Damar Hamlin: on injuries and heart problems on the court, by Elmer Huerta

The field assistants and the medical team entered, and one of the assistants, recognizing that the player had no pulse and had suffered cardiac arrest, began the resuscitation maneuver. The doctors used the electric defibrillator that was on hand. Seeing that Hamlin I was in a comaThey inserted an endotracheal tube and started assisted respiration. An ambulance entered the field of play and the player was taken to hospital. The game was suspended and the question that remained floating was what happened. Why did this serious incident occur? Why did a young athlete go into cardiac arrest in the middle of a match?

‘Commotio cordis’

Unlike numerous incidents of athletes who suffered a cardiac arrest in public – such as the Danish footballer Christian Eriksen in June 2021 – the Damar Hamlin episode had a clear antecedent: a violent blow to the chest.

This background has led multiple experts to postulate that what happened with Hamlin was an episode of ‘commotio cordis’ or heart disturbance.

According to the findings of the American Heart Association Task Force No. 13 on Cardiovascular Anomalies in Competitive Athletes, commotio cordis is defined as sudden cardiac death caused by a relatively innocent blow to the front of the chest (precordium). ).

Initially considered an extraordinarily rare event, in the last 20 years ‘commotio cordis’ has been reported more frequently in the US and the world. According to the committee, that higher frequency is not due to an actual increase in the frequency of events, but rather to better recognition of the condition and greater visibility of those events.

The committee specifies that ‘commotio cordis’ is one of the most common causes of sudden cardiac death in recreational and competitive sports, and is caused by a sudden electrical disorder of the heart called ventricular fibrillation, a potentially fatal type of arrhythmia.

“Only shocks that occur when the electrical T-wave is taking its upward path can cause fatal ventricular fibrillation.”

They also clarify that it must be differentiated from cardiac contusion, a situation in which a blow to the chest causes structural damage to the heart and that, secondarily, can cause an electrical disorder or arrhythmia within 24 hours after the blow.

In the US, the University of Minneapolis maintains a national registry of commotio cordis cases. Until 2012 they had registered more than 200 cases, calculating about 30 each year.

Risk factor’s

According to the registry, 95% of the cases occurred in adolescent males, 14 years old on average, and the impact with a hard spherical object (baseball, hockey puck) occurred on the left chest wall. The patient’s collapse was instantaneous and was caused by ventricular fibrillation.

The ‘commotio cordis’ has been replicated in experimental models in pigs, in which it has been shown that for a blow to the chest to cause ventricular fibrillation, it must fall perpendicularly on the cardiac silhouette with an object of a certain shape and size. The impact speed is slightly less than that which produces cardiac damage: 65 km/h is optimal; 80 km/h causes heart damage.

Finally, the animal model demonstrated a critical element, which is that there must be an exact synchronization between the moment of the blow and the phase in which the electrical cycle of the heart is found. In this sense, only the blows that occur when the upward path of the electrical T wave is originating can cause fatal ventricular fibrillation.

That is, not all blows to the chest cause a serious cardiac arrhythmia.

Forecast

According to data from the University of Minneapolis registry, the prognosis for commotio cordis has greatly improved over the past 30 years. From 10% survival at the beginning of the 90s of the last century, it is now close to 60%.

The patient’s prognosis will depend fundamentally on two elements: the promptness with which cardiopulmonary resuscitation is started and the availability of a cardiac defibrillator.

In the case of Damar Hamlin, the recovery has been extraordinary: 48 hours after the cardiac arrest, she regained consciousness in the ICU, obeying simple commands and asking (through writing) if her team had won the soccer game. At 96 hours the tracheal tube was removed, he recovered his spontaneous breathing and He was able to talk to his colleagues by videoconference. Only time will tell if he can play again.

Corollary

This extraordinary case should stimulate us to ask ourselves some questions. In an emergency, do you know how to take a person’s pulse and recognize cardiac arrest? Are you ready to start a cardiopulmonary resuscitation maneuver? Are there electric defibrillators in airports, shopping centers, sports centers and other public places? Would you know how to use an electrical defibrillator?