jiafm, 2010-32(2) april-june. - forensic medicine

J Indian Acad Forensic Med, 32(2) ISSN 0971-0973Case reportAcute Myocardial Infarction related to blunt Thoracic Trauma:Review of literature with two case reports*Dr Amit Sharma, MDAbstractCardiac injury occasionally occurs as a result of blunt chest trauma. Most cardiac complications in chesttrauma are due to myocardial contusion rather than direct damage to the coronary arteries. Coronary artery injuryrarely occurs after blunt chest trauma, but it can lead to extensive myocardial infarction and be frequentlyoverlooked. However, traumatic coronary injury has been reported, and a variety of underlying pathophysiologicalmechanisms have been proposed. For young adults, blunt chest trauma is one of the non-atherosclerotic mechanismsleading to acute myocardial infarction. Not only a severe trauma, but also a mild trauma such as sports trauma cancause acute myocardial infarction. Myocardial infarction after blunt chest trauma, however, is an extremely rareentity with most cases received conservative therapy. Here two cases of acute myocardial infarction due to bluntthoracic trauma are described in patients who were previously healthy and had no symptoms suggestive of coronaryartery disease.Key Words: Blunt Thoracic Trauma; Traumatic Coronary Injury; Acute Myocardial InfarctionIntroduction:In blunt chest trauma patients, it is importantto consider myocardial injury, which is mostly theresult of myocardial contusion. The consequences ofcontusion include ECG-changes, arrhythmia andnecrotic damage of the heart muscle. Direct damageto the coronary arteries however is a rare finding.Acute myocardial infarction (AMI) is described as arare complication of blunt thoracic trauma (BTT),although there is no accurate data available regardingthe true incidence of this condition.Early diagnosis is difficult due to thenonspecific post-trauma clinical picture presented bypatients. BTT may cause damage to the myocardium,cardiac valves, coronary arteries and pericardium,leading to serious complications such as arrhythmiasand sudden death. [1, 2, 3] In promoting acceleration,deceleration or direct compression of the chest, thetrauma can cause acute myocardial infarction throughthe following proposed mechanisms: dissection ofcoronary arteries, coronary thrombosis, vasospasmand rupture of atherosclerotic plaque. [4]This paper deals with two case reports ofpatients who evolved with AMI after a BTT, as wellas a review of literature.Corresponding Author:*Dr Amit Sharma,Senior Resident,Department of Forensic Medicine,Maulana Azad Medical College, New DelhiEmail: dr_amitsharma@hotmail.comCase Reports:Case 1:A 25 yrs old auto rickshaw (private threewheeler taxi) driver was rushed to the emergencyblock in unconscious state with history that hisvehicle overturned while negotiating a sharp turn. Hewas declared dead on arrival. During autopsyexamination it was noted that the deceased was ofaverage built and multiple contused grazed abrasionswere present over front of chest and abdominalregion, the largest being of size 5cmX4cm. Oninternal examination, effusion of blood present overthe thoracic and intercostal muscles. The thoraciccage was intact. Heart weighs 284gm. Onexamination of coronaries, the left anteriordescending artery lumen shows 85% block. All otherfindings were insignificant.Case 2:A 55 yrs old male was assaulted by hisneighbors over an issue of parking the car. Heallegedly received blows over his chest as stated byeyewitnesses. The person becomes unconscious aftersuffering the assault and was taken to the nearbyhospital where he was declared dead on arrival. OnPostmortem examination, he was of average built andwas wearing four layers of clothing‟s over his upperpart of the body, out of which one was a thick woolensweater and other is a leather jacket. On externalexamination minor abrasions were noted to bepresent over both elbow and knee regions. No otherinjuries present. During internal examination, thethoracic cage was intact and no internal contusions165