Assessment of diagnostic modalities in penetrating cardiac trauma for the haemodynamically stable patient
Surridge, Daniel Johnathan David
Introduction: One in 11.5 patients with a thoracic wound has cardiac involvement with potentially life-threatening consequences. Therefore, cardiac injury must be assumed in every patient with a penetrating chest lesion, even if the patient is haemodynamically stable. A need exists to diagnose or screen for “occult” cardiac injury. Methods: A retrospective analysis was conducted in patients with a penetrating injury to the chest at Charlotte Maxeke Johannesburg Academic Hospital Trauma Unit from 1 January 2007 to 30 June 2010. Data was compared between patients with and without cardiac injury. Clinical examination and special investigations were assessed for sensitivity, specificity, positive and negative predictive values. Results: Of 7 781 major injuries assessed, 1 591 (20%) sustained a penetrating injury to the chest. All cardiac injury was incurred through a precordial wound. Two investigations were found to be both significant and useful. Transthoracic echocardiography (TTE) had a sensitivity of 100% and specificity of 95%. Serial Troponin T (Trop T) levels showed a peak at 4 hours and by 6 hours post admission the specificity and negative predictive values were 100%. Conclusion: Of the investigations examined, TTE was found to have the best results. The need for specialised equipment and training make TTE less practical in a resource-limited environment. Serial Trop T shows a high negative predictive value and is a cost effective screening test for penetrating cardiac injury.