Commotio Cordis: Clinical Spectrum
Abstract & Commentary
Source: Maron BJ, et al. Clinical profile and spectrum of commotio cordis. JAMA 2002;287:1142-1146.
Commotio cordis (CC) is sudden cardiac death caused by a blunt, non-penetrating blow to the chest wall. Recent CC events have received increasing attention in the media, as early reports of CC in professional sports have been joined by reports of CC in youth sports and in seemingly benign activities. This paper examined a registry of 128 confirmed cases of CC in an attempt to describe the spectrum of causes and outcomes of CC events.
Each case met the following inclusion criteria: 1) witnessed blunt blow to the chest wall immediately preceding cardiovascular collapse; 2) detailed documentation of the circumstances from available sources; 3) lack of structural damage to the sternum, ribs, and heart; and 4) absence of underlying cardiovascular abnormalities. These cases were added to the registry through direct submission by involved or interested parties, U.S. Consumer Product Safety Commission reports, and news media and Internet accounts.
Of the 128 cases of CC, 95% were in males and the mean age was 13.6 years, with a range of 3 months to 45 years. Only 22% of cases occurred in victims age 18 years or older. At the time of the event, 79 cases (62%) were participants engaged in 11 different organized sports, with baseball, softball, and ice hockey accounting for 74% of cases. Many of these athletes were struck with projectiles, most commonly baseballs. Two of these balls were commercially marketed as softer-than-normal "training" balls designed to reduce injury. With the exception of one case caused by a soccer ball, each of the projectiles causing CC had a solid core.
Of the competitive athletes, 22 (28%) were wearing standard, commercially available chest protectors. These included 12 hockey players (including two goalkeepers), five football players, three lacrosse goalkeepers, and two baseball catchers. Further analysis of these events describes mechanisms in which many of the CC-inducing blows may have struck the chest wall directly despite the presence of padding. This may have been due to relatively small chest protectors used in hockey and football that may have been displaced during motions such as raising the arms. However, seven of the events (in two baseball catchers, three lacrosse goalies, and two hockey goalies) most likely occurred despite blows that struck the chest protector directly, rather than the chest wall itself.
The other 49 (38%) CC events occurred during a wide variety of activities. These included non-organized sports, backyard recreational activities, and seemingly mild bodily contact during non-sports activities. These events ranged from snowball fights to sledding injuries to a fall from "monkey bars" at a playground. Several of these events happened during parent-to-child discipline and during playful "shadow" boxing. One small child sustained CC by being struck in the chest by the head of her pet dog as it ran to greet her.
Of the 128 cases of CC, 107 (84%) resulted in death. Of the 21 survivors, 19 had resuscitative measures instituted at the scene, including two cases terminated by an automated external defibrillator. The other two survivors responded spontaneously without resuscitation. Among 68 cases in which resuscitation was instituted within three minutes, 25% resulted in survival. In the cases in which resuscitation was not initiated within three minutes (often due to the failure of bystanders to appreciate the nature of the collapse), there was only one (3%) survivor. Data from the initial electrocardiogram conducted after collapse (if available) revealed ventricular fibrillation/ventricular tachycardia in 36 cases, asystole (unlikely the initial rhythm after impact as per the authors) in 40 cases, bradyarrhythmia in three cases, idioventricular rhythm in two cases, and complete heart block in one case.
Commentary by Jacob W. Ufberg, MD
This report underscores the need for improved protective sports equipment, and not only for professional athletes. A 90 mph fastball or professional slapshot is not required to cause CC. It can occur in seemingly benign situations, and we must emphasize to the public the danger of blows to the chest under any conditions.
This article also re-emphasizes the urgency of timely resuscitative efforts. While the mortality of CC was high regardless of the time to resuscitation, the survival rates were improved greatly when that time was less than three minutes. Increased public awareness of CC and increased access to automated external defibrillators potentially could improve survival after CC events.
Dr. Ufberg, Assistant Professor of Emergency Medicine, Department of Emergency Medicine, Temple University School of Medicine, Philadelphia, PA, is on the Editorial Board of Emergency Medicine Alert.