Non-invasive assessment of aortic stenosis by Doppler ultrasound.

SummaryDoppler ultrasound flow examination, strain gauge plethysmography and contrast venography were performed in 160 lower limbs of 80 in-patients. Deep vein thrombosis (DVT) was suspected in 87 limbs. Using measurement of venous stop-flow pressure, the Doppler method had an overall sensitivity of 83%. By combined use of Doppler and Plethysmography, sensitivity was increased to 96%. Specificity was 62% and 51%, respectively. With a positive and a negative predictive value of 80% and 73%, respectively, the combination of both non-invasive methods cannot reliably replace venography in the diagnosis of DTV, although all (40/40) thromboses proximal to or involving the popliteal segment were detected by either Doppler and Plethysmography or both.After exclusion of 14 patients (18%) suffering from conditions known to alter the results of these non-invasive methods, the positive predictive value of abnormal findings in both Doppler and Plethysmography was increased to 94% for suspected limbs, whilst negative predictive value of both negative Doppler and Plethysmography was 90%, allowing the avoidance of venography in these patients.

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Tissue Doppler Ultrasound During Spontaneous Breathing and Non-invasive Ventilation in the Post-extubation Period.

Case Medical Research ◽

10.31525/ct1-nct03978221 ◽

2019 ◽

Author(s):

Keyword(s):

Doppler Ultrasound ◽

Spontaneous Breathing ◽

Tissue Doppler ◽

Invasive Ventilation ◽

Non Invasive ◽

Non Invasive Ventilation

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“overestimation” of catheter gradients by doppler ultrasound in patients with aortic stenosis: a predictable manifestation of pressure recovery

Journal of the American College of Cardiology ◽

10.1016/s0735-1097(99)00066-2 ◽

1999 ◽

Vol 33 (6) ◽

pp. 1655-1661 ◽

Cited By ~ 192

Author(s):

Helmut Baumgartner ◽

Thomas Stefenelli ◽

Julia Niederberger ◽

Heinrich Schima ◽

Gerald Maurer

Keyword(s):

Aortic Stenosis ◽

Doppler Ultrasound ◽

Pressure Recovery

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NON-INVASIVE EVALUATION OF AORTIC PRESSURE, FLOW AND VALVULO-ARTERIAL LOAD IN PATIENTS WITH AORTIC STENOSIS BEFORE AND AFTER TRANSCATHETER AORTIC VALVE REPLACEMENT

Journal of the American College of Cardiology ◽

10.1016/s0735-1097(21)02499-2 ◽

2021 ◽

Vol 77 (18) ◽

pp. 1140

Author(s):

Ning Song ◽

Audrey Adji ◽

Sara Hungerford ◽

Mayooran Namasivayam ◽

Christopher Hayward ◽

...

Keyword(s):

Aortic Valve ◽

Aortic Stenosis ◽

Aortic Valve Replacement ◽

Transcatheter Aortic Valve Replacement ◽

Aortic Pressure ◽

Non Invasive ◽

Transcatheter Aortic Valve ◽

Arterial Load ◽

Before And After ◽

Invasive Evaluation

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Non-invasive Fetal Electrocardiography for Intrapartum Cardiotocography

Frontiers in Pediatrics ◽

10.3389/fped.2020.599049 ◽

2020 ◽

Vol 8 ◽

Author(s):

Rik Vullings ◽

Judith O. E. H. van Laar

Keyword(s):

Heart Rate ◽

Doppler Ultrasound ◽

Fetal Heart Rate ◽

Fetal Heart ◽

Fetal Monitoring ◽

Irreversible Damage ◽

Scalp Electrode ◽

Non Invasive ◽

Electrophysiological Measurements ◽

Fetal Electrocardiography

Fetal monitoring is important to diagnose complications that can occur during pregnancy. If detected timely, these complications might be resolved before they lead to irreversible damage. Current fetal monitoring mainly relies on cardiotocography, the simultaneous registration of fetal heart rate and uterine activity. Unfortunately, the technology to obtain the cardiotocogram has limitations. In current clinical practice the fetal heart rate is obtained via either an invasive scalp electrode, that poses risks and can only be applied during labor and after rupture of the fetal membranes, or via non-invasive Doppler ultrasound technology that is inaccurate and suffers from loss of signal, in particular in women with high body mass, during motion, or in preterm pregnancies. In this study, transabdominal electrophysiological measurements are exploited to provide fetal heart rate non-invasively and in a more reliable manner than Doppler ultrasound. The performance of the fetal heart rate detection is determined by comparing the fetal heart rate to that obtained with an invasive scalp electrode during intrapartum monitoring. The performance is gauged by comparing it to performances mentioned in literature on Doppler ultrasound and on two commercially-available devices that are also based on transabdominal fetal electrocardiography.

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Invasive versus non-invasive assessment of valvuloarterial impedance in severe aortic stenosis

Open Heart ◽

10.1136/openhrt-2020-001240 ◽

2020 ◽

Vol 7 (1) ◽

pp. e001240

Author(s):

Lisa Stanberry ◽

Aisha Ahmed ◽

Paul Sorajja ◽

Joao L Cavalcante ◽

Mario Gossl

Keyword(s):

Aortic Stenosis ◽

Severe Aortic Stenosis ◽

Binary Classification ◽

Decision Rules ◽

Estimating Equation ◽

Left Ventricular ◽

Binary Decision ◽

Non Invasive ◽

Ventricular Afterload ◽

Patients At Risk

BackgroundAs a measure of the global left ventricular afterload, valvuloarterial impedance (ZVA) can be estimated using transthoracic echocardiography (TTE) and invasive measuring methods. The objective of this study was to compare the performance of TTE in measuring ZVA with invasive haemodynamics, direct Fick and thermodilution (TD), in patients with severe aortic stenosis (AS).MethodsThis is a retrospective cohort study of 66 patients with severe AS who underwent TTE and bilateral heart catheterisation preaortic valve replacement. ZVA was calculated non-invasively from TTE and invasively using TD and Fick. The differences in measurements were estimated using a generalised estimating equation approach. The exchangeability of the measurements from different methods was evaluated under binary risk stratification rules.ResultsThe mean±SD ZVA by TTE was 4.6±1.4 vs 4.9±1.6 by TD vs 4.3±1.2 mm Hg m2/mL by Fick. From multivariate analyses, ZVA by TTE was 5.9% (95% CI −15.0 to 2.5) lower than by TD and 5.9% (95% CI −1.5 to 12.8) higher than by Fick. At the same time, ZVA by TD was 12.5% (3.0 to 22.9) higher than with Fick. Risk classifications for ZVA-based binary decision rules showed poor agreement between TTE and invasive methods (kappa ≤0.3).ConclusionsThe differences in ZVA estimates between TTE and invasive standards do not appear to exceed those between the standards. As such TTE-based estimates may be deemed acceptable as a clinical measure of global haemodynamic load. However, TTE-based and invasive measurements may not be interchangeable to identify patients at risk using binary classification rules based on ZVA.

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