Left atrial cross-sectional area is a novel measure of atrial shape associated with cardioembolic strokes

Heart ◽  
2020 ◽  
Vol 106 (15) ◽  
pp. 1176-1182
Author(s):  
Timothy C Tan ◽  
Maria Carmo Pereira Nunes ◽  
Mark Handschumacher ◽  
Octavio Pontes-Neto ◽  
Yong-Hyun Park ◽  
...  
Keyword(s):  
Ischaemic Stroke ◽  
Flow Velocity ◽  
Left Atrial ◽  
Velocity Profiles ◽  
Left Ventricular ◽  
Cross Sectional Area ◽  
Left Ventricular Ejection ◽  
Sectional Area ◽  
Cross Sectional

ObjectiveCardioembolic (CE) stroke carries significant morbidity and mortality. Left atrial (LA) size has been associated with CE risk. We hypothesised that differential LA remodelling impacts on pathophysiological mechanism of major CE strokes.MethodsA cohort of consecutive patients hospitalised with ischaemic stroke, classified into CE versus non-CE strokes using the Causative Classification System for Ischaemic Stroke were enrolled. LA shape and remodelling was characterised by assessing differences in maximal LA cross-sectional area (LA-CSA) in a cohort of 40 prospectively recruited patients with ischaemic stroke using three-dimensional (3D) echocardiography. Flow velocity profiles were measured in spherical versus ellipsoidal in vitro models to determine if LA shape influences flow dynamics. Two-dimensional (2D) LA-CSA was subsequently derived from standard echocardiographic views and compared with 3D LA-CSA.ResultsA total of 1023 patients with ischaemic stroke were included, 230 (22.5%) of them were classified as major CE. The mean age was 68±16 years, and 464 (45%) were women. The 2D calculated LA-CSA correlated strongly with the LA-CSA measured by 3D in both end-systole and end-diastole. In vitro flow models showed shape-related differences in mid-level flow velocity profiles. Increased LA-CSA was associated with major CE stroke (adjusted relative risk 1.10, 95% CI 1.04 to 1.16; p<0.001), independent of age, gender, atrial fibrillation, left ventricular ejection fraction and CHA2DS2-VASc score. Specifically, the inclusion of LA-CSA in a model with traditional risk factors for CE stroke resulted in significant improvement in model performance with the net reclassification improvement of 0.346 (95% CI 0.189 to 0.501; p=0.00001) and the integrated discrimination improvement of 0.013 (95% CI 0.003 to 0.024; p=0.0119).ConclusionsLA-CSA is a marker of adverse LA shape associated with CE stroke, reflecting importance of differential LA remodelling, not simply LA size, in the mechanism of CE risk.

Left ventricular ejection activation in the in situ heart

1991 ◽  
Vol 260 (5) ◽  
pp. H1495-H1500
Author(s):  
Y. Igarashi ◽  
C. P. Cheng ◽  
W. C. Little
Keyword(s):  
Systolic Pressure ◽  
Left Ventricular ◽  
Cross Sectional Area ◽  
Aortic Flow ◽  
Aortic Occlusion ◽  
Ventricular Pressure ◽  
Left Ventricular Ejection ◽  
Sectional Area ◽  
Cross Sectional

We tested, in the in situ heart, the hypothesis that the end-systolic pressure (ESP) of small ejecting contraction (EC) is greater than that of an isovolumic contraction (IC) with a similar end-systolic volume. We produced ECs with varying amounts of ejection by partial aortic occlusion while measuring left ventricular pressure, one or two left ventricular dimensions (anteroposterior and septal-lateral), and aortic flow. In 11 dogs, we plotted ventricular pressure against the time integral of aortic flow of ECs and IC with the same end-diastolic anteroposterior dimension. The end-systolic pressure-volume line was drawn from the peak isovolumic pressure-volume point tangential to the left upper corner of the pressure-volume loop of ECs. The slope of the tangential line of the middle EC, whose stroke volume was 51 +/- 8% of that of the control EC, was decreased by 54 +/- 16% compared with that of the control EC. In eight dogs with two pairs of crystals, left ventricular volume was controlled by partial vena caval occlusion, and ICs were produced by total aortic occlusion. The end-systolic pressure of small ejections exceeded (11.3 +/- 7.7 mmHg, P less than 0.01) those of isovolumic contractions with the same end-systolic cross-sectional area, whereas the end-systolic pressure of beats with large ejections was similar (-9.4 +/- 14.4 mmHg, P = NS) to an IC with the same end-systolic cross-sectional area. We conclude that the end-systolic pressure-volume point of beats with a small ejection is located above the isovolumic end-systolic pressure-volume relation in the in situ dog left ventricle.

Determinants of coronary blood flow in humans: quantification by intracoronary Doppler and ultrasound

2005 ◽  
Vol 98 (3) ◽  
pp. 1076-1082 ◽  
Author(s):  
Heinrich Wieneke ◽  
Clemens von Birgelen ◽  
Michael Haude ◽  
Holger Eggebrecht ◽  
Stefan Möhlenkamp ◽  
...  
Keyword(s):  
Blood Flow ◽  
Flow Velocity ◽  
Coronary Flow ◽  
Left Ventricular ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Lumen Area ◽  
Cross Sectional ◽  
Coronary Flow Velocity ◽  
Intracoronary Doppler

The direct determinants of coronary flow are lumen area and blood flow velocity; however, the precise mechanisms that control these factors are not fully understood. The aim of the present study was to assess by which mechanisms lumen area and coronary flow velocity interact with hemodynamic and morphometric factors, thereby influencing coronary flow. Intracoronary Doppler and ultrasound measurements were performed in 28 patients without coronary lumen irregularities. Flow velocity and lumen cross-sectional area were measured in the proximal segments of all three coronary arteries. Global lumen cross-sectional area and global flow were obtained by adding up the values of all three coronary arteries. Left ventricular mass was assessed by echocardiography. Stress-mass-heart rate and pressure-rate products reflecting myocardial oxygen demand were calculated. Global coronary flow increased during adenosine-induced hyperemia from 197 ± 72 to 637 ± 204 ml/min ( P < 0.001). Global coronary flow closely correlated with the stress-mass-heart rate product ( r = 0.62; P < 0.001). Looking at the two constituents of flow separately, global coronary cross-sectional area was closely related to left ventricular muscle mass ( r = 0.61; P < 0.001), whereas mean coronary flow velocity at rest showed a strong linear relation with the pressure-rate product ( r = 0.64; P < 0.001). There was no interaction between cross-sectional area and blood flow velocity in any of the coronary vessels. Coronary lumen size and flow velocity, the two determinants of coronary flow, are principally determined by different physiological factors. Long-term flow adaptation is achieved by an increase in coronary lumen size, whereas short-term myocardial oxygen requirements are met by changes in resting flow velocity.

scholarly journals Rectus Femoris Mimicking Ultrasound Phantom for Muscle Mass Assessment: Design, Research, and Training Application

2021 ◽  
Vol 10 (12) ◽  
pp. 2721
Author(s):  
Nobuto Nakanishi ◽  
Shigeaki Inoue ◽  
Rie Tsutsumi ◽  
Yusuke Akimoto ◽  
Yuko Ono ◽  
...  
Keyword(s):  
Measurement Accuracy ◽  
Rectus Femoris ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Cross Sectional ◽  
Phantom Model ◽  
Ultrasound Measurements ◽  
Ultrasound Phantom

Ultrasound has become widely used as a means to measure the rectus femoris muscle in the acute and chronic phases of critical illness. Despite its noninvasiveness and accessibility, its accuracy highly depends on the skills of the technician. However, few ultrasound phantoms for the confirmation of its accuracy or to improve technical skills exist. In this study, the authors created a novel phantom model and used it for investigating the accuracy of measurements and for training. Study 1 investigated how various conditions affect ultrasound measurements such as thickness, cross-sectional area, and echogenicity. Study 2 investigated if the phantom can be used for the training of various health care providers in vitro and in vivo. Study 1 showed that thickness, cross-sectional area, and echogenicity were affected by probe compression strength, probe angle, phantom compression, and varying equipment. Study 2 in vitro showed that using the phantom for training improved the accuracy of the measurements taken within the phantom, and Study 2 in vivo showed the phantom training had a short-term effect on improving the measurement accuracy in a human volunteer. The new ultrasound phantom model revealed that various conditions affected ultrasound measurements, and phantom training improved the measurement accuracy.

A method of in-vitro measurement of the cross-sectional area of soft tissues, using ultrasonography

2002 ◽  
Vol 7 (2) ◽  
pp. 247-251 ◽  
Author(s):  
Masahiko Noguchi ◽  
Toshiya Kitaura ◽  
Kazuya Ikoma ◽  
Yoshiaki Kusaka
Keyword(s):  
Soft Tissues ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Cross Sectional ◽  
The Cross

Abstract 17979: Left Atrial Cross Sectional Area is a Novel Echocardiographic Measure Which Improves the Predictive Value of Chads2 Score in Risk Stratification of Cardioembolic Strokes

Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Timothy C Tan ◽  
Mark Handschumacher ◽  
Octavio M Pontes-Neto ◽  
Maria C Nunes ◽  
Yong H Park ◽  
...  
Keyword(s):  
Risk Stratification ◽  
Risk Prediction ◽  
Left Atrial ◽  
Stroke Risk ◽  
Thrombus Formation ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Chads2 Score ◽  
Cross Sectional ◽  
C Statistic

Background: Cardioembolic (CE) stroke carries significant morbidity and mortality. Current risk stratification tools such as CHADS2 score do not include any imaging parameters and are based on clinical features, which have limitations. Left atrial (LA) enlargement and remodeling may be associated with CE risk due to predisposition for atrial arrhythmias and thrombus formation. Left atrial cross sectional area (LACSA), a novel echo measure which reflects both LA size and shape, may improve CE stroke risk assessment. Aim: This study examined the value of LACSA in predicting CE stroke risk and the improvement in risk prediction when added to CHADS2 score. Methods: Clinical and echo parameters were examined in a prospective cohort of 1275 consecutive patients with ischemic stroke. Strokes were classified using the Causative Classification of Strokes and 259 (20%) were classified as CE stroke. LACSA was calculated using the formula: π/4*largest measured LA diameter*smallest measured LA diameter where mid LA diameter was measured in the parasternal long axis, 4 chamber and 2 chamber views. Results: Patients with CE stroke had greater LACSA (8.6 ± 2.3 vs 6.4 ± 1.8 cm2/m2; p<0.001) and mean CHADS2 score (2.25 ± 1.28 vs 1.87 ± 1.40; p<0.0001) compared to non-CE stroke patients. LACSA was independently associated with CE strokes (OR 1.21; 95% CI 1.08-1.34; p=0.001) in a multivariable model adjusted for CHADS2, gender, score, BMI, atrial fibrillation, anti-platelet and anti-coagulant use, E/E’ and LVEF. The addition of LACSA to CHADS2 score improved the prediction of CE stroke (c-statistic for predicting CE stroke using CHADS2 alone was 0.59 (95% CI 0.55-0.63) vs CHADS2 and LACSA 0.78 (95% CI 0.72-0.80) (p<0.001). Conclusion: LACSA is a novel measure of LA remodeling and associated with CE stroke. LACSA, an imaging parameter, enhances the risk prediction of the CHADS2 score, a clinical measure of risk, improving risk stratification for CE stroke and impacting therapeutic strategies.

Relation between Coronary Artery Cross Sectional Area and Left Ventricular Wall Mass

1990 ◽  
Vol 20 (4) ◽  
pp. 748
Author(s):  
Doo Hong Choi ◽  
Hak Sun Kim ◽  
Sun Ho Chang ◽  
Joo Young Cho ◽  
Sung Gu Kim ◽  
...  
Keyword(s):  
Coronary Artery ◽  
Left Ventricular ◽  
Cross Sectional Area ◽  
Left Ventricular Wall ◽  
Ventricular Wall ◽  
Sectional Area ◽  
Cross Sectional ◽  
Wall Mass

scholarly journals A Study of Sedimentation at the River Estuary on the Change of Reservoir Storage

2018 ◽  
Vol 31 ◽  
pp. 03001 ◽  
Author(s):  
Iskahar ◽  
Suripin ◽  
Isdiyana
Keyword(s):  
Flow Velocity ◽  
Water Level ◽  
Physical Model ◽  
River Estuary ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Sedimentation Pattern ◽  
Cross Sectional ◽  
Channel Angle ◽  
Reservoir Storage

Estuary of the river that leads to the reservoir has characteristics include: relatively flat, there is a change in the increase of wet cross-sectional area and backwater. The backwater will cause the flow velocity to be reduced, so that the grains of sediment with a certain diameter carried by the flow will settle in the estuary of the river. The purpose of this research is to know the distribution and sedimentation pattern at the river estuary that leads to the reservoir with the change of water level in the reservoir storage, so the solution can be found to remove / reduce sediment before entering the reservoir. The method used is the experimental, by making the physical model of the river estuary leading to the reservoir. This study expects a solution to reduce sedimentation, so that sedimentation can be removed / minimized before entering the reservoir. This research tries to apply bypass channel to reduce the sedimentation at the river estuary. Bypass channels can be applied to overcome sedimentation at the river estuary, but in order for the sediment to be removed optimally, it is necessary to modify the mouth of bypass channel and channel angle.

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