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HWN Suggests

Approach to shocky patient in AF w/ RVR

Overall when in doubt, it's probably best to err on the side of believing that the AF is a bystander – because this will lead you to complete a full evaluation of the patient and address everything that is going on. When folks incorrectly assume that AF is the sole driver of instability, that's when patients start getting assassinated by diltiazem.

Note that if the heart rate is insanely high (>>200) and QRS is wide-complex (and often with variable morphology) you're probably dealing with AF plus WPW – which is a uniquely evil situation. The approach to AF with WPW is really cardioversion, cardioversion, cardioversion, or possibly procainamide.

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  CHADS₂ Score

Calculates stroke risk for patients with atrial fibrillation, possibly better than the CHADS₂ Score.

  Unstable atrial fibrillation – ED management

The most common alternate management strategy I have encountered focuses on just using fluid boluses to support the pressure while loading amiodarone. There is no evidence that vasopressors help patients, so I can’t argue, but I have a hard time not temporarily making the numbers better while I wait for rate control to occur. Maybe I am treating my own anxiety more than the patient?

 More Atrial Fibrillation Management Pearls in the ED

Amiodarone or digoxin can be given if beta blockers or calcium channel blockers are unsuccessful or contraindicated, as in the setting of heart failure and/or hypotension.

 Recent-Onset Atrial Fibrillation

Determine whether the AF is in response to another underlying process or is simply lone atrial fibrillation. In patients where AF is a response to another underlying process, management should be directed at treating the underlying process NOT at the dysrhythmia.

Articles of Interest

Ottawa Aggressive Atrial Fibrillation Protocol

Atrial fibrillation (AF) is one of the most common dysrhythmias encountered in the ED. Patients with chronic AF often present with increased heart rates, chest pain and weakness among other presentations. However, it’s the patients with new onset AF that really peak our interest.

An Update: Rate Control in Atrial Fibrillation

Rate control strategy: First line therapy with either CCB IV (Diltiazem) or BBer IV (Metoprolol) is acceptable.

Episode 20: Atrial Fibrillation

Beta-blocker (works in 70% of patients): metoprolol 5mg IV q20min up to 15mg, followed by 25-50mg PO – consider using if patient has HTN, CAD, diabetes, prior MI or hyperthyroidism, but do NOT use in asthmatics or patients in acute heart failure. Calcium-channel blocker (works in 54% of patients): diltiazem 10-20mg IV, followed by PO.

Just Beat It (Atrial Fibrillation) with Diltiazem or Metoprolol?

I agree with the authors’ conclusions. Despite the above limitations, they did demonstrate non-inferiority of diltiazem to metoprolol for rapid rate control in patients with AF with RVR and this goes along with my clinical experience.

AFib in Wolff-Parkinson-White Syndrome

Treatment with AV nodal blocking drugs e.g. adenosine, calcium-channel blockers, beta-blockers may increase conduction via the accessory pathway with a resultant increase in ventricular rate and possible degeneration into VT or VF.

Afib with WPW

Treatment: · DO NOT give: adenosine, verapamil, diltiazem, digoxin, beta blocker or amio. Due to the presence of accessory pathway blocking down the AV node, may cause the accessory pathway to become the primary driver of conduction. · Treated with IV procainamide if clinically stable. Dose is 15-16 mg/kg given at a rate no faster than 50 mg/min. · If unstable: Immediate DC cardioversion.

Atrial Fibrillation in WPW Syndrome – Pearls and Pitfalls

AF in WPW – it looks similar to polymorphic VT but lacks the undulating baseline seen in torsades de pointes.

Atrial Fibrillation Rate Control in the ED: Calcium Channel Blockers or Beta Blockers?

From an ED standpoint, both CCBs and BBs appear to be effective. The highest quality study seemed to demonstrate that diltiazem performed better than metoprolol, though the metoprolol dose may have been too low.

Calcium before Diltiazem may reduce hypotension in rapid atrial dysrhythmias

Although most of the data is with verapamil, administering calcium before diltiazem may prevent some of the hypotension. There currently isn’t much published data for diltiazem. The one study, which was a negative one, had some limitations. The appropriate calcium dose is unknown, but 90 mg of elemental calcium (calcium gluconate 1 gm or calcium chloride 0.333 gm) is often used. We use 1 or 2 gm of calcium gluconate.

Irregular Wide Complex Tachycardia: VTach?

The differential diagnosis of irregularly irregular WCT is essentially limited to three main dysrhythmias. Dr. Littmann calls these FBI: Fast, Broad, and Irregular: Afib with LBBB Afib with RBBB Afib with WPW

Magnesium infusions for atrial fibrillation & torsade

The use of magnesium for AF has been a controversial topic for decades. Magnesium is a normal electrolyte, so it is cheap and has an excellent safety profile. Ironically, this is also magnesium's Achilles heel, because this has caused the pharmaceutical industry to have no interest in it. This leaves us with relatively sparse clinical evidence.

Management of atrial fibrillation in the emergency room and in the cardiology ward: the BLITZ AF study

Atrial fibrillation still represents a significant burden on health care system. Oral anticoagulant use increased over time even if compliance with guidelines, with respect to prevention of the risk of stroke, remains suboptimal.

Outcomes After Aggressive Management of Recent-Onset Atrial Fibrillation in the ED

Atrial fibrillation (AF) is one of the most common dysrhythmias encountered in the ED. The management of recent-onset AF and atrial flutter (AFl) in the ED continues to be debated. The discussion centers on whether patients with recent-onset AF should be rhythm controlled (e.g. converted back to sinus rhythm) or rate controlled only.

Patients with Atrial Fibrillation in the Emergency Department: Strategies to Achieve Best Outcomes

Atrial fibrillation (AF) and atrial flutter are two of the most common narrow complex tachyarrhythmias diagnosed in the ED.

Rapid Refresher: Atrial fibrillation (AF)

Be careful using these atrioventricular (AV) node–blocking agents in patients with AF and a wide QRS complex. This is because patients with preexcitation syndromes (eg, Wolff-Parkinson-White [WPW] syndrome) plus AF will have a wide complex and using these types of AV node–blocking agents may cause the accessory pathway to conduct at the atrial rate of 400 to 600 beats/min. Look at old ECGs.

Shock Through the Heart (Ottawa Aggressive Atrial Fibrillation Protocol)

Ottawa Aggressive Atrial Fibrillation Protocol: Once the patient is assessed and it’s determined that their symptoms began <48 hours prior to presentation, they were entered into the protocol. Rate control was given if either the patient was highly symptomatic while awaiting cardioversion or if cardioversion was not going to be pursued. Rhythm control was then initiated with an infusion of procainamide 1000 mg over 60 minutes. If procainamide worked, great the protocol was completed. If it didn’t work, the patient moved on to electrical cardioversion.

Sirens to Scrubs: Wolff-Parkinson-White Syndrome

As you begin to coach her through vagal maneuvers and reach for your adenosine she advises you ‘I have something called Wolff-Parkinson-White – does that change anything?’ You think maybe it does, but you’re not sure...

Tachydysrhythmias with Amal Mattu and Paul Dorion

Why is amiodarone contraindicated in patients with WPW associated with atrial fibrillation? What are the important differences in the approach and treatment of atrial fibrillation vs. atrial flutter? How can we safely curb the high bounce-back rate of patients with atrial fibrillation who present to the ED? and many more...

Why Don’t More Emergency Departments Cardiovert?

Cardioversion and discharge of recent onset AF is pretty much the accepted treatment in almost every country in the world with the exception of the United States.

Wolff-Parkinson Wait

It is imperative to recognize AF with WPW, as incorrect treatment with AV nodal blocking agents can be fatal. Blocking the AV node in these patients will result in preferential use of the accessory pathway. Rates may exceed 300 or 400 bpm and are at extreme risk for degeneration into ventricular fibrillation (VF).

Resources

Push Dose Phenylephrine

However, we all know that starting drips in emergent situations can take much too long. In practice, my go to vasopressor is often going to be push dose phenylephrine: Draw up 1ml of phenylephrine (10mg/ml) into a syringe. Inject the entire 1ml (or 10mg) into a 100ml bag of normal saline. You now have 10mg in a total of 100ml, or 100mcg/ml. Inject 0.5-2ml (50-200mcg) every 1-5minutes, as needed. Goal of diastolic blood pressure of ≥ 60.

Amiodarone

150mg IV bolus (slow IV push, or infused over 10 minutes), then 1mg/min IV infusion (for the first 6 hours – so hopefully someone has taken over by then)

Diltiazem

I give this is one of two ways: Diltiazem 25 mg in a minibag and slowly dripped in over about 10-15 minutes. Diltiazem 5-10mg (small doses) pushed by me every 1-2 minutes. After an appropriate heart rate is reached (for these very sick patients I am generally happy to get them to less than 130), I switch to either the conventional diltiazem drip at 5-15mg/hr or 30-60mg of PO diltiazem. There may be some value to giving IV calcium (1 or 2 grams of calcium gluconate) before starting the diltiazem to reduce the hypotensive effects of the medication.

Ibutilide

Dose: 0.015 – 0.02 mg/kg IV over 10-15 min Typically successful w/in 20 minutes if it works

Magnesium

2-4 grams IV over 10-15 minutes. Has been shown to modestly decrease heart rate and also possible increase the rate of spontaneous reversion to sinus rhythm.

Metoprolol

0.15 mg/kg (max of 10 mg) IV push Contraindications: Active reactive airway disease (i.e. asthma), acute decompensated heart failure, drug sensitivity

Procainamide

Dose: 18-20 mg/kg IV (administer 30-50 mg/min) Conversion rate: 60% success rate Monitor patient for QT and QRS prolongation and hypotension'

ACEP

An evidence-driven tool to guide the selection and management of emergency department patients with atrial fibrillation and atrial flutter.