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Jet Velocity (jet + velocity)

Distribution by Scientific Domains
Medical Sciences83%

Kinds of Jet Velocity

  • regurgitant jet velocity
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    Selected Abstracts

    Perimembranous Ventricular Septal Defect and Gerbode Defect

    ECHOCARDIOGRAPHY, Issue 2 2010
    Adolfo A. Blanco M.D.
    A 27-year-old male presented with a known history of congenital ventricular septal defect (VSD). A Gerbode-type defect was discovered intraoperatively that was originally misinterpreted as pulmonary hypertension. The case report will review the Gerbode defect and the transesophageal echocardiography findings. It is important, in patients with history of perimembranous VSD, to consider Gerbode-type defect when the tricuspid regurgitation jet velocity is high (Echocardiography 2010;27:215-217) [source]

    Correlation between Right Ventricular Indices and Clinical Improvement in Epoprostenol Treated Pulmonary Hypertension Patients

    ECHOCARDIOGRAPHY, Issue 5 2005
    Jayant Nath M.D.
    The aim of this study was to evaluate which parameter of right ventricular (RV) echocardiographic best mirrors the clinical status of patients with pulmonary arterial hypertension. Patients with pulmonary arterial hypertension on epoprostenol therapy were identified via hospital registry. Twenty patients, (16 females, 4 males) were included in the study, 9 with primary pulmonary hypertension and 11 with other diseases. Echocardiograms before therapy and at 22.7 (±9.3) months into therapy were compared. The right ventricular myocardial performance index (RVMPI) was measured as the sum of the isometric contraction time and the isometric relaxation time divided by right ventricular ejection time. Other measures included peak tricuspid regurgitation jet velocity (TRV), pulmonary artery systolic pressure (PASP), pulmonary valve velocity time integral (PVVTI), PASP/PVVTI (as an index of total pulmonary resistance) and symptoms by New York Heart Association (NYHA) functional class. Echo parameters of right ventricular function were analyzed in patients, before and during therapy. There was significant improvement of NYHA class in patients following epoprostenol therapy (P < 0.0001). Peak tricuspid regurgitant jet velocity (pre 4.2 ± 0.6 m/sec, post 3.8 ± 0.7 m/sec, P = 0.02) and PASP/PVVTI (pre 6.7 ± 3.3 mmHg/m per second, post 4.8 ± 2.2 mmHg/m per second, P < 0.0001) were significantly improved during treatment. RVMPI did not improve (pre 0.6 ± 0.3, post 0.6 ± 0.3, P = 0.54). Changes in NYHA class did not correlate with changes in RVMPI (P = 0.33) or changes in PASP/PVVTI (P = 0.58). Despite significant improvements in TRV, PASP/PVVTI, and NYHA class, there was no significant change in RVMPI on epoprostenol therapy. Changes in right ventricular indices were not correlated with changes in NYHA class. [source]

    Reproducibility of tricuspid regurgitant jet velocity measurements in children and young adults with sickle cell disease undergoing screening for pulmonary hypertension,

    AMERICAN JOURNAL OF HEMATOLOGY, Issue 10 2010
    Robert I. Liem
    The reproducibility of tricuspid regurgitant jet velocity (TRJV) measurements by Doppler echocardiography has not been subjected to systematic evaluation among individuals with sickle cell disease (SCD) undergoing screening for pulmonary hypertension. We examined sources of disagreement associated with peak TRJV in children and young adults with SCD. Peak TRJV was independently measured and interpreted a week apart by separate sonographers and readers, respectively, in 30 subjects (mean age, 15.8 ± 3.3 years) who provided 120 observations. We assessed intra-/inter-reader, intra-/inter-sonographer, sonographer-reader, and within subject agreement using Intraclass Correlation Coefficient (ICC) and Cohen's kappa (,). Agreement was examined graphically using Bland-Altman plots. Although sonographers could estimate and measure peak TRJV in all subjects, readers designated tricuspid regurgitation nonquantifiable in 10,17% of their final interpretations. Intra-reader agreement was highest (ICC = 0.93 [95% CI 0.86, 0.97], P = 0.0001) and within subject agreement lowest (ICC = 0.36 [95% CI 0.02, 0.64], P = 0.021) for single TRJV measurements. Similarly, intra-reader agreement was highest (, = 0.74 [95% CI 0.53, 0.95], P = 0.0001) and within subject lowest (, = 0.14 [95% CI ,0.17, 0.46], P = 0.38) when sonographers and readers categorized TRJV measurements. On Bland-Altman plots, absolute differences in observations increased with higher mean TRJV readings for intra-/inter-reader agreement. Peak TRJV measurements in individual children and young adults with SCD are affected by several sources of disagreement, underscoring the need for methodological improvements that ensure reproducibility of this screening modality for making clinical decisions in this population. Am. J. Hematol., 2010. © 2010 Wiley-Liss, Inc. [source]

    Cardiopulmonary complications leading to premature deaths in adult patients with sickle cell disease

    AMERICAN JOURNAL OF HEMATOLOGY, Issue 1 2010
    Courtney D. Fitzhugh
    Sickle cell disease (SCD) is associated with early mortality. We sought to determine the incidence, cause, and risk factors for death in an adult population of patients with SCD. All patients aged ,18 years seen at the Adult Sickle Cell Center at Duke University Medical Center between January 2000 and April 2005 were enrolled. Forty-three patients (21 males and 22 females) died during the study period. The median age of survival was 39 years for females (95% CI: 34,56), 40 years for males (95% CI: 34,48), and 40 years overall (95% CI: 35,48). Cardiac causes of death accounted for 25.6% (11/43 patients); pulmonary, 14.0% (six patients); other SCD related, 32.6% (14 patients); unknown, 14.0% (six patients); and others, 14.0% (six patients). Pulseless electrical activity arrest, pulmonary emboli, multiorgan failure, and stroke were the most frequent causes of death. Among the deceased patients, the most common premorbid conditions were cardiopulmonary: acute chest syndrome/pneumonia (58.1%), Pulmonary hypertension (pHTN; 41.9%), systemic HTN (25.6%), congestive heart failure (25.6%), myocardial infarction (20.9%), and arrhythmias (14.0%). Tricuspid regurgitant jet velocity was significantly higher (3.1 m/sec vs. 2.6 m/sec, P < 0.001) and hemoglobin significantly lower (8.3 g/dL vs. 9.2 g/dL, P < 0.05) in deceased patients when compared with patients who lived, respectively. With improved preventive and therapeutic advances, including hydroxyurea therapy, acute complications such as infection are no longer the leading cause of death; instead, causes of death and premorbid conditions are shifting to chronic cardiopulmonary complications. Further, arrhythmia leading to premature death is under-recognized in SCD and warrants further investigation. Am. J. Hematol., 2010. © 2009 Wiley-Liss, Inc. [source]

    Pulmonary thrombi are not detected by 3D magnetic resonance angiography in adults with sickle cell anemia and an elevated triscuspid regurgitant jet velocity,

    AMERICAN JOURNAL OF HEMATOLOGY, Issue 10 2009
    Joshua J. Field
    No abstract is available for this article. [source]

    A Discussion on Minimum Spout Velocity and Jet Penetration Length

    THE CANADIAN JOURNAL OF CHEMICAL ENGINEERING, Issue 1 2004
    Hsiaotao T. Bi
    Abstract The similarity and difference between the flat-bottom and cone-bottom cylindrical spouted beds, conical spouted beds and vertical upward jets in fluidized beds have been analyzed in this paper based on the effects of geometrical parameters on the minimum spouting velocity and operating stabilities of the spouted beds. The effect of angle on minimum spouting velocity was found to be only significant within the range of 30 to 60 degrees cone angles. Minimum spouting velocity in deep cylindrical spouted beds was proportional to the square root of the static bed height, but was proportional to the static bed height in conical spouted beds and large cylindrical spouted beds with small height-to-diameter ratio. The relationship between the minimum spouting velocity and the static bed height was consistent with that between jet velocity and the vertical jet penetration length in jetting fluidized beds. Les similitudes et différences entre les lits jaillissants cylindriques à fond plat et à fond conique, les lits jaillissants coniques et les jets ascendants verticaux dans des lits fluidisés, ont été analysées dans cet article en s'appuyant sur les effets des paramètres géométriques sur la vitesse de jaillissement minimale et la stabilité de fonctionnement des lits fluidisés. On a trouvé que l'effet de l'angle sur la vitesse jaillissante minimale était significatif seulement pour des angles de cône compris entre 30 et 60 degrés. La vitesse de jaillissement minimale dans les lits fluidisés jaillissants cylindriques profonds est proportionnelle à la racine carrée de la hauteur de lit statique, mais est proportionnelle à la hauteur de lit statique dans les lits jaillissants coniques et les grands lits jaillissants cylindriques d'un faible rapport hauteur-diamètre. La relation entre la vitesse de jaillissement minimale et la hauteur de lit statique est consistante avec celle obtenue entre la vitesse de jet et la longueur de pénétration de jet vertical dans les lits fluidisés à jets. [source]