Emergency Medical Services-CE27
CASE OF THE MONTH — August 2020
Paramedics respond to a business complex where a 24-year-old landscaper is unresponsive after sustaining an injury to his chest. His co-worker, who witnessed the event, states that the patient was standing approximately 10 feet away from a lawnmower when a rock projected from the lawnmower’s mulcher, struck him in the chest. He seemed dazed for a moment after the injury and then suddenly “fainted”. Bystanders are attempting to revive the patient by shaking his shoulders and fanning his face. He remains unresponsive.
The first step in evaluating any unresponsive patient is to perform an initial assessment, including checking for appropriate respirations and a palpable pulse. If the patient is pulseless, one should begin cardio-pulmonary resuscitation immediately.
EMS providers assess the patient and find no spontaneous respirations and no pulse. They immediately begin chest compressions and airway maneuvers, with administration of high-flow oxygen in accordance with TP-1210, Cardiac Arrest. The patient is in ventricular fibrillation, so paramedics defibrillate him immediately. The patient has return of spontaneous circulation after two defibrillations.
This case is an example of the phenomenon “commotio cordis” where a sudden, blunt precordial impact to the chest can lead to ventricular fibrillation cardiac arrest and subsequent sudden death if not recognized and defibrillated promptly. Case reports of commotio cordis have been documented in the medical literature as early as the 1800s, and were typically work-related injuries. More recently, cases of commotio cordis have occurred during sporting events, when objects like baseballs or pucks strike a player’s precordium, resulting in sudden death. In these cases, most occur in young male patients in their teens to early 20s. Commotio cordis is due to cardiac rhythm disruption, therefore cases typically do not demonstrate any evidence of cardio-thoracic trauma. These cases are due to the blunt force chest trauma initiating electrical activity in the heart that can result in dysrhythmia, typically ventricular fibrillation.
Animal study models suggest that commotio cordis occurs when a projectile strikes the chest wall at a vulnerable time period of the cardiac cycle, typically at the beginning of the t-wave. This results in cardiac repolarization abnormalities (R wave on T wave phenomenon) that result in rhythm degeneration to ventricular fibrillation. There may be genetic susceptibility to commotio cordis related to the type of myocardial electrolyte channels (used during cardiac repolarization) that are present in certain patients.
Click here for an example of Commotio Cordis during a martial arts tournament.
Figure 1. Commotio cordis risk window
The patient in this case has just sustained a witnessed cardiac arrest without bystander CPR. Defibrillation attempts by EMS were successful, leading to return of spontaneous circulation. Post-return of spontaneous circulation (post-ROSC) care must be initiated immediately in accordance with TP-1210, Cardiac Arrest. EMS should stabilize the patient prior to transport by initiating Normal Saline 1L IV/IO rapid infusion if SBP drops below 90 mmHg, as well as preparing to administer push-dose Epinephrine if needed. They should also consider establishing an advanced airway to facilitate ventilations during transport, as indicated, and perform a 12-lead ECG (transmitting to the SRC) prior to departure.
Patients with commotio cordis typically have healthy cardiac anatomy and physiology. Sudden death is prompted by a sudden cardiac dysrhythmia (ventricular fibrillation), prompted by a direct blow to the precordium during a vulnerable period of the cardiac cycle. Because the impact to the chest may seem minor to bystanders, cardiac arrest is often mistaken for syncope and many bystanders may not know to initiate CPR. However, early bystander CPR and defibrillation will lead to the most favorable outcome for this patient. It is equally important for EMS to recognize commotio cordis as a potential cause for cardiac arrest and to begin resuscitation immediately. In addition, commotio cordis may be an underlying cause for refractory ventricular fibrillation. These patients have a high chance for survival with full recovery if normal rhythm is restored, so EMS personnel should continue on-scene resuscitation until ROSC, or until the resuscitation is determined to be futile by a Base Physician. For agencies participating in the ECMO pilot, these patients may be appropriate for early transport to an ECMO-capable center, if the patient meets inclusion criteria.*
*An ECMO Pilot Study for eligible patients in refractory ventricular fibrillation is currently underway in Los Angeles County.
The patient sustains ROSC in the field and is transported to the closest SRC. The patient is beginning to regain consciousness on arrival to the Emergency Department with signs of good neurological function. The patient is admitted to the Cardiac Critical Care Unit overnight and is discharged the next day, making a full recovery.
- Commotio cordis is a phenomenon where a direct impact to the precordium causes sudden ventricular fibrillation, which can lead to death if not recognized and defibrillated promptly.
- Commotio cordis most commonly occurs during sporting events in young, male patients, though any person is potentially susceptible after a direct blow to the chest if it occurs during a vulnerable time period of the cardiac cycle.
- Immediate high-quality CPR and early defibrillation offer the best chance for a favorable outcome in commotio cordis patients. EMS must recognize cardiac arrest in these patients and resuscitate accordingly.
- If return of spontaneous circulation (ROSC) is achieved, the patient should be stabilized on scene prior to transport to the STEMI Receiving Center (SRC).
1. Link MS. Commotio Cordis. Circulation. 2012;5:425-432.
2. Nesbitt AD, Cooper PJ, Kohl P. Rediscovering Commotio Cordis. 2001;357:1195-1197.
Author: Dr. Denise Whitfield, MD