Presentation
What’s the greatest risk factor for Afib?
Age (especially > 65)
What timeframe of symptoms determines whether you treat hemodynamically stable Afib w/ RVR via rate or rhythm control?
48 hours!
- if <48 hours, IV rate or rhythm control
- if >48 hours, IV rate control.
Because rhythm control can dislodge clot if present, and clot more likely after 48 hours!
Can you name two methods of rhythm control for Afib?
Synchronized cardioversion
Flecainide, propafenone, ibutilide, dofetilide, and amiodarone.
Can you name two of the three most likely organs to be affected by Afib-caused embolism?
Brain, kidney, spleen.
Also intestines and limbs!
66F hx diabetes and aortic stenosis, p/w spontaneous-onset palpitations + mild dyspnea. Apple Watch alerted Afib. No preceding exertion or substance use.
Chest feels fluttering and feels mildly dyspneic. Appears uncomfortable but no distress. BP 178/116, HR 90s - 140s, 97% O2 on RA, 2/6 systolic murmur, lungs CTAB, pulses 2+ & irregular in bilateral upper and lower extremities, no pitting edema, good cap refill.
Study: Early or Delayed Cardioversion in Recent-Onset Atrial Fibrillation
Patients with hemodynamically stable, recent-onset (<36 hours), symptomatic Afib either got:
- cardioverted soon after presentation, or
- rate-control, wait 48 hours, then cardioverted
Primary end point: presence of sinus rhythm at 4 weeks.
PICO Breakdown
P (Patient): Hemodynamically stable adults with new-onset symptomatic atrial fibrillation (AF).
I (Intervention): Delayed cardioversion strategy (wait-and-see approach with rate control) – wait 48 hours then cardiovert.
C (Comparison): Early cardioversion (pharmacologic or electrical).
O (Outcome):
• Rates of sinus rhythm restoration.
- Met study inclusion criteria
- Similar demographic, CHA2DS2-VASC, and comorbidities.
Patients with Afib should always be evaluated for what structural cardiac abnormality (give 1 of 3)?
Mitral valve stenosis, mechanical heart valves, and HCM.
Because these significantly increases thromboembolic risk!
How do you treat:
- Unstable Afib with a pulse?
- Unstable Afib without a pulse?
- Unstable Afib with a pulse → sync cardioversion
- Unstable Afib without a pulse → ACLS (treat like non-shockable rhythm)
What test do you need to do before cardioverting Afib in a patient who is stable, but cannot wait the usual time to be sufficiently anticoagulated for cardioversion?
TEE
Does rhythm control have reduced mortality compared to rate control in Afib?
No.
What type of study was this?
Randomized controlled trial (RCT) with a noninferiority design.
RCT Characteristics: Patients were randomly assigned to early or delayed cardioversion groups.
Noninferiority design choice: when placebo is not available/appropriate; step before "superiority" study?
Noninferiority Goal: Determine if delayed cardioversion (wait-and-see approach) was not significantly worse than early cardioversion for achieving sinus rhythm at 4 weeks.
Where in the heart do the automaticity foci of Afib occur?
Pulmonary vein ostia.
• Versus the tricuspid annulus for atrial flutter
What's the target HR of rate control for either symptomatic or asymptomatic patients w/ Afib w/RVR?
• <110/min if asymptomatic and normal LVEF, or
• <80/min if symptomatic
Other than an a CHADSVASC for anticoagulation need, and TEE for presence of thrombus, what other risk/calculation should you consider before cardioverting an Afib patient?
Consider bleeding risk / calculate the HAS-BLED score.
A high-risk HAS-BLED score is not necessarily a reason to withhold anticoagulation; patients just require more frequent monitoring.
Does anticoagulation reduce all-cause mortality in AF?
Yes, primarily by reducing thromboembolic events.
What was the Vanderbilt Model Stage?
T2 Translational Research
- evaluated the effectiveness of interventions (e.g., delayed vs. early cardioversion) in clinical settings to guide real-world medical practice.
- scale and focus too small to be T3 or T4
How do the EKGs of Afib and Aflutter differ?
(Hint: compare the rhythms and p-waves)
Rhythms
- AFib = irregular
- AFlutter = regular
P-waves
- AFib = absent
- AFlutter = present (sawtooth/flutter waves)
Can you name the first (2), second (1), and third-line (1) medications for rate-control in Afib w/ RVR?
1st line: Beta blockers and nondihydropyridine CCBs
2nd line: digoxin
3rd line: amiodarone
What anticoagulation do you use to prepare for non-emergent cardioversion in a patient:
- without a mechanical valve?
- with a mechanical valve?
- without a mechanical valve? → DOAC
- with a mechanical valve? → warfarin
What is the success rate of electrical cardioversion for restoring sinus rhythm in new-onset AF?
~80–90%
Why was this research appropriate for my patient?
She presented with new-onset, symptomatic Afib, and we had to consider immediate cardioversion or delayed.
- RCTs are the gold standard for comparing interventions and minimizing bias.
- This study evaluated two widely used approaches in real-world ED settings.
- Noninferiority trials are good at assessing whether the less resource-intensive option (delayed cardioversion) performs just as well as the standard of care (early cardioversion).
What is the criteria for RVR in Afib?
Ventricular rate > 100-110/minute.
Fun Fact! Watch for the apex-pulse deficit → number of cardiac contractions > peripheral pulse rate. This is due to variability in diastolic intervals, which intermittently leads to a small-volume cardiac contraction that is not strong enough to transmit a pulse wave to the periphery.
Name a case when beta blockers and nonDHP CCBs are contraindicated rate control meds in Afib w/ RVR?
1) ADHF
- use digoxin instead
2) WPW
- if stable → procainamide or ibutilide
- if unstable → sync cardioversion @ 200J
How long should a patient with stable AFib and ≥48 hours of symptoms be anticoagulated for before cardioversion?
3 weeks
What is the risk of major bleeding with anticoagulation in AF?
~1–3% annually, depending on the anticoagulant and patient risk factors.
What were strengths and weaknesses of the article?
(and citations...)
Strengths:
- Large sample (437) → 90% power
- Noninferiority design → well-suited to determine if a less invasive, cost-effective strategy is equally effective.
Weaknesses:
- Limited follow up (4 weeks)
- Open-label design (no blinding; limited by difficulty in ability to blind)
- Population came exclusively from the Netherlands
- Patients with AF >36 hours or hemodynamic instability were excluded
Citations:
1. Pluymaekers NAHA, Dudink EAMP, Luermans JGLM, et al. Early or Delayed Cardioversion in Recent-Onset Atrial Fibrillation. N Engl J Med. 2019;380(16):1499-1508. doi:10.1056/NEJMoa1900353
2. Joglar JA, Chung MK, Armbruster AL, et al. 2023 ACC/AHA/ACCP/HRS Guideline for the Diagnosis and Management of Atrial Fibrillation: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines [published correction appears in Circulation. 2024 Jan 2;149(1):e167. doi: 10.1161/CIR.0000000000001207] [published correction appears in Circulation. 2024 Feb 27;149(9):e936. doi: 10.1161/CIR.0000000000001218] [published correction appears in Circulation. 2024 Jun 11;149(24):e1413. doi: 10.1161/CIR.0000000000001263]. Circulation. 2024;149(1):e1-e156. doi:10.1161/CIR.0000000000001193