Detection of central pulmonary artery thromboemboli by transesophageal echocardiography in patients with severe pulmonary embolism

Clinical Characteristics and Treatment Outcomes of Primary Pulmonary Artery Sarcoma in Korea

Pulmonary artery sarcomas (PAS) are rare malignant neoplasms. Right heart failure due to tumour location is the main cause of death in PAS patients. The hemodynamic influence of PAS may effect prognosis, but this has not been proven. We aimed to identify the clinical characteristics and prognostic factors of PAS in Korea, their association with pulmonary hypertension (PH). PAS patients treated at the Asan Medical Center between 2000 and 2014 were reviewed. We examined demographic characteristics, diagnostic and treatment modalities. Potential prognostic factors were evaluated by univariate and multivariate analysis. Twenty patients were diagnosed with PAS. Ten patients were male, the median age was 54 years (range, 33-75 years). The most common symptom observed was dyspnea (65%). The most common histologic type was spindle cell sarcoma (30%). Ten patients had a presumptive diagnosis of pulmonary embolism (PE) and received anticoagulation therapy. Seventeen patients underwent surgery, but only 5 patients had complete resection. Eleven patients received post-operative treatment (chemotherapy = 3, radiotherapy = 5, chemoradiotherapy = 3). PH was observed in 12 patients before treatment and in 6 patients after treatment. Overall median survival was 24 months. Post-treatment PH was associated with poor prognosis (HR 9.501, 95% CI 1.79-50.32; P = 0.008) while chemotherapy was negatively associated with mortality (HR 0.102, 95% CI 0.013-0.826; P = 0.032) in univariate analysis. Post-treatment PH was also associated with poor prognosis in multivariate analysis (HR 5.7, 95% CI 1.08-30.91; P = 0.041). PAS patients are frequently misdiagnosed with PE in Korea. Post-treatment PH is associated with a poor prognosis.

Pulmonary artery angiosarcoma confused with acute pulmonary thromboembolism: focusing on clinical and echocardiographic features in the differentiation of two categories

Although pulmonary artery angiosarcoma is rare, it can be misdiagnosed as pulmonary embolism because of its similar clinical and diagnostic features. The diagnosis is often delayed and the misdiagnosis brings unnecessary treatment. Because we made a wrong diagnosis of pulmonary artery angiosarcoma as an acute pulmonary embolism, we did thrombolytic therapy which could be dangerous to the patient. In this case report, we focused on the clinical and echocardiographic features of pulmonary artery angiosarcoma which can be used in differentiating the diagnosis from pulmonary embolism.

Focused critical care echocardiography

OBJECTIVE

Portable ultrasound is now used routinely in many ICUs for various clinical applications. Echocardiography performed by noncardiologists, both transesophageal and transthoracic, has evolved to broad applications in diagnosis, monitoring, and management of critically ill patients. This review provides a current update on focused critical care echocardiography for the management of critically ill patients.

METHOD

Source data were obtained from a PubMed search of the medical literature, including the PubMed "related articles" search methodology.

SUMMARY AND CONCLUSIONS

Although studies demonstrating improved clinical outcomes for critically ill patients managed by focused critical care echocardiography are generally lacking, there is evidence to suggest that some intermediate outcomes are improved. Furthermore, noncardiologists can learn focused critical care echocardiography and adequately interpret the information obtained. Noncardiologists can also successfully incorporate focused critical care echocardiography into advanced cardiopulmonary life support. Formal training and proctoring are important for safe application of focused critical care echocardiography in clinical practice. Further outcomes-based research is urgently needed to evaluate the efficacy of focused critical care echocardiography.

Perioperative pulmonary embolism

Pulmonary thromboembolism (PTE) is a perioperative complication that requires prompt diagnosis and treatment to minimize mortality. Detection of deep vein thrombosis (DVT) suggests the presence of PTE. The clinical presentation of PTE is mainly hemodynamic and gas exchange abnormalities. Diagnostic tools include ventilation/perfusion scan, pulmonary angiography, spiral CT, and echocardiography. Therapeutic options include hemodynamic support with inotropics, anticoagulation, systemic thrombolysis, surgical embolectomy and an inferior vena cava filter. DVT prophylaxis should be considered in all operative patients with high risk. Anesthesiologists should consider the appropriate anticoagulant management before and after surgery to optimize anesthetic choices.

[Echocardiography in the Intensive Care Unit]

The echocardiography can provide important and relevant information and the critically ill patient presents a challenge for the echocardiographer: from limitations in image acquisition to interpretation in the context of rapid physiological and intervention changes. The most frequent reason for requesting an echocardiogram in the ICU is probably to assess left ventricular function. In any case, information of direct relevance for clinical management can in relationship to abnormalities of structure and function can be obtained and used to estimate pulmonary arterial and venous pressures. It can help to investigate the consequences of myocardial ischemia, valvular dysfunction and pericardial disease and detect changes characteristic of specific conditions (e.g. sepsis, pulmonary thromboembolism), although this must be interpreted in the context of each individual patient. The echocardiography also can be used to monitor the therapeutic interventions. The applications of echocardiography in the critical care setting are reviewed, with special emphasis on the assessment of cardiac physiology.

Evaluation of hypoxemic patients with transesophageal echocardiography

OBJECTIVE

To summarize the use of transesophageal echocardiography when investigating hypoxemic patients in the intensive care unit, to assess its risks and benefits, and to evaluate which diseases of the cardiopulmonary system, mediastinum, and thorax it will help to guide therapeutic decisions.

DESIGN

A review of current literature and practice guidelines was performed.

RESULTS

Hypoxemia, due to a number of different reasons, is common in critically ill patients. Many diagnoses and therapeutic decisions have to rely on good-quality imaging. However, transthoracic echocardiography often produces poor-quality pictures; other imaging modalities involve transferring unstable patients to the imaging suite. Transesophageal echocardiography can safely be performed at the bedside and generates excellent image quality.

CONCLUSION

Transesophageal echocardiography is a safe procedure that can be performed at the bedside and that produces high-quality images of the heart, its related structures, and its function. It helps detect extracardiac pathology leading to hypoxemia and may be used to guide fluid resuscitation and optimize tissue oxygenation.

Bedside echocardiography in the assessment of the critically ill

Advances in ultrasound technology continue to enhance its diagnostic applications in daily medical practice. Bedside echocardiographic examination has become useful to properly trained cardiologists, anesthesiologists, intensivists, surgeons, and emergency room physicians. Cardiac ultrasound can permit rapid, accurate, and noninvasive diagnosis of a broad range of acute cardiovascular pathologies. Although transesophageal echocardiography was once the principal diagnostic approach using ultrasound to evaluate intensive care unit patients, advances in ultrasound imaging, including harmonic imaging, digital acquisition, and contrast for endocardial enhancement, has improved the diagnostic yield of transthoracic echocardiography. Ultrasound devices continue to become more portable, and hand-carried devices are now readily available for bedside applications. This article discusses the application of bedside echocardiography in the intensive care unit. The emphasis is on echocardiography and cardiovascular diagnostics, specifically on goal-directed bedside cardiac ultrasonography.

Relation of Ultrasound Morphologic Characteristics of Central Pulmonary Artery Thromboemboli to Their Ex Vivo Lysibility

BACKGROUND

Ultrasound morphology of massive central pulmonary artery thromboemboli (TE) is an independent predictor of 30-day mortality. The aim of this study was to asses ex vivo lysibility of morphologically different TE.

METHODS

Forty-five central pulmonary artery TE, collected at autopsies, were divided into hypoechoic (group A) and hyperechoic (group B) categories. TE were lysed with alteplase in a perfusing system simulating pulmonary circulation for 1 hour.

RESULTS

The grey scale mean of thrombi in group B was higher compared with group A (64 +/- 7 vs. 38 +/- 7, respectively, P < .01). Spontaneous lysis in group A did not differ compared with group B (2.2% +/- 0.5% vs. 2.1% +/- 0.4%, P = .4). After incubation with alteplase, the weight of TE was reduced more in group A than in group B (16% +/- 2% vs. 11% +/- 2%, P < .001). The grey scale mean negatively correlated with the percentage of TE weight reduction (0.768) (P < .001).

CONCLUSION

Ultrasound morphology of TE from central pulmonary arteries correlates significantly with ex vivo lysibility. Hypoechoic TE are more susceptible to thrombolysis than hyperechoic TE.

Characterization of pulmonary emboli ex vivo by magnetic resonance imaging and ultrasound

INTRODUCTION

Magnetic resonance imaging (MRI) and transesophageal ultrasound (US) are promising methods for detection and characterization of central pulmonary emboli. Both methods employ different physical principles. We tested how US and MRI characterized pulmonary emboli ex vivo.

METHODS

Thirty six ex vivo pulmonary emboli, obtained during routine autopsies of patients who died of massive pulmonary embolism, were subjected to US imaging (linear vascular probe, 5.7-10 MHz) and to high resolution three-dimensional T1-weighted spin-echo MRI. In another 3 pulmonary thromboemboli and 2 tumor emboli, we compared MRI with immunohistochemistry to platelets, red blood cells and renal carcinoma cells. We also studied model clots in vitro (retracted and non-retracted red whole-blood clots, platelet aggregates and compacted and non compacted fibrin-rich plasma clots) with MRI and US.

RESULTS

T1-weighted MR images of pulmonary thromboemboli consistently showed dark regions that corresponded to red cell-rich regions and bright layers that corresponded to platelet aggregates, but bright signal was obtained also from viable carcinoma cells and necrotic regions in tumor emboli. US images provided less structural detail than MRI, but clot retraction or compaction increased image brightness. The correlation between US and MRI characteristics of pulmonary emboli was poor.

CONCLUSIONS

T1-weighted MRI of pulmonary emboli is capable of non-invasive assessment of the red cell-rich and platelet-rich components of pulmonary thromboemboli. US imaging shows increased brightness with clot retraction or compaction. Thus, both methods detect clot characteristics that influence susceptibility to thrombolytic treatment.

Bedside ultrasonography in the ICU: part 1

Ultrasonography has become an invaluable tool in the management of critically ill patients. Its safety and portability allow for use at the bedside to provide rapid, detailed information regarding the cardiovascular system and the function and anatomy of certain internal organs. Echocardiography can noninvasively elucidate cardiac function and structure. This information is vital in the management hemodynamically unstable patients in the ICU. In addition, ultrasonography has particular value for the assessment and safe drainage of pleural and intra-abdominal fluid and the placement of central venous catheters. A new generation of portable, battery-powered, inexpensive, hand-carried ultrasound devices have recently become available; these devices can provide immediate diagnostic information not assessable by physical examination alone and allow for ultrasound-guided thoracocentesis, paracentesis, and central venous cannulation. This two-part article reviews the application of bedside ultrasonography in the ICU.

Diagnosis and differential assessment of pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH) is diagnosed by various investigations that are essential for making the diagnosis, and by additional tests to clarify the category of pulmonary hypertension (PH). A diagnostic algorithm can guide the evaluation of PH, but like all guidelines the algorithm can be modified according to specific clinical circumstances. Most patients are diagnosed as the result of an evaluation of symptoms, whereas others are diagnosed during screening of asymptomatic populations at risk. Right heart catheterization (RHC) must be performed in patients with suspected PH to establish the diagnosis and document pulmonary hemodynamics. Before initiation of medical therapy, assessment of acute vasoreactivity (during catheterization) is necessary to determine the appropriate therapy for an individual patient. An acute response is generally defined as a decrease in mean pulmonary arterial pressure of at least 10 mm Hg with the mean pulmonary arterial pressure decreasing to 40 mm Hg or below, accompanied by a normal or high cardiac output. After PAH is diagnosed, disease severity should be assessed in order to accurately determine risk:benefit profiles for various therapeutic options. Useful tools to predict outcome include functional class, exercise capacity, pulmonary hemodynamics, acute vasoreactivity, right ventricular function, as well as brain natriuretic peptide, endothelin-1, uric acid, and troponin levels. Repeating these tests serially on treatment is useful for monitoring the response to a given therapy. Close follow-up at a center specializing in management of PH is recommended, with careful periodic reassessment and adjustment of therapy.

Morphologic characteristics of central pulmonary thromboemboli predict haemodynamic response in massive pulmonary embolism

OBJECTIVE

On hospital admission, the morphology of the central pulmonary artery thromboemboli is an independent predictor of 30-day mortality in patients with massive pulmonary embolism (MPE). This may be due to the differential susceptibility of thromboemboli to thrombolysis. The aim of this study was to assess haemodynamic response to treatment in patients with MPE and morphologically different thromboemboli.

DESIGN

Prospective observational study.

SETTING

An 11-bed closed medical ICU at a 860-bed community general hospital.

PATIENTS

Twelve consecutive patients with shock or hypotension due to MPE and central pulmonary thromboemboli detected by transesophageal echocardiography who were treated with thrombolysis between January 2000 through April 2002.

PROCEDURES

Patients were divided into two groups according to the characteristics of detected central pulmonary thromboemboli: group 1, thrombi with one or more long, mobile parts; and group 2, immobile thrombi. Urokinase infusion was terminated when mixed venous oxygen saturation was stabilized above 60% for 15 min.

RESULTS

At 2 h, the total pulmonary vascular resistance index was reduced more in group 1 than group 2 [from 27+/-12 mmHg/(l.min.m(2)) to 14+/-6 mmHg/(l.min.m(2)) (-52%) vs 27+/-8 mmHg/(l.min.m(2)) to 23+/-10 mmHg/(l.min.m(2)) (-15%), respectively, P=0.04]. In group 1 thrombolysis was terminated earlier than group 2 (89+/-40 min vs 210+/-62 min, respectively, P= 0.0024). The cumulative dose of urokinase used in group 1 was lower than group 2 (1.7+/-0.3 M i.u. vs 2.7+/-0.5 M i.u., respectively, P= 0.023).

CONCLUSION

Haemodynamic stabilization is achieved faster in patients with mobile central thromboemboli detected by transesophageal echocardiography during MPE.

Papel da ecodopplercardiografia na avaliação da hipertensão arterial pulmonar

A adequada avaliação dos níveis de pressão na artéria pulmonar é fundamental para o diagnóstico e manuseio de pacientes com hipertensão arterial pulmonar (HAP) de qualquer etiologia. A ecocardiografia é um método nãoinvasivo, de baixo custo e amplamente disponível, que permite a avaliação anatômica e funcional das cavidades cardíacas direitas e a estimativa das pressões em artéria pulmonar, apresentando boa correlação com dados hemodinâmicos obtidos pelo cateterismo cardíaco. O mais preciso e confiável método utilizado pela ecocardiografia para a estimativa das pressões em artéria pulmonar é baseado na medida da velocidade do fluxo regurgitante da valva tricúspide, embora elas possam também ser estimadas pelo fluxo regurgitante pulmonar ou pela análise do fluxo sistólico pulmonar. Quando a qualidade da imagem obtida pela abordagem transtorácica não permite a avaliação adequada da anatomia cardíaca, a ecocardiografia transesofágica torna-se procedimento extremamente útil para complementar essa avaliação, permitindo, por vezes, a detecção de seus possíveis mecanismos causais. A ecocardiografia pode ser utilizada não só para o diagnóstico da HAP, mas também para orientar a conduta terapêutica e para a avaliação prognóstica desses pacientes. Em casos de tromboembolismo pulmonar agudo, já foi demonstrado que a detecção de disfunção ventricular direita pela ecocardiografia é um dado importante na indicação de terapia trombolítica. Da mesma forma, o método tem seu valor estabelecido para monitorização da resposta terapêutica em pacientes com HAP primária, na avaliação prognóstica de pacientes com doença pulmonar obstrutiva crônica e no acompanhamento de pacientes submetidos a transplante pulmonar.

Patients with acute pulmonary embolism should have an echocardiogram to guide treatment decisions

A 62-year-old man with a past medical history notable for hypertension, osteoarthritis, and calf deep vein thrombosis at age 55 following a total hip arthroplasty presents to the emergency department with acute-onset dyspnea and right-sided pleuritic chest pains. His medications consist of a calcium channel blocker and a COX-2 inhibitor. Pretest clinical suspicion for pulmonary embolism (PE) is high. Ventilation and perfusion lung scintigraphy are interpreted as being high-probability for PE. The nurse asks if a stat transthoracic echocardiogram should be ordered.

Diagnosing pulmonary embolism: a question of too much choice?

The diagnosis of pulmonary embolism (PE) is difficult with many patients treated without the disease or left untreated without an adequate diagnostic work up. Recent advances in PE diagnosis are reviewed. The use of risk stratification in PE diagnosis is strongly recommended and evidence on how it can best be performed summarized. The Ginsberg/Wells stratification rule is recommended currently as the best validated rule. Computed tomographic pulmonary angiography (CTPA) was found to have quite poor sensitivity and to be poorly validated. It is recommended as adequate as a positive test in moderate/high risk groups and an exclusionary test in low risk groups or where an adequate alternative diagnosis is found. For D-Dimer tests the only test with adequate sensitivity and validation in management studies is the VIDASCopyright D-Dimer. This is in low/intermediate risk groups in the ED population. The Simpli-RedCopyright test is also reviewed but is too insensitive for most populations. Echocardiography: this is good in compromised patients as it is a bedside test which when negative virtually excludes PE. If positive in the right setting it has a high positive predictive value. A negative echocardiogram predicts a benign clinical course for PE. The rest of the paper details the authors approach to integrating these new techniques with established algorithms and where progress is likely to occur in the next few years. These include improvements in CTPA (plus the addition of CT venography), new point of care D-Dimer tests, better risk stratification rules and integration of new strategies with artificial neural networks or computerized guidelines.

Phased-array intracardiac echocardiographic imaging of acute cardiovascular emergencies: Experimental studies in dogs

BACKGROUND

We evaluated a newly developed phased-array intracardiac echocardiographic catheter.

OBJECTIVE

Our aim was to evaluate the imaging capability of this new ICE catheter in an animal model simulating acute cardiovascular abnormalities.

METHODS

ICE images were obtained from the right atrium during (1) acute left ventricular dysfunction; (2) acute coronary occlusion; (3) pericardial effusion and tamponade; and (4) pulmonary embolism.

RESULTS

Left ventricular dysfunction, induced experimentally by halothane inhalation, resulted in a fall in echocardiography-calculated ejection fraction from 47% +/- 11% to 25% +/- 10%, P <.01. Regional contraction abnormalities after acute coronary occlusion were identified without and with the ultrasound contrast agent Optison. Pericardial effusion produced by saline infusion into the pericardium was detected in amounts as small as 15 mL. Right ventricular and atrial compression and respiratory variation in right ventricular inflow during tamponade were demonstrated. After injection of intravenous thrombin to create venous thromboembolism, we demonstrated right ventricular dilatation and dysfunction and thrombi attached to the tricuspid and pulmonary valves and in the pulmonary artery.

CONCLUSION

This new phased-array ICE catheter may be a useful clinical tool for the diagnosis of heart failure, ischemia, tamponade, and pulmonary embolism.

Impact of morphologic characteristics of central pulmonary thromboemboli in massive pulmonary embolism

STUDY OBJECTIVE

To assess the impact of morphologically different central pulmonary artery thromboemboli in patients with massive pulmonary emboli (MPEs) on short-term outcome.

DESIGN

A prospective registry of consecutive patients.

SETTING

An 11-bed closed medical ICU at a 860-bed community general hospital

PATIENTS

Forty-seven patients with shock or hypotension due to MPE and central pulmonary thromboemboli detected by transesophageal echocardiography who were treated with thrombolysis between January 1994 and April 2000.

PROCEDURES

Patients were divided into two groups according to the following characteristics of the detected thromboemboli: group 1, thrombi with one or more long, mobile parts; and group 2, immobile thrombi. Right heart catheterization was performed.

RESULTS

The incidence of both types of thromboemboli was comparable. Groups 1 and 2 showed no differences in demographic data, risk factors for pulmonary embolism, length of preceding clinical symptoms, percentage of patients in shock, hemodynamic variables, serum lactate levels on hospital admission, and treatment. Seven fatal cases due to obstructive shock and right heart failure were present in group 2, but none were present in group 1 (7 of 23 patients vs 0 of 24 patients, respectively; p < 0.05). At 12 h, the cardiac index was lower in group 2 than in group 1 (2.6 +/- 1.0 vs 3.1 +/- 0.9 L/min/m(2), respectively; p < 0.05), and the central venous pressure (15.0 +/- 6.2 vs 12.5 +/- 3.7 mm Hg, respectively; p < 0.05) and total pulmonary resistance (12.9 +/- 5.9 vs 8.6 +/- 2.7 mm Hg/L/min/m(2), respectively; p < 0.001) were higher in group 2 compared to group 1. On hospital admission, inclusion in group 2 (p < 0.03; hazard ratio, 9.53; 95% confidence interval [CI], 1.19 to 76.47) and preexisting chronic medical or neurologic disease (p < 0.01; hazard ratio, 16.4; 95% CI, 1.97 to 136.3) were independent predictors of 30-day mortality.

CONCLUSION

On hospital admission, morphology of the thromboemboli and the presence of pre-existing chronic medical or neurologic disease are independent predictors of 30-day mortality. Patients with immobile central pulmonary thromboemboli have a worse short-term outcome than those with mobile central pulmonary thromboemboli.

Major pulmonary embolism: review of a pathophysiologic approach to the golden hour of hemodynamically significant pulmonary embolism

Major pulmonary embolism (PE) results whenever the combination of embolism size and underlying cardiopulmonary status interact to produce hemodynamic instability. Physical findings and standard data crudely estimate the severity of the embolic event in patients without prior cardiopulmonary disease (CPD) but are unreliable indicators in patients with prior CPD. In either case, the presence of shock defines a threefold to sevenfold increase in mortality, with a majority of deaths occurring within 1 h of presentation. A rapid integration of historical information and physical findings with readily available laboratory data and a structured physiologic approach to diagnosis and resuscitation are necessary for optimal therapeutics in this "golden hour." Echocardiography is ideal because it is transportable, and is capable of differentiating shock states and recognizing the characteristic features of PE. Spiral CT scanning is evolving to replace angiography as a confirmatory study in this population. Thrombolytic therapy is acknowledged as the treatment of choice, with embolectomy reserved for those in whom thrombolysis is contraindicated.

Monitoring for suspected pulmonary embolism

It is fortunate that serious embolic phenomena are uncommon because, with the exception of neurosurgery in the sitting position and cardiac surgery, thoracic echocardiography and the precordial Doppler device, the most sensitive indicators of embolism, are seldom used. Vigilance is required of the anesthesiologist to recognize the rapid fall in end-tidal PCO2, the usual first indicator of a clinically significant PE. Any sudden deterioration in the patient's vital signs should include embolism in the differential diagnosis, particularly during procedures that carry a high risk of the complication.

Role of echocardiography in the diagnosis and treatment of acute pulmonary thromboembolism

The diagnosis and treatment of acute pulmonary thromboembolism (PE) remains a complex clinical challenge. Many studies have used both transthoracic and transesophageal echocardiography as a diagnostic and/or prognostic tool in this common disorder. In patients with central, hemodynamically significant PE, echocardiography can directly visualize thrombus or demonstrate the hemodynamic consequences of PE, whereas in the majority of patients, the sensitivity of echocardiography appears limited. Echocardiography may be useful in assessing the prognosis of patients with PE as well as their response to therapy. Further studies are needed in larger populations of patients to clarify the role of echocardiography in the assessment of patients with clinically suspected PE.

Diagnostic value of transoesophageal echocardiography in suspected haemodynamically significant pulmonary embolism

OBJECTIVE

To assess the value of transoesophageal echocardiography (TOE) for diagnosing suspected haemodynamically significant pulmonary embolism and signs of right ventricular overload at standard echocardiography.

METHODS

113 consecutive patients (58 male; 55 female), mean (SD) age 53.6 (13.3) years, in whom there was clinical suspicion of pulmonary embolism and right ventricular overload on transthoracic echocardiography, underwent TOE in addition to routine diagnostic procedures to identify pulmonary artery thrombi.

RESULTS

TOE revealed thrombi in 32 of 51 patients who had suspected acute pulmonary embolism and in 31 of 62 with suspected chronic pulmonary embolism. In one patient a pulmonary angiosarcoma rather than chronic pulmonary embolism was found at surgery. The diagnosis of pulmonary embolism was confirmed in 77 patients by scintigraphy, spiral computed tomography, angiography, or necropsy (reference methods). While TOE failed to provide a diagnosis of pulmonary embolism in 15 of these 77 patients, no false positive findings were reported (sensitivity 80.5%, specificity 97.2%). In 11 and 26 cases, respectively, the thrombi were confined to the left or right pulmonary artery. Bilateral thrombi were found in 25 patients. Mobile thrombi were observed only in acute pulmonary embolism (in 19 of 32 patients). No complications of TOE were noted.

CONCLUSIONS

TOE permits visualisation of pulmonary arterial thrombi, confirming the diagnosis in the majority of patients with pulmonary embolism and right ventricular overload. This may be useful for prompt decision making in patients with haemodynamic compromise considered for thrombolysis or embolectomy.

Transesophageal echocardiography (TEE) in the critical care patient

Critically ill patients often pose special diagnostic problems to the clinician, intensified by limited physical examination findings and difficulty in transportation to imaging suites. Mechanical ventilation and the limited ability to position the patient make transthoracic echocardiography difficult. Transesophageal echocardiographic (TEE) imaging, however, is well suited to the critical care patient and is frequently used to evaluate hemodynamic status, the presence of vegetations, a cardioembolic source, and an intracardiac cause of hypoxemia. Using proper precautions, TEE can be performed safely in unstable patients and frequently leads to important changes in management.

The incidence of pulmonary embolism in unexplained sudden cardiac arrest with pulseless electrical activity

PURPOSE

The cause of many cases of sudden cardiac arrest from pulseless electrical activity is unknown. We hypothesized that pulmonary embolism was responsible for a substantial proportion of these cases and used transesophageal echocardiography to identify pulmonary embolism among patients with sudden cardiac arrest.

SUBJECTS AND METHODS

We performed a prospective study at a tertiary care, university-operated county hospital, with a level 1 trauma center. Consecutive patients (n = 36) who were admitted with (n = 20) or unexpectedly developed (n = 16) sudden cardiac arrest of unknown cause were studied with transesophageal echocardiography during cardiopulmonary resuscitation. We determined the presence of central pulmonary embolism, right ventricular enlargement, and other causes of sudden cardiac arrest (such as myocardial infarction and aortic dissection) using prospectively defined criteria.

RESULTS

Of the 25 patients with pulseless electrical activity as the initial event, 9 (36%) had pulmonary emboli (8 seen with transesophageal echocardiography and 1 diagnosed at autopsy) compared with none of the 11 patients with other rhythms, such as asystole or ventricular tachycardia or fibrillation (P = 0.02). Of the 8 patients who had pulmonary embolism diagnosed by transesophageal echocardiography, 2 survived to hospital discharge.

CONCLUSIONS

Mortality from massive pulmonary embolism is high, particularly if patients present with sudden cardiac arrest. Earlier diagnosis of pulmonary embolus may permit wider use of thrombolytic agents or other interventions and may potentially increase survival.

Transthoracic echocardiographic demonstration of massive pulmonary thrombus caused by protein C deficiency

Few cases of pulmonary embolism detected by transthoracic echocardiography (TTE) have been reported. We present a case of a patient affected by pulmonary embolism caused by protein C deficiency. Transthoracic echocardiography showed a thrombus in transit (ie, visualization of a thrombus within the pulmonary artery). A hypercoagulable state caused by deficiency of protein C is a rare cause of pulmonary thromboembolism. Our experience demonstrates a massive pulmonary thrombus resulting from such a deficiency. Transthoracic echocardiography should be considered as the first diagnostic method for patients with suspected pulmonary embolism.

New diagnostic tests for pulmonary embolism

In 1990, the multicenter Prospective Investigation of Pulmonary Embolism Diagnosis (PIOPED), sponsored by the National Institutes of Health, compared the diagnostic value of the radioisotopic ventilation-perfusion lung scan (V/Q scan) with that of pulmonary angiography for the diagnosis of pulmonary embolism (PE). Despite the endurance of the radioisotopic V/Q scan as the most widely used test for evaluation of pulmonary embolism (PE), a better screening tool is clearly needed for use in the emergency department. During the past decade, several new modalities have emerged for evaluation of patients with suspected PE. We evaluate the diagnostic utility of the D-dimer test and the alveolar dead space determination as potential screening tests and of spiral computed tomography, magnetic resonance imaging, transthoracic echocardiography, and transesophageal echocardiography as potential confirmatory tests for PE. For comparison, recent data on the diagnostic utility of the alveolar-arterial oxygen gradient and the V/Q scan are included. The potential application of these new tests to a hypothetical ED population is described.

Central pulmonary artery lesions in chronic obstructive pulmonary disease: A transesophageal echocardiography study

BACKGROUND

In patients with acute pulmonary embolism, transesophageal echocardiography (TEE) often reveals presumably thrombotic lesions within the central pulmonary arteries (CPAs). These CPA lesions, when found in patients with primary pulmonary hypertension, have been attributed to in situ thrombosis or atherosclerosis. We hypothesized that similar CPA lesions may also develop in patients with chronic obstructive pulmonary disease (COPD) in the absence of pulmonary embolism.

METHODS AND RESULTS

We examined by TEE 25 patients with COPD and 27 control patients with left heart disease. None of the patients had previous pulmonary embolism or ileofemoral and popliteal vein thrombosis. By use of TEE, CPA lesions were found in 12 COPD patients (48%) and 2 control patients (7.4%) (P<0.01). When CPA lesions were subdivided into types 1 (protruding and mobile) and 2 (wall-adherent), type 1 lesions proved to be uncommon, being found within the pulmonary trunk in 12% and 3.7% of COPD and control patients, respectively (P=NS). Conversely, type 2 lesions, which were always localized in the right pulmonary artery, were frequent in COPD patients (36%) and rare in control patients (3.7%) (P<0.01). When available, helical CT and MR angiography confirmed TEE findings, supporting an atherosclerotic origin of type 2 lesions, which were different from typical thrombotic lesions. FEV(1)/FVC ratio, RV/TLC ratio, PaO(2), hematocrit value, and pulmonary artery systolic pressure were not significantly different in COPD patients with and without CPA lesions. At TEE, however, COPD patients with CPA lesions showed a larger size of the main and right pulmonary arteries.

CONCLUSIONS

TEE often reveals CPA lesions in stable patients with COPD even in the absence of significant pulmonary hypertension and not in close relation with the severity of pulmonary dysfunction.

The role of newer diagnostic techniques in the diagnosis of pulmonary embolism

Among the evolving techniques for the diagnosis of acute pulmonary embolism, contrast enhanced spiral CT takes a particularly prominent role because it is available at most centers, it images the pulmonary embolism directly, and it is minimally invasive. It has not yet been fully evaluated, however. Magnetic resonance angiography also has appeal for similar reasons. Few patients have been studied, however. Magnetic resonance angiography for pulmonary embolism is still in the early testing phase. Transesophageal echocardiography can image pulmonary embolism in central pulmonary arteries, but preliminary tests suggest that it has a low negative predictive value and cannot be used to exclude pulmonary embolism. Finally, it seems that a rapid and sensitive technique for measuring d-dimer may now be available, which may assist in eliminating the diagnosis of acute pulmonary embolism in a significant percentage of patients in whom the diagnosis is suspected.

Comparison of normal and diseased pulmonary artery morphology by intravascular ultrasound and histological examination

The study was performed to determine the morphological characteristics of normal and diseased pulmonary arteries by ultrasound (intravascular ultrasound, IVUS) and histology. Forty-nine cadaver segments of pulmonary arteries from 16 postmortem patients were imaged in vitro by IVUS and compared to matched histological sections. The pulmonary vasculature of 11 patients with pulmonary hypertension was investigated in vivo by IVUS. In the in vitro study, 34 of a total of 143 histological sections of the segmental pulmonary arteries showed fibrotic wall components; the remaining 109 sections had regular components. Imaged by IVUS, the wall of the regular and fibrotic arteries revealed a single layer histologically, representing the intima, media, adventitia and connective tissue. Adjacent lung tissue could be detected by IVUS and was confirmed by the histological section. In three patients with a history of chronic embolic pulmonary hypertension, IVUS revealed thrombi or a double vessel wall layer. Histologically, the material extracted after pulmonary thromboendarterectomy in two patients showed wall-adherent thrombus features of early organization. In all other patients only a single wall layer was seen. The vessel walls (intima, media, adventitia and connective tissue) of regular and slightly fibrosed pulmonary arteries show only a single layer. Wall-adherent organized thrombi in chronic embolic pulmonary hypertension can be detected by IVUS as a second inner vessel layer. Thus IVUS may represent an additional tool for detecting chronic embolic pulmonary hypertension when the results of pulmonary angiography or computed tomography are not definite.

A chronic, massive thrombus in the right main pulmonary artery: a case report and echocardiographic analysis

A chronic, large thrombus in the right main pulmonary artery (PA) was detected in a 54-year-old woman with a history of surgical repair of atrial septal defect. Color flow imaging revealed a prominent red signal along the right border of the markedly dilated PA. Pulsed Doppler echocardiography showed that the red signal was caused by flow reversal occurring during systole. According to the physics of blood flow, flow reversal probably represents secondary, helical flow, which may be related to thrombus formation.

The Role of Echocardiography Doppler in Pulmonary Embolism

The purpose of this review is to make a critical analysis of selected literature about the role of echo-Doppler in suspected or proved venous thromboembolism and to address some issues about the potential use of echo-Doppler in specific situations in patients with pulmonary embolism (PE). Echo-Doppler is of great value in patients with suspected PE because many conditions that may be clinically mistaken for PE will be diagnosed. Echo-Doppler should not be used alone to rule out the diagnosis of PE because the ability of the technique in proving the diagnosis of PE in a nonselected population is limited. Echo-Doppler may be of value for diagnosis in selected subgroups of PE patients, mostly in scenarios like the emergency department or intensive care unit. Echo-Doppler is valuable in the hemodynamic assessment of patients with PE, making possible a strategy for risk stratification of in-hospital death in relation to the degree of right ventricle dysfunction at the time of diagnosis of acute PE. Echo-Doppler is useful for serial assessment of patients with established diagnosis of chronic thromboembolic pulmonary hypertension. Echo-Doppler may be useful in follow-up of patients after a diagnosis of acute PE to enable early identification of patients with persistent pulmonary hypertension/right ventricle dysfunction.

Should Transesophageal Echocardiography Become a Routine Test in Patients with Suspected Pulmonary Thromboembolism?

Pulmonary thromboembolism presents in two clinical subsets: acute pulmonary embolism (PE) with or without right heart thrombi or paradoxical embolism and chronic thromboembolic pulmonary hypertension (CTEPH). Both PE and CTEPH have been underdiagnosed and carry high mortality rates. Acute massive PE is a hemodynamic entity leading to right ventricular overload readily identified with the use of transthoracic echocardiography. Transesophageal echocardiography (TEE) is a noninvasive bedside technique that has high diagnostic accuracy for the detection of central pulmonary thromboembolism. Due to the high prevalence of central pulmonary thromboembolism in acute PE, TEE is a useful method to provide the necessary proof for the institution of thrombolytic therapy. In the subset of patients with acute PE combined with right heart thrombi or paradoxical embolism, TEE is the technique of choice to guide surgery. CTEPH presents as primary pulmonary hypertension, but it has become a surgically curable disease. TEE is a fast, fairly sensitive, and highly specific diagnostic bedside modality to select surgical candidates with CTEPH. TEE should become a routine test in patients with suspected massive acute PE, suspected right heart thrombi, or paradoxical embolism associated with acute pulmonary embolism and in patients with primary pulmonary hypertension to select those having CTEPH who are suitable for surgery.

Echocardiography in pulmonary embolism disease

Pulmonary embolism is a very common disease often misdiagnosed, because of variable and nonspecific clinical manifestations. Therefore it has a burden of high mortality, particularly in nonrecognized cases. Pulmonary angiography, which is usually considered the gold standard, and ventilation/perfusion pulmonary scan have shown good results in this field, but the first is costly and invasive, and both are not easily and rapidly available in all centers. Echocardiography can be helpful in the diagnosis of pulmonary embolism; transthoracic echo in particular is able to recognize indirect signs of the disease, due to acute pressure right overload; it is also possible to evaluate pulmonary artery systolic pressure by continuous wave Doppler. Transthoracic echocardiography can be negative in cases of small pulmonary embolism, in which the pressure overload and therefore haemodynamic impairment is trivial. The sensitivity and specificity of transthoracic echo is low, but its role in the diagnosis and management of pulmonary embolism may be important, because it can easily and rapidly show the presence and degree of right ventricular pressure overload and therefore it can help in addressing therapy and prognosis. Transesophageal echo may directly demonstrate thrombotic masses in the main pulmonary arteries or, less often, floating intracavitary thrombi. In this field it is showing promising results.

Diagnosis and treatment of shock due to massive pulmonary embolism: approach with transesophageal echocardiography and intrapulmonary thrombolysis

STUDY OBJECTIVES

To evaluate the diagnostic value of transesophageal echocardiography (TEE) as an initial diagnostic tool in shocked patients. The second objective was to study therapeutic impact of intrapulmonary thrombolysis in patients with diagnosed massive pulmonary embolism.

DESIGN

Prospective observational study.

SETTING

Medical ICU in 800-bed general hospital.

PATIENTS

Twenty-four consecutive patients with unexplained shock and distended jugular veins.

MEASUREMENTS AND MAIN RESULTS

In 18 patients, right ventricular dilatation with global or segmental hypokinesis was documented. In addition, central pulmonary thromboemboli (12 patients), reduced contrast flow in right pulmonary artery (one patient), and right ventricular free wall akinesis (one patient) were found. No additional echocardiographic findings were apparent in four patients. According to pulmonary scintigraphy or autopsy, sensitivity of TEE for diagnosis of massive pulmonary embolism (MPE) in patients with right ventricular dilatation was 92% and specificity was 100%. In patients without right ventricular dilatation, left ventricular dysfunction (four patients) or cardiac tamponade (two patients) was confirmed. Intrapulmonary thrombolysis was evaluated in 11 of 13 patients with MPE. Two patients died prior to attempted thrombolysis. Three patients received streptokinase and eight received urokinase. Twenty-four hours after beginning of treatment, total pulmonary resistance index significantly decreased for 59% and mean pulmonary artery pressure for 31%. Cardiac index increased for 74%. Nine of 11 patients receiving thrombolysis survived to hospital discharge.

CONCLUSION

Bedside TEE is a valuable tool for diagnosis of MPE. It enables immediate intrapulmonary thrombolysis, which seems to be an effective therapeutic alternative in our group of patients with obstructive shock.

Diagnostic accuracy of transesophageal echocardiography during cardiopulmonary resuscitation

OBJECTIVES

We sought to establish the diagnostic accuracy of transesophageal echocardiography (TEE) during cardiopulmonary resuscitation.

BACKGROUND

Because of its bedside diagnostic capabilities, excellent cardiac images and lack of interference with resuscitation efforts, TEE is ideally suited to determine the cause of a circulatory arrest that is not due to severe arrhythmia. However, the diagnostic accuracy of TEE during resuscitation is unknown.

METHODS

TEE was performed in patients with prolonged circulatory arrest. The TEE diagnoses were compared with diagnoses from autopsy, surgery and clinical follow-up.

RESULTS

Of the 48 study patients (29 male, 19 female, mean age +/- SD 61 +/- 20 years), 28 had an in-hospital cardiac arrest and 20 an out-of-hospital onset of arrest. Forty-four patients eventually died; four survived to discharge. The diagnoses made with TEE were cardiac tamponade (n = 6), myocardial infarction (n = 21), pulmonary embolism (n = 6), ruptured aorta (n = 1), aortic dissection (n = 4), papillary muscle rupture (n = 1), other diagnosis (n = 2) and absence of structural cardiac abnormalities (n = 7). A definite diagnosis from a reference standard was available in 31 patients. The TEE diagnosis was confirmed in 27 of the 31-by postmortem examination (n = 19), operation (n = 2), angiography (n = 2) or clinical course (n = 4). In the other four patients the TEE diagnosis proved incorrect by postmortem examination. The sensitivity, specificity and positive predictive value of TEE were 93%, 50% and 87%, respectively. In 15 patients (31%), major therapeutic decisions were based on TEE findings.

CONCLUSIONS

TEE can reliably establish the cause of a circulatory arrest during cardiopulmonary resuscitation.

Noninvasive diagnosis of suspected severe pulmonary embolism: transesophageal echocardiography vs spiral CT

OBJECTIVE

Patients with pulmonary embolism (PE) and echocardiographic signs of right ventricular overload have worse prognosis and may require aggressive therapy. Unequivocal confirmation of PE is required before thrombolysis or embolectomy. This study compares the value of transesophageal echocardiography (TEE) and spiral CT (sCT) in direct visualization of pulmonary artery thromboemboli in patients with suspected PE and echocardiographic signs of right ventricular overload.

MATERIAL AND METHODS

Forty-nine consecutive patients (29 men and 20 women), aged 52.2+/-18.3 years, with clinical suspicion of acute (23) or chronic (26) PE and otherwise unexplained right ventricular overload at transthoracic echocardiography underwent TEE and sCT. Main and lobar (central) pulmonary arteries were searched for emboli with both TEE and sCT, while segmental and subsegmental (distal) pulmonary arteries were searched only with sCT.

RESULTS

Of 40 patients with PE confirmed by high-probability lung scan (27) or angiography (13), central pulmonary arterial emboli were found at TEE and sCT in 32 (80%) and 36 (90%) patients, respectively. Neither method reported false central PE (specificity, 100%). When distal pulmonary arteries were analyzed, sensitivity of sCT increased to 97.5%, but three patients with primary pulmonary hypertension according to standard tests were misclassified as having distal PE (specificity, 90.1%). Most patients had bilateral PE according to sCT (34/36) and standard tests (40/40) but not TEE (15/32), probably due to its topographic limitations.

CONCLUSIONS

Because of high prevalence of bilateral central pulmonary thromboemboli in patients with hemodynamically significant PE, both sCT and TEE allow its definitive confirmation in most cases. Thrombi reported by sCT distally to lobar arteries should be interpreted with caution.

Multiplane transesophageal echocardiography to detect effectiveness of selective pulmonary recombinant tissue-type plasminogen activator thrombolysis in pulmonary embolism and patent foramen ovale

A functionally patent foramen ovale can create a relevant right-to-left shunt during massive pulmonary embolism. This associated feature, although maintaining adequate cardiac output, may explain both the paradoxic embolism and the uneffectiveness of peripherally administered drugs. This case demonstrates the potential of transesophageal echocardiography in monitoring the hemodynamic findings of such patients and, consequently, the effectiveness of thrombolytic treatment.

The Role of Echocardiography in the Management of Patients with Massive Pulmonary Embolism

Acute massive pulmonary embolus (PE) when undiagnosed may lead to hemodynamic compromise and death. Echocardiography offers several clues to the diagnosis of PE. We describe how transesophageal echo was used in the diagnosis and management of two patients with this disorder.

Intravascular ultrasound in patients with acute pulmonary embolism after treatment with intravenous urokinase and high-dose heparin

OBJECTIVE

To compare the diagnostic value of intravascular ultrasound (IVUS) with angiography in patients with pulmonary embolism.

DESIGN

Open, prospective clinical study.

SETTING

Two university hospitals.

PATIENTS

Angiography and IVUS were used in 11 patients (5 men) (mean (SD) age 50 (18) years) with acute pulmonary embolism.

INTERVENTIONS

At a mean (SD) of 6 (4) hours after thrombolytic therapy with urokinase and full-dose heparin, all patients underwent pulmonary artery angiography. Then 3.5 F mechanical, 20 or 30 MHz IVUS catheters were advanced into the pulmonary circulation.

MAIN OUTCOME MEASURES

The pulmonary circulation was studied by both methods to detect the presence of thrombus, and a modified Miller score (assessing perfusion defects only and not velocity of flow) was used to quantify the angiographic images.

RESULTS

The modified Miller score was mean (SD) 7.4 (2.3) points. 168 pulmonary artery segments (diameter range 2-14 mm) were studied by angiography and IVUS. On angiography, seven segments showed complete obstruction and 49 partial obstruction; 112 were normal. Two distinct types of thrombus formation were found by IVUS. Type A thrombus only partly adhered to the wall but otherwise was mobile and type B predominantly adhered to the wall. IVUS confirmed all seven angiographically complete obstructions but missed three (6%) of the 49 partial occlusions. Forty (87%) of the remaining 46 segments had type A thrombus and six (13%) type B. IVUS indicated a thrombus in 38 (34%) of the 112 angiographically normal segments; 20 (53%) showed a type A pattern and 18 (47%) a type B pattern (P < 0.001).

CONCLUSION

IVUS was more sensitive than angiography in detecting thrombus but the clinical impact of this finding is not clear as yet.

Atrial and pulmonary mass: intracardiac thrombus mimicking myxoma on multiplane transesophageal echocardiography

Transesophageal echocardiography is the method of choice for investigating suspected intracardiac masses. It also plays a valuable role in the detection of central pulmonary artery embolism. We present a case that highlights the use of transesophageal echocardiography for imaging of a mass in the right atrium and the right pulmonary artery.