Cardiac trauma is a critical injury, with penetrating cardiothoracic injury accounting for up to a third of traumatic deaths.1–4 These injuries often involve the heart or great vessels and include traumatic insertion of a foreign body, including invasive iatrogenic injury.1–8 Blunt cardiac trauma occurs in a wide range of patients, with 8–71% of patients with cardiothoracic trauma demonstrating signs of cardiac injury.1,2,8 Blunt cardiac injury encompasses all types of injury associated with blunt thoracic trauma to the heart.8–13 Up to 20% of deaths from motor vehicle collisions (MVCs) are due to this type of injury. Patients with thoracic great vessel injury due to penetrating injury have a high mortality rate (over 90% die at the scene),14,15 and blunt injury to the thoracic vessels is commonly due to motor vehicle accident.12,13,16,17 These injuries can result in chest, upper abdominal, back, arm/shoulder, or lower neck pain, as well as hemodynamic instability, nausea/vomiting, and shortness of breath.
Cardiac trauma is a critical injury, with penetrating cardiothoracic injury accounting for up to a third of traumatic deaths.1–4 These injuries often involve the heart or great vessels and include traumatic insertion of a foreign body, including invasive iatrogenic injury.1–8 Blunt cardiac trauma occurs in a wide range of patients, with 8–71% of patients with cardiothoracic trauma demonstrating signs of cardiac injury.1, 2, 8 Blunt cardiac injury encompasses all types of injury associated with blunt thoracic trauma to the heart.8–13 Up to 20% of deaths from motor vehicle collisions (MVCs) are due to this type of injury. Patients with thoracic great vessel injury due to penetrating injury have a high mortality rate (over 90% die at the scene),14, 15 and blunt injury to the thoracic vessels is commonly due to motor vehicle accident.12, 13, 16, 17 These injuries can result in chest, upper abdominal, back, arm/shoulder, or lower neck pain, as well as hemodynamic instability, nausea/vomiting, and shortness of breath.
Penetrating injury most commonly occurs due to guns or knives, often involving only the cardiac wall. The right ventricle (RV) is most commonly affected (40%), followed by the left ventricle (LV) (35%), right atrium (20%), and left atrium (5%) (Figure 14.1).2, 9, 17–20 Other structures such as valves, the septum, coronary arteries, or the conduction system may be affected. There are many injuries associated with penetrating injury (Box 14.1).
Blunt cardiac injury results from a direct blow to the pericardium, often from a sudden deceleration in MVC (Box 14.2). This results in a wide range of symptoms including dysrhythmia to wall rupture (the most devastating injury).8, 9, 12, 16
Great vessel injury is due to penetrating or blunt etiology, both with high mortality rates. Blunt injury of the great vessels is often due to rapid deceleration, with the chest hitting the steering wheel in MVC.14, 21
Figure 14.1 Patients with precordial penetrating wounds. Every penetrating injury to the chest, especially in the presence of hypotension, should be considered as a cardiac injury until proven otherwise
Retained foreign body
Valvular, leaflet, papillary muscle, chorda tendineae injury
Coronary vessel injury
Damage to conduction system
Direct thoracic impact
Abrupt pressure change in chest and abdomen
Shearing injury from rapid deceleration
Injury from rib fracture segment
The cardiac box consists of the sternal notch in the superior part, the xiphoid process inferiorly, and the nipples laterally.1–3, 13, 22 Knife wounds can directly enter this region, though gunshot wounds can enter the cardiac box through another site due to travel across the mediastinum.
The heart is surrounded by two layers of pericardium, with the pericardial space containing approximately 5–15 cc of pericardial fluid at baseline.
The thoracic great vessels include the aorta and brachiocephalic vessels, the left subclavian/left common carotid/pulmonary vessels, the superior and inferior vena cava, and the innominate and azygos veins.2–4
Penetrating injuries with knives usually affect one chamber, though gunshot wounds (GSW) may result in multi-chamber perforation.2, 9, 17–20 Stab wounds are associated with improved outcomes due to the production of a single slit defect.
Blunt injury with myocardial contusion includes subendocardial bleeding with leukocyte migration to the affected area. Coronary blood flow may redistribute due to the injury and release of immune mediators.4–8
Dysrhythmias, acute heart failure, laceration of coronary vessels, and ventricular wall rupture can result in immediate death. Valvular or septal injury can result in regurgitation and shunting, respectively. Vascular spasm from affected coronary vessels may result in presentation similar to myocardial infarction (MI).4–8
Injury, including penetrating and blunt, to the great vessels can result in rapid exsanguination. Vascular injury can lead to dissection, fistula, aneurysm, or pseudoaneurysm formation.
The proximal descending aorta is the most common injured vessel in the chest (over 80% of cases) at its attachment of the left subclavian artery and ligamentum arteriosum. Branch vessels are involved in 15% of cases (Figure 14.2).2, 23–25
Figure 14.2 Illustration and autopsy specimen of the typical site of blunt aortic rupture, distal to the left subclavian artery (A). Intraoperative photograph of a transected thoracic aorta found at emergency room thoracotomy (B). Intraoperative appearance of thoracic aortic rupture (RLN = Recurrent Laryngeal Nerve) (C). Surgical specimen of a contained aortic rupture. The outside layer of the aorta is intact (D)
These patients may demonstrate nonspecific signs and symptoms or present in cardiac arrest. Multisystem injuries and altered sensorium can cloud the picture, and specific signs of cardiac injury such as murmurs may not be detectable in the resuscitation bay due to other patient factors (hypotension) and ambient noise/lighting.2, 9
Penetrating – Mechanism, vital signs, patient course, suspected injuries, and treatments in the field are valuable. If unstable, history is likely unobtainable. Immediate resuscitation is required for hemodynamic instability.2, 9
Blunt – Similar to penetrating trauma, though the quality of chest pain should also be ascertained. Be wary of attributing symptoms to only superficial chest wall injuries, which may hide pericardial/myocardial injury. Dyspnea may be due to a wide range of etiologies, and lightheadedness and palpitations are also common.2–9, 12
Great vessel – As discussed, many patients with great vessel injury die at the scene. Patients who arrive in the ED are frequently unstable. They may complain of chest pain, shortness of breath, back pain, limb weakness, and anuria. Mechanism of injury, speed of collision (if MVC), seat belt use, and other injuries should be assessed.2, 12, 13, 16
Initial vital signs and assessment of ABCs are imperative. Hemodynamic status must be continually monitored, as patients may decompensate quickly. Tachycardia that is unexplained may be the only finding in blunt cardiac trauma.2, 3, 9
Crackles in the lungs, murmurs, extra heart sounds (S3), and jugular venous distension indicate acute heart failure.
Vital signs, ABCs, and focused secondary examination are essential, including neurovascular examination of the upper and lower extremities. Deficit may be due to great vessel injury (traumatic dissection). Ultrasound (US) is beneficial as part of the secondary examination to evaluate for cardiac effusion, cardiac tamponade, pulmonary edema, and lung sliding.2, 3, 9
Most patients with great vessel injury depict outer physical exam signs such as bruising or a wound.
Hypotension, unequal blood pressures between the upper extremities or upper and lower extremities, thoracic outlet hematoma, seatbelt signs, palpable rib fractures, and flail chest suggest great vessel injury.
There are several severe injuries associated with death in penetrating injury to the heart.
Pericardial injury: A large defect in the pericardium can result in sudden bleeding into the thoracic cavity and exsanguination. If the defect is smaller, the injury may result in pericardial tamponade.2, 9
Atrial and coronary vessel injuries may be subtle, but injuries can cause rapid decompensation.
This condition results from fluid accumulation under pressure into the pericardial space, found in 2% of penetrating injuries to the chest and abdomen. Up to 80% of stab wounds to the heart result in tamponade. GSWs cause larger pericardial defects and less likely cause tamponade.
Blood in the pericardial cavity may form a hematoma. Fluid results in elevated pericardial pressures, decreasing RV and LV filling. HR increases to improve RA and RV filling. Even amounts less than 100 mL may result in elevated pericardial pressures.9, 11, 19, 20
RV distension pushes the septum into the LV, decreasing LV filling and cardiac output. This leads to shock and death.9
US is essential in evaluation, as tamponade is difficult to diagnose in trauma patients. Elevated HR and vascular resistance can partially compensate for tamponade, with tachycardia often the first indication. Beck’s triad (muffled heart sounds, hypotension, and JVD) is found in less than 10% of patients, and pulsus paradoxus is also not reliable.10 Narrowed pulse pressure is frequent, and hypotension is an early sign of decompensation.
This may result from direct injury or embolization. If retained from another site, patients are often stable and observed.
Treatment of these missiles is dependent on size, mechanism, shape, and location. If symptoms or hemodynamic instability are present, patients should go to the OR for removal of the missile. Others that require removal include those within coronary vessels or those that have embolized.26–28
Pericardiocentesis, chest tube placement, coronary catheterization, and electrophysiological and valvular procedures may result in injury.29
Several types of blunt cardiac injury are associated with trauma. The most common is myocardial or cardiac contusion, though the term “blunt cardiac injury” has replaced “cardiac contusion” (Figure 14.3). This new term encompasses the following injuries:2–10, 12
(A) Illustration of the mechanism of blunt cardiac injury from steering wheel (left). Photograph of blunt chest trauma to the anterior chest from a steering wheel injury (right). This patient arrived in ventricular tachycardia.
(B) Lateral chest radiograph and CT scan showing sternal fractures. This injury is often associated with cardiac trauma. These patients should be evaluated by ECG and serial troponin levels
This is the most severe form of blunt cardiac injury. The right side is at highest risk for rupture, and patients often die at the scene.2, 10, 30 Patients who survive may display a murmur. US may immediately diagnose this condition, and if discovered, the patient requires thoracotomy.
Injury to cardiac vessels is rare. The most common injured vessel is the left anterior descending artery. Coronary vessel dissection and coronary artery disease most often occur in the first 7 days.31–34 Patients most commonly present with chest pain. Patients require percutaneous intervention, though anticoagulation requires consultation with cardiology and cardiothoracic surgery due to risk of hemorrhage.2, 9, 10
Valvular damage occurs in 10% of cardiac trauma cases, though it usually occurs with other injuries. The aortic valve is the most common valve injured, which may cause aortic regurgitation and pulmonary edema. Injury to the cardiac septum may occur but is rare.31, 32, 35 Any new murmur or pulmonary edema in a patient with chest trauma requires US and resuscitation with surgical consultation. Small injuries may heal on their own, but this is not common.
Defects in the pericardium may result from blunt impact, often parallel to the phrenic nerve on the left side of the pericardium.2, 8, 9 These defects are often missed, and they may not be associated with symptoms. If herniation occurs, cardiac conduction is often interrupted. Exam can demonstrate pericardial rub, though this is not common. US or CT may demonstrate injury, which requires surgical repair.2, 8–10
The frequency of this injury is unknown and difficult to determine in the multisystem trauma patient. Patients usually present with chest pain, and patients may also have pulmonary vascular injury, decreasing LV preload, and in combination with RV output, reduced cardiac output may occur. Damage to the myocardial tissue and conduction system can also further harm cardiac output. Monitoring is needed for dysrhythmias, which include tachycardia, bundle branch block, high degree blocks, supraventricular tachycardia, ventricular fibrillation, and premature ventricular contractions, which can occur up to 48 hours after blunt injury.2, 3, 13, 35
This injury consists of sudden death associated with blunt injury to the anterior chest wall and is the most common cause of death in young athletes (baseball and lacrosse).8–10, 36 Commotio cordis injury is usually due to a low impact blow that strikes the heart and results in ventricular fibrillation, occurring 10–30 ms before the peak of the T wave. Cardiac anatomy is usually normal. Survival rate is less than 15%. If suspected, immediate compressions and defibrillation are required.36, 37
|Other thoracic injury|
Great vessel injury
Injury occurs due to direct injury or indirectly through kinetic injury of a passing missile. Great vessel injury can be iatrogenic. Embolization of missiles (such as a bullet) can occur, though this may not result in symptoms.38–41 As discussed, the most common vessel injured is the aorta. Rupture of the ascending aorta is associated with severe blunt cardiac injury and cardiac rupture.
Once this is completed, focused secondary examination is needed. A focused neurovascular exam of the extremities should be conducted if possible to evaluate for great vessel injury.
An ECG is needed when able. A normal ECG alone is not enough to exclude significant injury, which may miss up to 20% of cases.13, 16, 42, 43 A significant dysrhythmia can occur within 48 hours of the initial injury (Table 14.2).
The ECG is more sensitive for left sided rather than right sided injuries. One of the most common findings is persistent tachycardia, which is nonspecific with a variety of etiologies. ST changes, especially elevation, may suggest MI.9, 12, 16, 44
If initial ECG is normal but concern for blunt injury is present, 4–6 hours of continuous cardiac monitoring is needed. If monitoring is normal with no new symptoms, patients may be appropriate for discharge. Any ECG abnormality requires further evaluation.9, 12
|Myocardial injury||New Q wave|
ST segment elevation or depression
T wave changes
|Conduction disorder||Right or left bundle branch block (right more common)|
Fascicular block (1st, 2nd, or 3rd degree block)
|Dysrhythmia||Sinus tachycardia (most common)|
Atrial, ventricular extra beats
|Nonspecific||Pericarditis (PR depression, diffuse ST elevation)|
A great deal of controversy is present concerning biomarkers.
Creatine kinase (CK)-MB elevates with injuries of other systems such as the liver or intestines. Also, isolated elevation of CK-MB does not predict mortality, and it is not recommended.
Troponin is specific for myocardial injury, though not the etiology.9, 45–47 Troponin sensitivity for cardiac contusion ranges from 12–23%, with specificity over 97% in the setting of trauma.45–48 Causes of shock other than primary cardiac etiology may also result in troponin elevation.
The use of troponin and ECG may improve risk stratification, as negative ECG and troponin are associated with extremely low risk of blunt cardiac injury. Abnormal ECG warrants troponin testing. Any abnormality in ECG and troponin testing strongly suggests blunt cardiac injury.47–51
The FAST exam requires cardiac images via the subxiphoid or parasternal long axis view. FAST exam allows evaluation of gross cardiac function and the presence of cardiac effusion (Figure 14.4). US displays a sensitivity and specificity over 99% for detection of pericardial effusion.2, 3, 52–56
Figure 14.4 Ultrasound with evidence of pericardial tamponade. Solid white arrow is RV, while clear arrow is pericardial effusion
Transesophageal Echocardiography (TEE)
TEE is portable and fast, with immediate bedside results. This is promising; however, few emergency physicians are trained in this modality. This modality is also useful in the potentially unstable patient.58 TEE can detect aortic lesions (including full rupture and intimal defects). However, it is contraindicated in patients with potential airway issues (if not already intubated) or cervical spine injury.54–56
This imaging modality is not sensitive or specific for injury. Cardiomegaly is rare in acute pericardial effusion and tamponade. Widened mediastinum may suggest aortic dissection, with width greater than 8 cm (Figure 14.5, Table 14.3).2, 3, 59–62 Other findings include esophageal deviation more than 1 cm to the right of the spine at the T4 level.62, 63 A normal chest X-ray does not rule out aortic injury.
Figure 14.5 Blunt thoracic aortic injury. Chest x-ray shows a widened mediastinum and deviation of the trachea to the right (left). CT image confirms thoracic aortic injury (right)
|Mediastinum||Aortic knob obliteration|
Left mainstem bronchus depression
Paravertebral pleural stripe loss
Aortic knob layering with calcium
Lateral displacement of the trachea
Nasogastric tube deviation at T4
|Lateral X-ray||Trachea anterior displacement|
Aortic/pulmonary window absence
|Others||Apical pleural hematoma|
CT of the chest with contrast is the modality of choice for penetrating and blunt chest trauma (Figure 14.6, Table 14.4). Multidetector scanners display sensitivity and specificity approaching 100% for vascular and lung injuries. In penetrating injury, evaluation of injury tract and vascular involvement is essential. However, in blunt cardiac injury, CT may detect wall motion abnormalities.23–25 CT with IV contrast is definitive for great vessel injury, with defects appearing as irregular vascular contours, vessel lumen abnormalities, dissection, aneurysm/pseudoaneurysm, and acute bleeding. CT also depicts the tract of injury, including knives and missiles.2, 9, 23–25
Hemorrhage around the aorta
Tracheal and esophageal displacement to the right
Luminal intimal flap
|Uncommon||Intimal disruption with luminal clot|
Change in aortic caliber suddenly
Small aortic caliber in the lower chest and abdomen
In the setting of penetrating trauma with new pericardial effusion and unstable vital signs, preparation for thoracotomy is required.2, 9, 64 Pericardiocentesis may be used to temporize the patient.2, 9, 56, 64, 65
Unstable patients with cardiac activity and penetrating cardiac injury require the OR emergently. Patients who lose pulses in the ED with penetrating or blunt trauma are eligible for EDT (Table 14.5).2, 3, 9, 66–68 Others include patients with penetrating thoracic trauma and hemodynamic instability, despite fluid resuscitation or if pulseless less than 15 minutes.69–72
The patient should be intubated with NG/OG placed before the procedure. The left 4th or 5th intercostal space should be identified (the intercostal space below the male’s nipple or inframammary fold in a woman), with primary incision at this location.
The site should be quickly sterilized and incised with one broad stroke through all layers to the intercostal muscles down to the posterior axillary line. These muscles should be cut with Mayo scissors.
A Finochietto retractor is then placed within the chest, with the crank near the bed. The retractor is opened to expose the left chest cavity.
Control any hemorrhage with direct pressure. Move the lung to expose the pericardium.
Signs of cardiac injury include distended, discolored, and tense pericardial sac. The pericardium should be incised anterior to the phrenic nerve to allow inspection of the heart for injury.
Digital occlusion of the wound can be the first maneuver, but a finger should never be inserted into the heart, which can extend the injury.
Staples via skin stapler is fast and effective. Suturing is also effective but difficult due to cardiac activity. A Foley catheter can be placed within a wound, the balloon inflated and gentle retraction placed on the catheter, and then the catheter sutured into place.
When suturing, horizontal mattress sutures or interrupted sutures are effective, and pledgets may reinforce the suture and prevent further damage to the heart.
If cardiac function is absent, internal cardiac massage should be performed. Care should be taken to avoid coronary vessel damage.
If no left-sided injury is discovered, the thoracotomy should be extended to the right with a clam shell across the sternum and down the right. This may assist with improved exposure to the right side of the heart, as well as the right lung.
The descending aorta can be cross-clamped.
If the patient regains pulses or vital signs improve, the patient requires the OR. Survival rate approaches 80% for knife wounds and 40% for gunshot wounds.
|Eastern Association for the Surgery of Trauma|
|Western Trauma Association|
Figure 14.7 Emergency room resuscitative thoracotomy for injury to the heart. (A) Illustration of the incision for a resuscitative emergency department left anterolateral thoracotomy. (B) Photographs showing incisions for resuscitative thoracotomy, in a female and a male patient. (C, D) Illustration and photo of the pericardium at thoracotomy. The phrenic nerve is seen on the lateral aspect of the pericardium. The pericardium should be opened above the nerve (C). The pericardium is opened and the heart exposed (D). (E) Illustration and intraoperative photograph showing the use of a Foley catheter for temporary bleeding control from a cardiac wound. (F) Photograph of a cross-clamping of the thoracic aorta. The clamp should be applied about 3–4 cm above the diaphragm. (G) Photograph of internal cardiac defibrillation during emergency room resuscitative thoracotomy
Hypotension in the setting of blunt trauma requires intravascular expansion with IV fluids, preferably blood products. The most common cause of hypotension is injury other than the heart. If the heart is the primary cause of symptoms or hypotension, admission for comprehensive echocardiography and monitoring is required.9, 13 ACLS measures are needed for patients with dysrhythmias. Injuries from blunt trauma such as cardiac rupture, valve injury, papillary muscle/chordae injury, or MI need PCI or surgery.2, 3, 9
Patients with minor ECG changes such as premature atrial/ventricular contractions should be admitted for monitoring and echocardiography. For evaluation of cardiac dysrhythmia or hemodynamic instability, 24–48 hours of monitoring are recommended.4, 5, 57