Date: June 20th, 2019

Reference: Pluymaeker et al. Early or Delayed Cardioversion in Recent-Onset Atrial Fibrillation. NEJM 2019

Guest Skeptic: Dr. David Glaser, emergency physician from a community teaching hospital in Denver and faculty member for the annual Emergency Medicine and Acute Care course series. Dave is also residency-trained and boarded in internal medicine.

Case: A 62-year-old woman with a history of hypertension presents with four hours of palpitations, described as a racing heart. Her vital signs: BP 148/90, HR 135, RR 16, T 37oC, O2 Sat 96%. Lungs are clear and cardiac exam shows a tachycardic and irregularly irregular rhythm without murmur. The ECG shows atrial fibrillation without ischemic changes. How do you proceed?

Background: New-onset atrial fibrillation is a common occurrence in the emergency department, and practitioners differ on whether to take a primary rate-control approach versus a rhythm-control approach utilizing either electrical or pharmacological cardioversion. We are not going to settle this debate on this podcast.

In the United States especially, these patients are often admitted to the hospital with rate control and cardiology decides on cardioversion.

In Canada, these patients are often cardioverted and discharged home. We covered the Ottawa Aggressive Protocol on SGEM#88. That episode reviewed a 2010 cohort study done by the Legend of Emergency Medicine, Dr. Ian Stiell. The results from this observational study was 92% of patients were electrically cardioverted, 97% discharged home with 93% in sinus rhythm at discharge.

Things are starting to change in the US. A study published in AEM showed that implementing a new atrial fibrillation algorithm decreased hospital admissions from 80% to 67% and cardioversion increased from 17% to 21% (SGEM#222).

Clearly there is a difference in the management of patients with recent onset of rapid atrial fibrillation depending on your practice location.

Clinical Question: In adult patients who present with hemodynamically stable, symptomatic, recent-onset atrial fibrillation without signs of myocardial ischemia, is a wait-and-see approach, inferior to an immediate cardioversion strategy.

Reference: Pluymaeker et al. Early or Delayed Cardioversion in Recent-Onset Atrial Fibrillation. NEJM 2019

* Population: Adults(18 years and older) who presented to the emergency department of 15 hospitals in the Netherlands (3 academic, 8 non-academic teaching, and 4 non-teaching hospitals) with hemodynamically stable, symptomatic, recent-onset (< 36 hours), first-detected or recurrent atrial fibrillation, without signs of myocardial ischemia or a history of persistent atrial fibrillation (defined as lasting > 48 hours).

* Exclusions: Signs of myocardial infarction on ECG, hemodynamically unstable, presence of pre-excitation syndrome, history of sick sinus syndrome, history of unexplained syncope, history of persistent AF (episode of AF lasting more than 48 hours), acute heart failure or deemed unsuitable for participation by attending physician.

* Intervention: Delayed cardioversion (“wait-and-see” approach). This was defined as administration of a rate-control medication, including intravenous or oral beta-blockers, nondihydropyridine calcium-channel blockers, or digoxin, given in increasing doses to obtain relief of symptoms and a HR of 110 BPM or less.