scholarly journals Inferring the Frank–Starling Curve From Simultaneous Venous and Arterial Doppler: Measurements From a Wireless, Wearable Ultrasound Patch

2021 ◽  
Vol 3 ◽  
Author(s):  
Jon-Émile S. Kenny ◽  
Igor Barjaktarevic ◽  
David C. Mackenzie ◽  
Philippe Rola ◽  
Korbin Haycock ◽  
...  

The Frank–Starling relationship is a fundamental concept in cardiovascular physiology, relating change in cardiac filling to its output. Historically, this relationship has been measured by physiologists and clinicians using invasive monitoring tools, relating right atrial pressure (Pra) to stroke volume (SV) because the Pra-SV slope has therapeutic implications. For example, a critically ill patient with a flattened Pra-SV slope may have low Pra yet fail to increase SV following additional cardiac filling (e.g., intravenous fluids). Provocative maneuvers such as the passive leg raise (PLR) have been proposed to identify these “fluid non-responders”; however, simultaneously measuring cardiac filling and output via non-invasive methods like ultrasound is cumbersome during a PLR. In this Hypothesis and Theory submission, we suggest that a wearable Doppler ultrasound can infer the Pra-SV relationship by simultaneously capturing jugular venous and carotid arterial Doppler in real time. We propose that this method would confirm that low cardiac filling may associate with poor response to additional volume. Additionally, simultaneous assessment of venous filling and arterial output could help interpret and compare provocative maneuvers like the PLR because change in cardiac filling can be confirmed. If our hypothesis is confirmed with future investigation, wearable monitors capable of monitoring both variables of the Frank–Starling relation could be helpful in the ICU and other less acute patient settings.

2020 ◽  
Vol 13 ◽  
Author(s):  
Theodora Katsila ◽  
Dimitrios Kardamakis

Background: Malignant gliomas constitute a complex disease phenotype that demands optimum decisionmaking. Despite being the most common type of primary brain tumors, gliomas are highly heterogeneous when their pathophysiology and response to treatment are considered. Such inter-individual variability also renders differential and early diagnosis extremely difficult. Recent evidence highlight that the gene-environment interplay becomes of fundamental importance in oncogenesis and progression of gliomas. Objective: To unmask key features of the gliomas disease phenotype and map the inter-individual variability of patients, we explore genotype-to-phenotype associations. Emphasis is put on microRNAs as they regulate gene expression, have been implicated in the pathogenesis of gliomas and may serve as theranostics, empowering non-invasive strategies (circulating free or in exosomes). Method: We mined text and omic datasets (as of 2019) and conducted a mixed-method content analysis. A novel framework was developed to meet the aims of our analysis, interrogating data in terms of content and context. We relied on literature data from PubMed/Medline and Scopus, as they are considered the largest abstract and citation databases of peer-reviewed literature. To avoid selection biases, both publicly available and private texts have been assessed. Both percent agreement and Cohen's kappa statistic have been calculated to avoid biases by SAS macro MAGREE with multicategorical ratings. Results: Gliomas serve as a paradigm for multifaceted datasets, despite data sparsity and scarcity. miRNAs and miRNAbased therapeutics are ready for prime time. Exosomal miRNAs empower non-invasive strategies, surpassing circulating free miRNAs, when accuracy and precision are considered. Conclusion: miRNAs holds promise as theranostics.


2021 ◽  
Vol 22 (Supplement_1) ◽  
Author(s):  
D Pedicino ◽  
A Angelini ◽  
G Russo ◽  
A D"aiello ◽  
E Rocco ◽  
...  

Abstract Funding Acknowledgements Type of funding sources: None. Background High-flow nasal cannulae oxygen therapy (HFNCOT) represents a better tolerated alternative to non-invasive pressure support ventilation (NIPSV) for acute cardiogenic pulmonary edema (ACPE) treatment. However, there are still few data on the effect of HFNCOT on cardiac function and hemodynamic. Purpose To assess and compare the effects of NIPSV and HFNCOT in ACPE setting on right ventricular (RV) systolic function and on indices of cardiac filling and output, as measured by echocardiography.  Methods  This is a cross-over controlled study, enrolling 15 consecutive patients admitted to our Cardiovascular Intensive Care Unit for ACPE and hypoxaemic, normo/hypocapnic acute respiratory failure, with P/F ratio < 200. Each patient received NIPSV, followed by HFNCOT. Full echocardiographic assessment and blood gas analysis (BGA) were performed 40 minutes from onset of each ventilation modality, respectively before NIPSV to HFNCOT switch and before HFNCOT interruption. In particular, RV function parameters, together with RV and atrial strain, were prospectively collected. Results  In spite of not significant changes in BGA, RV function was significantly improved under HFNCOT, as compared to NIPSV, as assessed by the following parameters: tricuspid annular plane excursion (TAPSE) (P = 0.001), RV S’ wave (P = 0.007), RV fractional area change (RVFAC) (P = 0.006). Strain analysis confirmed the significant improvement in RV function, with free wall global longitudinal strain (GLS) and free wall and septum GLS significantly higher under HFNCOT, as compared to NIPSV (-21% vs -18% P < 0.001, and -15% vs -19% P = 0.008, respectively,), and a significant increase in right atrial positive longitudinal strain (P < 0.001).  Conclusions NIPSV significantly affect RV function making more complex the management of patients presenting with ACPE. In this setting, HFNCOT represents a valuable alternative, providing similar respiratory outcomes while preserving good right ventricle performance.


2021 ◽  
pp. emermed-2020-209771
Author(s):  
Nienke K Koopmans ◽  
Renate Stolmeijer ◽  
Ben C Sijtsma ◽  
Paul A van Beest ◽  
Christiaan E Boerma ◽  
...  

BackgroundLittle is known about optimal fluid therapy for patients with sepsis without shock who present to the ED. In this study, we aimed to quantify the effect of a fluid challenge on non-invasively measured Cardiac Index (CI) in patients presenting with sepsis without shock.MethodsIn a prospective cohort study, CI, stroke volume (SV) and systemic vascular resistance (SVR) were measured non-invasively in 30 patients presenting with sepsis without shock to the ED of a large teaching hospital in the Netherlands between May 2018 and March 2019 using the ClearSight system. After baseline measurements were performed, a passive leg raise (PLR) was done to simulate a fluid bolus. Measurements were then repeated 30, 60, 90 and 120 s after PLR. Finally, a standardised 500 mL NaCl 0.9% intravenous bolus was administered after which final measurements were done. Fluid responsiveness was defined as >15% increase in CI after a standardised fluid challenge.Measurements and main resultsSeven out of 30 (23%) patients demonstrated a >15% increase in CI after PLR and after a 500 mL fluid bolus. Fluid responders had a higher estimated glomerular filtration rate (eGFR) (64 (44–78) vs 37 (23–47), p=0.009) but otherwise similar patient and treatment characteristics as non-responders. Baseline measurements of cardiac output (CO), CI, SV and SVR were unrelated to PLR fluid responsiveness. The change in CI after PLR was strongly positive correlated to the change in CI after a 500 mL NaCl 0.9% fluid bolus (r=0.88, p<0.001).ConclusionThe results of the present study demonstrate that in patients with sepsis in the absence of shock, three out of four patients do not demonstrate a clinically relevant increase in CI after a standardised fluid challenge. Non-invasive CO monitoring in combination with a PLR test has the potential to identify patients who might benefit from fluid resuscitation and may contribute to a better tailored treatment of these patients.


Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Yuko Fukuda ◽  
Hidekazu Tanaka ◽  
Yoshiki Motoji ◽  
Keiko Ryo ◽  
Hiroki Matsuzoe ◽  
...  

Background: The development of right ventricular (RV) dysfunction in patients with pulmonary hypertension (PH) has been associated with adverse outcomes. Right atrial (RA) function could be a prognostic factors as well as RV function, but non-invasive evaluation of RA function is limited. Our objective was thus to test the hypothesis that RA function was associated with hemodynamic parameters of RV performance in PH patients. Methods: Eighty PH patients with mean pulmonary artery pressure (PAP) of 40±11mmHg (all≥25mmHg) were recruited in this study. RA function was assessed by using two-dimensional speckle-tracking strain from RV-focused apical 4-chamber view. RA strain was calculated with the reference point set at the P wave, which enabled the recognition of peak negative (RAneg), positive strain (RAposi), and the sum of those values (RAtotal), corresponding to RA contractile, conduit, and reservoir function, respectively. All patients underwent right-heart catheterization for measurement of mean PAP and pulmonary vascular resistance (PVR). Results: RAneg (r=0.24 and p=0.03), RAposi (r=0.31 and p=0.01) and RAtotal (r=0.35 and p=0.001) were significantly correlated with mean PAP. In addition, RAposi (r=0.41 and p<0.001) and RAtotal (r=0.44 and p<0.001) were also correlated with PVR. Conclusions: Non-invasively assessed RA strains were associated with mean PAP and PVR. RA strain may be of a valuable additive factor for the management of PH patients, and thus have potential clinical applications.


2021 ◽  
Author(s):  
Moataz Dowaidar

Given the complexity of acute rejection (AR) pathogenesis and its vast spectrum of clinical symptoms, no methodology (invasive or non-invasive) can provide all the information needed to identify functionally and prognostically relevant AR, treatment selection, and therapy monitoring early. Only the use of EMBs in combination with non-invasive technologies and methods to detect subclinical changes in myocardial contractile function (e.g., TDI and STE), to detect alloimmune activation (e.g., IM assay, assessment of complement-activating donor-specific anti-HLA Abs (DSAbs), screening of circulating cfdDNA), and to predict the imminent risk of immune-mediated injury (e.g., assessment of complement-activating DSAbs).Searching for both ACR and AMR in all EMBs is a key prerequisite for accurate diagnosis and decision-making in individuals suspected of AR. Close non-invasive allograft surveillance to detect patients at high risk of AR, along with properly planned EMBs (depending on the particular risk profile of the patient), can improve AR surveillance while decreasing rsEMBs. Because rsEMBs are less prevalent after the first post-HTx year and largely symptom-driven diagnostic EMBs, ongoing development of comprehensive, non-invasive technology to monitor both ACR and AMR is of significant importance. This is especially helpful for detecting late subclinical AMR, which would otherwise go unreported.The most useful and commonly available AR surveillance strategies are routine monitoring of myocardial functions utilizing sensitive ECHO techniques (TDI and STE for acute subclinical dysfunction diagnosis) and DSAb monitoring. As a result, early and late use of HTx is strongly suggested. New IM technologies such as T-cell function assays and genomic medicine approaches such as GEP, circulating dd-cfdDNA screening and microRNA assessment are promising non-invasive monitoring tools for future clinical use, but it is still necessary to test the practical value of their individual or combined use for AR detection (including both ACR and AMR), not just for ACR.


Circulation ◽  
2020 ◽  
Vol 142 (Suppl_3) ◽  
Author(s):  
Pratik Doshi ◽  
John Tanaka ◽  
Jedrek Wosik ◽  
Natalia M Gil ◽  
Martin Bertran ◽  
...  

Introduction: There is a need for innovative solutions to better screen and diagnose the 7 million patients with chronic heart failure. A key component of assessing these patients is monitoring fluid status by evaluating for the presence and height of jugular venous distension (JVD). We hypothesize that video analysis of a patient’s neck using machine learning algorithms and image recognition can identify the amount of JVD. We propose the use of high fidelity video recordings taken using a mobile device camera to determine the presence or absence of JVD, which we will use to develop a point of care testing tool for early detection of acute exacerbation of heart failure. Methods: In this feasibility study, patients in the Duke cardiac catheterization lab undergoing right heart catheterization were enrolled. RGB and infrared videos were captured of the patient’s neck to detect JVD and correlated with right atrial pressure on the heart catheterization. We designed an adaptive filter based on biological priors that enhances spatially consistent frequency anomalies and detects jugular vein distention, with implementation done on Python. Results: We captured and analyzed footage for six patients using our model. Four of these six patients shared a similar strong signal outliner within the frequency band of 95bpm – 200bpm when using a conservative threshold, indicating the presence of JVD. We did not use statistical analysis given the small nature of our cohort, but in those we detected a positive JVD signal the RA mean was 20.25 mmHg and PCWP mean was 24.3 mmHg. Conclusions: We have demonstrated the ability to evaluate for JVD via infrared video and found a relationship with RHC values. Our project is innovative because it uses video recognition and allows for novel patient interactions using a non-invasive screening technique for heart failure. This tool can become a non-invasive standard to both screen for and help manage heart failure patients.


2014 ◽  
Vol 10 (1) ◽  
pp. 92-93 ◽  
Author(s):  
Bernardo Dell’Osso ◽  
A. Carlo Altamura

Transcranial magnetic stimulation (TMS) and transcranial direct current stimulation (tDCS) are non-invasive brain stimulation techniques that, by means of magnetic fields and low intensity electrical current, respectively, aim to interefere with and modulate cortical excitability, at the level of dorsolateral prefrontal cortex, in patients with major depression and poor response to standard antidepressants. While the clinical efficacy of TMS in major depression has been extensively investigated over the last 10 years, tDCS has attracted research interest only in the last years, with fewer randomized clinical trials (RCTs) in the field. Nevertheless, in spite of the different rationale and mechanism of action of the two techniques, tDCS recent acquisitions, in relation to the treatment of major depression, seem to parallel those previously obtained with TMS, in terms of treatment duration to achieve optimal benefit and patient's history of drug-resistance. After briefly introducing the two techniques, the article examines possible common pathways of clinical use for TMS and tDCS, emerging from recent RCTs and likely orienting future investigation with non invasive brain stimulation for the treatment of major depression.


2018 ◽  
Vol 75 (5) ◽  
pp. 512-515 ◽  
Author(s):  
Sasa Hinic ◽  
Jelena Saric ◽  
Predrag Milojevic ◽  
Jelena Gavrilovic ◽  
Tijana Durmic ◽  
...  

Introduction. Myxoma is the most common primary benign heart tumor. The most frequent location is the left atrium, the chamber of the heart that receives oxygen- rich blood from the lungs. Myxomas usually develop in women, typically between the ages of 40 and 60. Symptoms may occur at any time, but most often they are asymptomatic or oligosymptomatic for a long period of time. Symptoms usually go along with body position, and are related to compression of the heart cavities, embolization and the appearance of general symptoms. The diagnosis of benign tumors of the heart is based on anamnesis, clinical features and findings of the tumor masses by use of non-invasive and invasive imaging methods. Extensive surgical resection of the myxoma is curative with minimal mortality. Long term clinical and echocardiographic follow-up is mandatory. Case report. We reported a case of a 62-year-old male, presented with 15 days of intermittent shortness of breath, dizziness and feeling of heart palpitations and subsequently diagnosed with right atrial myxoma based on transthoracic echocardiography . The patient was emergently operated in our hospital. Long-term followup did not reveal recurrence. Conclusion. Our case was an atypical localisation of right atrial myxoma. Whether the intracardiac mass is benign or malignant, early surgery is obligatory in order to prevent complications.


2006 ◽  
Vol 100 (6) ◽  
pp. 1895-1901 ◽  
Author(s):  
Michael K. Stickland ◽  
Robert C. Welsh ◽  
Stewart R. Petersen ◽  
John V. Tyberg ◽  
William D. Anderson ◽  
...  

Subjects with greater aerobic fitness demonstrate better diastolic compliance at rest, but whether fitness modulates exercise cardiac compliance and cardiac filling pressures remains to be determined. On the basis of maximal oxygen consumption (V̇o2max), healthy male subjects were categorized into either low (LO: V̇o2max = 43 ± 6 ml·kg−1·min−1; n = 3) or high (HI: V̇o2max = 60 ± 3 ml·kg−1·min−1; n = 5) aerobic power. Subjects performed incremental cycle exercise to 90% V̇o2max. Right atrial (RAP) and pulmonary artery wedge (PAWP) pressures were measured, and left ventricular (LV) transmural filling pressure (TMFP = PAWP − RAP) was calculated. Cardiac output (CO) and stroke volume (SV) were determined by direct Fick, and LV end-diastolic volume (EDV) was estimated from echocardiographic fractional area change and Fick SV. There were no between-group differences for any measure at rest. At a submaximal workload of 150 W, PAWP and TMFP were higher ( P < 0.05) in LO compared with HI (12 vs. 8 mmHg, and 9 vs. 4 mmHg, respectively). At peak exercise, CO, SV, and EDV were lower in LO ( P < 0.05). RAP was not different at peak exercise, but PAWP (23 vs. 15 mmHg) and TMFP (12 vs. 6 mmHg) were higher in LO ( P < 0.05). Compared with less fit subjects, subjects with greater aerobic fitness demonstrated lower LV filling pressures during exercise, whereas SV and EDV were either similar (submaximal exercise) or higher (peak exercise), suggesting superior diastolic function and compliance.


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