Chest trauma

Case Presentation

Case presentation

• A paramedic call is received in the emergency department (ED) reporting a 10-min estimated time of arrival for a 13-year-old male who was found in cardiac arrest following a blow to the chest.

Case presentation

• Prehospital personnel reveals a history of witnesses reporting that the patient, a center outfielder for a local baseball team, was trying to catch a baseball when one of his teammates accidentally ran into him, elbowing him in the middle of his chest.

• The patient immediately dropped to the ground and was unresponsive. Cardiopulmonary resuscitation (CPR) was initiated by his coach after no pulses were palpated.

Case presentation

• The paramedics arrived 5 minutes later and, found the patient to be in ventricular fibrillation.

• The patient returned to spontaneus circulation with one 200 joule defibrilation.

• A normal sinus rhythm was noted and the patient was noted to regain consciousness.

• Upon arrival at the ED, the patient reports only mild anterior chest wall pain and denies any substernal chest pain, shortness of breath, palpitations, weakness, or confusion.

• He states that he has never before fainted. The patient and his mother deny any significant past medical or family history, including any arrhythmias, unexplained sudden deaths, or cardiac structural diseases.

• He denies having a lower exercise tolerance than his teammates and also denies any smoking, drinking, use of medications, illicit substance abuse, or doping practices.

• The primary survey of his airway, breathing, and circulation is unremarkable.

• Vitals : Blood pressure of 130/71 mm Hg ,heart rate of 106 bpm, with a normal rhythm. The respirations are 28-30 breaths/min. The initial oxygen saturation is 83% while the patient is breathing room air, but it corrects to 98% on a non-rebreather mask and, subsequently, to 99% on 2 L nasal cannula.

• His mentation is intact and he remains alert, with a Glasgow Coma Scale rating of 15. The skin examination reveals mild ecchymosis just anterior to his sternum.

• The rest of examination is normal. They noted not Marfanoid in appearance.

The ECG

Further investigations

• ECG : sinus tachycardia at a rate of 110 bpm, with mild right-axis deviation.

• The QRS complex, QT interval, ST/T waves, and P waves are all noted to be normal.

• A portable, upright chest radiograph shows somewhat underaerated lungs but no signs of fractures, widening of the mediastinum, cardiomegaly, or hemopneumothorax.

The X-ray

Blood work• FBC is normal, except for a mildly elevated white blood

cell (WBC) count of 13.6 ×103/µL (13.6 ×109/L). • A metabolic panel is normal, including normal potassium

and magnesium findings. • The initial troponin I is 0.04 ng/mL (0.04 µg/L; normal

range, 0.02-0.04 ng/mL; indeterminate 0.05-0.30 ng/mL).• A urine drug screen is negative. • Computed tomography (CT) scanning of the chest is

remarkable only for mild pulmonary and periportal edema.

• The patient is admitted to the pediatric intensive care unit (PICU) for continuous cardiac monitoring and cardiology consultation. An echocardiogram is ordered in the ED, to be done in the PICU.

Diagnosis please

• What is the likely pathophysiology that led to this patient's cardiac arrest?

• Hint: The mechanism of injury and the occurrence of ventricular fibrillation are linked.

1. Hypertrophic cardiomyopathy

2. Myocardial infarction

3. Commotio cordis

4. Long QT syndrome

Commotio Cordis• Commotio cordis (which is Latin for "disturbance of the

heart") is, in essence, a concussion of the heart.• Initially described as early as 1857, it is defined as an

instantaneous cardiac arrest produced by a witnessed, nonpenetrating blow to the chest, in the absence of preexisting heart disease or identifiable morphologic injury to the sternum, ribs, chest wall, or heart.

• Commotio cordis is a diagnosis of exclusion in that other causes, such as substance abuse, myocardial infarction, electrolyte abnormality, prolonged QT syndrome, and hypertrophic obstructive cardiomyopathy (HOCM), must first be ruled out with examinations such as urine drug screens, serial assessment of cardiac biomarkers and EKGs, electrolyte level testing, and echocardiography.

• Second most common cause of sudden cardiac arrest in young athletes (behind HOCM).

• The United States Commotio Cordis Registry (USCCR), in Minneapolis, Minnesota, reported that as of September 2001, only 180 cases had been documented. Up to 62% of these cases involved engagement in organized, competitive sports, with two-thirds of the patients being younger than 16 years of age and 80% being male.

• The oldest reported case was that of a 20-year-old man struck in the chest by a baseball, and the youngest case was that of a 7-week-old crying infant struck in the chest by his frustrated father.

• Eighty-one percent of cases involved a blunt, precordial blow from a projectile object propelled against a stationary chest wall, resulting in a relatively localized area of contact. It is notable that those who are most susceptible to commotio cordis are young athletic males.

• This is probably the result of the fact that there is less protection of the heart by subcutaneous fat, muscle bulk, and fully ossified ribs, all of which become more common in adulthood

• Not all impacts to the anterior chest will lead to the ventricular fibrillation observed in commotio cordis.

• The impact must be delivered 10-30 milliseconds before the peak of the T wave in the cardiac cycle in order to induce ventricular fibrillation.

• If impact occurs during other portions of the cardiac cycle, different conduction disturbances, such as heart block, bundle branch block, or transient ST segment elevation, may be induced.

• Induction is likely secondary to the activation of potassium-carrying ion channels via mechanoelectric coupling.

• The activation of these ion channels generates an inward current, thus locally augmenting repolarization and resulting in premature ventricular depolarization and the initiation of unstable ventricular arrhythmias.

A few key points

1. Cardiovascular collapse in the absence of cardiac disease.

2. Associated ventricular fibrillation.

3. Impact by a projectile at speeds less than 50mph

4. Instantaneous cardiac arrest

5. No significant laboratory abnormalities 

The bottom line• Regardless of etiology, if a young athlete

goes into sudden cardiac arrest, CPR should be implemented immediately. Of sports-related cases of commotio cordis documented in the USCCR, 15% of patients survived. In cases in which CPR was instituted within 3 minutes of the impact, 68% of patients survived; however, if CPR was delayed by more than 3 minutes, only 3% of patients survived.