Cullen Buchanan, MD
Pending Expert Review from Andrew Prouse, MD (University of Colorado, Division of Cardiology)
- Recognize atrial fibrillation (AF) with rapid ventricular rate (RVR) on ECG
- Evaluate a patient with new AF
- Develop a framework for management of heart rate control in AF with RVR
Plan to spend at least 20 minutes preparing for this talk by using the interactive board for learning/preparing, clicking through the graphic, and becoming familiar with the order the content appears on the graphic. The teaching script below details how to walk through the talk. Every interactive or “clickable” element is denoted with a mouse icon.
Anticipated time to deliver the talk with and without cases or other features: without cases 15-20 minutes. The cases may take an additional 10-15 min.
The talk can be presented in two ways:
- Project the “interactive Board for Presentation” OR
- Reproduce your own drawing of the presentation on a whiteboard.
- Have a learner interpret the initial ECG. They should be able to recognize there is a narrow complex tachycardia (QRS < 120 ms), no identifiable P waves, and a ventricular rate > 100 bpm. Click on “DIAGNOSIS” to reveal the answer.
- Bonus: An exception to the general rules highlighted on the slide is that AF with RVR can be associated with a wide complex tachycardia in the setting of underlying bundle branch block or AF with aberrancy.
- Click on the “Pathophysiology” tab in the right-hand menu to reveal a diagram of the electrical activity of the heart. Highlight the irregular and disorganized atrial activity and variable conduction down through the AV node and the rest of the conduction system.
Objective 2: (Evaluation):
The approach to identifying etiology is broken down into cardiac and non-cardiac causes. Click the respective “Cardiac” and “Non-cardiac” buttons to reveal a thorough work-up. It is important to highlight that the tests listed should be ordered in the right clinical context and every patient does not need all of these tests.
Objective 3 (Management):
- The first step in evaluating a patient with AF with RVR is determining hemodynamic stability. Ask your learners what factors are used to determine stability. Click on the “1” button to reveal the criteria as well as the management of unstable patients. Unstable patients should proceed to synchronized cardioversion. Sedation and analgesia can be considered but should not delay cardioversion.
- Bonus: All patients who anticipate receiving cardioversion or undergo cardioversion should be started on anticoagulation. Patients who undergo cardioversion should be anticoagulated for a minimum of 4 weeks as they are at increased risk of thrombosis because of transient dysfunction of the atrial appendage after cardioversion.
- If patients are hemodynamically stable, they should receive medications to achieve rate control with an ultimate goal of HRs < 110. Click on “#2” button to discuss the approach to rate control in a patient with stable AF with RVR.
- Acute heart rate goal is HR < 130. Patients with RVR with HR > 130s should receive IV medications to bring their HR below this goal.
- Chronic heart rate goal is HR < 110. Patients with RVR with HRs between 110-130s should receive oral medications to bring them below this chronic HR goal.
- Click on “#3” button to discuss medications to achieve heart rate control. There are four main classes of medications used for heart rate control – beta-blockers, calcium channel blockers, digoxin, and amiodarone. Ask your learners to identify where these medications act and whether there are notable contraindications. Click on each medication class to reveal additional information on the mechanism of action, impact on BP, and cautions.
- In the learner version, you may click on “Click for detailed table” or “Meds table” buttons to be directed to a more in-depth discussion of the medications.
- Of note, beta-blockers such as metoprolol and calcium channel blockers such as diltiazem are considered first-line agents. Amiodarone and digoxin are second-line agents but may be considered in specific clinical scenarios.
- Amiodarone can cause lung, liver, and thyroid toxicity, especially if it is continued long term for rate control.
- Patients who fail to achieve heart rate control with escalating doses of one agent alone can be started on a second agent (e.g., addition of a calcium channel blocker to beta-blocker).
- Bonus: Start anticoagulation with heparin or enoxaparin for patients who are anticipated to undergo cardioversion or have a high thromboembolic risk based on their CHA2DS2-VASc score.
Use for Presenting – there is less text and fewer pop-ups
Take Home Points
- Evaluation of new AF should include consideration of cardiac and noncardiac triggers for AF. This work-up should include a TTE, chemistry panel, and TSH.
- Patients with unstable narrow complex tachycardia, characterized by hypotension and altered mentation, should receive direct current cardioversion (DCCV).
- Beta-blockers and calcium channel blockers are typical first line agents for rate control. Digoxin and amiodarone can be considered in select clinical scenarios. IV medications should be used if HRs are > 130.
- Andrade JG, Macle L, Nattel S, Verma A, Cairns J. Contemporary Atrial Fibrillation Management: A Comparison of the Current AHA/ACC/HRS, CCS, and ESC Guidelines. Can J Cardiol. 2017;33(8):965-976. doi:10.1016/j.cjca.2017.06.002
- Van Gelder IC, Groenveld HF, Crijns HJ, et al. Lenient versus strict rate control in patients with atrial fibrillation. N Engl J Med. 2010;362(15):1363-1373. doi:10.1056/NEJMoa1001337