Thoracic trauma is a significant cause of morbidity and mortality in children.  We have already discussed the most common conditions associated with pediatric thoracic trauma (Pulmonary Contusion and Pneumothorax). We have also covered some procedural strategies for managing the child with a pneumothorax.  Additionally, we have discussed the rare entity of pediatric traumatic aortic injury.  One other condition that deserves attention with respect to thoracic injury is Commotio Cordis.

Commotio Cordis – What is it?

• The phenomenon that follows a direct impact to the chest and produces a severe arrhythmia that can lead to sudden death.
• Patients have structurally normal hearts.
• Once felt to to be a rare event, but now known to be the second leading cause of sudden death in athletes.
  • #1 is Hypertrophic Obstructive Cardiomyopathy (HOCM).
• Half the patients collapse immediately after the impact. Others can have momentarily pre-syncopal symptoms before collapsing.

Commotio Cordis – Why does it occur?

• Like you would expect, it is multifactorial.
• Swine models do demonstrate that an impact to the chest can lead to Ventricular Fibrillation (VF).
  • An impact of a small, compact sphere (like baseballs or lacrosse balls) at speeds between 40-50 mph produce VF in a Swine model 50% of the time.
  • Impact at higher speeds tended to cause more cardiac contusion.
• Location matters
  • Impacts over the center of the left ventricle are more likely to produce VF than those off center.
  • Impacts that don’t overly the cardiac borders at all did not ever lead to VF in the model.
• Anatomy matters
  • Children have thin, compliant chest walls that do not dissipate the force of the impact as well as older people’s chest walls.
• Appropriate myocardium sensitivity is required also.
  • The impact needs to occur during the vulnerable time of repolarization.
  • The impact can cause focal ventricular depolarization of the cardiac tissue that was impacted.
  • Activation of ion channels, in the surrounding cardiac tissue, that respond to the stretching caused from the impact also increase the likelihood that the electrical discharge will propagate.
• There may be a genetic predisposition as well.
  • For instance, a patient with Prolonged QTc Syndrome.

• Essentially, you need a small, hard sphere to strike the thin and minimally protective chest of a child who’s heart just happens to be at the wrong part of depolarization.

Commotio Cordis – Who is at Risk?

• Athletes
  • 75% of the reported cases are in the setting of sports.
  • Naturally, we may just be missing those that are not this environment.
• Age range 8 – 18 years with peak incidence of 11 – 19 years. Mean of 14 years.
  • The thin, compliant chest wall plays a role.
• Males account for 95% of cases.
  • May be just that males tend to participate in the sports with greater likelihood of being struck in the chest with small, hard spheres.

Commotio Cordis – Treatment

• Initial experience with this condition demonstrated survival rates of only 10%.
• Now with improved awareness and easy access to Automated External Defibrillators (AEDs), the data shows survival rates approaching 60%.

• So, naturally, the main treatment is excellent BLS and rapid defibrillation.

• Prevention is the best treatment!
  • Wearing appropriate Chest Protective Equipment.
  • Education for coaches and families on the condition and on how to do BLS and use an AED.
  • Altering the construction of the sports’ projectiles.
• If the patient who has had an aborted episode of Commotio Cordis (from rapid BLS and AED use) arrives to your ED, what do you do?
  • Great question. Here is what I think is reasonable:
    • Serial ECGs and Continuous Cardiac Monitoring.
    • Pay specific attention to conduction abnormalities or abnormal intervals (QTc?).
    • Check electrolytes and cardiac markers (with Commotio Cordis, labs are usually normal).
    • Admit for observation and formal Echocardiogram (to rule out structural abnormality or wall motion abnormality).
    • Go home and remind your kids to wear their chest protectors and to avoid being hit in the chest.

     

   

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