B P7 C66 Atrial Fibrillation: Clinical Features, Mechanisms, and Management

Question 1

Atrial fibrillation (AF) is a supraventricular arrhythmia characterized electrocardiographically by _____. The f waves, _____ beats/min, are variable in amplitude, shape, and timing.

Atrial flutter waves have a rate of 250 to 350 beats/min and are constant in timing and morphology

Answer 1

Low-amplitude baseline oscillations (fibrillatory or f waves from the fibrillating atria) and an irregularly irregular ventricular rhythm

300 to 600 bpm

Question 2

The ventricular rate during untreated AF typically is _____ beats/min.

Patients with the Wolff-Parkinson-White (WPW) syndrome can experience ventricular rates during AF exceeding _____ beats/min because of conduction over the accessory pathway

Answer 2

100 to 160 bpm

250 bpm

Question 3

The ventricular rate during AF can appear more regular when _____.

Answer 3

(1) Rate is extremely rapid (>170 beats/min)
(2) Junctional tachycardia independently controls the ventricles
(3) High-degree atrioventricular (AV) block with a regular escape rhythm
(4) QRS complexes all are paced

Question 4

Atrial fibrillation that terminates spontaneously within 7 days is termed _____, and AF present continuously for more than 7 days is called _____. AF that persists for longer than 1 year is termed _____. The term _____ AF is used when the patient and clinician jointly decide to abandon further attempts at restoring and/or maintaining sinus rhythm

Answer 4

Paroxysmal: < 7 days
Persistent: > 7 days
Longstanding persistent: > 1 year
Permanent AF: abandon attempts at restoring/maintaining SR

Question 5

_____ atrial fibrillation refers to AF that occurs in patients younger than 60 years who do not have hypertension or any evidence of structural heart disease.This designation is a historical descriptor that has been variably applied to different low-risk subsets of AF patients.

Answer 5

Lone AF

Question 6

Paroxysmal AF also can be classified clinically on the basis of the autonomic setting in which it most often occurs. Approximately 25% of patients with paroxysmal AF have _____ AF, in which AF is initiated in the setting of high vagal tone, typically in the evening when the patient is relaxing or during sleep. Drugs exerting a vagotonic effect (e.g., digitalis) can aggravate vagotonic AF, and drugs with a vagolytic effect (e.g., disopyramide) may be particularly appropriate for prophylactic therapy.

_____ AF occurs in approximately 10% to 15% of patients with paroxysmal AF in the setting of high sympathetic tone, as during strenuous exertion. In patients with adrenergic AF, beta blockers not only provide rate control but may prevent episodes of AF. Most patients have a mixed or random form of paroxysmal AF, with no consistent pattern of onset. In some, alcohol can be a precipitant.

Answer 6

Vagotonic AF (25% of Paroxysmal AF)

Adrenergic AF (10-15% of paroxysmal AF)

Question 7

_____ is the most common arrhythmia treated in clinical practice and the most common arrhythmia for which patients are hospitalized; approximately 33% of arrhythmia-related hospitalizations are for AF.

Answer 7

Atrial fibrillation

Question 8

Independent risk factors for the development of AF

Answer 8

Advanced age
CHF
Male sex
Tall stature
Family hx of AF < 50 y/o
LAE
Hypertension
Obesity
OSA

Question 8

***The three main mechanistic concepts of AF that have emerged over time consist of _____.

Answer 8

Multiple reentrant wavelets
Rapidly discharging autonomic foci
Single reentrant circuit with fibrillatory conduction

Question 9

A key breakthrough that had an immediate therapeutic impact was the recognition that in many patients, AF is triggered and/or maintained by rapidly firing foci in the _____.

Answer 9

Pulmonary veins

Question 10

In persistent AF, changes in the atrial substrate, including _____ that contributes to slow, discontinuous, and anisotropic conduction, may give rise to wandering or stationary reentry. It is for this reason that the outcomes of AF ablation targeted at the pulmonary veins (PVs) alone results in lower efficacy than in patients with paroxysmal AF.

Answer 10

Interstitial fibrosis

Question 11

It is now well established that susceptibility to AF is heritable. Individuals who have a first-degree relative with AF have a ___% increased risk of developing AF.

Answer 11

40%

Question 12

The majority of patients with AF have _____.

Answer 12

Hypertension (usually with left ventricular hypertrophy) or some other form of structural heart disease

Question 13

The most common cardiac abnormalities associated with AF are:

Answer 13

Hypertensive heart disease
Ischemic heart disease
Mitral valve disease
Hypertrophic cardiomyopathy
Dilated cardiomyopathy

Question 14

The possible mechanisms of AF in patients with sleep apnea include _____.

Answer 14

Hypoxia
Autonomic tone surges
Hypertension

Question 15

Available data suggest that _____ are responsible for the relationship between obesity and AF.

Answer 15

Atrial dilation

Increase in local and systemic inflammatory factors

Question 16

A growing body of data has demonstrated that ____ fat is strongly associated with the presence, severity, and recurrence of AF in many clinical settings.

Answer 16

Epicardial fat

Question 17

The most likely arrhythmogenic mechanisms by which epicardial fat predisposes to AF include _____.

Answer 17

Adipocyte infiltration
Profibrotic effects
Proinflammatory effect

Question 18

The _____ study demonstrated that sustained weight loss and exercise can reduce the AF burden.

Answer 18

LEGACY

Question 19

The most common symptoms are _____._____ can occur because of release of atrial natriuretic peptide.

Answer 19

Palpitations
Fatigue
Dyspnea
Effort intolerance
Lightheadedness

Polyuria

Question 20

A _____ may be helpful by maintaining sinus rhythm for at least a few days to determine whether a patient feels better in sinus rhythm.This strategy is especially valuable in a patient under the age of 80 years who presents for a routine physical examination and is found to be in AF.

Answer 20

“Diagnostic cardioversion”

Question 21

Rather than quickly declaring the patient “asymptomatic,” many experienced clinicians will _____ to evaluate symptomatic improvement. This strategy also is useful in patients with newly diagnosed persistent AF as the longer a patient is in continuous AF, the more difficult it is to restore and maintain sinus rhythm. This approach can provide a basis to pursue a rhythm-control versus rate-control strategy.

Answer 21

Restore sinus rhythm with a cardioversion

Question 22

Causes of syncope in AF

Answer 22

(1) long sinus pause on termination of AF in a patient with the sick sinus syndrome
(2) AF with a RVR because of neurocardiogenic (vasodepressor) syncope triggered by the tachycardia or because of a severe drop in blood pressure caused by a reduction in cardiac output

Question 23

The hallmark of AF on physical examination is an _____.

Answer 23

Irregularly irregular pulse

Question 24

Short R-R intervals during AF do not allow adequate time for left ventricular diastolic filling, resulting in a low stroke volume and the absence of palpable peripheral pulse.This results in a _____ during which the peripheral pulse is not as rapid as the api- cal rate

Answer 24

Pulse deficit

Question 25

When it is unclear from the history, _____ weeks of continuous or autotrigger ambulatory monitoring, or by mobile cardiac outpatient telemetry, is useful to determine whether AF is paroxysmal or persistent and to quantitate the AF burden in patients with paroxysmal AF.

Answer 25

2-4 weeks

Question 26

If the symptoms occur on a daily basis, a _____ is appropriate. However, extended monitoring for 2 to 4 weeks with an event monitor or continuous rhythm monitor or by mobile cardiac outpatient telemetry is appropriate for patients whose symptoms are sporadic. Another option is an insertable monitor, which is placed subcutaneously and has a battery life of approximately 3 years.

Answer 26

Daily: 24-hour Holter recording

Sporadic: 2-4 weeks event monitor/continuous rhythm monitor

Question 26

One of the most important benefits of a continuous monitor over weeks to years is that the _____.

Answer 26

Burden of AF can be precisely defined

Question 27

The most important therapeutic goal in AF patients is to _____.

Answer 27

Prevent thromboembolic complications, especially stroke

Question 28

The strongest predictors of ischemic stroke and systemic thromboembolism are _____.

Answer 28

(1) History of stroke or TIA
(2) Mitral stenosis

Question 28

Aside from prior stroke, the best-established risk factors for stroke in patients with nonvalvular AF are _____.

Answer 28

Diabetes (RR 1.7)
Hypertension (RR, 1.6)
Heart failure (RR,1.4)
Age 70 or older (RR,1.4 per decade).

Question 29

Renal failure also is an independent risk factor for stroke in patients with AF. The RR of a thromboembolic event in the absence of anticoagulation was ___ in patients with non–end-stage chronic kidney disease and ___ in patients requiring hemodialysis or a renal transplant.

Answer 29

Non endstage CKD (RR 1.4)
ESRD (HD/KT) (RR 1.8)

Question 30

At present the CHA2DS2 -VASc score is recommended for estimation of stroke risk (_____).

Each risk factor counts as 1 point, with the exception of prior stroke or transient ischemic events and age 75 years, which count for 2 points.

Answer 30

Cardiac failure
Hypertension
Age >75 years (2 pts)
Diabetes
Stroke, or transient ischemic attack (TIA) (2 pts)
Vascular disease
Age 65 to 74 years
female Sex category

Question 31

Correction for the inclusion of female sex is accomplished in the updated 2019 AF Guidelines by specifying a higher CHA2DS2-VASc score in women than in men (i.e.,____ in women and ___ in men to achieve a class I recommendation for anticoagulation) for each anticoagulation cutoff

Answer 31

Women: at least 3
Men at least 2

Question 32

When considering the CHA2DS2-VASc score, it is important to recognize that there are risk factors for stroke that are not included in the CHA2DS2-VASc score. These include _____.

Answer 32

Left atrial size
AF burden
Mitral annular calcification

Question 33

The annual risk of stroke is zero or close to zero when the CHA2DS2 -VASc score is ___, compared with approximately 3% when the CHA2DS2-VASc score is ____.

Answer 33

Risk 0% = Score 0

Risk 3% = score 3

Question 34

The AF burden in persistent AF is ___% and always higher than in patients with paroxysmal AF

Answer 34

100%

Question 35

The 2019 AHA/ACC/HRS AF Guidelines provides a class I level of evidence (LOE) B recommendation that the presence of _____ on an implanted device should prompt further evaluation to document clinically relevant AF to guide treatment decisions

Answer 35

Recorded atrial high rate episodes

Question 36

In the absence of data from clinical trials, most clinicians today would advise anticoagulation for patients with device-detected AF who have episodes of _____.

Answer 36

At least 5 hours in duration and have an elevated stroke risk profile

Question 37

An important consideration in patients treated with an oral anticoagulant is the risk of bleeding. Several risk-scoring systems have been developed to assess a patient’s susceptibility to hemorrhagic complications. The scoring system with the best balance of simplicity and accuracy is the HAS-BLED score. The components of this score are _____.

Each of these components is 1 point. As the score increases from 0 to the maximum of 9, there is a stepwise increase in the risk of bleeding in patients treated with warfarin.

Answer 37

Hypertension
Abnormal renal or liver function
Stroke
Bleeding history or predisposition
Labile international normalized ratio (INR)
Elderly (>75 years)
Drug (antiplatelet agent or NSAID) or alcohol use

Question 38

The 2019 AHA/ACC/HRS AF Guidelines give a class I LOE A recommendation for anticoagulation of men with a CHA2DS2-VASc score of __ or higher and women with a CHA2DS2-VASc score of __ or higher.

Answer 38

Men: 2 or higher

Women: 3 or higher

Question 39

Aspirin is _____ for preventing thromboembolic complications in patients with AF

Answer 39

Not effective

Question 40

A meta-analysis of the major randomized clinical trials that compared warfarin with placebo for prevention of thromboembolism in patients with AF demonstrated that warfarin reduced the risk of all strokes (ischemic and hemorrhagic) by approximately _____%

Answer 40

60%

Question 41

The target INR should be _____. This range of INRs provides the best balance between stroke prevention and hemorrhagic complications.

Answer 41

2.0 to 3.0

Question 42

Maintaining the INR at a level of 2.0 or higher is important because even a relatively small decrease in INR from 2.0 to ____ more than doubles the risk of stroke.

Answer 42

1.7

Question 43

The annual risk of a major hemorrhagic complication during anticoagulation with warfarin is in the range of _____%, and a strong predictor of major bleeding events is an INR greater than _____

Answer 43

1-2%

> 3.0

Question 44

Direct thrombin inhibitors and factor Xa inhibitors have several advantages over vitamin K antagonists such as warfarin: _____

Answer 44

(1) Fixed dosing regimen that eliminates the need for monitoring the INR
(2) Rapid onset and offset
(3) Equal or greater efficacy for stroke prevention
(4) Lower risk of intracranial hemorrhage
(5) No interactions with dietary factors such as alcohol or vitamin-K containing foods
(6) Fewer drug interactions

Question 45

_____, an oral direct thrombin inhibitor, and _____, which are factor Xa inhibitors, are approved by the U.S. Food and Drug Administration (FDA) for prevention of stroke/ embolism in patients with nonvalvular AF. Randomized clinical trials demonstrated that each of these four DOACs is noninferior or superior to warfarin in efficacy and safety in patients with nonvalvular AF who had risk factors for stroke

Answer 45

Dabigatran - direct thrombin inhibitor

Rivaroxaban, Apixaban, and Edoxaban - FXa inhibitors

Question 46

One of the most serious risks of anticoagulation is intracranial hemorrhage.

The trials, which were performed for FDA approval of each of these NOACs, revealed that the risk of intracranial hemorrhage is about ___% lower with DOACs compared with warfarin.

Answer 46

50% lower

Question 47

DOACs also have some disadvantages compared with warfarin:

Answer 47

(1) Higher cost
(2) More gastrointestinal side effects in the case of dabigatran
(3) Twice-daily dosing for dabigatran and apixaban
(4) Absence of a readily available laboratory test to verify compliance
(5) Restricted use in patients with prosthetic valves
(6) Requires great care in patients with severe renal disease

Question 48

Until recently another limitation of DOACs was that there were no specific reversal agents. However, reversal agents now are available for all DOACs. The first reversal agent to receive FDA approval, both for uncontrolled bleeding and the need for urgent surgery, was _____, an antibody fragment that reverses the anticoagulant effects of dabigatran within minutes. Since that time andexanet alfa has been approved for acute major bleeding in patients taking a factor Xa inhibitor. A limitation of andexanet alfa is high cost compared with a prothrombin concentrate.

Answer 48

Idarucizumab - Dabigatran

Andexanet Alfa - Factor Xa inhibitors

Question 49

When a reversal agent is not available or not desired, administration of _____ can reverse the anticoagulant effect of the DOACs

Answer 49

Prothrombin complex concentrate

Question 50

Valvular AF is defined as AF in patients with a _____.

Answer 50

Prosthetic valve

or

Moderate to severe mitral stenosis

Question 50

The onset of action of the DOACs is approximately _____ hours after a dose.Their half-life is approximately _____ hours.The rapid onset of action and washout eliminates the need for bridging therapy with heparin when treatment with one of the DOACs is interrupted for a surgical or invasive medical procedure.

Answer 50

Onset: 1.5 to 2 hrs
t1/2: 12 hours

Question 51

Because LMWH can be self-injected outside the hospital, it is a practical alternative to unfractionated heparin for initiation of anticoagulation with warfarin in patients with AF. Bridging therapy with LMWH should be continued until the INR is _____.

Answer 51

2.0 or higher

Question 52

Approximately 90% of left atrial thrombi form in the _____, and therefore successful excision or closure of the LAA should greatly reduce the risk of thromboembolic complications in patients with AF.

Answer 52

Left atrial appendage

Question 53

In recent years, several percutaneous LAA occlusion and ligation devices have been developed as alternatives to surgical closure techniques. These devices have their greatest utility in _____.

Answer 53

High-risk AF patients who cannot tolerate or who refuse to take an oral anticoagulant.

Question 54

The only percutaneous occlusion device approved by the FDA specifically for stroke prevention as an alternative to warfarin is the _____. This nitinol plug covered with fenestrated fabric became widely available for clinical use after FDA approval in 2015.

After implantation of the device using femoral vein access and transeptal catheterization, anticoagulation with warfarin is recommended for at least _____ days, at which time anticoagulation can be discontinued if there is no TEE evidence of _____.

Answer 54

WATCHMAN (Boston Scientific, Marlborough, Massachusetts)

At least 45 days of warfarin

Peridevice flow

Question 55

Another device used in the United States for LAA occlusion is the _____. This device has FDA approval for soft tissue approximation (not stroke prevention) and has been used off-label in clinical practice in the United States and elsewhere for LAA occlusion. A guidewire with a magnetic tip is inserted into the left atrium after transseptal catheterization and is positioned at the tip of the LAA. It functions as a rail for an epicardial snare.Entry into the pericardial space is attained using a percutaneous approach. A snare with a pretied suture is inserted into the pericardial space and guided toward the LAA.The pretied suture then is tightened to occlude the LAA

Answer 55

LARIAT (Sentreheart, Redwood City, California)

Question 56

At present, the LARIAT device is being used in the ____ clinical trial, which is seeking to determine whether PV isolation plus appendage ligation with the LARIAT device is superior to PV isolation alone in patients with persistent AF.

Answer 56

AMAZE

Question 57

_____ are considered class IIa and IIb recommendations, respectively, in situations where anticoagulation is contraindicated or the patient is undergoing cardiac surgery

Answer 57

Percutaneous (IIa) or surgical LAA occlusion(IIb)

Question 58

Patients who present to the emergency department because of AF often have a rapid ventricular rate, and control of the ventricular rate is most rapidly achieved with intravenous _____

Answer 58

IV Diltiazem or esmolol

Question 59

Cardioversion should ideally be preceded by TEE to rule out a left atrial thrombus if the AF has been _____.

Answer 59

Present for longer than 48 hours

or

If the duration is unclear and the patient is not already anticoagulated

Question 60

However, if the patient has _____, immediate cardioversion without a TEE is advised.

Answer 60

Marked hemodynamic compromise

Question 61

If the patient is hemodynamically stable, the decision to restore sinus rhythm by cardioversion is based on several factors, including _____

Answer 61

Symptoms
Prior AF episodes
Age
Left atrial size
Current AAD therapy

Question 62

The advantages of early cardioversion are:

Answer 62

(1) Rapid relief of symptoms
(2) Avoidance of the need for TEE or therapeutic anticoagulation for 3 to 4 weeks before cardioversion if cardioversion is performed within 48 hours of AF onset
(3) Possibly a lower risk of early AF recurrence because of less atrial remodeling

Question 63

A reason to defer cardioversion is the _____.

Answer 63

(1) Unavailability of TEE in a patient who has not been anticoagulated with AF of unclear duration or duration more than 48 hours.
(2) Left atrial thrombus by TEE
(3) Suspicion (based on prior AF episodes) that AF will convert spontaneously within a few days
(4) Correctable cause of AF such as hyperthyroidism

Question 64

Pharmacologic cardioversion has the advantage of _____. In addition, the probability of an immediate recurrence of AF is _____ with pharmacologic cardioversion than with electrical cardioversion.

Answer 64

Not requiring general anesthesia or deep sedation

Lower (Pharmacologic cardioversion)

Question 65

Pharmacologic cardioversion is unlikely to be effective if the duration of AF is longer than ___ days.

Answer 65

> 7 days

Question 66

Drugs that can be administered intravenously for cardioversion of AF consist of _____.

Answer 66

Ibutilide
Procainamide
Amiodarone

For AF episodes fewer than 2 to 3 days in duration, efficacy is approximately:
60% to 70% for ibutilide
40% to 50% for amiodarone
30% to 40% for procainamide

Question 67

To minimize the risk of QT prolongation and polymorphic ventricular tachycardia, the use of ibutilide should be limited to patients with an ejection fraction _____.

Answer 67

> 35%

Question 68

Acute pharmacologic cardioversion of AF also can be attempted with oral drugs in patients without structural heart disease.The most common oral agents for acute conversion of AF are _____.

Answer 68

Propafenone (300 to 600 mg)
Flecainide (100 to 200 mg)

Question 69

When flecainide is used, patients generally take a _____on AF onset and then take the flecainide one or more hours later.

It is recommended that these drugs be administered under surveillance upon first use, as patients may have a pronounced _____. If no adverse drug effects are observed, the patient may then be an appropriate candidate for episodic, self-administered AAD therapy on an outpatient basis (the “pill-in-the-pocket” approach).

Answer 69

Beta blocker

Postconversion pause

Question 70

The efficacy of transthoracic cardioversion exceeds ____%. Biphasic waveform shocks convert AF more effectively than monophasic wave- form shocks and allow the use of lower energy shocks, resulting in less skin irritation. An appropriate first-shock strength using a biphasic wave-form is _____J, followed by higher output shocks if needed.

If a 360-J biphasic shock is unsuccessful, _____ should be infused before another shock is delivered because it lowers the defibrillation energy requirement and improves the success rate of transthoracic cardioversion.

Answer 70

> 95%

Biphasic: 150-200J, ff by higher output shocks

Ibutilide (Lowers defibrillation energy)

Question 71

Transthoracic cardioversion can fail to restore sinus rhythm. An _____, often results in successful repeat cardioversion

Answer 71

Increase in shock strength
Infusion of ibutilide
Repeat CV with greater pressure applied to the defibrillation patches

Question 72

The second type of failure is an _____.This occurs in approximately 25% of AF episodes less than 24 hours in duration and 10% of episodes more than 24 hours in duration. For this type of cardioversion failure, an increase in shock strength is of no value. If the patient has not been receiving an oral rhythm-control agent, infusion of ibutilide may be helpful to prevent an immediate recurrence of AF.

Answer 72

Immediate recurrence of AF within a few seconds of successful conversion to sinus rhythm

Question 73

Regardless of whether cardioversion is performed pharmacologically or electrically, therapeutic anticoagulation is necessary for _____ before cardioversion to prevent thromboembolic complications if the AF has been ongoing for more than 48 hours

Answer 73

Before cardioversion: 3 weeks or more of anticoagulation

Question 74

If the time of onset of AF is unclear, for the sake of safety, the AF duration should be assumed to be more than 48 hours. These patients should be therapeutically anticoagulated for ______ after cardioversion to prevent thromboembolic complications that may occur because of _____.

Answer 74

Post cardioversion: 4 weeks

Atrial stunning

Question 75

If the duration of AF is known to be _____ hours, cardioversion can be performed without anticoagulation

Answer 75

< 48 hrs

Question 75

When AF duration exceeds 48 hours or is unclear, an alternative to 3 weeks of therapeutic anticoagulation before cardioversion is _____. If no thrombi are seen, the patient can be cardioverted safely but still requires 4 weeks of therapeutic anticoagulation after cardioversion to prevent thromboembolism related to atrial stunning

Answer 75

Anticogulation with heparin and a TEE to check for a left atrial thrombus

Question 76

The major clinical benefit of the TEE-guided approach over the conventional approach is that _____.

Answer 76

Sinus rhythm is restored several weeks sooner

Question 77

Several randomized studies have compared a rate-control strategy with a rhythm-control strategy in patients with AF. Overall, these studies have demonstrated a _____.

Answer 77

Significantly lower rate of rehospitalization with a rate-control strategy

But no significant differences in other major outcomes, such as all-cause mortality, strokes, bleeding events, worsening heart failure, or quality of life

Question 78

The decision to pursue a rhythm-control strategy versus a rate- control strategy should be individualized based on several factors. These include the _____.

Answer 78

(1) Nature, frequency, and severity of symptoms
(2) Length of time that AF has been present continuously in patients with persistent AF
(3) Left atrial size
(4) Comorbidities
(5) Response to prior cardioversions
(6) Age
(7) Side effects and efficacy of the AADs already used to treat the patient
(8) Patient age and activity level
(9) Patient’s preference.

Question 78

The duration of continuous AF is a predictor of the ability to restore and maintain sinus rhythm.The chance of successful AF rhythm control is higher in patients with paroxysmal or early persistent AF (<_____ months) than for patients who have been in continuous AF for one or more years.This is an important consideration when faced with asymptomatic or minimally symptomatic patients with newly diagnosed persistent AF.

Answer 78

< 6 mo

Question 79

This prospective randomized clinical trial randomized 2204 patients with AF to catheter ablation or medical therapy.The primary endpoint was a composite of death, disabling stroke, serious bleeding, or cardiac arrest.

No difference in the primary endpoint was present after a median follow-up of 48.5 months.

But the secondary endpoint of death or cardiovascular hospitalizations was significantly lower in the ablation arm than in the medical therapy arm (51.7% vs. 58.1%, p = 0.001).

For this reason, the 2017 HRS/EHRA/ECAS Consensus Document on AF ablation provides a class IIb recommendation for catheter ablation of AF in patients who are asymptomatic

Answer 79

CABANA Trial

Question 80

The 2014 and 2019 ACC/ AHA/HRS AF Guidelines advise that the optimal metric for rate control is a resting heart rate <_____ beats/min. Based on a single European clinical trial, a more lenient rate control metric of <110 beats/ min is provided with a class IIb recommendation. Assessment of the degree of heart rate control can be obtained with a 24-hour Holter monitor.A 12-lead ECG provides an indication of the resting ventricular rate but fails to provide information on the ventricular rate during a patient’s daily activities

Answer 80

AHA/HRS: <80 bpm

European: <110 bpm

Question 81

Oral agents available for long-term heart rate control in patients with AF are digitalis, beta blockers, calcium channel antagonists, and amiodarone. The first-line agents for rate control are _____. A combination is often used to improve efficacy or to limit side effects by allowing the use of smaller dosages of the individual drugs.

Answer 81

Beta blockers and the calcium channel antagonists verapamil and diltiazem

Question 82

In patients with sinus node dysfunction and tachycardia-bradycardia syndrome, the use of a beta blocker with _____ may provide rate control without aggravating sinus bradycardia

Answer 82

Intrinsic sympathomimetic activity

Pindolol
Acebutolol

Question 82

Digitalis may adequately control the rate at rest but often does not provide adequate rate control during exertion as it works mainly by _____.Digitalis is no longer recommended for rate control except in patients with _____ because digitalis has been shown to increase the risk of all-cause mortality, particularly among patients with AF.

Answer 82

Increasing vagal tone

Heart Failure

The 2014 and 2019 AHA/ACC/HRS Guidelines recommend digoxin for rate control only in patients with heart failure

Question 83

Amiodarone is much less frequently used for rate control than the other negative dromotropic agents because of the risk of organ toxicity associated with long-term therapy. Amiodarone can be an appropriate choice for rate control if the other agents are not tolerated or are ineffective. For example, amiodarone would be an appropriate choice for a patient with _____ who cannot tolerate either a calcium channel antagonist or a beta blocker and who has a rapid ventricular rate despite treatment with digitalis.

Answer 83

Persistent AF, heart failure, and reactive airway disease

Amiodarone as a rate-control medication is provided with a class IIb recommendation in the 2014 ACC/AHA/HRS AF Guidelines.

Question 84

The results of studies on the efficacy of AADs for suppression of AF suggest that all the available drugs except amiodarone have similar efficacy and are associated with a _____% reduction in the odds of recurrent AF during 1 year of treatment

Answer 84

40% to 60%

Question 85

The one drug that stands out as having higher efficacy than the others is amiodarone. In studies that directly compared amiodarone with sotalol or class I drugs, amiodarone was _____% more effective in suppressing AF. However, because of the risk of organ toxicity, amiodarone is not appropriate first-line drug therapy for most patients with AF. The 2014 and 2019 AHA/ACC/HRS AF Guidelines recommend that amiodarone be used as first-line antiarrhythmic medication only in patients with heart failure.

Answer 85

60% to 70%

Question 86

Ventricular proarrhythmia from class Ia agents (quinidine, pro- cainamide, disopyramide) and class III agents (sotalol, dofetilide, dronedarone,amiodarone) is manifested as _____.

Risk factors for this type of proarrhythmia include _____.

Answer 86

QT prolongation and polymorphic ventricular tachycardia (torsades de pointes)

Female sex
LV dysfunction
Hypokalemia
Concomitant use of another QT-prolonging drug

Question 87

The ventricular proarrhythmia from class Ic agents (flecainide and propafenone) manifests as _____, but not QT prolongation. They also increase the propensity for ventricular fibrillation in the setting of myocardial ischemia or infarction. For this reason, class Ic agents are not recommended in patients with established _____

Answer 87

Monomorphic ventricular tachycardia
Sometimes with widening of the QRS complex during sinus rhythm

Coronary artery disease (CAD) - contraindication for Class Ic drugs

Question 88

In patients with AF in the setting of a structurally normal heart, _____ are all reasonable first-line drugs. _____ can be considered if the first-line agents are ineffective or not tolerated, especially if AF ablation is not preferred by the patient

Answer 88

Flecainide
Propafenone
Sotalol
Dofetilide
Dronedarone

Amiodarone

Question 89

In patients with CAD, class Ic drugs have been found to increase the risk of death, and the safest first-line options are _____ ,with _____ reserved for use as a second-line agent.

Answer 89

1st line:
Dofetilide
Sotalol
Dronedarone

2nd line:
Amiodarone

Question 90

In patients with heart failure, several AADs have been associated with increased mortality, and the only two drugs known to have a neutral effect on survival are _____.

Answer 90

Amiodarone
Dofetilide

Question 91

After a higher mortality risk was demonstrated in a subsequent randomized clinical trial, _____ was labeled as being contraindicated when used as a rate-control agent and also in patients with decompensated heart failure.

Answer 91

Dronedarone

Question 92

Experimental studies have indicated that _____ have favorable effects on electrical and structural remodeling

Answer 92

ACEi and ARBs

Question 93

4 Pillars of AF management

Answer 93

Stroke prevention
Rate control
Rhythm control
Risk factor management

“S3R”

Question 94

The modifiable AF risk factors consist of _____.

Answer 94

CAD
Obesity
Lack of cardiovascular fitness
Diabetes

Sleep apnea
Heart failure
Hypertension
Alcohol use
Tobacco

COLD SHHAT

Question 95

Obesity is closely linked to the development of AF.The risk of developing AF increases _____% with every 5-point increase in BMI.

Answer 95

29% per 5 point increase in BMI

Question 96

Hypertension is a modifiable risk factor for AF. Hypertension causes _____.

Answer 96

Ventricular hypertrophy
Atrial enlargement
Renin-angiotensin system

Question 96

There also is a strong association between diabetes and AF, probably because of _____.

Answer 96

Fibrotic changes in the atria
Downregulation of connexin-43
Abnormalities of conduction in the atrium

Question 97

Cigarette smoking augments the risk of AF by causing an increase in _____.

Answer 97

Sympathetic tone
Inflammation
Endothelial dysfunction
Atrial fibrosis
Oxidative stress

SIEAO MAI and Cigarette

Question 98

Alcohol use has also been linked to development of AF. This link results from _____. A recent study demonstrated that abstinence from alcohol results in a reduction in AF burden

Answer 98

Acute oxidative stress
Direct cellular effects of alcohol on atrial myocytes
Activation of the sympathetic nervous system

ADA ALCOHOL

Question 99

Based on the growing body of literature linking AF development to the presence of modifiable risk factors, especially obesity, the AHA/ ACC/HRS 2019 AF Guideline provides a class I LOE B recommendation that overweight and obese patients with AF should lose weight as part of a risk factor modification program. The goal of weight loss ideally should be a BMI of </=_____.

Answer 99

27 kg/m2

Question 100

The arrhythmia substrate of AF is ______. Furthermore, several factors that promote AF cannot be addressed simply by catheter ablation, including comorbidities (e.g., hypertension, obesity, obstructive sleep apnea), structural remodeling of the atria, systemic inflammatory factors, and genetic factors.

Answer 100

Not completely understood
Usually widespread
Variable between patients
Progressive

Question 101

AF can recur after an initially successful ablation procedure. For this reason, AF ablation should not be considered a “cure” for AF but rather a _____ to keep the patient in sinus rhythm for as long as possible

Answer 101

Palliative measure

Question 102

Circumferential antral isolation of the PVs results in 1 year of freedom from AF of between _____.

Answer 102

60% and 80% in patients with paroxysmal AF
40% to 60% in patients with persistent AF
20% to 40% in patients with longstanding persistent AF

Question 103

The efficacy of AF ablation is closely linked with how success is defined and the intensity of ECG monitoring postablation. In general, the more monitoring performed, the _____.

Answer 103

Lower the success rate

Question 104

The _____ trial recently examined this relationship closely. In this trial, 346 patients with paroxysmal AF were randomized to catheter ablation with the cryoballoon or with RF energy. An implantable rhythm monitor was implanted at least 1 month before ablation in all patients.

The success of AF ablation was approximately 55% at 1 year if the definition of success was defined as freedom from a 30 second or longer episode of an atrial arrhythmia after the 3-month blanking period.

The success rate increased to approximately 80% if the defi- nition of success was freedom from a symptomatic atrial arrhythmia.

Importantly, AF burden was reduced by approximately 98%.

The outcomes of AF ablation were similar in the cryoballoon and RF arms of the study.These results have been reproduced in a more recent trial.

Answer 104

CIRCA-DoSE Trial

Question 105

In contrast to point-by- point RF ablation around the PVs, the _____ was designed to fit into the antrum of a PV and to create a circumferential ablation lesion using cryoenergy. Cryoenergy is delivered through the entire distal half of the second-generation cryoballoon catheter currently in clinical use. Complete occlusion of the PV by the inflated balloon is essential for reliable PV isolation.

Answer 105

Cryoballoon

Question 106

Avoidance of entry of the cryoballoon into the luminal portion of a PV is important to avoid _____.The most commonly used cryoballoon catheter has a 28-mm diameter when the balloon is fully inflated.The relatively large size of the balloon typically allows occlusion of a PV from the antrum.A multielectrode catheter inserted through a central lumen of the cryoballoon catheter often allows recording of PV potentials during an application of cryoenergy. The endpoint of the cryoballoon ablation procedure is electrical isolation of all PVs

Answer 106

PV stenosis

Question 107

_____ within the first minute of a cryoenergy application is a strong independent predictor of durable PV isolation.

Other independent predictors are a _____

In addition to the cryoballoon, a visually-guided laser balloon (VGLB) system now also is available for clinical use.

Answer 107

Disappearance or dissociation of PV potential

Other:
(1) Temperature recorded by a thermocouple proximal to the balloon of at least −40°C within 60 seconds of an application of cryoenergy
(2) Interval thaw time to 0°C of >10 seconds upon completion of a cryoenergy application

Question 108

The cryoballoon procedures are _____.

Answer 108

Generally shorter
Require more fluoroscopy
Higher risk of phrenic nerve injury
Lower risk of pericardial tamponade

Question 109

When performed by experienced operators, catheter ablation of AF has a major complication rate of _____%. The potential complications include _____.

Answer 109

1-3%

Femoral vein-related complications (1%)
Stroke (0.5%)
Cardiac tamponade (0.5% to 1.5%)
Pulmonary vein stenosis (0.5%)
Phrenic nerve injury (0.2%)
Death (0.1%)

Question 110

The most feared complication of AF ablation is an ______.

The risk of esophageal perforation is reported to be in the range of 0.01% to 0.02%.60 Despite its rarity, this complication is of great concern because it often is lethal.

Patients typically present 3 to 14 days after ablation with one of more of the following: dysphagia, odynophagia, fever, leukocytosis, bacteremia, and stroke.

Computed tomography of the chest with intravenous contrast is the diagnostic test of choice.The presence of contrast in the esophagus or air in the mediastinum or cardiac chambers is indicative of an esophageal perforation or fistula formation. Instrumentation of the esophagus should be avoided.

Answer 110

Atrial esophageal fistula

Question 111

There is evidence that _____ reduce the risk of esophageal injury.

Answer 111

(1) Limiting the power of RF energy applications to 20 to 25 watts for less than 30 seconds when ablating along the posterior left atrial wall

(2) Use of periprocedural proton pump inhibitors

Question 112

This trial randomized 363 patients with AF heart failure, each of whom had an ICD, to catheter ablation or medical therapy. After a median follow-up of 37.8 months, the primary composite endpoint of death from any cause or hospitalization for worsening heart failure was lower in the ablation arm.

Answer 112

CASTLE AF study

AF in HF + ICD -> Catheter ablation vs Medical therapy

Question 113

Because of the absence of strong data demonstrating a survival benefit of AF ablation in the absence of heart failure, this procedure is most commonly performed to improve quality of life in patients with symptomatic AF. Other factors to consider when recommending catheter ablation include the _____.

Answer 113

(1) Type of AF (paroxysmal, persistent, or longstanding persistent)
(2) Duration of continuous AF
(3) Severity of symptoms and quality of life
(4) Age
(5) Left atrial size
(6) Response to rate- and rhythm-control medications
(7) Response to cardioversion
(8) Patient preference

Question 114

The current iteration of the procedure is the _____. This procedure has a similar lesion set, but various tools are used to create the lines of block instead of surgical incisions.These tools include a bipolar clamp RF ablation tool to electrically isolate the PVs. Cryoablation energy delivered with a handheld probe is used to create linear lesions. A bipolar RF clamp is used to electrically isolate the LAA.AF ablation using this open-chest approach is performed in conjunction with open-chest heart surgical procedures such as mitral valve repair or replacement or coronary artery bypass grafting.

Answer 114

Cox maze 4

Question 114

A single randomized clinical trial and a review of cohort studies have indicated that surgical ablation has greater efficacy than catheter ablation but that it is associated with a higher rate of complications including the need for a _____.

Answer 114

Permanent pacemaker

Question 115

In many centers, surgical ablation is reserved for AF patients who are poor candidates for catheter ablation, often due to the _____.

Answer 115

Presence of longstanding persistent AF
Severe left atrial dilation
Inefficacy of catheter ablation procedures

Question 116

It is a useful strategy in patients who are symptomatic from AF because of a rapid ventricular rate that cannot be adequately controlled pharmacologically by medications and who either are not good candidates for AF ablation or have already undergone unsuccessful attempts at ablation.

Answer 116

AV node ablation

AV node ablation also can be helpful in patients with heart failure and AF to maximize the benefits of cardiac resynchronization therapy (CRT) if there already is not 100% ventricular pacing.

Question 117

In patients with AF and an uncontrolled ventricular rate, AV node ablation improves the left ventricular ejection fraction (EF) if there is a _____.AV node ablation also has been shown to improve symptoms, quality of life, and functional capacity and to reduce the use of health care resources

Answer 117

Tachycardia-induced cardiomyopathy

Question 118

The disadvantages of AV node ablation are that _____. Although symptoms and functional capacity typically improve after AV node ablation in patients with AF and an uncontrolled ventricular rate, some patients may not feel as well as during sinus rhythm.

Answer 118

iI creates a lifelong need for ventricular pacing and does not restore AV synchrony

Question 119

Atrioventricular node ablation is a technically simple procedure with an acute and long-term success rate of 98% or higher and a very low risk of complications. In patients with persistent AF, a _____ is implanted.A _____ is appropriate if the AF is paroxysmal. Most patients have a good clinical outcome with right ventricular pacing, but in patients with left ventricular dysfunction, _____ is appropriate

Answer 119

Persistent AF: ventricular pacemaker

Paroxysmal AF: Dual-chamber pacemaker

LV dysfunction: biventricular pacing for CRT

Question 120

In patients with an ischemic or nonischemic cardiomyopathy and EF of 30% to 35% or lower, an _____ may be appropriate for primary prevention of sudden death. However, a pacemaker without the ICD often is adequate for patients with a borderline EF (30% to 35%) and a rapid ventricular rate because the EF typically improves after the ventricular rate has been controlled by AV node ablation

Answer 120

CMP + EF <30-35%: PPI + ICD (primary prevention of SCD)

Borderline EF 30-35%: Pacemaker without ICD (EF improves with VR control after AVN ablation)

Question 121

In patients without a bundle branch block, _____ pacing is optimal because it avoids the dyssynchrony associated with right ventricular pacing and eliminates the need for a lead in the coronary sinus that is required for biventricular pacing.

Answer 121

His bundle pacing

Question 122

Atrial fibrillation is common after open heart surgery, occurring in _____% of patients who undergo coronary artery bypass graft (CABG) surgery or valve replacement. AF in this setting is associated with a twofold increase in the risk of postoperative stroke and is the most common reason for prolonged hospitalization

Answer 122

25-40%

Question 123

The incidence of AF peaks on the _____ postoperative day.

Answer 123

2nd

Question 124

The pathogenesis of postoperative AF is multifactorial and probably involves various combinations of _____.

Answer 124

Adrenergic activation
Atrial ischemia
Inflammation
Genetic factors
Electrolyte disturbances

Question 125

Several risk factors for AF after open heart surgery have been identified, including _____.

Answer 125

Age over 70 years
History of prior AF
Male sex
LV dysfunction
Left atrial enlargement
Chronic lung disease
Diabetes
Obesity

Question 126

The incidence of AF after open heart surgery can be significantly reduced by prophylactic treatment with _____.

Answer 126

Beta blockers
Amiodarone
Sotalol

Question 127

______ is common after open heart surgery and can heighten the risk of AF.Magnesium administration has been reported to decrease the risk of postoperative AF

Answer 127

Hypomagnesemia

Question 128

_____ pacing using temporary electrodes has been reported to reduce the risk of postoperative AF

Answer 128

Right atrial or biatrial

Question 129

A number of other interventions have been assessed for their efficacy in reducing the incidence of AF after cardiac surgery, typically not in large randomized clinical trials.The use of _____ to address postoperative inflammation have produced variable results in reducing AF burden

Answer 129

Colchicine
Statins
Steroids

Question 130

Another approach to the prevention of AF after cardiac surgery is injection of _____ toxin into the four major epicardial fat pads at operation.This causes temporary autonomic blockade and has been shown to reduce the incidence of AF after CABG to less than 10% and reduced the AF burden for up three years after surgery.

Answer 130

Botulinum

Question 131

AF that occurs after cardiac surgery often resolves within ___ months.

Answer 131

3 months

Question 132

Treatment with an oral anticoagulant should be ____ after discharge. Because new-onset AF after cardiac surgery often does not recur after 60 to 90 days, rhythm- control medications can be discontinued at that time, and if there is no subsequent evidence of symptomatic or asymptomatic AF, as confirmed by monitoring (e.g., 3- to 4-week autotrigger event monitor), anticoagulation can be safely discontinued unless needed for another indication.

Answer 132

Continued

Question 133

New-onset AF occurs postoperatively in less than _____% of patients undergoing major noncardiac surgery. Some of the possible mechanisms of postoperative AF after cardiac surgery (e.g., sympathetic activation, electrolyte abnormalities, hypoxia) most likely also play a role in AF after noncardiac surgery. _____ have been shown to significantly reduce the risk of AF after major noncardiac surgery, but one must be vigilant for the development of _____.

Answer 133

<5%

Beta blockers

Bradycardia and hypotension

Question 134

Patients with WPW syndrome who present in AF with a rapid ventricular rate should undergo _____ if there is hemodynamic instability.If the patient is hemodynamically stable, intravenous _____ can be used for pharmacologic cardioversion. Procainamide may be preferable to ibutilide because it blocks _____ before AF has converted to sinus rhythm

Answer 134

Unstable: transthoracic cardioversion

Stable: procainamide or ibutilide IV

Procainamide: blocks accessory pathway conduction and slows the ventricular rate

Question 134

Patients with the WPW syndrome and an accessory pathway with a short refractory period can experience a very rapid ventricular rate during AF. Ventricular rates greater than _____ beats/min can result in loss of consciousness or precipitate ventricular fibrillation and a cardiac arrest.

Answer 134

250 to 300 bpm

Question 135

Digitalis and calcium channel antagonists are contraindicated in patients with WPW syndrome and AF.These agents selectively block conduction in the AV node and can result in acceleration of conduc- tion through the accessory pathway

Answer 135

Digitalis and CCB

Question 136

The preferred therapy for patients with WPW syndrome and AF with a rapid ventricular rate is _____.

Answer 136

Catheter ablation of the accessory pathway

Question 137

Atrial fibrillation is a common arrhythmia in patients with heart failure, with a prevalence ranging from ___% in patients with NYHA functional Class I up to ___% in Class IV patients

Answer 137

NYHA I: 10%
NYHA IV: 50%

Question 138

The deleterious hemodynamic effects of AF in HF are mediated by a _____.

Answer 138

Rapid and/or irregular ventricular rate and loss of AV synchrony.

Question 139

The most appropriate rate-control drugs in patients with AF and systolic heart failure are _____. If necessary, _____ also can be used for rate control. In patients with diastolic heart failure, _____ can be used safely for rate control.

_____ are the only two rhythm-control drugs that are not associated with an increased risk of death in patients with heart failure.

Answer 139

Systolic HF: BB, Digitalis, Amiodarone

Diastolic HF: NDHP CCB

Amiodarone and dofetilide

Question 140

Because left ventricular dysfunction and heart failure can be aggravated by right ventricular pacing, _____ pacing should be instituted after AV node ablation.

Answer 140

Biventricular

Question 141

The decision to implant a biventricular pacemaker versus a biventricular ICD is based on clinical judgment. If it seems likely that the EF will remain less than 30% to 35% after optimal heart rate control, a _____ is appropriate for primary prevention of sudden cardiac death.It may take 2 to 3 months to evaluate the response of the LVEF to restoration of sinus rhythm.

Answer 141

Biventricular ICD

Question 142

The _____ trial randomized 363 heart failure patients, each of whom had an ICD in place, to AF catheter ablation or medical therapy. After a median follow-up of 37.8 months, the pri- mary composite endpoint of death from any cause or hospitalization for worsening heart failure was lower in the ablation arm.64 While these studies strongly suggest that AF ablation should be considered in patients with heart failure, it is important to recognize that these trials were limited by small numbers of highly selected patients.

It is for this reason that the 2019 AHA/ACC/HRS AF Guidelines provides only a class ____ recommendation for AF ablation in patients with heart failure.

Answer 142

CASTLE AF

Class IIb AF ablation in HF

Question 143

Atrial fibrillation occurs in approximately ___% of patients with hyper- trophic cardiomyopathy (HCM) and can cause severe hemodynamic impairment because of an inadequate diastolic filling time and loss of atrial-ventricular synchrony

Answer 143

25%

Question 144

The prevalence of AF during pregnancy is very low, approximately 60/100,000 pregnancies. When it occurs, there often is underlying _____.

Answer 144

Congenital or valvular heart disease
Thyrotoxicosis
Electrolyte abnormalities

Question 145

Transthoracic cardioversion is considered safe at ____ stages of pregnancy.

Answer 145

All

Question 146

The decision to anticoagulate a pregnant woman with AF should be made using the same criteria as in nonpregnant women. If anticoagulation is deemed necessary, _____ is recommended from the _____ the due date, and _____ is recommended during the _____month of pregnancy.

Answer 146

Warfarin (not a DOAC)
Second trimester until 1 month before

Subcutaneous LMWH
First trimester and during the final month

Question 147

The recommended pharmacologic agents for acute management of AF in pregnancy consist of intravenous _____ for rate control and _____ for conversion to sinus rhythm.

If ongoing therapy is deemed necessary, the recommended rate-control drug is _____. If ineffective, a _____ can be used, but only after the first trimester.

If there is no structural heart disease, _____ are recommended for long-term rhythm control.

In the patient with structural heart disease, _____ is recommended for rhythm control.

Answer 147

Rate control: IV metoprolol

Rhythm control: Flecainide or sotalol

Digoxin -> Beta blocker

Long term rhythm control (no structural disease): Flecainide, Sotalol
Structural disease: Amiodarone

Question 148

The guidelines now recommend that _____ be considered for stroke prevention in patients who cannot tolerate or refuse to take an oral anticoagulant.

Answer 148

ASA + clopidogrel

Question 149

The guidelines include specific recommendations of drugs for rate control during AF and that the effects of drug therapy on ventricular rate be measured at rest and during exercise to ensure adequate heart rate control.The criteria used for rate control are rates of _____ beats/min at rest and 90 to 115 beats/min during moderate exercise.

Answer 149

Rest: 60-80 bpm

Moderate exercise: 90-115 bpm

Question 150

AF is present in up to ___% of patients with ACS and increases with patient age and severity of myocardial infarction (MI).AF is associated with increased in-hospital, 30-day ,and 1-year mortality rates in patients with ACS. Stroke rates are higher in patients with ACS and AF than in those without AF.AF is an independent predictor of poor long-term out- come in patients with ACS.

Answer 150

25%

Question 151

Intravenous administration of _____ to patients with AF and a preexcitation syndrome may paradoxically accelerate the ventricular response and is not recommended.

Answer 151

Digitalis glycosides or nondihydropyridine calcium channel antagonists

Question 152

The guidelines recommend intravenous _____ to slow the ventricular rate in patients and to improve LV function in patients with an acute MI.

If there is no LV dysfunction, bronchospasm, or AV block, an _____ is recommended for rate control.

Answer 152

(IV) amiodarone or digitalis

IV beta blocker or nondihydropyridine calcium antagonist

Question 153

In _____, patients with HFrEF and ICDs or CRT-D and AF (paroxysmal or persistent) were randomized to receive catheter ablation versus medical therapy (rate or rhythm control) in addition to guideline directed management and therapy for HFrEF. Patients in the catheter ablation group had significantly reduced overall mortal- ity, hospitalization rate for worsening HF, and freedom from AF. Both studies were limited by relatively small and highly selected patient populations

Answer 153

CASTLE-AF (Catheter Ablation vs. Standard Conventional Treatment in Patients With LV Dysfunction and AF)

and

AATAC (Ablation versus Amiodarone for Treatment of Atrial Fibrillation in Patients with Congestive Heart Failure)

Question 154

The _____ trial in 2204 patients randomized to either catheter ablation or drug therapy did not demonstrate that AF ablation was superior to drug therapy for the primary cardiovascular outcomes of death, disabling stroke, serious bleeding, or cardiac arrest over a median of 48 months of follow-up.

Answer 154

CABANA (Catheter Ablation verses Anti-arrhythmic Drug Ther- apy for Atrial Fibrillation)

Question 155

_____ of the accessory pathway is recommended in patients with symptomatic AF and the WPW syndrome.

Immediate _____ is recommended if there is AF with a rapid ventricular rate and hemodynamic instability.

If the patient is hemodynamically stable, IV _____ is recommended for pharmacologic conversion of AF.

IV _____ should be avoided in patients with ventricular preexcitation during AF.

Answer 155

Catheter ablation

Electrical cardioversion

Procainamide or ibutilide

Digitalis and nondihydropyridine calcium channel antagonists

Question 156

The guidelines recommend a _____ as first-line therapy for rate control in patients with AF and thyrotoxicosis. If a beta blocker cannot be used, _____ should be used for rate control. Prevention of thromboembolic complications is similar to patients without hyperthyroidism.

Answer 156

Beta blocker

Verapamil or diltiazem

Question 157

The guidelines point out that there are not adequate data on the best rhythm-control medication to use for AF in the setting of HCM.The preferred therapy is either _____ for rate control or _____ by itself.

Answer 157

Disopyramide + beta blocker, verapamil, or diltiazem

Amiodarone

Question 158

The guidelines recommend _____ for rate control of AF during pregnancy.

_____ is recommended if there is hemodynamic instability.

Except in patients with a low-risk profile,either aspirin or an anticoagulant is recommended for prevention of thromboembolic complications, depending on the stage of pregnancy.

_____ can be considered during the first trimester and last month of pregnancy in patients with risk factors for thromboembolism, and an oral anticoagulant can be considered during the second trimester in patients at high risk of thromboembolism.

When AF occurs during pregnancy, _____ can be considered for pharmacologic cardioversion in hemodynamically stable patients.

Answer 158

Digoxin,
Beta blocker
Nondihydropyridine calcium channel antagonist

DC cardioversion

Unfractionated or low-molecular- weight heparin

quinidine or procainamide

Question 159

The primary therapy for AF in the setting of an acute pulmonary illness or exacerbation of chronic pulmonary disease should be correction of _____

_____ is recommended for rate control in patients with obstructive pulmonary disease.

_____ are not recommended in patients with bronchospastic disease, and _____are not recommended in patients with obstructive lung disease.

Answer 159

Hypoxemia and acidosis

Verapamil or diltiazem

Theophylline and beta-adrenergic agonists X Bronchospastic disease

Beta blockers, sotalol, propafenone, and adenosine X COPD

Question 160

Obesity is associated with atrial remodeling and AF. Randomized and nonrandomized trials as well as observational studies support _____ to reduce AF burden.

Risk factor modification includes assessment and treatment of unde lying sleep apnea, hypertension, hyperlipidemia, glucose intolerance, and alcohol and tobacco use.

Answer 160

Weight reduction in addition to risk factor modification