Question Of The Day #59

question of the day
38 - atrial fibrillation

Which of the following is the most likely cause for this patient’s respiratory condition?

This patient presents to the Emergency Department with palpitations, generalized weakness, and shortness of breath after discontinuing all her home medications.  She has hypotension, marked tachycardia, and pulmonary edema (crackles on lung auscultation).  The 12-lead EKG demonstrates atrial fibrillation with a rapid ventricular rate.  This patient is in a state of cardiogenic shock and requires prompt oxygen support, blood pressure support, and heart rate control. 

Pulmonary embolism (Choice A) can sometimes manifest as new atrial fibrillation with shortness of breath and tachycardia, but pulmonary embolism initially causes obstructive shock.  If a pulmonary embolism goes untreated, it can progress to right ventricular failure, pulmonary edema, and cardiogenic shock.  This patient has known atrial fibrillation and stopped all her home medications.  The abrupt medication change is a more likely cause of the patient’s cardiogenic shock.  Dehydration (Choice D) and systemic infection (Choice D) are less likely given the above history of abruptly stopping home maintenance medications.  Untreated cardiac arrythmia (Choice B) is the most likely cause for this patient’s pulmonary edema and cardiogenic shock. 

The chart below details the categories of shock, each category’s hemodynamics, potential causes, and treatments.  



Cite this article as: Joseph Ciano, USA, "Question Of The Day #59," in International Emergency Medicine Education Project, October 15, 2021,, date accessed: December 2, 2023

Acute Atrial Fibrillation in the ED: Almost all goes home

Atrial fibrillation (AF) is the most common dysrhythmia presenting to ED. The management options depend on patient stability, presence of underlying causes and factors in the patient history. In stable patients presenting in AF with a rapid ventricular response, both rate and rhythm control are acceptable approaches. Physicians often tend toward rate control because evidence has shown no mortality benefit between the two approaches. The Atrial Fibrillation Follow-up Investigation of Rhythm Management (AFFIRM) trial contributed to this trend when it concluded no survival advantage and higher risk of adverse drug effects with rhythm control. However, rhythm control is the preferred approach for the management of acute stable AF in Canadian guidelines. The advantages are a higher rate of symptom resolution, restoration of sinus rhythm and avoiding the need for rate control prescriptions, decreased ED length of stay, and hospital admissions.

In the electrical versus pharmacological cardioversion for emergency department patients with acute atrial fibrillation (RAFF2) trial, it was found that both drug–shock and shock-only strategies were effective, rapid, and safe with 96% of patients discharged home in sinus rhythm. The drug infusion worked for 50% of patients avoiding procedural sedation.

The evidence that supports the management of acute AF in the ED without hospital admission is increasing. Implementing practices to achieve that will markedly decrease the burden on the health care system.

ED Management

Approach of Atrial fibrillation

AF might be secondary to variable causes, including ACS, Heart failure, PE, sepsis and bleeding. In patients with secondary AF, cardioversion might be harmful, and the mainstay of treatment is tackling the underlying cause. Those patients will require hospital admission. For primary AF, if the patient is unstable, electrical cardioversion should be done without delay. Stable primary AF may be managed with rate or rhythm control.

Rate control can be achieved with the following:

CCB: Diltiazim 0.25 mg/kg over ten mins, repeat q15-20 mins, up to three doses (avoid in heart failure)

BB: Metoprolol 2.5-5 mg q15-20 mins

Digoxin: 0.25-0.5 mg loading dose then 0.25 mg q4-6 hs (if hypotension or acute HF occur)

Target is HR <100 at rest or <110 walking

Rhythm control is safe with the following according to The CAEP AF best practice guidelines:

  1. Anticoagulated for three or more weeks.
  2. No valvular heart disease, prior stroke or TIA plus: 
  • Onset in 12 hours or less
  • Onset more than 12 hours but less than 48 hours plus less than two of :
    • Age less than 65, DM, HTN, HF.
  • Cleared by TOE


  • Procainamide 15mg/kg in 500 ml of NS over an hour.

Other agents: Amiodarone, Ibutilide, flecainide, etc.

  • Electrical: 150-200 J synchronized. Requires sedation.


If CHADS positive then discharge on DOAC or Warfarin.


Almost all patients can be discharged home after cardioversion or effective rate control with appropriate follow up: within a week if warfarin or rate control agent prescribed, otherwise in 4 weeks.

Patients will require admission if one of the following:

  • Highly symptomatic after treatment.
  • ACS
  • Acute heart failure not improved in the ED

References and Further Reading

  1. Stiell, I. G., Macle, L., & CCS Atrial Fibrillation Guidelines Committee (2011). Canadian Cardiovascular Society atrial fibrillation guidelines 2010: management of recent-onset atrial fibrillation and flutter in the emergency department. The Canadian journal of cardiology27(1), 38–46.
  2. Wyse, D. G., Waldo, A. L., DiMarco, J. P., Domanski, M. J., Rosenberg, Y., Schron, E. B., Kellen, J. C., Greene, H. L., Mickel, M. C., Dalquist, J. E., Corley, S. D., & Atrial Fibrillation Follow-up Investigation of Rhythm Management (AFFIRM) Investigators (2002). A comparison of rate control and rhythm control in patients with atrial fibrillation. The New England journal of medicine347(23), 1825–1833.
  3. Baymon, D. E., & Baugh, C. E. (2020). Patients with Atrial Fibrillation in the Emergency Department: Strategies to Achieve Best Outcomes.
  4. Martín, A., Coll-Vinent, B., Suero, C., Fernández-Simón, A., Sánchez, J., Varona, M., Cancio, M., Sánchez, S., Carbajosa, J., Malagón, F., Montull, E., Del Arco, C., & HERMES-AF investigators (2019). Benefits of Rhythm Control and Rate Control in Recent-onset Atrial Fibrillation: The HERMES-AF Study. Academic emergency medicine : official journal of the Society for Academic Emergency Medicine26(9), 1034–1043.
  5. Stiell, I. G., Sivilotti, M., Taljaard, M., Birnie, D., Vadeboncoeur, A., Hohl, C. M., McRae, A. D., Rowe, B. H., Brison, R. J., Thiruganasambandamoorthy, V., Macle, L., Borgundvaag, B., Morris, J., Mercier, E., Clement, C. M., Brinkhurst, J., Sheehan, C., Brown, E., Nemnom, M. J., Wells, G. A., … Perry, J. J. (2020). Electrical versus pharmacological cardioversion for emergency department patients with acute atrial fibrillation (RAFF2): a partial factorial randomised trial. Lancet (London, England)395(10221), 339–349.
  6. Ian G. Stiell, et al. (2021). 2021 CAEP Acute Atrial Fibrillation/Flutter Best Practices Checklist.
Cite this article as: Israa M Salih, UAE, "Acute Atrial Fibrillation in the ED: Almost all goes home," in International Emergency Medicine Education Project, September 13, 2021,, date accessed: December 2, 2023

Defibrillator: Clear!

Defibrillator clear

So, this is your first day at your internship rotation in the Emergency Department. You see some movement in the resuscitation room, and someone shouts: CODE!

Then, you approach the team, excited to learn and help with cardiopulmonary resuscitation (CPR). The attending physician looks at you and asks: Do you know how to use the defibrillator?

What would your answer be?

Knowing the main functions of the defibrillator is essential but not enough; you need to get used to the model in your hospital to be able to help safely with an emergency.

Defibrillators are devices used to apply electrical energy manually or automatically. Their use is indicated for electrical cardioversion, defibrillation or as a transcutaneous pacemaker.

Later that day, another patient presents with unstable atrial fibrillation (AFib).

The attending suggests cardioverting the patient. Do you know how to prepare the defibrillator?

Defibrillation versus cardioversion

Both defibrillation and cardioversion are techniques in which an electrical current is applied to the patient, through a defibrillator, to reverse a cardiac arrhythmia.


Defibrillation is a non-synchronized electrical discharge applied to the chest, which aims to depolarize all myocardial muscle fibres, thus literally restarting the heart, allowing the sinoatrial node to resume the generation and control of the heart rhythm, and reversing the severe arrhythmias. It is indicated for pulseless ventricular tachycardia and ventricular fibrillation during CPR.

Electrical Cardioversion

Electrical cardioversion is the application of shock in a synchronized way to ensure the electric discharge is released in the R wave, that is, in the refractory period because accidental delivery of the shock during the vulnerable period, that is, the T wave, can trigger VF. It is reserved for severe arrhythmias in unstable patients with a pulse. It can usually be an elective procedure.

Special Situations

Digital Intoxication

Digital intoxication can present with any type of tachyarrhythmia or bradyarrhythmia. Cardioversion in this situation is a relative contraindication, as digital makes the heart sensitive to electrical stimulation. Before considering cardioversion, correct all electrolyte imbalances, otherwise, the cardioversion can degenerate the rhythm to a VF.

Pacemaker / Implantable cardioverter-defibrillator (ICD)

Cardioversion can be performed, but with care. The inadequate technique can damage the generator, the conductive system, or the heart muscle, leading to dysfunction of the device. The blades must be positioned at least 12 cm away from the generator, preferably in the anteroposterior position. The lowest possible electrical charge must be used.


Cardioversion can be used safely during pregnancy. The fetal beat should be monitored throughout the procedure.

Things To Consider

Keep your devices tested!

Working in the ED is not easy. This is the place where organization and preparation should be routine. Constant checking of materials and operation of the equipment must be the rule because the smallest detail can cause a difference in saving a life.

During adversity, it is necessary to remain calm, trying to not affect the reasoning and disposition of the team. It is an arduous job, it takes practice and a lot of effort. Errors can only be corrected after they are recognized and must have the right time to be exposed. It happens.

There is no time for despair, yelling and stress when it comes to CPR.

No conductive gel, what can we do?

The main guidelines regarding the use of the conductive gel used in the defibrillator paddles are:

  • Using the proper gel for this purpose is essential. The gel is an electrically conductive material that decreases the resistance to the flow of electric current between the paddle and the chest wall. The absence of conductive material can lead to the production of an arc that causes burns in the patient and the risk of explosion if there is an oxygen source very close, among others.
  • Avoid the use of gauze soaked in saline solution, as the excess serum can cause burns on the patient’s skin, but it is a reasonable option, in an emergency
  • Do not use the ultrasound gel
  • The preference is to use adhesive paddles that already come with their own conductive gel (but this is rare in Brazil).

Location recommended by Advanced Cardiac Life Support (ACLS)


One paddle is placed on the right side of the sternum, right below the clavicle and the other laterally where the cardiac appendix would be in the anterior or medial axillary line (V5-V6).

Adhesive paddles can also be placed in an anteroposterior position: The anterior one is placed in the cardiac appendage or precordial region, and the posterior one is placed on the back in the right or left infrascapular region.

During the shock, the provider must ensure that no one is in contact with the patient. A force of approximately 8k must be used to increase the contact of the paddles with the chest. Do not allow a continuous flow of oxygen over the patient’s chest to avoid accidents with sparks.


  • Electric arc (when electricity travels through the air between the electrodes and can cause explosive noises, burns and impair current delivery)
  • Electrical injuries in spectators
  • Risk of explosion if there is a continuous flow of oxygen during the shock
  • Burning of the skin by repeated shocks
  • Myocardial injury and post-defibrillation arrhythmias and myocardial stunning
  • Skeletal muscle injury
  • Fracture of thoracic vertebrae

References and Further Reading

  1. Sunde, K., Jacobs, I., Deakin, C. D., Hazinski, M. F., Kerber, R. E., Koster, R. W., Morrison, L. J., Nolan, J. P., Sayre, M. R., & Defibrillation Chapter Collaborators (2010). Part 6: Defibrillation: 2010 international consensus on cardiopulmonary resuscitation and emergency cardiovascular care science with treatment recommendations. Resuscitation81 Suppl 1, e71–e85.
  2. Panchal, A. R., Bartos, J. A., Cabañas, J. G., Donnino, M. W., Drennan, I. R., Hirsch, K. G., Kudenchuk, P. J., Kurz, M. C., Lavonas, E. J., Morley, P. T., O’Neil, B. J., Peberdy, M. A., Rittenberger, J. C., Rodriguez, A. J., Sawyer, K. N., Berg, K. M., & Adult Basic and Advanced Life Support Writing Group (2020). Part 3: Adult Basic and Advanced Life Support: 2020 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care. Circulation142(16_suppl_2), S366–S468.
  3. Ionmhain, U. N. (2020). Defibrillation Basics. Life in The Fastlane. Retrieved April 26, 2020, from
  4. Paradis, N. A., Halperin, H. R., Kern, K. B., Wenzel, V., & Chamberlain, D. A. (Eds.). (2007). Cardiac arrest: the science and practice of resuscitation medicine. Cambridge University Press.
  5. Nickson, C. (2020). Defibrillation Pads and Paddles. Life in The Fastlane. Retrieved April 26, 2020, from
Cite this article as: Jule Santos, Brasil, "Defibrillator: Clear!," in International Emergency Medicine Education Project, August 9, 2021,, date accessed: December 2, 2023

Acute Management of Supraventricular Tachycardias

Acute management of SVT

The term “supraventricular tachycardia (SVT)” expresses all kinds of rhythms that meet two criteria: Firstly, the atrial rate must be faster than 100 beats per minute at rest. Secondly, the mechanism must involve tissue from the His bundle or above. Mechanism-wise, atrial fibrillation resembles SVTs. However, supraventricular tachycardia traditionally represents tachycardias apart from ventricular tachycardias (VTs) and atrial fibrillation (1,2).

Supraventricular tachycardias are frequent in the ED!

The SVT prevalence is 2.25 per 1000 persons. Women and adults older than 65 years have a higher risk of developing SVT! SVT-related symptoms include palpitations, fatigue, lightheadedness, chest discomfort, dyspnea, and altered consciousness.

How to manage supraventricular tachycardia?

In clinical practice, SVTs are likely to present as narrow regular complex tachycardias. Concomitant abduction abnormalities may cause SVTs to manifest as wide complex tachycardias or irregular rhythms. However, 80% of wide complex tachycardias are VTs. Most importantly, SVT drugs may be harmful to patients with VTs. Therefore, wide complex tachycardias should be treated as VT until proven otherwise (1,2).

The chart below summarizes acute management of regular narrow complex tachycardias:

Acute Management of Regular Narrow Tachycardias

References and Further Reading

  1. Brugada, J., Katritsis, D. G., Arbelo, E., Arribas, F., Bax, J. J., Blomström-Lundqvist, C., … & Gomez-Doblas, J. J. (2019). 2019 ESC Guidelines for the management of patients with supraventricular tachycardia: the Task Force for the management of patients with supraventricular tachycardia of the European Society of Cardiology (ESC). European Heart Journal, 00, 1-66.
  2. Page, R. L., Joglar, J. A., Caldwell, M. A., Calkins, H., Conti, J. B., Deal, B. J., … & Indik, J. H. (2016). 2015 ACC/AHA/HRS guideline for the management of adult patients with supraventricular tachycardia: a report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines and the Heart Rhythm Society. Journal of the American College of Cardiology67(13), e27-e115.

Cardiac Monitoring Pearls

Cardiac Monitoring chapter written by Stacey Chamberlain from USA is just uploaded to the Website!