Chest trauma: evaluation by two-dimensional echocardiography

Ultrasound in cardiac trauma

In the perioperative period, the emergency department or the intensive care unit accurate assessment of variable chest pain requires meticulous knowledge, diagnostic skills, and suitable usage of various diagnostic modalities. In addition, in polytrauma patients, cardiac injury including aortic dissection, pulmonary embolism, acute myocardial infarction, and pericardial effusion should be immediately revealed and treated. In these patients, arrhythmias, mainly tachycardia, cardiac murmurs, or hypotension must alert physicians to suspect cardiovascular trauma, which would potentially be life threatening. Ultrasound of the heart using transthoracic and transesophageal echocardiography are valuable diagnostic tools that can be used interchangeably in conjunction with other modalities such as the electrocardiogram and computed tomography for the diagnosis of cardiovascular abnormalities in trauma patients. Although ultrasound of the heart is often underused in the setting of trauma, it does have the advantages of being easily accessible, noninvasive, and rapid bedside assessment tool. This review article aims to analyze the potential cardiac injuries in trauma patients, and to provide an elaborate description of the role of echocardiography for their accurate diagnosis.

Role of Transesophageal Echocardiography in Blunt Chest Trauma

Patients who suffer blunt chest trauma are at risk for injury to the heart, and the thoracic aorta and its branch vessels. Unrecognized injury to the heart or aorta may lead to life threatening complications. Therefore, the physician caring for the trauma patient must be able to accurately and rapidly diagnose cardiac and thoracic aortic injury. Transesophageal echocardiography is an ideal tool to diagnose cardiac and aortic injury in the patient with blunt chest trauma because it provides high quality images of the heart and thoracic aorta and can safely and rapidly be performed in the emergency department, operating suite or intensive care unit. To utilize transesophageal echocardiography most effectively, the echocardiographer must be familiar with the indications, limitations, and piffalls of transesophageal echocardiography in patients with blunt chesttrauma. This review describes the role of transesophageal echocardiography in evaluating the patient with blunt chest trauma for cardiac, thoracic aortic, and mediastinal injury.

Blunt Trauma Causing Delayed Cardiac Tamponade

A 17-year-old patient suffered multiple trauma from a motor vehicle accident that involved blunt chest trauma. During the initial hospitalization and laparotomy for abdominal injuries, the cardiac silhouette remained normal on chest roentgenogram and there were no signs of pericardial tamponade. He went home and returned 2 weeks later with a 3 to 4-day history of increasing dyspnea and findings of cardiac tamponade. A loculated, blood-filled mass was found by echocardiography and at surgery, compressing the right heart. This type of delayed pericardial tamponade after blunt trauma has not previously been described.

Cardiac Injuries: A Review of Multidetector Computed Tomography Findings

Trauma is the leading cause of death in United States in the younger population. Cardiac trauma is common following blunt chest injuries and is associated with high morbidity and mortality. This study discusses various multidetector computed tomography (MDCT) findings of cardiac trauma. Cardiac injuries are broadly categorized into the most commonly occurring blunt cardiac injury and the less commonly occurring penetrating injury. Signs and symptoms of cardiac injury can be masked by the associated injuries. Each imaging modality including chest radiographs, echocardiography, magnetic resonance imaging and MDCT has role in evaluating these patients. However, MDCT is noninvasive; universally available and has a high spatial, contrast, and temporal resolution. It is a one stop shop to diagnose and evaluate complications of cardiac injury. MDCT is an imaging modality of choice to evaluate patients with cardiac injuries especially the injuries capable of causing hemodynamic instability.

Transthoracic echocardiogram is a useful tool in the hemodynamic assessment of patients with chest trauma

INTRODUCTION

The utility of transthoracic echocardiogram (TTE) in patients on the trauma service is not well defined. The aim of this study was to evaluate the frequency of abnormal echocardiographic findings that would aid in the assessment and management of cardiovascular hemodynamics in patients with chest trauma.

METHODS

A retrospective analysis of all patients who had a TTE on the trauma service at a level 1 trauma center during a 12-month period was performed.

RESULTS

There were 94 patients in the study. TTE was performed after cardiac surgery in 5 patients. One of the 5 patients with prior cardiac surgery was excluded from the study because of poor quality images, and each of the remaining 4 patients showed significant TTE abnormalities. Of the 89 patients without prior cardiac surgery, 38 (43%) had significant TTE findings although 32 (84%) of them had no known history of cardiac abnormalities. A decreased left ventricular ejection fraction (<50%) was found in 18% of all patients, and half of them were hemodynamically unstable. Significant valvular regurgitation or stenosis was found in 31 patients, pulmonary hypertension in 25 patients, left ventricular wall motion abnormalities in 12 patients and pericardial effusion in 11 patients.

CONCLUSION

Significant echocardiographic abnormalities are detected by TTE in patients with chest trauma. Such findings can be used in the hemodynamic assessment and management of unstable patients during their hospitalization and in planning long-term follow-up and management of these patients after discharge from the hospital.

The echocardiographic diagnosis, characterization, and extraction guidance of cardiac foreign bodies

Echocardiography is ideal for localizing cardiac foreign bodies and for characterizing associated cardiac and vascular injury before and during extraction. We report 5 cases of traumatic and iatrogenic cardiac foreign bodies that illustrate the central role of transthoracic and transesophageal ultrasonography in the management of these patients.

Troponin I, troponin T, CKMB-activity and CKMB-mass as markers for the detection of myocardial contusion in patients who experienced blunt trauma

Myocardial contusion is an infrequent, but sometimes serious complication in patients who experienced deceleration (blunt) trauma. We investigated the assessment of the new cardiac markers troponin I (cTnI) and troponin T (cTnT) in relation to the conventional CKMB-activity, the CKMB-activity/CK-total ratio, CKMB-mass and the CKMB-mass/CK-total ratio for the detection of myocardial contusion in 89 patients with blunt trauma (38 patients with thoracic injuries and 51 patients without thoracic injuries). All parameters were analysed at admission (t1) and 24 h after admission (t2). For the patients with thoracic injuries, at t1 cTnI was elevated in three, and cTnT in four patients; at t2 both cTnI and cTnT were elevated in nine patients. At t1, eighteen to thirty patients had increased levels of the conventional parameters; at t2 this was true for six to thirty-five patients. For the patients without thoracic injuries all cTnI and cTnT levels were within the reference ranges at t1. At t2 one patient, who experienced an acute myocardial infarction, had elevated cTnI and cTnT levels. At t1, five to thirty-five patients had increased levels of the conventional parameters; at t2 this was true for four to forty-two patients. From this study we conclude that the conventional parameters are not useful for the detection of myocardial contusion in patients experiencing blunt trauma. The parameters cTnI and cTnT are equally accurate and more reliable for the selection of patients who require intensive cardiac monitoring. If at admission the cTnI or the cTnT levels are within the reference ranges, a second analysis after admission is necessary to reach a reliable conclusion concerning myocardial contusion as a result of trauma on basis of the troponin levels.

The surgeon's use of transesophageal echocardiography

Transesophageal echocardiography has become an instrumental diagnostic modality for the accurate evaluation of cardiac and aortic anatomy and function. Multiplanar technology has facilitated improved visualization of structures and enhanced TEE over TTE in many situations. Care of the trauma patient and critically ill patient is improved with the appropriate and timely performance of TEE. Education, certification, credentialing, and determination of competency are areas that need to be addressed continually in the future.

Traumatic pericardial tamponade: relearning old lessons

Traumatic pericardial tamponade is a serious and rapidly fatal injury. As penetrating chest wounds are becoming more common, early diagnosis of tamponade is important so that life saving treatment can be started. The classical features of tamponade may be modified by hypovolaemia and the presence of associated injuries; acute tamponade may also be precipitated by rapid administration of large volumes of fluid. Pericardiocentesis, while sometimes life saving, is dangerous and of limited value. Echocardiography is limited by availability and operator dependence. A high degree of clinical suspicion in patients with chest injuries, together with close monitoring and reevaluation, particularly during volume replacement, is essential. Four cases are described which presented to the accident and emergency department of Glasgow Royal Infirmary, in three of which there was a significant delay in the diagnosis.

Cardiac trauma. Diagnosis, management, and current therapy

In cardiac trauma the two main mechanisms of injury are blunt and penetrating trauma. Common cardiac effects of trauma include myocardial rupture, contusion, laceration, pericardial insult, coronary injury, valvular damage, arrhythmias, and conduction abnormalities. Hemodynamic instability can develop rapidly and pose marked risk to patient survival. An adequate level of clinical awareness and timely use of diagnostic techniques such as echocardiography, aortography, and cardiac angiography are essential for rapid identification of cardiac trauma. Once the diagnosis is made, prompt surgical intervention is often the key to survival.

Improved detection of cardiac contusion with cardiac troponin I

Detecting cardiac injury in patients with chest trauma is difficult because the level of the MB isoenzyme of creatine kinase (MBCK) can be elevated from skeletal muscle injury alone. However, the level of cardiac troponin I (cTnl) is not elevated by skeletal muscle injury. To determine whether its measurement would improve the ability to detect cardiac injury in patients with blunt chest trauma, 44 patients were studied. Serial echocardiograms and serial blood samples were obtained. Six patients had evidence of cardiac injury by echocardiography; all had elevations of MBCK and cTnl. One patient had elevations of both MBCK and cTnl with only a pericardial effusion. Twenty-six of the 37 patients without contusion had elevations of MBCK; none had elevations of cTnl. The ratio of MBCK to total creatine kinase improved specificity at the expense of sensitivity. Measurement of cTnl accurately detects cardiac injury in patients with blunt chest trauma and should facilitate the diagnosis and management of such patients.

Echocardiography in the evaluation of thoracic trauma

Echocardiography has become a useful diagnostic modality in the evaluation of cardiovascular injury after thoracic trauma. Valuable information about cardiac wall motion, valvular function, pericardial effusions, and ventricular volume status can be obtained without significant risk. More recent application for the diagnosis of traumatic aortic disruption provides a safer, easier, less expensive, and more accurate method for detecting these injuries. Cardiac evaluation with TTE is unsuccessful in approximately 20% of examinations and is unable to provide the image resolution of the more invasive transesophageal approach.

Incomplete ventricular septal tear after blunt chest trauma: medical management with serial echocardiographic follow-up

Incomplete ventricular septal tears are uncommon or probably underreported cardiac lesions caused by blunt chest trauma. This report describes two cases of incomplete ventricular septal tears that were not suspected clinically. Transthoracic and transesophageal echocardiography provided the diagnostic information in both of these cases. Despite associated valvular lesions, the patients' stable in-hospital course lead to the decision to treat them medically with no specific treatment to the incomplete ventricular septal tears. Accordingly, these two cases were observed for a mean period of 1.5 years with serial echocardiographic studies to track the natural history of these lesions. During the follow-up period, both of these cases did not manifest any changes in the extent of ventricular septal tear, septal structure, or any left-to-right shunting through the tear. There were no significant changes in left ventricular size, shape, or systolic function. Thus echocardiographic imaging proved to be useful both in initial diagnosis and follow-up.

Diagnosis, Management, and Complications of Nonpenetrating Cardiac Trauma: A Perspective for Practicing Clinicians

We provide a state-of-the-art review for practicing clincians concerning diagnosis and treatment of patients with non-penetrating cardiac trauma. Internists, cardiologists, and intensivists are becoming increasingly involved in the diagnosis and management of patients with nonpenetrating cardiac injuries. Electrocardiography and cardiac isoenzyme determinations are the least expensive and most common laboratory tests used to diagnose this condition. Despite widespread use, however, these tests have significant limitations in diagnostic sensitivity and specificy. Two-dimensional echocardiography is advocated by some to improve diagnostic accuracy and to identify patients at increased risk of cardiovascular complications. Patients identified as low risk may be suitable for limited monitoring and early hospital discharge. Transesophageal echocardiography is a useful diagnostic tool that offers many advantages over standard transthoracic imaging. Nuclear medicine techniques, including radionuclide-labeled antimyosin scanning, also represent exciting new developments in this area. Invasive techniques such as cardiac catheterization and pumonary artery catheterization should be reserved for patients with hemodynamic instability and overt mechanical complications. Appropriate selection of diagnostic tests can assist clinicians in rapid traging of patients with nonpenetrating cardiac trauma. Identification of patients at low risk for cardiovascular complications may lead to more appropriate use of hospital resources.

Severe right ventricular contusion mimicking cardiac tamponade: the value of transesophageal echocardiography in blunt chest trauma

Clinically, severe right ventricular contusion may mimic cardiac tamponade. We report two cases of suspected cardiac tamponade after blunt chest trauma in which the diagnosis of severe right ventricular contusion was made only by transesophageal echocardiography, avoiding unnecessary and hazardous pericardiocentesis. These cases illustrate the value of transesophageal echocardiography in diagnosing blunt chest trauma.

Sternal fracture: what investigations are indicated?

A retrospective study of 55 patients with sternal fractures is presented in an attempt to determine which investigations are predictive of complications. We conclude that isolated sternal fractures, in the absence of clinical evidence of cardiac or respiratory complications, and with a normal electrocardiogram and postero-anterior chest radiograph, require no further investigation.

Two-dimensional and color Doppler echocardiographic diagnosis of penetrating missile wounds of the heart: chronic complications from intracardiac course of a bullet

Two-dimensional echocardiography has gained a role in the management of the acute complications of penetrating cardiac trauma and in precisely localizing retained bullet fragments within the heart. We report the case of an 8-year-old boy with chronic symptoms after a bullet wound. In this case, traumatic mitral regurgitation caused by mitral leaflet perforation and retention of the bullet in the tricuspid annulus occurred because of an unusual intracardiac course of the projectile. The diagnosis was made by transthoracic echocardiography. The ability of two-dimensional echocardiography to delineate the true location of the foreign body within the heart and Doppler ultrasound to identify mitral valve perforation helped guide a prompt, efficient, and successful surgical procedure.

[Myocardial contusions in closed thoracic injuries: a prospective study]

Various laboratory investigations were assessed with respect to their accuracy in detecting myocardial contusion in patients with blunt chest trauma. All patients, aged between 18 and 50 years, admitted to the intensive care unit for flail chest, sternal fracture, pulmonary contusion, pleural or mediastinal lesion not requiring surgery, were included over a twelve month period. A complete cardiac assessment was carried out, including a physical examination, electrocardiogram, chest X-ray, enzyme assay (ALAT, ASAT, LDH, CPK and MB isoenzyme), two-dimensional echocardiography (2D-EC), thallium-201 scintigraphy. Myocardial contusion was diagnosed when an area of decreased or absent thallium-201 uptake was found in the scintigraphy. These latter results were compared with those obtained with the other investigations. Sixteen patients, mean age 34 years, were included; two who died before the end of the investigations were excluded. 2D-EC provided the most useful data (pericardial effusions in a third of the cases). The physical examination, enzyme assays, and chest films were of low value. The investigations carried out six months after the initial trauma showed that long term follow-up was not required. All patients were asymptomatic ten months after their trauma Although the diagnosis of myocardial contusion was made in half the cases using thallium-201 scintigraphy, 2D-EC provided reliable data and had the advantage to be carried out at the patient's bedside.

The asymptomatic patient with suspected myocardial contusion

Diagnostic criteria and guidelines for hospital admission for suspected myocardial contusion (MCC) remain unclear. This study defines and examines the clinical sequelae of patients admitted with a suspicion of MCC. Criteria for observation following isolated, minor blunt chest trauma are suggested. Hospital and trauma registry records of patients admitted over a 33-month period with suspected MCC were reviewed. Conventional evaluation criteria, cardiac-related complications, and associated injuries were analyzed for 524 patients. Twenty-eight cardiac-related complications occurred in 27 of 524 patients (5%). These complications included 23 dysrhythmias, 3 infarctions, and 2 pericardial effusions. There were 23 patients with abnormal admission electrocardiograms and 4 with normal ones. Of the latter, one patient developed dysrhythmia 4 hours after admission, and three had other major multi-system injuries requiring admission to the intensive care unit. The overall incidence of cardiac-related complications in minimally injured patients was 0.1%. There were no complications in patients with isolated chest wall contusions, a normal admission electrocardiogram, and a normal rhythm at 4 hours. There was no significant association between creatine phosphokinase isoenzymes or echocardiogram and cardiac-related complications. The complete absence of significant cardiac sequelae in patients with isolated chest wall contusion, normal admission and 4-hour electrocardiograms, and no other associated major injuries suggests that these patients need not be admitted.

Principles of emergency ultrasound and echocardiography

Ultrasound is a form of imaging that addresses many needs in emergency medicine. It is fast, accurate, safe, noninvasive, and painless. It rapidly diagnoses immediately life-threatening conditions and reduces the number of invasive or delayed diagnostic methods. However, successful imaging requires an understanding of ultrasonic principles. The physical principles of ultrasound imaging with emphasis on its limitations and the benefits of emergency echocardiography are highlighted.

Clinical significance of radionuclide angiographically-determined abnormalities following acute blunt chest trauma

Abnormalities of right and left ventricular ejection fraction and segmental wall motion may be detected by radionuclide angiography (RNA) following blunt chest trauma. Of 111 patients with blunt chest trauma who were admitted to a large regional shock trauma center and underwent combined first-pass and equilibrium gated RNA, abnormalities were present in 40 (36%). These abnormalities were confined to the right ventricle in 33 patients. There was a positive association between RNA abnormalities and the presence of right bundle branch block (10 of 40, p less than 0.05) and a negative association between RNA abnormalities and the finding of rib fractures (6 of 40, p less than 0.05). The in-hospital death rate of these patients was low (3 of 40 patients with an abnormal RNA and 2 of 71 patients with a normal RNA). Follow-up RNA was performed at 10 +/- 4 days in 26 of the 40 patients with initially abnormal scans, and 22 (85%) of the 26 had reverted to normal. Thus although RNA abnormalities appear common following blunt chest trauma, among patients who survive for more than 24 hours and who undergo subsequent RNA, the complication rate is low despite an abnormal scan. We conclude that routine RNA adds little to clinical management following acute blunt chest trauma.

Frequency of cardiac contusion in nonpenetrating chest injury

Seventy-five patients with nonpenetrating chest injuries were evaluated with electrocardiography, cardiac enzyme determination, 2-dimensional echocardiography and radionuclide ventriculography to document the incidence of cardiac abnormalities. Although the electrocardiograms showed ST-T wave changes in 25 patients (33%), sensitivity (47%) and specificity (79%) for echocardiographic and radionuclide abnormalities were poor. Cardiac enzymes were abnormal in 10 patients (13%), sensitivity for echocardiographic or radionuclide abnormalities, or both, was 29% and specificity 90%. Wall motion abnormalities were detected in 11 patients (18%) by radionuclide studies and in 3 patients (6%) by echocardiography. A pericardial effusion was present in 5 patients (10%). Two patients (4%) died of noncardiac causes; neither had wall motion abnormalities. This study documents the favorable outcome of patients with blunt chest injuries and does not suggest that echocardiography or radionuclide studies should be performed routinely on such patients.