A 22-year-old Hispanic male is operating a string trimmer as part of a residential lawn maintenance crew. A nearby co-worker operating a commercial riding lawnmower approximately 20 feet away runs over a lacrosse ball that was hidden deep in the grass. The ball, ejected and traveling at a high velocity, strikes the victim directly in the chest.
The victim immediately collapses and has no signs of life. Bystanders perform high-quality chest compressions until local EMS arrive on scene. The patient’s initial rhythm on EMS telemetry is
v fib; thus, he’s quickly defibrillated into a sinus tachycardia. His reported time from full cardiac arrest to return of spontaneous circulation is eight minutes.
He’s emergently transported to a tertiary care medical center capable of 24-hour percutaneous coronary intervention and therapeutic hypothermia. Upon arrival, he’s minimally responsive and not following commands, with a blood pressure of 134/76, respiratory rate of 14, oxygen saturation 98% on nasal cannula and heart rate of 76.
His electrocardiogram shows sinus tachycardia.
Given his poor neurologic examination, his respirations are assisted and he’s promptly intubated, sedated, chemically paralyzed, and admitted for cardiac monitoring and therapeutic hypothermia.
He has an uneventful hospital course without further arrhythmia or sign of myocardial ischemia. He’s successfully extubated after completing the cooling protocol and discharged five days post event, neurologically intact, with preserved right and left ventricular function and ejection fraction without residual wall motion abnormalities.
Commotio cordis is derived from Latin, meaning “agitation of the heart,” and is typically manifested by v fib and sudden death in young athletes. The phenomenon of v fib being caused by a direct blow to the chest was documented in the medical literature as early as 1932.1 Commotio cordis has also been documented in the literature from seemingly mild, low-velocity, non-sport related chest wall trauma.
Blunt force trauma to the chest wall, generally over the precordium, is the causative event of v fib and cardiac arrest. The impact occurs within a narrow 10–30 millisecond portion of the cardiac rhythm cycle. This narrow portion is during the ascending phase of the T wave during the period of systole to diastole. The impact causes v fib, which, without immediate intervention, is universally fatal.
In 1996, the United States Commotio Cordis Registry was started to compile cases and information regarding the incidence of commotio cordis, and currently has > 200 cases registered.2 The most common activity of commotio victims are team sports such as soccer, baseball, football, hockey and softball. The mean patient age is 15 and the occurrence is primarily seen in males (> 90%).2
Non-sport-related activities can also cause commotio cordis; reports of seemingly harmless blows to the chest have resulted in cardiac arrest. Some of these incidents have resulted in legal charges being brought against the perpetrator in cases of assault.3,4
Identifying these patients can be difficult. Victims will suffer some type of blunt chest trauma that bystanders often report appears minor. Some patients have a brief lucid interval prior to arrest and some even have purposeful movement (ambulating, picking up and throwing a ball).5
CPR may be delayed due to observers underestimating the severity of the incident or assuming a pure syncopal event. One of the keys to identifying these patients is obtaining a good history.
Data from the United States Commotio Cordis Registry shows the mortality rate to be very high at 82%.5 The key to survival in patients experiencing such an event is prompt, immediate and uninterrupted chest compressions followed by defibrillation within three minutes of arrest.
Implications for EMS
Prompt CPR and quick defibrillation matter with all cardiac arrest patients, but it’s especially true in these patients. Obtaining an accurate history will aid in identifying these patients; be especially observant for young males who have chest trauma while playing sports and subsequently suffer cardiac arrest. Emphasizing and maintaining good, high-quality CPR and prompt defibrillation is vital.
On the public health side of the equation, the increasing use of chest protection in sports along with the availability of automated external defibrillators may impact the prevalence of commotio cordis.
Although rare, commotio cordis is a very real possibility that results from myocardial stunning during the ventricular repolarization cycle of the heart. EMS personnel that encounter patients in full cardiac arrest after blunt chest trauma need to consider commotio cordis in their list of possible causes of arrest.
1. Schlomka G: Commotio cordis und ihre Folgen (Die einwirkung stumpfer brustwandtraumen auf das herz). Julius Springer: Berlin, Germany, pp. 1–94,1934.
2. Maron B. Global epidemiology and demographics of commotio cordis. Heart Rhythm. 2011;8(12):1969–1971.
3. Froede RC, Lindsey D, Steinbronn K. Sudden unexpected death from cardiac concussion (commotio cordis) with unusual legal complications. J Forensic Sci. 1979;24(4):752–756.
4. Maron BJ, Mitten MJ, Greene Burnett C. Criminal consequences of commotio cordis. Am J Cardio. 2002;89(2):210–213.
5. Maron BJ, Doerer JJ, Haas TS, et al. Sudden deaths in young competitive athletes: Analysis of 1,866 deaths in the United States, 1980–2006. Circulation. 2009;119(8):1085–1092.