ABSTRACT
Introduction: Commotio cordis (CC), or concussion of the heart, is typically characterized by a sudden impact to the chest wall precipitating ventricular fibrillation arrest. There have been very few documented cases of atrial fibrillation (AF) resulting from this mechanism. A relative consensus exists in the crucial nature of the timing of a blow at the vulnerable ventricular repolarization in the cardiac cycle, with suggestion of the impact occurring during atrial repolarization, triggering paroxysmal atrial fibrillation. Case Presentation: We present the case of a 17-year-old male patient who sustained two significant chest wall blows over the course of 8 months with initial electrocardiogram evidence of both atrial and ventricular irritability, subsequently developing AF, which did not spontaneously resolve. Conclusions: Although the focus of CC has been management of immediate and lethal ventricular arrhythmias, atrial arrhythmias such as atrioventricular block, atrial flutter, or AF can occur from abnormal depolarization or occult damage to the conduction system. Detection of these rhythms may be delayed due to lack of initial collapse. Clinicians in the emergency department need to consider the possibility of late complications even in patients who do not exhibit immediate ventricular arrhythmia.