[size=20px]A 15-year old baseball pitcher is struck squarely in the chest by a hit baseball. He immediately collapses to the ground. Upon evaluation, he has no pulse. What is the most likely diagnosis in the pulseless child after blunt chest trauma?

 

A tension pneumothorax

 

B pericardial tamponade

 

C commotio cordis

 

D sternal fracture

 

E ruptured aorta[/size]

C

C.

ommotio cordis typically involves young, predominantly male, athletes in whom a sudden, blunt, nonpenetrating and innocuous-appearing trauma to the anterior chest results in cardiac arrest and sudden death from ventricular fibrillation.

correct answer

C commotio cordis

 

Commotio cordis is a unique phenomenon in pediatric trauma. It is defined as sudden cardiac arrest in the absence of apparent structural heart disease after a nonpenetrating chest injury. The blow to the chest is often innocuous in nature but triggers ventricular fibrillation in the absence of structural damage. Animal models demonstrate the ability to induce ventricular fibrillation, complete heart block and ST segment elevation with low energy blows to the chest. Ventricular fibrillation was consistently produced when the impact occurred during cardiac repolarization - just prior to the peak of the T wave.

 

The occurrence of commotio cordis is thought to require this rare confluence of a blow directly over the heart and precise timing during the vulnerable phase of repolarization. Unless recognized, such events cause sudden death - most commonly in young males. Sports related commotio cordis deaths have triggered considerable interest in chest barriers to protect young participants from catastrophic precordial blows. However, cases of commotio cordis have been reported even in the setting of protective gear.

 

Commotio cordis is a survivable phenomenon. However, prompt identification of ventricular tachyarrhythmias at the scene or in the emergency department along with the availability and proper use of an automated external defibrillator is required.