Diagnostic utility of echocardiography in patients with suspected pulmonary embolism

Perioperative Point of Care Ultrasound for Hemodynamic Assessment: A Narrative Review

While transesophageal echocardiography (TEE) has traditionally been used in perioperative care, there is growing evidence supporting point of care ultrasound (POCUS) for the anesthesiologist in guiding patient care. It is a quick way to non-invasively evaluate hemodynamically unstable patients and ascertain their state of shock, determine volume status, and guide resuscitation in cardiac arrest. In addition, through use of POCUS, the anesthesiologist is able to identify signs of chronic heart disease to provide a more tailored and safer approach to perioperative care.

Low concordance between CTPA and echocardiography in identification of right ventricular strain in PERT patients with acute pulmonary embolism

PURPOSE

Right ventricular strain (RVS) is used to risk stratify patients with acute pulmonary embolism (PE) and influence treatment decisions. Guidelines suggest that either computed tomography pulmonary angiography (CTPA) or transthoracic echocardiography (TTE) can be used to assess RVS. We sought to determine how often CTPA and TTE yield discordant results and to assess the test characteristics of CTPA compared to TTE.

METHODS

We analyzed data from a single-center registry of PE cases severe enough to warrant activation of the hospital's Pulmonary Embolism Response Team (PERT). We defined RVS as a right ventricular to left ventricular ratio (RV/LV) ≥ 1 or radiologist's interpretation of RVS on CTPA or as the presence of either RV dilation, hypokinesis, or septal bowing on TTE.

RESULTS

We included 554 patients in our analysis, of whom 333 (60%) had concordant RVS findings on CTPA and TTE. Using TTE as the reference standard, CTPA had a sensitivity of 95% (95% CI 92-97%) and a specificity of 4% (95% CI 2-8%) for identifying RVS.

CONCLUSIONS

In a selected population of patients with acute PE for which PERT was activated, CTPA is highly sensitive but not specific for the detection of RVS when compared to TTE.

Role of echocardiography in acute pulmonary embolism

Although pulmonary embolism (PE)-related mortality rate has decreased because of prompt diagnosis and effective therapy use, acute PE remains a potentially lethal disease. Due to its increasing prevalence, clinicians should pay attention to diagnosing and managing patients with acute PE. Echocardiography is the most commonly used method for diagnosing and managing acute PE; it also provides clues about hemodynamic instability in an emergency situation. It has been validated in the early risk stratification and impacts management strategies for treating acute PE. In hemodynamically unstable patients with acute PE, echocardiographic detection of right ventricular dysfunction is an indication for administering thrombolytics. In this review article, we discuss the role of echocardiography in the diagnosis and management of patients with acute PE.

Diagnosis, Diagnostic Tools, and Risk Stratification for Contemporary Treatment of Pulmonary Embolism

Pulmonary embolism (PE) is quite common and is associated with significant morbidity and mortality. It is estimated that it is the cause of approximately 100,000 annual deaths in the United States. With great variability in presenting symptoms of PE, poor recognition of PE can be fatal. As such, many risk scores have been created to identify the sickest patients. Choosing the appropriate imaging modality is also critical. Invasive pulmonary angiography was once the gold standard to establish the diagnosis. With the advent of nuclear imaging, V/Q scans, invasive angiography has been phased out for diagnosing acute PE. At present, the standard for diagnosis of acute PE is computed tomography pulmonary angiography. In select patient cohorts, nuclear studies remain the modality of choice. Once the diagnosis of acute PE is established, there is a broad spectrum of severity in outcome which has led to substantial focus and development of risk stratification prediction models. We will discuss making the proper diagnosis with contemporary diagnostic tools and risk stratifying patients with PE to receive the correct treatment.

Evaluating cardiopulmonary function following acute pulmonary embolism

INTRODUCTION

Pulmonary embolism is a common cause of cardiopulmonary mortality and morbidity worldwide. Survivors of acute pulmonary embolism may experience dyspnea, report reduced exercise capacity, or develop overt pulmonary hypertension. Clinicians must be alert for these phenomena and appreciate the modalities and investigations available for evaluation.

AREAS COVERED

In this review, the current understanding of available contemporary imaging and physiologic modalities is discussed, based on available literature and professional society guidelines. The purpose of the review is to provide clinicians with an overview of these modalities, their strengths and disadvantages, and how and when these investigations can support the clinical work-up of patients post-pulmonary embolism.

EXPERT OPINION

Echocardiography is a first test in symptomatic patients post-pulmonary embolism, with ventilation/perfusion scanning vital to determination of whether there is chronic residual emboli. The role of computed tomography and magnetic resonance in assessing the pulmonary arterial tree in post-pulmonary embolism patients is evolving. Functional testing, in particular cardiopulmonary exercise testing, is emerging as an important modality to quantify and determine cause of functional limitation. It is possible that future investigations of the post-pulmonary embolism recovery period will better inform treatment decisions for acute pulmonary embolism patients.

An Approach to Standard Perioperative Transthoracic Echocardiography Practice for Anesthesiologists-Perioperative Transthoracic Echocardiography Protocols

The use of intraoperative transesophageal echocardiography (TEE) has become the standard of care for most cardiac surgical procedures. There are guidelines established for training, practice, and quality improvement in perioperative TEE by the joint efforts of the American Society of Echocardiography and Society of Cardiovascular Anesthesiologists. Cardiac point-of-care ultrasound (POCUS) increasingly is being incorporated into anesthesiologists' training and practice. While a special "certification in Critical Care Echocardiography" was created by the National Board of Echocardiography in 2019, there currently exist no guidelines for training, certification, and practice of perioperative TTE by anesthesiologists. In this review, the authors describe the categories, indications and applications of perioperative TTE and provide a recommended sequence for performing an examination tailored to the evaluation of perioperative patients. Although the authors describe a protocol utilized at their institution, there are no standards described in the literature for PTTE. Cardiac anesthesiologists and cardiac anesthesia societies (Society of Cardiovascular Anesthesiologists, European Association of Cardiothoracic Anesthesiologists) must come forward to establish standards working in collaboration with echocardiography societies (American Society of Echocardiography, European Society of Cardiology).

Diagnostic accuracy of focused deep venous, lung, cardiac and multiorgan ultrasound in suspected pulmonary embolism: a systematic review and meta-analysis

OBJECTIVE

To determine the diagnostic accuracy of point-of-care ultrasound in suspected pulmonary embolism.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

MEDLINE, Embase, CINAHL and Cochrane library were searched on 2 July 2020 with no restrictions on the date of publication. Subject headings or subheadings combined with text words for the concepts of pulmonary embolism, ultrasound and diagnosis were used.

ELIGIBILITY CRITERIA AND DATA ANALYSIS

Eligible studies reported sensitivity and specificity of deep venous, lung, cardiac or multiorgan ultrasound in patients with suspected pulmonary embolism, using an adequate reference-test. Prospective, cross-sectional and retrospective studies were considered for eligibility. No restrictions were made on language. Studies were excluded if a control group consisted of healthy volunteers or if transesophageal or endobronchial ultrasound was used. Risk of bias was assessed using quality assessment of diagnostic accuracy studies-2. Meta-analysis of sensitivity and specificity was performed by construction of hierarchical summary receiver operator curves. I² was used to assess the study heterogeneity.

MAIN OUTCOME MEASURES

The primary outcome was overall sensitivity and specificity of reported ultrasound signs, stratified by organ approach (deep venous, lung, cardiac and multiorgan). Secondary outcomes were stratum-specific sensitivity and specificity within subgroups defined by pretest probability of pulmonary embolism.

RESULTS

6378 references were identified, and 70 studies included. The study population comprised 9664 patients with a prevalence of pulmonary embolism of 39.9% (3852/9664). Risk of bias in at least one domain was found in 98.6% (69/70) of included studies. Most frequently, 72.8% (51/70) of studies reported >24 hours between ultrasound examination and reference test or did not disclose time interval at all. Level of heterogeneity ranged from 0% to 100%. Most notable ultrasound signs were bilateral compression of femoral and popliteal veins (22 studies; 4708 patients; sensitivity 43.7% (36.3% to 51.4%); specificity 96.7% (95.4% to 97.6%)), presence of at least one hypoechoic pleural-based lesion (19 studies; 2134 patients; sensitivity 81.4% (73.2% to 87.5%); specificity 87.4% (80.9% to 91.9%)), D-sign (13 studies; 1579 patients; sensitivity 29.7% (24.6% to 35.4%); specificity 96.2% (93.1% to 98.0%)), visible right ventricular thrombus (5 studies; 995 patients; sensitivity 4.7% (2.7% to 8.1%); specificity 100% (99.0% to 100%)) and McConnell's sign (11 studies; 1480 patients; sensitivity 29.1% (20.0% to 40.1%); specificity 98.6% (96.7% to 99.4%)).

CONCLUSION

Several ultrasound signs exhibit a high specificity for pulmonary embolism, suggesting that implementation of ultrasound in the initial assessment of patients with suspected pulmonary embolism may improve the selection of patients for radiation imaging.

PROSPERO REGISTRATION NUMBER

CRD42020184313.

Clinical Method Applied to Focused Ultrasound: The Case of Wells' Score and Echocardiography in the Emergency Department: A Systematic Review and a Meta-Analysis

Background and Objectives: bedside cardiac ultrasound is a widely adopted method in Emergency Departments (ED) for extending physical examination and refining clinical diagnosis. However, in the setting of hemodynamically-stable pulmonary embolism, the diagnostic role of echocardiography is still the subject of debate. In light of its high specificity and low sensitivity, some authors suggest that echocardiographic signs of right ventricle overload could be used to rule-in pulmonary embolism. In this study, we aimed to clarify the diagnostic role of echocardiographic signs of right ventricle overload in the setting of hemodynamically-stable pulmonary embolism in the ED. Materials and Methods: we performed a systematic review of literature in PubMed, Web of Science and Cochrane databases, considering the echocardiographic signs for the diagnosis of pulmonary embolism in the ED. Studies considering unstable or shocked patients were excluded. Papers enrolling hemodynamically stable subjects were selected. We performed a diagnostic test accuracy meta-analysis for each sign, and then performed a critical evaluation according to pretest probability, assessed with Wells' score for pulmonary embolism. Results: 10 studies were finally included. We observed a good specificity and a low sensitivity of each echocardiographic sign of right ventricle overload. However, once stratified by the Wells' score, the post-test probability only increased among high-risk patients. Conclusions: signs of echocardiographic right ventricle overload should not be used to modify the clinical behavior in low- and intermediate- risk patients according to Wells' score classification. Among high-risk patients, however, echocardiographic signs could help a physician in detecting patients with the highest probability of pulmonary embolism, necessitating a confirmation by computed tomography with pulmonary angiography. However, a focused cardiac and thoracic ultrasound investigation is useful for the differential diagnosis of dyspnea and chest pain in the ED.

[Cardiac arrest under special circumstances]

These guidelines of the European Resuscitation Council (ERC) Cardiac Arrest under Special Circumstances are based on the 2020 International Consensus on Cardiopulmonary Resuscitation Science with Treatment Recommendations. This section provides guidelines on the modifications required for basic and advanced life support for the prevention and treatment of cardiac arrest under special circumstances; in particular, specific causes (hypoxia, trauma, anaphylaxis, sepsis, hypo-/hyperkalaemia and other electrolyte disorders, hypothermia, avalanche, hyperthermia and malignant hyperthermia, pulmonary embolism, coronary thrombosis, cardiac tamponade, tension pneumothorax, toxic agents), specific settings (operating room, cardiac surgery, cardiac catheterization laboratory, dialysis unit, dental clinics, transportation [in-flight, cruise ships], sport, drowning, mass casualty incidents), and specific patient groups (asthma and chronic obstructive pulmonary disease, neurological disease, morbid obesity, pregnancy).

Validation of the 2019 European Society of Cardiology Risk Stratification Algorithm for Pulmonary Embolism in Normotensive Elderly Patients

BACKGROUND

 The 2019 European Society of Cardiology (ESC) guidelines recommend evaluation for right ventricular dysfunction in all normotensive patients with acute pulmonary embolism (PE). We compared the predictive performance of the 2019 and 2014 ESC risk stratification algorithms and the Pulmonary Embolism Severity Index (PESI).

METHODS

 We performed a posthoc analysis of normotensive patients aged ≥ 65 years with acute PE from a prospective cohort. The primary outcome was overall mortality; secondary outcomes were PE-related mortality and adverse outcomes (PE-related death, cardiopulmonary resuscitation, intubation, catecholamine use, recurrent venous thromboembolism) at 30 days. We assessed outcomes in intermediate-high, intermediate-low, and low-risk groups according to the 2019 and 2014 ESC algorithms and the PESI. Discriminative power was compared using the area under the receiver operating characteristic curve (AUC).

RESULTS

 Among 419 patients, 14 (3.3%) died (7 from PE) and 16 (3.8%) had adverse outcomes within 30 days. The 2019 ESC algorithm classified more patients as intermediate-high risk (45%) than the 2014 ESC algorithm (24%) or the PESI (37%), and only 19% as low risk (32% with 2014 ESC or the PESI). Discriminatory power for overall mortality was lower with the 2019 ESC algorithm (AUC: 63.6%), compared with the 2014 ESC algorithm (AUC: 71.5%) or the PESI (AUC: 75.2%), although the difference did not reach statistical significance (p = 0.063). Discrimination for PE-related mortality and adverse outcomes was similar.

CONCLUSION

 While categorizing more patients in higher risk groups, the 2019 ESC algorithm for PE did not improve prediction of short-term outcomes compared with the 2014 ESC algorithm or the PESI.

What are the echocardiographic findings of acute right ventricular strain that suggest pulmonary embolism?

INTRODUCTION

Pulmonary embolism (PE) is a potentially fatal disease encountered in the hospital setting. Prompt diagnosis and management can improve outcomes and survival. Unfortunately, a PE may be difficult to diagnose in a timely manner. Point-of-care ultrasound (POCUS) can assist in the evaluation for suspected PE by assessing for acute right ventricular strain. Physicians should thus be aware of these echocardiographic findings.

OBJECTIVE

This manuscript will review ten echocardiographic findings of right ventricular strain that may suggest a diagnosis of PE. It will provide a description of each finding along with the associated pathophysiology. It will also summarize the literature for the diagnostic utility of echocardiography for this indication, while providing reference parameters where applicable. Along with labeled images and video clips, the review will then illustrate how to evaluate for each of the ten findings, while offering pearls and pitfalls in this bedside evaluation.

DISCUSSION

The ten echocardiographic findings of right ventricular strain are: increased right ventricle: left ventricle size ratio, abnormal septal motion, McConnell's sign, tricuspid regurgitation, elevated pulmonary artery systolic pressure, decreased tricuspid annular plane systolic excursion, decreased S', pulmonary artery mid-systolic notching, 60/60 sign, and speckle tracking demonstrating decreased right ventricular free wall strain.

CONCLUSIONS

Physicians must recognize and understand the echocardiographic findings and associated pathophysiology of right ventricular strain. In the proper clinical context, these findings can point toward a diagnosis of PE and thereby lead to earlier initiation of directed management.

European Resuscitation Council Guidelines 2021: Cardiac arrest in special circumstances

These European Resuscitation Council (ERC) Cardiac Arrest in Special Circumstances guidelines are based on the 2020 International Consensus on Cardiopulmonary Resuscitation Science with Treatment Recommendations. This section provides guidelines on the modifications required to basic and advanced life support for the prevention and treatment of cardiac arrest in special circumstances; specifically special causes (hypoxia, trauma, anaphylaxis, sepsis, hypo/hyperkalaemia and other electrolyte disorders, hypothermia, avalanche, hyperthermia and malignant hyperthermia, pulmonary embolism, coronary thrombosis, cardiac tamponade, tension pneumothorax, toxic agents), special settings (operating room, cardiac surgery, catheter laboratory, dialysis unit, dental clinics, transportation (in-flight, cruise ships), sport, drowning, mass casualty incidents), and special patient groups (asthma and COPD, neurological disease, obesity, pregnancy).

Evaluating the Right Ventricle in Acute and Chronic Pulmonary Embolism: Current and Future Considerations

The right ventricle (RV), due to its morphologic and physiologic differences, is susceptible to sudden increase in RV afterload, as noted in patients with acute pulmonary embolism (PE). Functional impairment of RV function is a stronger presage of adverse outcomes in acute PE than the location or burden of emboli. While current iterations of most clinical prognostic scores do not incorporate RV dysfunction, advancements in imaging have enabled more granular and accurate assessment of RV dysfunction in acute PE. RV enlargement and dysfunction on imaging is noted only in a subset of patients with acute PE and is dependent on underlying cardiopulmonary reserve and clot burden. Specific signs like McConnell's and "60/60" sign are noted in less than 20% of patients with acute PE. About 2% of patients with acute PE develop chronic thromboembolic pulmonary hypertension, characterized by continued deterioration in RV function in a subset of patients with a continuum of RV function from preserved to overt right heart failure. Advances in molecular and other imaging will help better characterize RV dysfunction in this population and evaluate the response to therapies.

Diagnostic comparison of anterior leads T-wave inversion and McGinn-White sign in suspected acute pulmonary embolism: A systematic review and meta-analysis

Introduction:

Acute pulmonary embolism is the leading cause of cardiovascular mortality in which only 7% of total suspected cases were correctly diagnosed. Prompt diagnosis is essential to reduce disease burden. 12-lead electrocardiography has become standard of examination in any acute cardiovascular setting. Several abnormalities associated with right ventricular dysfunction include the classic McGinn-White and anterior leads T-wave inversion pattern due to conduction abnormalities. Nevertheless, studies conducting research in evaluating diagnostic values of both patterns have not come to definite conclusion. This review evaluates the diagnostic value of T-wave inversions in anterior leads difference compared to that of McGinn-White sign in patients with suspected acute pulmonary embolism.

Methods:

Literature searching was conducted from medical databases. Inclusion-exclusion criteria and study eligibility were assessed to select the included studies in this systematic review. Three final articles were selected and critically appraised using the Oxford Center of Evidence-Based Medicine appraisal tools for diagnostic study.

Results:

Considering the compared importance of selected studies, T-wave inversion shows better specificity (90.9% vs 88.7%) and sensitivity (35.5% vs 28.9%) although both signs exhibit minor impact in terms of sensitivity index. Analyses suggest higher averaged accuracy (accuracy index) and Youden index found in T-wave inversion than that of McGinn-White sign (accuracy index: 57.97% vs 56.16%; Youden index: 0.16 vs 0.12), providing more meaningful diagnostic value. Furthermore, anterior leads T-wave inversion possesses better diagnostic odds ratio than that of McGinn-White sign (5.52 vs 3.17).

Conclusion:

Anterior lead T-wave inversions present better diagnostic value than that of classic pattern of McGinn-White sign in electrocardiographic presentation of suspected acute pulmonary embolism.

Return of spontaneous circulation in patients with out-of-hospital cardiac arrest caused by pulmonary embolism using early point-of-care ultrasound and timely thrombolytic agent application: Two case reports

Introduction:

Acute pulmonary embolism is a confirmed cause of up to 5% of out-of-hospital cardiac arrest and 5%–13% of unexplained cardiac arrest in patients. However, the true incidence may be much higher, as pulmonary embolism is often clinically underdiagnosed. Thrombolytic therapy is a recognized therapy for pulmonary embolism–associated cardiac arrest but is not routinely recommended during cardiopulmonary resuscitation. Therefore, clinicians should attempt to identify patients with suspected pulmonary embolism. Many point-of care ultrasound protocols suggest diagnosis of pulmonary embolism for cardiac arrest patients.

Case presentation:

We describe two male patients (60 years and 66 years, respectively) who presented to the emergency department with cardiac arrest within a period of 1 week. With administration of point-of care ultrasound during the ongoing cardiopulmonary resuscitation in both patients, fibrinolytic therapy was initiated under suspicion of cardiac arrest caused by pulmonary embolism. Both patients had return of spontaneous circulation; however, only the second patient, who received fibrinolytic therapy relatively early, was discharged with a good outcome. In this report, we discussed how to diagnose and manage patients with cardiac arrest–associated pulmonary embolism with the help of point-of care ultrasound. We also discuss the different clinical outcomes of the two patients based on the experience of the clinicians and the timing of thrombolytic agent application.

Conclusions:

If acute pulmonary embolism is suspected in patients with out-of-hospital cardiac arrest, we recommend prompt point-of care ultrasound examination. Point-of care ultrasound may help identify patients with pulmonary embolism during cardiopulmonary resuscitation, leading to immediate treatment, although the clinical outcomes may vary.

A Shifting Paradigm: The Role of Focused Cardiac Ultrasound in Bedside Patient Assessment

Transthoracic echocardiography is the standard of care in anatomic and functional cardiovascular assessment; however, focused cardiac ultrasound (FoCUS) performed with portable ultrasound equipment is increasingly being used as an adjunct to comprehensive history and physical examination. FoCUS assessments, unlike formal echocardiography, are intended to assist physicians in answering explicit clinical questions with a narrow differential diagnosis in real time. Over the past decade, a growing body of literature has repeatedly shown the value that FoCUS adds to clinical evaluation. Specifically, FoCUS improves point-of-care diagnostic accuracy, which in turn modifies treatment plans, decreases time to diagnosis, and reduces resource utilization. Although less robust, there is also evidence showing improvement in clinical outcomes. Based on this evidence, clinicians, training programs, and clinical societies have embraced FoCUS as a tool to complement bedside patient evaluation. Herein, we review the evidence for FoCUS in clinical practice, specifically evaluating the diagnostic accuracy, the impact on clinical decision-making, and the effect on clinical outcomes.

[On the Causes of Angina Pectoris in Patients With Pulmonary Embolism]

Objective Compare the distance between the pulmonary artery (PA) and the left coronary artery (LCA) using pulmonary angiography and the rate of detection of the signs of left ventricular myocardial ischemiain the first electrocardiogram (ECG) in pulmonary embolism (PE) patients with or without angina to detect possible causes of angina pectoris.Material and Methods Measurement of the minimum distance between the PA and LCA in multislice spiral computed tomography and analysis of the first ECG were performed in 55 PE patients. 15 (27.3%) patients had angina pectoris at the onset of the disease.Results Angina pectoris was observed in 14 (93.3%) of 15 patients with the distance between the PA andLCA less than 4.3 mm, and in one (2.5%) of 40 patients with the distance between these vessels equalto or exceeding the specified value (p<0.001). In the first ECG, the ST elevation in the aVR lead wasdetected in 10 (66.7%) patients with angina pectoris, and only in 3 (7.5%) patients without anginapectoris (p<0.001).Conclusions The findings suggest that angina pectoris in acute pulmonary embolism may be caused by compression of the LCA by the dilated PA.

Incremental Value of ePLAR—The Echocardiographic Pulmonary to Left Atrial Ratio in the Assessment of Sub-Massive Pulmonary Emboli

Background: Acute pulmonary embolism (PE) is characterized hemodynamically by abrupt obstruction in trans-pulmonary blood flow. The echocardiographic Pulmonary to Left Atrial ratio (ePLAR, tricuspid regurgitation Vmax/mitral E/e’) has been validated as a non-invasive surrogate for trans-pulmonary gradient (TPG) that accurately differentiates pre-capillary from post-capillary chronic pulmonary hypertension. This study assessed ePLAR as an incremental echocardiographic assessment tool compared with traditional measures of right ventricular pressure and function. Methods: In total, 110 (57.4 ± 17.6 years) patients with confirmed sub-massive pulmonary emboli with contemporaneous echocardiograms (0.3 ± 0.9 days) were compared with 110 age-matched controls (AMC). Results: Tricuspid velocities were higher than AMC (2.6 ± 0.6 m/s vs. 2.4 ± 0.3 m/s, p < 0.05), although still consistent with “normal” right ventricular systolic pressures (34.2 ± 13.5 mmHg vs. 25 ± 5.3 mmHg, p < 0.05) with lower mitral E/e’ values (8.2 ± 3.8 vs. 10.8 ± 5.1, p < 0.05). ePLAR values were higher than AMC (0.36 ± 0.14 m/s vs. 0.26 ± 0.10, p < 0.05) suggesting significantly elevated TPG. Detection of abnormal echocardiographic findings increased from 29% (TRVmax ≥ 2.9 m/s) and 32% (reduced tricuspid annular plane systolic excursion) to 70% with ePLAR ≥ 0.3 m/s. Conclusions: Raised ePLAR values in acute sub-massive pulmonary embolism suggest elevated trans-pulmonary gradients even in the absence of acutely increased pulmonary artery pressures. ePLAR dramatically increases the sensitivity of echocardiography for detection of hemodynamic perturbations in sub-massive pulmonary embolism patients, which may offer clinical utility in diagnosis and management.

Increased Sensitivity of Focused Cardiac Ultrasound for Pulmonary Embolism in Emergency Department Patients With Abnormal Vital Signs

BACKGROUND

Focused cardiac ultrasound (FOCUS) is insensitive for pulmonary embolism (PE). Theoretically, when a clot is large enough to cause vital sign abnormalities, it is more likely to show signs of right ventricular dysfunction on FOCUS, although this has not been well quantified. A rapid bedside test that could quickly and reliably exclude PE in patients with abnormal vital signs could be of high utility in emergency department (ED) patients. We hypothesized that in patients with tachycardia or hypotension, the sensitivity of FOCUS for PE would increase substantially.

METHODS

We performed a prospective observational multicenter cohort study involving a convenience sample of patients from six urban academic EDs. Patients suspected to have PE with tachycardia (heart rate [HR] ≥ 100 beats/min) or hypotension (systolic blood pressure [sBP] < 90 mm Hg) underwent FOCUS before computed tomography angiography (CTA). FOCUS included assessment for right ventricular dilation, McConnell's sign, septal flattening, tricuspid regurgitation, and tricuspid annular plane systolic excursion. If any of these were abnormal, FOCUS was considered positive, while if all were normal, FOCUS was considered negative. We a priori planned a subgroup analysis of all patients with a HR ≥ 110 beats/min (regardless of their sBP). We then determined the diagnostic test characteristics of FOCUS for PE in the entire patient population and in the predefined subgroup, based on CTA as the criterion standard. Inter-rater reliability of FOCUS was determined by blinded review of images by an emergency physician with fellowship training in ultrasound.

RESULTS

A total of 143 subjects were assessed for enrollment and 136 were enrolled; four were excluded because they were non-English-speaking and three because of inability to obtain any FOCUS windows. The mean (±SD) age of enrolled subjects was 56 (±7) years, mean (±SD) HR was 114 (±12) beats/min, and 37 (27.2%) subjects were diagnosed with PE on CTA. In all subjects, FOCUS was 92% (95% confidence interval [CI] = 78% to 98%) sensitive and 64% specific (95% CI = 53% to 73%) for PE. In the subgroup of 98 subjects with a HR ≥ 110 beats/min, FOCUS was 100% sensitive (95% CI = 88% to 100%) and 63% specific (95% CI = 51% to 74%) for PE. There was substantial interobserver agreement for FOCUS (κ = 1.0, 95% CI = 0.31 to 1.0).

CONCLUSIONS

A negative FOCUS examination may significantly lower the likelihood of the diagnosis of PE in most patients who are suspected of PE and have abnormal vital signs. This was especially true in those patients with a HR ≥ 110 beats/min. Our results suggest that FOCUS can be an important tool in the initial evaluation of ED patients with suspected PE and abnormal vital signs.

Change in right ventricular function in an American cocker spaniel with acute pulmonary thromboembolism

A 12-year-old neutered female American cocker spaniel weighing 9.9 kg was presented for evaluation with a 2-day history of dyspnea and anorexia. Echocardiography revealed severe pulmonary hypertension (estimated systolic pulmonary arterial pressure, 93.4 mmHg) with right heart enlargement, pulmonary arterial dilation, and right ventricular dysfunction. The dilation of left heart and congenital cardiac shunt were not observed. Pulmonary thromboembolism (PTE) was confirmed by computed tomographic angiography. After treatment with antiplatelet and anticoagulant, the clinical sign and the echocardiographic abnormality of right heart were improved. These echocardiographic findings are not specific for PTE, but it can be useful as a rule-in test for PTE when other causes of pulmonary hypertension are excluded and a monitor of therapeutic efficacy.

Survival after Cardiac Arrest Secondary to Massive Pulmonary Embolism

Introduction

It is estimated that the diagnosis of pulmonary embolism (PE) is missed in as many as 84% of all cases of PE. Cardiac arrest following PE is generally associated with poor outcomes.

Case Report

A 43-year-old man presented to the Emergency Department (ED) in cardiac arrest. Swelling of his right lower limb was noted on arrival. Point of care ultrasound was performed during ongoing cardiopulmonary resuscitation (CPR) and showed a thrombus in the right iliofemoral vein as well as dilatation of the right ventricle. Fibrinolytic therapy was initiated immediately and a return of spontaneous circulation (ROSC) was achieved 30 minutes later. The diagnosis of PE was finally confirmed on computed tomography pulmonary angiography once haemodynamic stability was achieved. The patient was thereafter transferred to the intensive care unit for postresuscitation care and further management. Several days later, he was discharged home neurologically intact and fully recovered.

Discussion

Since outcomes after cardiac arrest following PE are generally dismal, available and potentially life-saving interventions to restore pulmonary circulation should be rapidly implemented when PE is the likely cause of cardiac arrest.

Cardiac arrest due to pulmonary embolism

Pulmonary embolism (PE) is a potentially life threatening clinical condition that is fairly non-specific in presentation. Massive pulmonary embolism (PE) without cardiac arrest has been associated with a mortality rate of 30%. However, when cardiac arrest ensues, mortality may be as high as 95%. Since outcomes of cardiac arrest following PE are generally dismal, any available potentially life-saving measure must be instituted when the diagnosis of PE is suspected. Despite a lack of randomized controlled trials guiding the management of suspected PE in the cardiac arrest victim, thrombolysis and other therapies have been associated with good outcomes in the handful of published case reports and other small studies.

Dramatic Normalization of the Echocardiographic Pulmonary-to-Left Atrial Ratio with Thrombolysis in a Case of Life-Threatening Submassive Pulmonary Emboli

•A 74 year old male presented with bilateral submassive pulmonary emboli with moderately severe pulmonary hypertension with right ventricular systolic pressure (RVSP) 63 mm Hg. •Echocardiographic pulmonary-to-left atrial ratio (ePLAR) markedly elevated at 0.78 m/s (normal range for age 0.30 ± 0.09 m/s) suggesting significantly elevated transpulmonary gradient. •Thrombolysis almost fully resolved symptomatic embolic burden and normalized right ventricular function. RVSP 37 mm Hg, ePLAR 0.32 m/s. •One month after lysis, RVSP 26 mm Hg, ePLAR 0.22 m/s, now within the normal range for age.

[Pulmonary embolism]

Pulmonary embolism is a potentially fatal disorder and frequently seen in critical care and emergency medicine. Due to a high mortality rate within the first few hours, the accurate initiation of rational diagnostic pathways in patients with suspected pulmonary embolism and timely consecutive treatment is essential. In this review, the current European guidelines on the diagnosis and therapy of acute pulmonary embolism are presented. Special focus is put on a structured patient management based on the individual risk of early mortality. In particular risk assessment and new risk-adjusted treatment recommendations are presented and discussed in this article.

Guidelines for the Use of Echocardiography in the Evaluation of a Cardiac Source of Embolism

Embolism from the heart or the thoracic aorta often leads to clinically significant morbidity and mortality due to transient ischemic attack, stroke or occlusion of peripheral arteries. Transthoracic and transesophageal echocardiography are the key diagnostic modalities for evaluation, diagnosis, and management of stroke, systemic and pulmonary embolism. This document provides comprehensive American Society of Echocardiography guidelines on the use of echocardiography for evaluation of cardiac sources of embolism. It describes general mechanisms of stroke and systemic embolism; the specific role of cardiac and aortic sources in stroke, and systemic and pulmonary embolism; the role of echocardiography in evaluation, diagnosis, and management of cardiac and aortic sources of emboli including the incremental value of contrast and 3D echocardiography; and a brief description of alternative imaging techniques and their role in the evaluation of cardiac sources of emboli. Specific guidelines are provided for each category of embolic sources including the left atrium and left atrial appendage, left ventricle, heart valves, cardiac tumors, and thoracic aorta. In addition, there are recommendation regarding pulmonary embolism, and embolism related to cardiovascular surgery and percutaneous procedures. The guidelines also include a dedicated section on cardiac sources of embolism in pediatric populations.

Prognostic Value of Right Ventricular Dysfunction Markers for Serious Adverse Events in Acute Normotensive Pulmonary Embolism

BACKGROUND

Right ventricular dysfunction (RVD) in pulmonary embolism (PE) has been associated with increased morbidity. Tools for RVD identification are not well defined. The prognostic value of RVD markers to predict serious adverse events (SAE) during hospitalization is unclear.

OBJECTIVE

Prospectively compare the incidence of SAE in normotensive emergency department patients with PE based upon RVD by goal-directed echocardiography (GDE), cardiac biomarkers, and right-to-left ventricle ratio by computed tomography (CT). Simplified Pulmonary Embolism Severity Index (sPESI) was calculated. Deaths and readmissions within 30 days were recorded.

METHODS

Consecutive normotensive PE patients underwent GDE focused on RVD (RV enlargement, hypokinesis, or septal bowing), serum troponin, and brain natriuretic peptide (BNP), and evaluation of the CT ventricle ratio. In-hospital SAE and complications within 30 days were recorded.

RESULTS

We enrolled 123 normotensive PE patients (median age 59 years, 49% female). Twenty-six of 123 (26%) patients had one or more SAE. RVD was detected in 26% by GDE, in 39% by biomarkers, and in 38% with CT. In-hospital SAE included one death, six respiratory interventions, six dysrhythmias, three major bleeding episodes, and 21 hypotension episodes. Forty-one percent of patients RVD positive by GDE had SAE, compared to the 18% RVD negative by GDE. Odds ratios for GDE, CT, BNP, troponin, and sPESI for SAE were 3.2 (95% confidence interval [CI] 1.2-8.5), 2.0 (95% CI 0.8-5.1), 3.3 (95% CI 1.3-8.6), 4.2 (95% CI 1.4-13.5), and 2.9 (95% CI 1.1-8.3), respectively. Five patients had non-PE-related deaths within 30 days.

CONCLUSION

The incidence of SAE within days of PE was significant in our cohort. Those with RVD had an increased risk of nonmortality SAE.

Prognostic value of transthoracic echocardiography and biomarkers of cardiac dysfunction in community-acquired pneumonia

The aim of this study was to determine the prognostic role of echocardiography and compare with admission N-terminal proB-type natriuretic peptide (NT-proBNP) levels in adult patients with community-acquired pneumonia (CAP). Consecutive adult patients hospitalized with CAP were prospectively enrolled and followed-up until hospital discharge or death. Echocardiography was performed within the first 48 hours. Complicated hospitalization (CH) was defined as intensive care unit admission, need for mechanical ventilation or in-hospital mortality. This study was registered with ClinicalTrials.gov, number NCT02441855. A total of 15 CH (13.5%) occurred among 111 patients with CAP. CAP patients with a CH compared with those without CH had significantly higher NT-proBNP values (1267.4±1146.1 vs. 305.6±545.7 pg/mL, p <0.001) and troponin I (23.8±24.3 vs. 10.3±6.3 ng/mL, p 0.02) but had lower left ventricle ejection fraction (52.7±8.7 vs. 60.5±6.7%, p <0.001) and tricuspid annular plane systolic excursion (TAPSE), which is a measure of right ventricular systolic function (17.1±4.4 vs. 21.8±4 mm; p 0.001). Patients with elevation of NT-proBNP and decreased TAPSE at presentation had a significantly higher probability of CH (60%) than patients with either elevated NT-proBNP or decreased TAPSE (40%). Patients with neither elevated NT-proBNP nor decreased TAPSE had a 0% probability of CH. This is the first study to demonstrate that decreased right ventricular systolic function is associated with increased rates of adverse events in patients with CAP.

Echocardiographic Pattern of Acute Pulmonary Embolism: Analysis of 511 Consecutive Patients

BACKGROUND

There is no comprehensive analysis of transthoracic echocardiographic findings of pulmonary embolism (PE). The aim of this study was to assess the frequency of right ventricular (RV) dysfunction (RVD), typical echocardiographic signs of acute PE (TES), and incidental abnormalities.

METHODS

A single-center, retrospective analysis was conducted of 511 consecutive patients (281 women; mean age, 64.0 ± 18.6 years) with PE confirmed by contrast-enhanced multidetector computed tomography who underwent transthoracic echocardiography for the assessment of left ventricular and RV alterations. The McConnell sign, the "60/60" sign, and right heart thrombus were regarded as TES. RVD included RV free wall hypokinesis and RV to LV end-diastolic ratio > 0.9. Incidental echocardiographic alterations were also reported.

RESULTS

RV enlargement, RV free wall hypokinesis, and interventricular septal flattening were found in 27.4%, 26.6%, and 18.4% of patients, respectively. Tricuspid regurgitation peak systolic gradient > 30 mmHg and pulmonary ejection acceleration time < 80 msec were measured in 46.6% and 37.2% of patients, respectively. RVD was found in 20.0% of patients, while normal RV function was present in 33.4% of patients. The McConnell sign, 60/60 sign, and right heart thrombus were found in 19.8%, 12.9%, 1.8% of subjects, respectively. All 16 hemodynamically unstable patients with PE presented enlarged hypokinetic right ventricle and at least one TES. However, in three of them, RV to LV end-diastolic ratio was <0.9. Incidental abnormalities were found in 9.6% of 364 stable patients with PE without RVD and TES.

CONCLUSIONS

Transthoracic echocardiography showed no significant abnormalities suggestive of PE in 71% of patients with PE, while in approximately 10%, transthoracic echocardiography revealed incidental findings. The coexistence of an enlarged hypokinetic right ventricle with the McConnell sign together with the 60/60 sign seems to be the most useful echocardiographic criterion for RVD.

Image-based resuscitation of the hypotensive patient with cardiac ultrasound: An evidence-based review

This article is a detailed review of the literature regarding the use of cardiac ultrasound for the resuscitation of hypotensive patients. In addition, figures regarding windows and description of how to perform the test are included.

[Pulmonary embolism]

Pulmonary embolism is a potentially fatal disorder and frequently seen in critical care and emergency medicine. Due to a high mortality rate within the first few hours, the accurate initiation of rational diagnostic pathways in patients with suspected pulmonary embolism and timely consecutive treatment is essential. In this review, the current European guidelines on the diagnosis and therapy of acute pulmonary embolism are presented. Special focus is put on a structured patient management based on the individual risk of early mortality. In particular risk assessment and new risk-adjusted treatment recommendations are presented and discussed in this article.

Prognostic value of Tpeak-Tend interval in patients with acute pulmonary embolism

Background

The aim of this study was to examine the Tpeak-Tend (Tpe/corrected Tpe) interval, which is an indicator of transmural myocardial repolarization, measured non-invasively via electrocardiogram in patients with acute pulmonary embolism (PE), and to investigate the relationship with 30-day mortality and morbidity.

Methods

The study included 272 patients diagnosed with acute PE, comprising 154 females and 118 males, with a mean age of 63.1 ± 16.8 years. Tpe/cTpe intervals were calculated from the electrocardiograms with a computer program after using a ruler or vernier caliper manual measuring tool to obtain highly sensitive measurements. The relationship between the electrocardiogram values and 30-days mortality and morbidity were measured.

Results

The study group was divided into three groups according to cTpe intervals: Group 1, < 113 ms; Group 2, 113–133 ms; and Group 3, > 133 ms. White blood cell count and troponin T levels, corrected QT intervals with QRS complex durations, percentage of right ventricle dilatation with right/left-ventricular ratio, 30-day death, and combinations of these values were seen at a higher rate in Group 3 patients compared to the other groups. Kaplan–Meier analysis showed that the cTpe interval measured at > 126 ms could be used as a cut-off value in the prediction of mortality and morbidity. The cTpe cut-off values of 126 ms had sensivity, specificity, negative predictive value, and positive predictive value of 80.56 %, 59.32 %, 95.2 %, and 23.2 %, respectively.

Conclusions

cTpe interval could be a useful method in early risk stratification in patients with acute PE.

Submassive pulmonary embolism

Pulmonary embolism (PE) is a common diagnosis in critical care. Depending on the severity of clot burden, the clinical picture ranges from nearly asymptomatic to cardiovascular collapse. The signs and symptoms of PE are nonspecific. The clinician must have a high index of suspicion to make the diagnosis. PE is risk stratified into 3 categories: low-risk, submassive, and massive. Submassive PE remains the most challenging with regard to initial and long-term management. Little consensus exists as to the appropriate tests for risk stratification and therapy. This article reviews the current literature and a suggested approach to these patients.

Is there a potential role for echocardiography in adult patients with CAP?

BACKGROUND

The role of echocardiography in adult patients with community-acquired pneumonia (CAP) has not been tested in a clinical trial. The aim of the study was to assess the cardiac changes secondary to CAP by echocardiography and to find out the correlation between echocardiographic findings and the severity of CAP.

METHODS

A total of 111 unselected consecutive adult patients hospitalized with CAP were enrolled. The control group consisted of 100 consecutive sex- and age-matched patients. The severity of CAP was evaluated with the pneumonia severity index and the CURB-65 (confusion, urea, respiratory rate, arterial blood pressure and age) score. Blood samples were taken and echocardiography was performed within the first 48 hours.

RESULTS

White blood count, N-terminal pro-brain natriuretic peptide, and red blood cell distribution width were significantly higher in the CAP group compared with the control group. The 2 groups did not differ in terms of left and right ventricle ejection fraction, left atrial diameter, pulmonary artery systolic pressure, and left ventricular end-diastolic and end-systolic diameter. However, tricuspid annular plane systolic excursion (21.1 ± 4.3 vs 22.3 ± 4.1 mm; P = .04), aortic distensibility (2.5 ± 0.9 vs 3.5 ± 0.9 cm(2):dyne:10, P < .001), and aortic strain (5.8% ± 2% vs 6.5% ± 1.9%, P = .009) were significantly reduced in CAP group than in controls. The plasma concentration of N-terminal pro-brain natriuretic peptide correlated with aortic strain, aortic distensibility, tricuspid annular plane systolic excursion, pneumonia severity index score, and CURB-65 score.

CONCLUSIONS

Tricuspid annular plane systolic excursion and elastic properties of aorta may play a role in the diagnosis and clinical assessment of CAP severity, which could potentially guide the development of new prognostic models.

Competitive assessments of pulmonary embolism: Noninvasiveness versus the golden standard

Diagnosis of suspected pulmonary embolism (PE) is crucial as undiagnosed and over-diagnosis can both lead to serious consequences. Contemporary diagnostic approach of PE is a sequential combination assessment beginning with clinical assessment, validated with D-dimer measurement and confirmed with pulmonary angiography or imaging. Since the invasive pulmonary angiography is risky and costly, imaging is a warranted tool in the diagnosis procedure. CT pulmonary angiography is a less-invasive method with general availability, studies provide favorable evidences for CT pulmonary angiography as a stand-alone test for excluding PE, and it has become the first choice of tests in emergency department for suspected PE in most centers. Ventilation/perfusion single-photon emission CT signifies a new era in nuclear medicine. It has excellent sensitivity and specificity, fast procedure, low radiation exposure, few complications and contradictions. Besides, MR angiography is another possible and promising approach for diagnosis of suspected PE with much safer contrast agents than CT and no ionizing radiation. With wide availability and less invasive effects, imaging becomes a firsthand tool to obtain optimal accuracy in the diagnosis work up in clinic nowadays. This review summarizes the current methods in diagnosing PE and the update of imaging assessments of the disease.