Atrial rupture following blunt chest trauma (a case report).
Chamber rupture of the heart following blunt trauma to the chest is an uncommon condition encountered in surgical practice. We had one such case at the King Edward VII Memorial Hospital and rarity of this condition prompted us to publish the data.
R. L. S., a 22 year old male, was brought to the emergency ward after an automobile accident. He was crushed between a truck and a wall. He was conscious but irritable, and perceived oral commands. His pulse was 80/minute, regular but of low volume. Systolic blood pressure recorded was 60 mm of Hg in the right upper limb. The patient was pale but was not cyanosed. Neck veins were engorged in 30° elevated position. Multiple abrasions were seen on the chest. No other injury was noted. Examination of the respiratory system was normal. Heart sounds appeared distant but regular. Abdominal examination was normal.
Haemoglobin on admission was 7.0 gm%. Except for minimal widening of cardiac silhoutte, radiograph of the chest was normal. Central venous pressure was raised to 20-25 cm of water. Electrocardiogram was normal. A clinical diagnosis of cardiac tamponade was made. Urgent ultrasonography revealed hemopericardium which was confirmed by pericardial paracentesis.
The patient was explored through a median sternotomy incision. There was large amount of hemopericardium. On opening the pericardium, a 4 cm, tear was seen at the junction of the right atrium and superior vena cava. [Fig. 1] The tear was sutured with 5/0 prolene. The chest was closed after putting a drain within the pericardium. The patient received 12 units of blood. His post-operative haemoglobin was 9.5 gm% .
The post-operative course was uneventful till 4th post-operative day, when he started deteriorating due to fulminant pneumonia and expired on the 8th post-operative day inspite of antibiotics and physiotherapy.
Postmortem confirmed death was due to pneumonia and cerebral oedema. Heart sutures were intact without any complications.
The spectrum of cardiac injury after blunt chest trauma ranges from clinically insignificant myocardial contusion to full thickness cardiac rupture. Blunt cardiac rupture is reported to have an incidence of 0.5% in a six year review by Martin et al. Parmley et al reported 353 cases of cardiac rupture in a collective review of 207, 548 autopsies, showing incidence of 0.4%. They noted that slightly less than half of the patients with cardiac rupture died of their cardiac injury rather than from concommitant injuries and death from cardiac rupture was due to tamponade or exsanguination.
Mayfield reported two distinct clinical courses following cardiac injury-acute and subacute. The acute type is due to rupture of a chamber which may lead to death at the site of accident or is fatal during a few hours after injury unless treated by surgical intervention. Subacute type as that due to contusion diminishes cardiac reserve placing patient at risk of death due to cardiac complications remote from the site of injury.
Trueblood et al reported the commonest site of rupture to be the atrial appendege presumably due to it being thinnest and weakest area of the heart. He also reported three cases of cardiac rupture at the junction of atria and great veins as in our case. They felt that rapid movement of the heart into the left chest coupled with compression force, presumably led to tear in relatively fixed superior and/or inferior vena caval junction with the atria.
According to Martin et al, the etiologic mechanisms which induce blunt cardiac rupture are complex. The prime mechanism seems to be rapid deceleration and precordial impaction especially in an atrial rupture. The ruptures occurring at the junction of the atria and the great veins was attributed to difference in the deceleration rates of atria and veins, so that maximum stress during deceleration occurs at these junctional areas.
Bright and Beek and Parmley et al hold indirect forces responsible for cardiac rupture due to rapid increase in intravascular hydrostatic pressure as a result of compression of the lower extremities and abdomen.
Diagnosis of blunt cardiac injury is difficult to make due to: (a) associated injuries which divert physician's attention; (b) lack of physical findings; and (c) lack of specificity of non-invasive tests available in an emergency room.
According to Thomas,6 early diagnosis and prompt treatment can mean difference between successful outcome and tragic death. 80% of patients die instantaneously, and 20% live one hour or longer. The patient presents with temponade or exsanguinating shock depending on the integrity of the pericardium. In these patients, there is not much time of diagnostic evaluation and immediate surgical intervention is necessary.
In the present case, all the investigations were inconclusive inspite of strong clinical suspicion of a tamponade. Emergency ultrasonography enabled us to diagnose hemo-pericardium and subject the patient to early surgery. We therefore recommend use of ultrasonography for early diagnosis of haemo-pericardium.
We thank Dr. G. B. Parulkar, Dean, Seth G. S. Medical College and K.E.M. Hospital for permitting us to publish the data. We also thank the Department of Radiology, K.E.M. Hospital for timely help in getting the ultrasonography and diagnose haemopericardium.