The spectrum of blunt cardiac injury varies from the asymptomatic cardiac concussion to the immediately fatal cardiac rupture. Although the majority of victims sustaining blunt cardiac rupture die before receiving medical attention, some survive to evaluation. The diagnosis of cardiac rupture, if established, typically results from the signs and symptoms of pericardial tamponade. However, some patients may have remarkably few signs and symptoms suggestive of cardiac injury and represent a significant diagnostic challenge. We provide two cases of cardiac rupture in which the diagnosis was delayed by the presence of an associated pericardial tear with decompression into the mediastinum and pleural space. In neither of the cases did existing institutional algorithms for blunt cardiac injury assist in establishing the diagnosis before the acute demise of the patient. The presence of a coexisting pericardial injury in these patients with blunt cardiac rupture obscured the diagnosis, leading to the deaths of these patients. A discussion of these two cases and review of the literature is provided with recommendations for diagnostic algorithms in patients sustaining blunt thoracic trauma with possible cardiac and pericardial injury.