Ultrasound-Enhancing Agent Safely Enhances Left Ventricular Visualization by Transthoracic Echocardiography in Patients on ECMO Support.

OBJECTIVE: The authors investigated if the use of ultrasound-enhancing agents (UEA) can safely improve left ventricular (LV) image quality by transthoracic echocardiography (TTE) in patients on extracorporeal membrane oxygenation (ECMO). DESIGN AND SETTING: This study was performed in a tertiary cardiothoracic and ECMO center in London, United Kingdom. PARTICIPANTS: The authors included 18 prospectively identified consecutive patients requiring TEE supported on peripherally implanted ECMO. INTERVENTION AND MEASUREMENTS: TTE was performed before and after the UEA administration. The authors assessed the LV image quality using the biplane (apical-4-chamber and apical-2-chamber views) endocardial border definition index (1 = good, 2 = suboptimal, 3 = poor, and 4 = unavailable), as well as the feasibility of LV ejection fraction (LVEF) measurement. The authors also gathered sequential clinical information for the next 24 hours. MAIN RESULTS: The patients' median age was 47 years (35, 65), and 5 (28%) were women. The biplane endocardial border definition index improved from the suboptimal to the good range (2.167 [1.812, 3.042] v 1.500 [1.417, 1.792], p = 0.0004) after the use of UEA. The feasibility of LVEF tripled from 25% (n = 5) to 83% (n = 15) (p = 0.0008) with UEA use. The UEA did not set off the bubble alarm and did not impact clinical or ECMO parameters. CONCLUSION: The use of UEA significantly improved the quality of LV biplane images by transthoracic echocardiography, transforming them from suboptimal to good in patients supported with peripherally implanted ECMO. UEA use tripled the feasibility of measuring LVEF by TTE without affecting clinical and ECMO parameters.

The Role of Focused 2-Dimensional Echocardiography in Managing Left Ventricular Outflow Tract Obstruction Mimicking Cardiogenic Shock.

Left ventricular outflow tract obstruction (LVOTO) is a common cardiogenic shock (CS) mimic. We present 3 cases of patients presenting with CS following myocardial infarction, exhibiting a poor response to conventional treatment with inotropy and mechanical circulatory support. This triggered echocardiographic assessment by critical care physicians using focused 2-dimensional (2D) echocardiography. This timely assessment identified anterior mitral valve leaflet entrainment into the left ventricular outflow tract (LVOT), causing LVOTO as the underlying shock mechanism. Echocardiographic findings have led to significant changes in management. The patients underwent fluid administration, weaning from inotropy, and mechanical circulatory support explantation, leading to relief of LVOTO and improved hemodynamics. Critical care basic 2D echocardiography accreditations focus on myocardial function and pericardial effusions. Relevant societies administering these accreditations should consider adding LVOT assessment to enable timely diagnosis of this life-threatening CS mimic.

Right ventricular echocardiographic parameters and prediction of stroke volume in ischemic cardiogenic shock: A retrospective study.

PURPOSE: This study investigated which commonly used right ventricular (RV) echocardiographic parameter correlates best with stroke volume (SV) estimated by Doppler echocardiography in ischemic cardiogenic shock (CS). MATERIALS AND METHODS: We retrospectively reviewed the records of 100 patients admitted to the ICU over 34 months with CS. Tricuspid annular plane systolic excursion (TAPSE), Tricuspid annulus systolic velocity (RV S'), Tricuspid regurgitation maximum velocity (TR Vmax), and RV outflow tract velocity time integral (RVOT VTI) were correlated to SV. RESULTS: Mean age was 62.6 ± 12.7 years and 78% were male. The mean SV, TAPSE, RV S', TR Vmax, and RVOT VTI were 47 ± 16 ml, 16 ± 5 mm, 11 ± 4 mm/s, 1.97 ± 0.73 m/s, and 12.7 ± 5 cm, respectively. RVOT VTI correlated best to SV (r = 0.39 p = 0.01) compared to TAPSE, RV S', and TR Vmax (r = 0.26 p = 0.01, r = 0.15 p = 0.21, r = 0.03 p = 0.78). RVOT VTI independently predicted SV. Univariate analysis demonstrated that only RVOT VTI predicted SV (OD = 1.18 p = 0.04) and had the best area under the curve (0.70, p = 0.03). CONCLUSION: RVOT VTI correlated better (albeit weakly) to and best predicted SV compared to TAPSE, RV S', and TR Vmax in patients admitted to intensive care with CS. This study suggests that RVOT VTI has the potential as a therapeutic target to optimize SV in CS.

Left Ventricular Ejection Fraction Correlation With Stroke Volume as Estimated by Doppler Echocardiography in Cardiogenic Shock: A Retrospective Observational Study.

OBJECTIVES: Echocardiography is the main tool for cardiac assessment and helps to guide management in patients admitted to the intensive care unit (ICU) with cardiogenic shock (CS). Left ventricular ejection fraction (LVEF) is a commonly used echocardiographic surrogate for left ventricular (LV) systolic function. In this hypothesis-generating study, the authors investigated the correlation between LVEF and stroke volume (SV)/SV index (SVI) estimated by Doppler echocardiography in patients admitted to the ICU with CS and reduced LVEF. DESIGN AND SETTING: This retrospective analysis was performed in a single tertiary cardiac center in London, United Kingdom. PARTICIPANTS: Patients admitted to the ICU over a 34-month period with ST elevation myocardial infarction (STEMI) complicated by CS and LVEF <40%. INTERVENTIONS: Clinical and echocardiographic data were collected. LVEF (total, by visual estimate and by modified Simpson's method) was correlated with SV and SVI estimated by Doppler echocardiography. MEASUREMENTS AND MAIN RESULTS: One-hundred patients were included. The mean age was 62.6 ± 12.7 years and 78% were male patients. The median LVEF was 29% (20-35) and the mean SV and SVI by Doppler echocardiography were 47 mL ± 16 and 25 mL ± 9, respectively. Analysis revealed a weak yet statistically significant correlation among LVEF and Doppler SV and SVI (r = 0.44, confidence interval [CI] 0.26-0.60, p < 0.0001, r = 0.47, CI 0.28-0.62, p < 0.001, respectively). Visually estimated LVEF (n = 74) correlated weakly with Doppler SV and SVI yet better compared to LVEF by Simpson's method (n = 25) (r = 0.48, CI 0.27-0.65, p < 0.0001 and r = 0.49, CI 0.28-0.66, p < 0.0001, respectively, v r = 0.36, CI 0.05-0.67, p = 0.08 and r = 0.37, CI -0.04-0.67, p 0.07, respectively). CONCLUSIONS: There is a weak correlation between LVEF and SV or SVI estimated by Doppler echocardiography in patients admitted to the ICU with STEMI complicated by CS and reduced LVEF. Visually estimated LVEF correlated slightly better with Doppler SV compared to modified Simpson's LVEF.

Contrast-Enhanced Echocardiography Application in Patients Supported by Extracorporeal Membrane Oxygenation (ECMO): A Narrative Review.

Extracorporeal membrane oxygenation (ECMO) is a lifesaving intervention increasingly used to support patients with severe respiratory and cardiac dysfunction. Echocardiography is an important tool, aiding implantation and monitoring during ECMO therapy, but often its use is limited by poor acoustic windows. This limitation may be overcome by the use of echocardiography contrast agents to improve diagnostic yield and reduce the need for other imaging modalities that may require patient transfer, involve ionizing radiation and, occasionally, nephrotoxic radio-opaque contrast medium. In this article the authors review the literature addressing the use of contrast-enhanced echocardiography (CEE) in ECMO-supported patients. The authors discuss the role of CEE in guiding implantation of ECMO, cardiac assessment and diagnosis of complications during ECMO therapy, as well as the safety of ultrasound-enhancing agents in this cohort of patients.

Right ventricular function is associated with 28-day mortality in myocardial infarction complicated by cardiogenic shock: A retrospective observational study.

Background: Right ventricular (RV) function is increasingly being recognised as an important factor influencing outcomes in ST elevation myocardial infarction (STEMI) complicated by cardiogenic shock (CS). In this study, we investigated RV echocardiographic parameters' association with 28-day mortality in patients admitted to intensive care with STEMI complicated by CS with reduced left ventricle ejection fraction (LVEF). Method: We performed a retrospective analysis of patients admitted to intensive care unit (ICU) in a single tertiary cardiac centre over a 34-month period with STEMI complicated by CS and LVEF < 40%. Clinical and echocardiographic data were collected and correlated with 28-day mortality. Results: One-hundred patients were included with a mean age of 62.6 ±12.7 years and 78% were male. Mortality at 28 days was 37%. Respectively, 85%, 40% and 25% of patients required mechanical ventilation, mechanical circulatory support and renal replacement therapy. Tricuspid annulus peak systolic velocity (RV S') was significantly higher in survivors (12 ± 3.3 v 10 ± 3.5 cm/s, p = 0.03) and was an independent predictor of mortality (odds ratio 1.2, 95% confidence interval 1.1-1.4, p = 0.04). RV S' of 10.5 cm/s exhibited best sensitivity and specificity (64% and 65%, respectively; p = 0.02) for mortality. The Kaplan-Meier curve demonstrated 85% risk of 28-day mortality for RV S' < 10.5 cm/s v 53% for RV S' > 10.5 cm/s (p = 0.02). Conclusion: RV function is associated 28-day mortality in patients admitted to ICU with STEMI complicated by CS with reduced LVEF. RV S' predicted mortality with good sensitivity and specificity.

Fulminant myocarditis: use of echocardiography from diagnosis to extracorporeal membrane oxygenation.

Fulminant myocarditis can present with life-threatening arrhythmias and cardiogenic shock due to ventricular failure. The diagnosis of myocarditis usually requires histological and immunological information, as its aetiology may be infectious (viral or non-viral), autoimmune or drug related. The treatment of fulminant myocarditis depends on the underlying cause but usually includes high dose systemic steroids as well as physiological support. Veno-arterial extracorporeal membrane oxygenation (V-A ECMO) can be used to support patients as a bridge to recovery by supporting biventricular function and decompressing the heart. V-A ECMO carries risks and complications of its own such as thrombus formation or bleeding. Different diagnostic modalities, such as transthoracic echocardiogram (TTE) and transoesophageal echocardiogram (TOE), are central to the monitoring of progression of disease and recovery of heart function. This case highlights the importance of early recognition and early support with V-A ECMO in fulminant myocarditis, as well as the role of repeated echocardiography when weaning from physiological support.

Lessons of the month 5: Cardiac tamponade after an acute myocardial infarction: the clinical diagnosis.

We present the case of a late presenting ST-elevation myocardial infarction with a coronary dissection. After primary percutaneous coronary intervention, the patient went on to develop pericardial effusion with tamponade. Despite only a small volume of fluid, we demonstrate how it can have significant clinical consequences in the diseased heart. We also highlight the value of being able to carry out bedside echocardiography in the acutely unwell post-myocardial infarction patient.

Eosinophilic Myocarditis Secondary to T-Cell Lymphoma Complicated by Left Ventricular Thrombus and Tear.

We describe a 54-year-old male in whom eosinophilic myocarditis secondary to T-cell lymphoma complicated by bilateral ischemic stroke was diagnosed. The source, identified as an apical tear with thrombus formation, was revealed by transthoracic echocardiography. (Level of Difficulty: Advanced.).

Identification of an activated neutrophil phenotype in polymyalgia rheumatica during steroid treatment: a potential involvement of immune cell cross-talk.

We have reported the existence of a distinct neutrophil phenotype in giant cell arteritis (GCA) patients arising at week 24 of steroid treatment. In the present study, we investigated whether longitudinal analysis of neutrophil phenotype in patients with polymyalgia rheumatica (PMR) could reveal a novel association with disease status and immune cell cross-talk. Thus, we monitored PMR patient neutrophil phenotype and plasma microvesicle (MV) profiles in blood aliquots collected pre-steroid, and then at weeks 1, 4, 12 and 24 post-steroid treatment.Using flow cytometric and flow chamber analyses, we identified 12-week post-steroid as a pivotal time-point for a marked degree of neutrophil activation, correlating with disease activity. Analyses of plasma MVs indicated elevated AnxA1+ neutrophil-derived vesicles which, in vitro, modulated T-cell reactivity, suggesting distinct neutrophil phenotypic and cross-talk changes at 24 weeks, but not at 12-week post-steroid.Together, these data indicate a clear distinction from GCA patient neutrophil and MV signatures, and provide an opportunity for further investigations on how to 'stratify' PMR patients and monitor their clinical responses through novel use of blood biomarkers.

Microvesicle Subsets in Sepsis Due to Community Acquired Pneumonia Compared to Faecal Peritonitis.

RATIONALE: Microvesicles (MV) act as a nonsoluble means of intercellular communication, with effector roles in disease pathogenesis and potentially as biomarkers. Previously, we reported that neutrophil MV expressing alpha-2-macroglobulin (A2MG) are protective in experimental sepsis and associate with survival in a small cohort of patients with sepsis due to community acquired pneumonia (CAP). OBJECTIVES: To characterize MV profiles in sepsis due to CAP or fecal peritonitis (FP) and determine their relation to outcome. To investigate the effects of novel sepsis treatments (granulocyte-macrophage colony stimulating factor (GM-CSF) and interferon-υ (IFN-γ)) on MV production and functions in vitro. METHODS: Flow cytometry analysis of MV identified the cell of origin and the proportion of A2MG expression in the plasma of patients with sepsis secondary to CAP (n = 60) or FP (n = 40) and compared with healthy volunteers (HV, n = 10). The association between MV subsets and outcome was examined. The ability of GM-CSF and IFN-γ on A2MG MV production from whole blood was examined together with the assessment of their effect on neutrophil and endothelial functions. RESULTS: Circulating cell-derived and A2MG MV were higher in CAP compared with FP and HV. A2MG MV were higher in survivors of CAP, but not in FP. GM-CSF and IFN-γ enhanced A2MG MV production, with these MV eliciting pathogen clearance in vitro. CONCLUSIONS: Plasma MV profiles vary according to the source of infection. A2MG MV are associated with survival in CAP but not FP. We propose specific MV subsets as novel biomarkers in sepsis and potential effector for some of the actions of experimental therapeutic interventions.

Microparticle alpha-2-macroglobulin enhances pro-resolving responses and promotes survival in sepsis.

Incorporation of locally produced signaling molecules into cell-derived vesicles may serve as an endogenous mediator delivery system. We recently reported that levels alpha-2-macroglobulin (A2MG)-containing microparticles are elevated in plasma from patients with sepsis. Herein, we investigated the immunomodulatory actions of A2MG containing microparticles during sepsis. Administration of A2MG-enriched (A2MG-E)-microparticles to mice with microbial sepsis protected against hypothermia, reduced bacterial titers, elevated immunoresolvent lipid mediator levels in inflammatory exudates and reduced systemic inflammation. A2MG-E microparticles also enhanced survival in murine sepsis, an action lost in mice transfected with siRNA for LRP1, a putative A2MG receptor. In vitro, A2MG was functionally transferred onto endothelial cell plasma membranes from microparticles, augmenting neutrophil-endothelial adhesion. A2MG also modulated human leukocyte responses: enhanced bacterial phagocytosis, reactive oxygen species production, cathelicidin release, prevented endotoxin induced CXCR2 downregulation and preserved neutrophil chemotaxis in the presence of LPS. A significant association was also found between elevated plasma levels of A2MG-containing microparticles and survival in human sepsis patients. Taken together, these results identify A2MG enrichment in microparticles as an important host protective mechanism in sepsis.