Monday Back to Basics

From the Archives: Cardiac Tamponade with Dr. Rebecca Fenderson

What is cardiac tamponade?

-Cardiac tamponade is a medical or traumatic emergency that occurs when enough fluid accumulates in the pericardial sac to cause compression of the heart, leading to a decrease in cardiac output and obstructive shock.

Risk factors for tamponade:

-Besides hemorrhage (from something such as a stab wound or a left ventricular wall rupture s/p MI), other risk factors include infection (i.e., TB, myocarditis), autoimmune diseases, neoplasms, uremia, inflammatory disorder such as pericarditis.

True or false: the size of the pericardial effusion directly correlates with the risk of developing tamponade.

-FALSE! The rate at which fluid accumulates in the pericardial sac correlates with the risk of developing tamponade. The classic example is a traumatic cardiac injury which leads to hemopericardium. The rapid build-up of blood in the sac quickly leads to the inability of the chambers relax, which leads to decreased venous return, decreased diastolic filling, and decreased cardiac output.

-In situations such as neoplasms where the effusions grow at a much slower rate, there is time for the pericardial sac to stretch; these volumes can be substantially higher without causing tamponade physiology to develop.

What is one of the first compensatory vital signs seen in tamponade physiology, and also the most common EKG finding?

-Sinus tachycardia. The classic finding of electrical alternans is only present to 5-10% of cases of tamponade.

How does the patient present? What are their physical exam findings?

-Patients present with symptoms consistent with obstructive shock – lethargy, tachypnea, chest pain, palpitations. In severe cases, patients can experience dizziness, syncope, and/or altered mental status.

-Beck’s Triad: hypotension, jugular venous distention, muffled heart sounds.

-Pulsus paradoxus is defined as a decrease in systolic blood pressure of >10mmHg with inspiration. It is an important finding suggesting tamponade but may be absent in people with an elevated diastolic blood pressure, ASD, pulmonary hypertension, or aortic regurgitation.

What are ultrasound findings suggestive of cardiac tamponade?

-A plethoric IVC is the most sensitive finding of tamponade. IVC plethora is defined by a diameter equal or greater to 2 cm with less than 50% collapsibility during inspiration. 

-Right ventricular free wall collapse during diastole is considered to be the most specific sonographic finding of tamponade. RV free wall collapse can also be used as a measurement of severity. Initially, collapse of the RV free wall will only be present during expiration, but as the pressure increases, detection is possible throughout the respiratory cycle.

-Right atrial collapse (most often during systole, when the intra-atrial pressure is low) is often observed before right ventricular collapse. RA collapse longer than 1/3 of the total cardiac cycle has been described as an 100% sensitive and specific finding of tamponade.


Stashko E, Meer JM. Cardiac Tamponade. [Updated 2021 Aug 11]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2021 Jan-. Available from:

Kalter HH, Schwartz ML. Electrical alternans. NY State J Med. 1948;1:1164-66.

Pérez-Casares, Alejandro et al. “Echocardiographic Evaluation of Pericardial Effusion and Cardiac Tamponade.” Frontiers in pediatrics vol. 5 79. 24 Apr. 2017, doi:10.3389/fped.2017.00079

Mugmon, Marc. “Electrical alternans vs. pseudoelectrical alternans.” Journal of community hospital internal medicine perspectives vol. 2,1 10.3402/jchimp.v2i1.17610. 30 Apr. 2012, doi:10.3402/jchimp.v2i1.17610

Monday Back to Basics

Pediatric Penile Pain with Dr. Edward Guo

​Differential Diagnosis​Clinical Findings​Management
​Balanoposthitis (cellulitis of glans or foreskin)​Glans, foreskin, or both are erythematous, tender, or edematous​Warm soaks +/- oral antibiotic or antifungal cream depending on etiology 
​Phimosis​Stenosis of distal foreskin preventing retraction of foreskin over the glans​Most uncircumcised infants have normal, physiologic phimosis that will spontaneously resolve by 5 years of age.
Rarely requires treatment other than daily hygiene.
Monitor for if foreskin completely seals off causing acute urinary retention – true emergency.
ParaphimosisEntrapped ring of foreskin retracted proximal to glans of penis causing pain, erythema, and swelling​Consult pediatric urology emergently!
In cases when urology is not immediately available or necrosis of penis is imminent, ED physician may attempt reduction.

– Liu DR. Pediatric Urologic and Gynecologic Disorders. In: Tintinalli JE, Ma O, Yealy DM, Meckler GD, Stapczynski J, Cline DM, Thomas SH. eds. Tintinalli’s Emergency Medicine: A Comprehensive Study Guide, 9e. McGraw Hill; 2020

Monday Back to Basics

Uveitis and Iritis with Dr. Carlos Cevallos


Walker, R.A. Adhikari, S. Eye Emergencies. In Tintinalli’s Emergency Medicine: A Comprehensive Study Guide (9th ed.).

Monday Back to Basics

Transvenous Pacing

The last two weeks, Dr. Cash taught us about bradycardia and transcutaneous pacing. This week, we dug back years into the archives and pulled out Dr. Pelletier-Bui’s famous post on transvenous pacing.

A timeless classic! Just be sure to know what supplies are available in your department, where to find them, and alternate options if your supplies differ.


Bessman, E. (2019). Emergency cardiac pacing. In Roberts et al (Eds.), Roberts and Hedges’ clinical procedures in emergency medicine and acute care (pp. 288-308).  Elsevier, Inc.

Bohanske. (2013, November 4). Transvenous pacemaker placement – Part I: The walkthrough.  Taming the Sru. 

Mason, J. [EM:RAP Productions] (2018, October 11).  Placing a transvenous pacemaker [Video]. YouTube.

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Bradycardia, Part 2 with Dr. Allison Cash

  1. Treat possible underlying cause if known 
  1. Atropine
    •  Class 2a treatment
    • Dose 0.5 mg IV every 3-5 minutes, up to total dose 3 mg 
    • Can produce paradoxical worsening bradycardia 
    • Less effective in patients with cardiac transplant 
    • Skip if unstable, move directly to pacing 
  1. Transcutaneous pacing  
    • Class 1a recommendation
    • Place pads in anterior lateral or anterior posterior position 
    • Consider sedation or pain control  
    • Set monitor to “Pacer” 
    • Set rate, usually around 60 bpm 
    • Start current at 0 mA and slowly increase until capture is obtained. Consider different placement of pads if capture not achieved by 130 mA 
    • Confirm capture by feeling pulse or cardiac ultrasound 
    • Transcutaneous pacing is ultimately a bridge to transvenous pacing or permanent pacemaker – discuss with cardiology or transfer to center with these capabilities  
    • Capture (pictured below) shows pacer spike followed by a wide QRS and then ST and/or T wave  


  1. Judith E. Tintinall, et al. (2020). Tintinalli’s Emergency Medicine : A Comprehensive Study Guide (Ninth Edition). New York: McGraw-Hill. 
  1. Doukky R, Bargout R, Kelly RF, Calvin JE. Using transcutaneous cardiac pacing to best advantage: How to ensure successful capture and avoid complications. J Crit Illn. 2003 May;18(5):219-225. PMID: 30774278; PMCID: PMC6376978. 
  1. Holger J S, Lamon R P, and Minnigan H J et al.: Use of ultrasound to determine ventricular capture in transcutaneous pacing. Am J Emerg Med.  2003; 21: 227