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78 Cards in this Set
- Front
- Back
What kind of tachycardia is AF?
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supraventricular
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Does AF occur more in men or women and what age group?
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men and elderly
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What is acute AF?
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onset within 48 hours
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What is paroxysmal AF?
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terminates spontaneously in <7 days
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What is recurrent AF?
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2 or more episodes
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What is persistent AF?
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duration >7 days and doesn't terminate spontaneously
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What is permanent AF?
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does not terminate with pharmacologic and electrical cardioversion attempts
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What are the characteristics of AF?
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atrial rate 400-600bpm
disorganized atrial activation |
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Why is ventricular response considerably slower than atrial rate?
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AV junction will not conduct most supraventricular impulses
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What are characteristics of atrial flutter?
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atrial rate 300bpm
regular atrial activation |
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What is type I flutter?
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common classic form with atrial rate 300bpm and typical "sawtooth" pattern of atrial activation
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What is type II flutter?
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faster than type I, hyprid between flutter and AF
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What is the predominant mechanism of AF and flutter?
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reentry
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What causes AF?
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multiple reentrant loops
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What causes atrial flutter?
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single dominant reentrant substrate
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Do AF pts typically have syncope?
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no
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What is a severe complication that can result for AF?
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stroke
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How much more of a risk for stroke is a person with AF and rheumatic heart disease compared to pt at sinus rhythm?
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17x
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What is a risk of restoring rhythm in AF pts?
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thromboembolism
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When is DCC first line to restore rhythm?
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if pt is not hemodynapically stable (severy hypotension, angina, pulmonary edema)
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What energy level is usually required in DCC for AF?
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200 joules
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What energy level is usually required in DCC for atrial flutter?
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50 joules
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If pt is hemodynamically stable, what should tx focus on?
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restoring rate
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What drugs are used for resoring rate?
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drugs that slow conduction and increase refractoriness in the AV node
BB (II) nondihydropyridine (IV) digoxin |
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What rate controlling drug is not used if pt has normal LV systolic function (LVEF >40%)?
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digoxin
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Why is digoxin not used if normal LV systolic function (LVEF>40%)?
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slow onset and inability to control heart rate during exercise
full control is not achieved for 24-48hrs not good if increased sympathetic tone (surgery, thyrotoxicosis) because slows AV nodal conduction |
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Why are BB and nondihydropyridine CCBs preffered?
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quick onset and can control rate at rest and exercise
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What drug is effective at controlling ventricular rate if increased sympathetic tone?
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BB
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What IV BB are used for AF?
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propranolol, metoprolol, esmolol
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How are the BB given?
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propranolol and metoprolol are given in intermittent IV boluses
esmolol is given as a loading dose then continuous infusion because t1/2 5-10min |
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How are nondihydropyridines CCB given IV?
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bolus then continuous infusion
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What is first line if pt is in HF and LVEF <40%?
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diltiazem or amiodarone
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Why are CCB avoided in HF?
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potent negative inotropic effects
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What is risk of using amiodarone for rate control?
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may be rhythm control also and cause thromboembolic event
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What should be present if slow ventricular response and going to do DCC?
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pacemaker
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What drugs should not be used if slow ventricular response?
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BB, CCB, or digoxin
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When should rhythm tx be considered?
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after decrease in ventricular rate
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What were the results of the AFFIRM trial?
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mortality was not different between rate and rhythm control. Rate control is a viable alternative to rhythm control.
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If on BB or CCB chronically for rate control, what can be added if not getting effect?
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digoxin
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If bb, CCB, and digoxin do not control rate at rest and exercise, what is an alternative tx?
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amiodarone
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What should be used to treat chronic pts if LVEF <40%?
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BB or digoxin, BB over digoxin because survival benefits in pt with LV systolic dysfunction is greater
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If pt is have decompensated HF, what is first line for rate control?
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digoxin
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What is it called when chronic tachycardia results in progressive decline in LV function?
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tachycardia-induced cardiomyopathy
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What is tx for tachycardia induced cardiomyopathy?
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transvenous catheter delivering radiofrequency current
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When does pt become at increased risk of thrombotic event when in AF?
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AF longer than 48 hours
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When should pt receive antithrombotic before cardioversion?
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if AF longer than 48hrs or unsure how long
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How long, what drug, what goal for antithrombotic tx?
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warfarin for atleast 3 weeks before cardioversion, INR goal 2-3, continue 4 weeks after cardioversion
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After cardioversion, how long before rhythm returns to normal?
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3-4 weeks
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If thrombus present, can you do cardioversion?
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not until thrombus is gone, anticoagulate indefinately
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How do you prepare for cardioversion if AF <48 hrs?
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don't need anticoagulant for 3 weeks because there wasn't time for thrombi to form.
Pt should receive unfractionated heparin or LMW heparin prior to cardioversion |
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What are disadvantages of pharmacologic cardioversion?
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risk of significant SE (TdP), DDI, less effective than DCC
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What are the advantages of DCC (direct current cardioversion)?
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quick and more often successful
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What are disadvantages of DCC (direct current cardioversion)?
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sedation, serious complication such as sinus arrest or ventricular arrhythmias
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When is pharmacologic cardioversion most effective?
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if initiated within 7 days of AF
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What pharmacologic agents are used most often?
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type III pure Ik blockers (ibutilide, dofetilide), type Ic, and amiodarone
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What is "pill-in-the-pocket" method?
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outpatient single loading dose of flecainide or propafenone
only use if this worked inpatient before |
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What is tx for cardioversion of pt has AF for longer than 7 days?
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dofetilide, amiodarone, and ibutilide (type III)
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What can be used for cardioversion if no heart disease present?
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loading dose of propafenone or flecainide (type Ic)
ibutilide can be used also but inpatient only because IV |
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If underlying heart disease what agents should be used?
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amiodarone or dofetilide
the others increase risk of proarrhythmia amiodarone can be done outpatient dofetilide is inpatient only because low proarrhythmic potential |
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What antiarrhythmics can actually increast ventricular response?
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Ia and Ic
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What are the risk factors that require long term anticoagulation with warfarin?
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rheumatic mitral valve disease
previous ischemic stroke TIA any other embolic event >75 years old moderate or severe LV systolic dysfunction congestive HF HTN prosthetic heart valve |
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Who is at intermediate risk? What should they be treated with?
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65-75 years old with no risk factors
warfarin or aspirin 325mg/day |
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Who is at low risk? What tx?
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<65 years old
aspirin 325mg/day |
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When are type Ia agents considered?
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last line in pt without HD, with HTN, without LV dysfunction, without CAD
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What pts should avoid Ic?
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pt with structural heart disease because proarrhythmic
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What is the most effective antiarrhythmic?
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amiodarone
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Can sotolol be used for rhythm control?
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not effective for conversion but effective for maintaining sinus rhythm
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Can dofetilide be used for rhythm control?
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yes, also shown efficacy if pt with LV dysfunction
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Which antiarrhythmic drugs have the most long-term safety profile?
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flecainide, propafenone, sotalol
if no structural heart disease |
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What can alternative be if pt fails or does not tolerate one of the above?
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amiodarone or dofetilide
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Which drugs should be avoided in heart disease?
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flecainide, propafenone, proarrhythmic
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What is used if LV dysfunction present?
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amiodarone
dofetilide if alternative needed |
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What is used if pt has CAD?
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sotalol
amiodarone or dofetilide for alternative |
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What is highly effective nondrug for pure type I atrial flutter?
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ablation with radiofrequency current (can be considered 1st line)
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What surgery can be done for AF?
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maze operation, highly complex and invasive
only use for highly drug refractory pts |
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What nondrug is recommended for AF?
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catheter ablation
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When is catheter ablation considered?
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pt with symptomatic episodes of recurrent AF who fail or do not tolerate at least one antiarrhythmic drug
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what is first line if pt is HTN with LVH?
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amiodarone
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