CC July 2015 Atrial fibrillation

echoecho's version from 2015-07-26 07:59


Question Answer
What is the most common cardiac dysrhythmia?atrial fibrillation
The prevalence increases with ____?age
An estimated ___% of Medicare beneficiaries > 65 years of age are affected? The prevalence among those 80 years and older is estimated to be ____%?9%; 35%
What are the 4 key components of AF management?1) assessment for underlying cardiac or noncardiac pathology 2) control of the ventricular heart rate 3) selection of appropriate therapy for stroke prevention 4) recognizing patients who may benefit from referral for rhythm-control therapy
Updated guidelines classify AF in 3 classifications, list and define these?1. paroxysmal AF is one or more discrete episodes, each of which teminates (with or w/o intervention) within 7 days. 2) continuous AF occurs longer than 7 days and is classified as persistent 3) Long-standing persistent occurs longer than 12 months
Permanent AF refers to teh therapeutic decision to do what?not to pursue rhythm-restoring therapy (this term describes a clinical strategy RATHER than an intrinsic characteristic of the dysrhythmia
Guidelines further distiguish between what types of AF?valvular and nonvalvular AF
What is the most important risk factor for AF?age
List common causes of AF?chronic HTN, alcohol abuse, obesity, pulmonary disease (COPD and OSA), valvular and other structural cardiac disease, hyperthyroidism
*** What is the initial evaluation for patients with AF1) assessment of renal and hepatic function 2) CBC 3) TSH 4) echocardiogram 5) CXR should be obtained if the hx suggests pulmonary disease
What is the most sensitive and specific echo for detection ot atrial trhombi and is useful for determining the timing of a procedure if cardioversion or ablation is being considered?TEE (transesophageal echo)
Is TTE (transthoracic echo sensitive enought to r/o the presence of atrial thrombi?no
Trials have compared rate-control vs rhythm control, using what modalities?electrial cardioversion and/or medications to restore and maintain sinus rhythm
Comment on mortality, stroke or cardiovascular endpoints in reductions with rhythm control?has not resulted in reductions in mortality, stroke or other cardiovascular endpoints
Rhythm control is associated with more ______ than are rate control strategies?hospitalizations
the results (in addition to the potential _____ of antiarrhythmic drugs), suggest that rate control is a reasonable intial strategy, especially for what type of patient?toxicity; older patients and those with few or no symptoms
List the medications that are first-line agents for rate control? Do these provide control for both rest and during exercise1) beta blockers 2) non-dihydropyridine calcium channel blockers like verapamil (Calan) and diltiazem (Cardizem) 3. yes
What medication can also be used to control resting heart rate, but it is ineffective in controlling heart rate during exercise and so should not be used as monotherapy in what type of patients?Digoxin; physically active patients
What is the target for heart rate in patients treated with rate-control medication?trials looked at strict goal of < 80 bpm vs. more leninent goal < 110 and it showed that the lenint strategy was noninferior to the strict goal.
AF increases the risk of embolic stroke by a factor of ____ for nonvalvular AF and a factor of ____ for AF associated with mitral valve stenosis?5; 20
What therapy substantially mitigates the risk of embolic stroke?oral anticoagulaton therapy
***The ACC/AHA/HRS guidelines recommend use of what score for assessment of stroke risk and need for anticoagulation in patients with nonvalvular AF. ?the CHA2DS2 - VASc score
*** List the clinical features and associated score if using the CHA2DS2 - VASc score?1) CHF = +1 point 2) HTN = +1 point 3) age > 75 = +2 points 4) diabetes = +1 point 5) CVA or TIA (hx of) = +2 points 6) vascular disease (prior to MI, PVD or aortic plaque) = + 1 point 7) age 65-74 years = + 1 point 8) sex category = + 1 point for female
*** Oral anticoaulation is recommended for patients with a hx of either what two conditions OR CHA2DS2-VASc score of what?1) TIA 2) CVA 3) score of > 2
*** When can anticoagulation be omitted in patients score wise?0
***For pts with a CHA2DS2-VASc score of 1, what 3 options are acceptable?1) ommission of anticoagulation 2) use of ASA 3) full anticoagulation
*** For decades, warfarin was the only evidence-based therapy to reduce stroke risk in AF. Warfarin remains the only anticoag recommended for treatment of what 2 conditions, why?1) AF assoc'd w/ mechanical heart valves OR hemodynamically significant mitral stenosis 2) these two group of patients were excluded from trials of the newer anticoagulants
However, several new oral anticoags have been shown to be noninferior to warfarin for stroke prevention in what type of AF? non-valular
*** In nonvalvular AF, what 4 medications are all considered reasonable first-line options?1) Warfarin (a vit K antagonist) 2) Dabigatran (pradaxa - a direct thrombin inhibitor), 3) Rivaroxaban (Xarelto - direct factor Xa inhibitors) 4) Apixaban (Eliquis - direct factor Xa inhibitor)
Safety and efficacy of newer anticoags have not been established in pts with what medical condition, although guidelines suggest that they may be used at reduced doses in pts w/ what level of CKD?1) CKD 2) moderate CKD
Why are Dabigatran (Pradaxa) and Rivaroxaban (Xarelto) contraindicated in pts on hemodialysis?due to insufficient evidence that their benefits outweigh harms.
What is the primary advantage of warfarin?low cost
What are the disadvantages of warfarin?multiple drug-diet and drug-drug interactions and need for regular monitoring of international normalized ratio (INR)
What are the advantages of the newer anticoagulants?1) ability to omit routine blood testing 2) a lower rate of serious bleeding compared to warfarin
What are the disadvantages of the newer anticoagulants?1) cost 2) lack of a specific antidote
***In addition, because of their relatively short half-lives, the newer oral anticoagulatnes are associated with an increased risk of what?thrombosis (The FDA has mandated a black-box warning of this risk in the officially approved labels for dabigatran, apixaban and rivaroxaban)
Although randomized trials have not shown a survival benefit for rhythm control compared to rate control, some trials show improved _____ ____ ______ in pts for whom sinus rhythm was successfully maintained?quality of life
What does an increase duration of AF predict?a lower likelihood of successful restoration of sinus rhythm
The ACC/AHA/HRS guidelines indicate that _____ (rate vs rhythm) control is an option for patients with persistent symptoms attributable to AF?rhythm
Pts who may be candidates for rhythm control are usually referred to a cardiologist for what?determination of the most appropriate strategy
When can elective direct current cardioversion be attempted?after at least 3 weeks of therapeutic anticoagulation OR after TEE has ruled out atrial thrombi
Initiation of what group of drugs PRIOR to cardioversion may increase the success rate?antiarrhythmic
Some pts desiring a rhythm control strategy may be candidates for what procedure to restore sinus rhythm?catheter ablation
The strongest evidence for efficacy of catheter ablation is in what type of patients?relatively young patients with paroxysmal AF and no structural heart disease
Question Answer
*** Has rhythm control resulted in reductions in mortality, stroke or other cardiovascular endpoints?no
*** Rhythm-control strategies are associated with more or less hospitalizations then are rate-control strategies?more
*** What group of drugs are the typical first-line agents for rate control?1) beta blockers 2) non-dihydropyridine calcium channel blockers (Verapamil [Calan] and diltiazem [Cardizem]
*** What score is used for assessment of stroke risk and need for anticoagulation in patients with nonvalvular AF?Cha2DS2-VASc score
*** What anticoagulant remaines the only anticaogulant recommended for rx of AF assoc'd w/ mechanical heart valves or hemodynamically significant mitral stenosis?Warfarin
*** What are the 4 medications that are all considered reasonable first-line options for non-valvular AF?1) Warfarin (a vit K antagonist) 2) Dabigatran (pradaxa - a direct thrombin inhibitor), 3) Rivaroxaban (Xarelto - direct factor Xa inhibitors) 4) Apixaban (Eliquis - direct factor Xa inhibitor)
*** Rhythm control is an option for patients with what?persistent symptoms of AF
*** Other factors favoring rhythm control?younger age, difficulty maintaining rate control