pt demographics, co-morbid deseases medications, cost |
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digoxin for chronic ventricular rate control |
-less effective in younger pts and does not control exercise-induced HR |
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drugs for chronic ventricular rate control in heart failure pts |
beta blocker +/- digoxin |
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drugs for chronic ventricular rate control in CAD pts |
beta blocker (preferred) CCB (non-dihydropyridine: diltiazem, verapamil) combination RX |
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drugs for chronic ventricular rate control in pts w no heart failure or CAD |
-beta blocker -CCB (non-dhydropyridine: diltiazem, verapamil) -digoxin (may be considered as monotherapy only in particularly sedentary individuals) -combination rx |
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chronic antiarrhythmic therapy not indicated for |
-not indicated after single episode of AF, or infrequent asymptomatic AF |
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chronic antiarrhythmic therapy drugs |
all more effective than placebo at maintaining NSR: quinidine disopyramide propafenone flecainide sotalol amiodarone dronedarone in general, amiodarone may delay recurrences of AF better than other agents but more ADE -agent selection depends on co-morbid conditions (HT, CAD, HF), meds, ADE profile |
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dronedarone efficacy |
-effective at controlling HR in AF/AFL -prolongs time to first recurrence of symptomatic AF in popn primarily w/o HF -increases mortality in popn of admitted HF pts w NHYA class II, III, IV -prolongs time to "first" hospitalization due to CV event in pts w hx of paroxysmal/persistent AF has not been compared directly to propafenone, flecainide or sotalol |
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dronedarone SEs |
increases risk of: -rash -n/v/d -QTc prolongation -creatinine increase -drug interactions -WD due to ADEs |
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dronedarone new risks |
-reports of acute liver toxicity, transplants, deaths -report of 'PALLAS' study, increased risk of stroke, hospitalization for HF, CV death do not use dronedarone for AF pts w HF< rate control for permanent AF, or pts at risk of liver toxicity |
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chronic antiarrhythmic therapy: no co-morbidity or HT alone |
first choice: -propafenone -flecainide -sotalol alternative -amiodarone -dofetilide |
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chronic antiarrhythmic therapy: CAD (stable, post-ACS, or PCI) |
first choice: -sotalol -amiodarone alternative: -dofelitide |
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chronic antiarrhythmic therapy: heart failure |
first choice: -amiodarone alternative: -dofetilide |
