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Atrial Fibrillation
Introduction
o Atrial fibrillation is the most common type of supraventricular arrhythmia. It occurs when
multiple waves of electrical impulses in the atria result in an irregular (and usually rapid)
ventricular response.
o A rapid response may lead to decreased output which can lead to hypotension and worsen
underlying ischemia and HF.
Etiology
o Risk factors
 Age >60 years old
 Diabetes
 HTN
 Hyperthyroidism
 Heart disease
 Sleep apnea, asthma, or COPD
 Excessive alcohol or stimulant use (increases HR)
o Causes
 Myocardial ischemia or infarction
 Non-cardiac conditions:
 Electrolyte imbalances (K+, Mg, Na, Ca)
 Hyperthyroidism
 Infection
 Drugs (illicit drugs, anti-arrhythmic, QT-prolongating drugs)

Types of AF
o Valve involvement: Patients may have valvular AF (caused by rheumatic disease of the mitral
valve or with a history of valve replacement) or nonvalvular AF.
o Paroxysmal AF: AF that ends in fewer than 7 days and can be recurrent. This includes episodes
that end spontaneously or are resolved with cardioversion.
o Persistent AF: Continuous AF that is sustained longer than 7 days.
o Long-standing persistent AF: Continuous AF that lasts longer than 12 months’ duration, with
continued efforts to restore to sinus rhythm.
o Permanent AF: Continuous AF of longer than 12 months’ duration, when no further
interventions to restore to sinus rhythm are planned.

Diagnosis
o Clinical Presentation
 Asymptomatic
 Heart feels as if “fluttering” or “skipping a beat”
 Dizziness, fatigue
 SOB
o
 Lightheadedness
 Chest pain
Initial evaluation: history, physical examination, ECG, chest radiography, CBC, electrolytes, liver
and kidney function tests, and thyroid hormone test
 ECG: Holter monitor (24-hour recorded)
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Evaluation/Treatment of Atrial Fibrillation

Rate control vs rhythm control
o Preference for rate control - most asymptomatic patients with AF, particularly long-standing or
recurrent
o Preference for4de4r rhythm control – most symptomatic patients particularly those at high
cardiovascular risk patients and AF diagnosed within one year; may be more beneficial in patients
aged 65 and older with HF with preserved EF

Rate Control
o Essential part of Afib treatment in acute and chronic settings
o
o
Goal: Resting HR of <80 bpm (<110 bpm may be reasonable)
Medications
 Beta Blockers (preferred)
 nCCB
 Digoxin
 Beta Blockers
Drug
Metoprolol
tartrate/succinate
(Lopressor, Toprol
XL)
Dosing
Acute control:
2.5-5 mg IV bolus
over 2 min, repeat
every 5 min (max
dose: 15 mg)
Safety/Side Effects/Monitoring
CI: Severe bradycardia; 2nd or 3rd degree heart block or sick sinus
syndrome, overt cardiac failure or cardiogenic shock
Maintenance:
Metoprolol tartrate
25-100 mg po bid
Side effects: bradycardia, fatigue, hypotension, dizziness,
depression, impotence
Warnings: use in caution in patients with diabetes and
bronchospastic disease, can exacerbate Reyanud’s
Monitoring: HR, BP
Esmolol
(Brevibloc)
Propranolol
Metoprolol
succinate: 50-400
mg po daily
Acute control:
500 mcg/kg IV
bolus over 1 min,
then 50
mcg/kg/min IV
Acute control:
1 mg IV over 1
min, repeat every 2
min (max dose: 3)
Maintenance: 30160 mg/day in 3 to
4 divided doses
Non-DHP Calcium Channel Blockers
Drug
Dosing
Acute control:
Diltiazem
0.25 mg/kg IV
(Cardizem)
bolus over 2 min,
then 5-15 mg/hr
Verapamil (Calan
SR)
Maintenance:
120-360 mg
PO daily
Acute control:
0.075-0.15 mg/kg
IV bolus over 2
min; may give 10
mg if no response
after 30 minutes.
Follow with 0.005
mg/kg/min infusion
Safety/Side Effects/Monitoring
CI: severe hypotension, 2nd/3rd heart block/sick sinus syndrome,
cardiogenic shock, HFrEF, Wolff-Parkinson-White syndrome with
Afib
Warnings: hypotension, HF, 1st degree AV block with sinus
bradycardia, increased LFTs
Side effects: edema, arrhythmias, constipation, gingival hyperplasia
Monitoring: ECG, BP, HR, electrolytes, LFTs
Maintenance:
180-480 mg
PO daily
Digoxin
Drug
Digoxin
(Digitek, Digox)
Dosing
Acute control:
0.25 mg IV with
repear dosing
(max: 1.5 mg
daily)
Safety/Side Effects/Monitoring
CI: ventricular fibrillation
Warnings: 2nd/3rd degree heart block, Wolff-Parkinson-White
syndrome with Afib
SI: dizziness, mental disturbances, N/V/D
Typical dose: 0.125
– 0.25 mg PO daily
Monitoring: ECG, HR, electrolytes, renal function, and digoxin level
Therapeutic range
= 0.8-2 ng/mL for
Afib
If CrCl <50
mL/min: decrease
dose or frequency

Rhythm Control
o Cardioconversion
 Restores normal sinus rhythm
 Main indication: unstable or poorly tolerated A.fib that is unresponsive to drug therapy
 Unless done emergently or when the duration of arrhythmia is known to be less
than 48 hours, anticoagulation is required
 Electrical cardioversion: delivers high-energy shock through the chest wall and breaks
the incorrect cycle, stops the arrhythmia and allows sinus node to begin firing again
o Anti-arrhythmic medication for pharmacologic cardioversion
 Amiodarone (oral and IV)
 Flecainide
 Ibutilide
 Propafenone
Amiodarone
Drug
Dosing
Safety/Side Effects/Monitoring
600-800 mg/day x
CI: iodine hypersensivity
Amiodarone
1-3 weeks, then
(Nextrenone,
600-800/day for 4
Warnings: hyper- and hypothyroidism is common, visual
Pacerone)
weeks, then 400
impairment, photosensitivity, peripheral neuropathy, and skin
mg/day
reactions
Side effects: hypotension, bradycardia, corneal microdeposits,
photosensitivity, hepatotoxicity
Monitoring:
ECG, BP, HR, electrolytes, eye exams, thyroid
Major drug interaction: warfarin INR can be increased by 200%
Flecainide
Drug
Dosing
Safety/Side Effects/Monitoring
50-100 mg PO
q12h
Flecainide
CI: structural heart disease (HF, MI), concurrent ruse of ritonavir
Warnings: avoid use in severe hepatic impairment
Side effects: dizziness, visual disturbances, dyspnea
Correct electrolyte imbalances prior to therapy
Ibutilide
Drug
Ibutilide
(Corvert)
Propafenone
Drug
Propafenone
(Rythmol SR)
Dosing
1 mg over 10
minutes
(0.01 mg/kg < if 60
kg)
Safety/Side Effects/Monitoring
Side effects: Ventricular tachycardias, hypotension, QT prolongation
Dosing
IR: 150-300 mg po
every 8 hours
Safety/Side Effects/Monitoring
CI: Similar to flecainide, hypotension, bronchospastic disorders
(asthma)
ER: 225 mg every
12 hours
Side effects: Taste disturbances (metallic), dizziness, visual
disturbances, N/V
Correct hypokalemia and hypomagnesemia prior to use
Correct electrolyte imbalances prior to therapy
o

AF ablation and surgery
Anticoagulation
o Essential part of atrial fibrillation management
o Reduces risk of embolic stroke, but increases bleeding risk
o To determine if patient need to be anti-coagulated  CHADS2VASc
 CHF (1)
 HTN (1)
 Age 75 years or older (2)
 DM (1)
 Stroke (2)
 Vascular disease (MI, PAD) (1)
 Age 65-74 years (1)
 Sex (female) 1
o Recommended therapy is different for males vs females
 No AC recommended: Score 0 (males) and 1 (females)
 AC may be considered: Score 1 (males) and 2 (females)
 AC is recommended: Score 2 (males) and 3 (females)
o Treatment
 DOAC is recommended over warfarin
 Options include: warfarin, apixaban, dabigatran, edoxaban, rivaroxaban
References:
1. American Family Physician. 2016. Diagnosis and Treatment of Atrial Fibrillation. Retrieved from
https://www.aafp.org/afp/2016/0915/p442.html
2. January CT, Wann LS, Alpert JS, et al.; ACC/AHA Task Force Members. 2014 AHA/ACC/HRS guideline
for the management of patients with atrial fibrillation: a report of the American College of
3.
Cardiology/American Heart Association Task Force on practice guidelines and the Heart Rhythm Society
[published correction appears in Circulation. 2014;130(23):e272–274]. Circulation. 2014;130(23):e199–
e267
2022 RxPrep Book
What is a Watchman Device’s?
WATCHMAN is a one-time, minimally invasive procedure for people with atrial fibrillation not
caused by a heart valve problem (also known as non-valvular AFib) who need an alternative to
blood thinners.
Non-valvular Afib can mean a lifetime of blood thinners. It can also mean a lifetime of worry
about issues like bleeds and falls. More than 150,000 people have left blood thinners behind with
WATCHMAN.
In people with AFib not caused by a heart valve problem, more than 90% of stroke-causing clots
that come from the heart are formed in the LAA.1 That’s why closing off this part of the heart is
an effective way to reduce stroke risk.
The WATCHMAN Implant fits right into your LAA. It’s designed to permanently close it off
and keep those blood clots from escaping. WATCHMAN is about the size of a quarter and made
from very light and compact materials commonly used in many other medical implants.
Any literature that shows DOAC is as good as warfarin or better?
https://pubmed.ncbi.nlm.nih.gov/33780291/
Effectiveness and Safety of Direct Oral Anticoagulants Versus Warfarin in
Patients with Valvular Atrial Fibrillation: A Population-Based Cohort Study
Recent July 2021
Background: Direct oral anticoagulants (DOACs) are increasingly used in place of warfarin, but
evidence about their effectiveness and safety in patients with valvular atrial fibrillation (AF)
remains limited.
Objective: To assess the effectiveness and safety of DOACs compared with warfarin in patients
with valvular AF.
Design: New-user retrospective propensity score-matched cohort study.
Setting: U.S.-based commercial health care database from 1 January 2010 to 30 June 2019.
Participants: Adults with valvular AF who were newly prescribed DOACs or warfarin.
Measurements: The primary effectiveness outcome was a composite of ischemic stroke or
systemic embolism. The primary safety outcome was a composite of intracranial or
gastrointestinal bleeding.
Results: Among a total of 56 336 patients with valvular AF matched on propensity score, use of
DOACs (vs. warfarin) was associated with lower risk for ischemic stroke or systemic embolism
(hazard ratio [HR], 0.64 [95% CI, 0.59 to 0.70]) and major bleeding events (HR, 0.67 [CI, 0.63
to 0.72]). The results for the effectiveness and safety outcomes remained consistent for apixaban
(HRs, 0.54 [CI, 0.47 to 0.61] and 0.52 [CI, 0.47 to 0.57], respectively) and rivaroxaban (HRs,
0.74 [CI, 0.64 to 0.86] and 0.87 [CI, 0.79 to 0.96], respectively); with dabigatran, results were
consistent for the major bleeding outcome (HR, 0.81 [CI, 0.68 to 0.97]) but not for effectiveness
(HR, 1.03 [CI, 0.81 to 1.31]).
Limitation: Relatively short follow-up; inability to ascertain disease severity.
Conclusion: In this comparative effectiveness study using practice-based claims data, patients
with valvular AF who were new users of DOACs had lower risks for ischemic stroke or systemic
embolism and major bleeding than new users of warfarin. These data may be used to guide riskbenefit discussions regarding anticoagulant choices for patients with valvular AF.
Read Tikosyn
Warning: can cause TdP
CI: congenital or acquired long QT syndromes, baseline QT interval or QTc >440 msec, severe
renal impairment (CrCl <20), known hypersensitivity, and drug interaction:
-HCTZ, trimethroprim, verapamil, ketoconazole, megestrol, prochlorperazine, cimetidine
All initiation-preinitiation orders for dofetilide must be ordered by the cardiology service only.
Patient must be located on the telemetry floors, the ICU, or the ED. Patient must be admitted for
a minimum of 3 days before initiation. Must be provided medication guide. Previous
antiarrythmic agents is recommended to be withdrawn for a minimum of 3 plasma half-lives
before initiation
Prior to ordering dofetilide get: BMP (K, replace if <4, Mg replace if <1.8). Order baseline ECG
to look at QT interval.
Dose adjustment:
If WTC on the ECG, 2 hours after the first dose is >15% baseline or QTc >500, the dose should
be adjusted. IF anytime after the second dose the QTC is >500, d/c
Actual body weight for dosing for CrCl
Read rate vs rhythm
AFFIRM:
Among patients with atrial fibrillation and a high risk of stroke or death, what are the effects of
rate control versus rhythm control on mortality?
Bottom Line
In patients with nonvalvular AF, there is no survival benefit between rate and rhythm control, but
rhythm trends toward increased mortality.
-Largest and first study to compare rate and rhythm control.
Design






Multicenter, parallel-group, randomized, controlled trial
N=4,060 patients with nonvalvular atrial fibrillation
o Rate-control strategy (n=2,027)
o Rhythm-control strategy (n=2,033)
Setting: 213 clinical sites and their satellite sites, including University of Washington
Median follow-up: 3.5 years
Analysis: Intention-to-treat
Primary outcome: All-cause mortality at 5 years
What are coagulase negative staph?
Nor MRSA and not MSSA
Coagulase is an enzyme needed to make a blood clot. This enzyme is present in S. aureus
bacteria. Several types of CoNS bacteria falls into this category:
1. S. epidermidis
- commonly lives on skin and doesn’t usually cause infection
2. S. saprophyticus
-Can collect in the urinary tract and cause UTIs
3. S. Lugdunensis
-This bacteria can cause infectious endocarditis.
S. simulans, S. hominis, S. haemolyticus, S. warnerii
Greatest risk: people who have compromised immune system, people with indwelling urinary
catheter, people with a central IV line, people who’ve undergone certain procedures
Treatment:
Agent of choice for empiric: vancomycin
Methicillin-resistant CoNS bacteremia: daptomycin or vancomycin
Additional medications: linezolid, ceftaroline, telavancin
Methicillin-susceptible CoNS: nafcillin, oxacillin, cefazolin,
What does calcium, insulin, and dextrose do for hyperkalemia?
Calcium prevents the deleterious cardiac effects of severe hyperkalemia that may occur before
the serum potassium level is corrected. Insulin and glucose moves the potassium from blood into
cells, thus lowering the potassium level in blood.
Severe hyperkalemia treatment
Normal: 3.5-5
Mild: 5.5-6.0
Moderate: 6.1-7.0
Severe: >= 7.0 mEq/L
Also include clinical manifestations or ECG chances (tall peak T waves, shrinking and then loss
of P waves, widening of QRS interal)
Clinical manifestations:
S&S: muscle weakness and ventricular arrhythmias
Two major mechanism of hyperkalemia: increased potassium release form cell (hyperglycemia,
rhabdomyolysis) reduced potassium excretion in urine (hypoaldosternism, renal failure)
Early management:
Obtain ECG and put on continuous cardiac monitoring
In patients with hyperkalemic emergency:
Calcium gluconate 1000 mg or calcium chloride 500-1000 mg IV over 2-3 minutes
Give insulin and glucose (<250 glucose). Bolus injection of 10 units of regular insulin, followed
immediately by 50 mL of 50% dextrose.
**board question**
HD should be performed in ESRD or severe renal impairment to remove potassium
Diuretics or saline infusion with IV diuretics can be admistered (40 mg of furosemide every 12
hours) to nonoliguric patients
A IG cation exchanger (patiromer 8.4 g orally) or SZX (10 gram three times daily for 48 hours)
Sodium polystyrene sulfonate or kayexalate (15 to 30 g orally) should not be given unless there
are no other options to effectively remove potassium from body. SPS can lower potassium in
patients presenting with hyperkalemic emergency.
Lokelma 10 gram administered three times daily lowered serum potassium by -0.7 at 48 hours.