Our case referred with an aorto-right ventricular fistula accompanied with aortic regurgitation and delayed tamponade following a stab in the chest. The case presented with a simple stab wound into anterior chest wall, whose cardiac injury was missed at the first admission and managed only for left hemopnumothorax. Two months later, he referred with delayed cardiac tamponade and post traumatic intracardiac defects. The patient displayed three aspects of heart injury which are unusual and rare namely showing no initial cardiac symptoms and signs, unnoticing two important intracardiac lesions (Ao-RV Fistula and aortic valve injury) and also, delayed cardiac tamponade as late sequel of penetrating cardiac trauma.
This presentation demonstrates that para-sternal penetrating trauma, even without cardiac symptoms and signs, may have cardiac and intracardiac injuries. Cardiac evaluation is necessary to exclude probable cardiac injury. Ignoring cardiac injury can lead to late cardiac complications. In the past, the incidence of post traumatic intracardiac lesions was reported to be less than 5% (5
). However, thanks to echocardiography and color-flow Doppler, especially transesophageal echocardiography (TEE), these simultaneous lesions have been reported to be about 20% in recent decades (13
). The most common post penetrating intracardiac lesion is ventricular septal defect (VSD) (14
). Mitral and tricuspid valves injuries have been reported sporadically in traumatic patients (4
). Our patient had a rare heart injury with a connection between the infundibulum of the RV and right Valsalva sinus of the aorta and also aortic valve perforation created by the knife tip. Aorto-RV fistula due to injury is rare and in 35% of cases, it can be accompanied with aortic valve injury and aortic regurgitation (7
). After traversing through the chest wall, a pericordial stab penetrates the anterior wall of infundibulum which can tear posterior wall of infundibulum (Conus). Then it goes through the wall of right Valsalva sinus located just behind the conus. At first, the Ao-RV fistula can be tolerated well and the patient may be asymptomatic. But, after a period of time (days or even years), it leads to heart failure and therefore, needs to be repaired. Despite the importance of physical examinations, the continuous murmur of this entity can be detected in only one-third of the patients on admission. Also, this murmur can be heard in 34% of other cases more than one week following trauma. The mean interval time to detect the murmur is reported to be 59 days after trauma (7
). Therefore, a traumatic Aorto-RV fistula maybe missed at first. Furthermore, to diagnose intracardiac injuries, echocardiography provides useful information. However, in a trauma patient (emergency situation, lack of time, bleeding wounds and chest tube, pneumothorax and poor echo-window condition) initial echocardiography may not reveal cardiac damage. Consequently, it is advised to do serial echocardiography (16
). Although our patient was managed only for a stab wound in the chest and hemopnumothorax, these two important intracardiac injuries (Ao-RV fistula and aortic valve injury) were missed at the first admission because he did not undergo any serial clinical and echocardiograph evaluations. Then two months later, the major patient`s clinical picture was a post traumatic delayed pericardial effusion and tamponade. It is important to consider that a missed penetrating cardiac injury may rarely lead to delayed pericardial effusion and cardiac tamponade (2
). A combination of post traumatic Ao-RV fistula with aortic valve perforation and delayed cardiac tamponade, similar to the current presentation, was reported by Kaya (11
). Traumatic delayed pericardial effusion can cause postpericardiotomy syndrome, infectious pericarditis and secondary bleeding. Rondon et al. recommend performing echocardiography for every patient with penetrating chest injury as soon as possible after admission to the emergency department and for up to six months, because delayed pericardial effusion may occur after injury (2
As cardiac injury can occur in every pericordial stab in the chest, serial physical examinations and serial transthoracic or even transesophageal echocardiography should be performed to exclude intracardiac injuries. In order to prevent late cardiac complications, every intrapericardial or intracardial injury ought to be evaluated and repaired at the same hospital stay.