Articles: blood-flow-velocity.
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J. Thorac. Cardiovasc. Surg. · Apr 2020
Multicenter StudyIntraoperative transit-time flow measurement and high-frequency ultrasound assessment in coronary artery bypass grafting.
We evaluated the influence of transit-time flow measurement with epicardial and epiaortic high-frequency ultrasound in patients undergoing coronary artery bypass grafting procedure. ⋯ Surgical changes related to the aorta, conduits, coronary targets, and anastomosis were made in 25% of patients. This was associated with low operative mortality and low major morbidity. Transit-time flow measurement and high-frequency ultrasound may improve the quality, safety, and efficacy of coronary artery bypass grafting procedures and should be considered as a routine procedural aspect.
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J Am Soc Echocardiogr · Jan 2019
Multicenter StudyThe Prognostic Value of Coronary Flow Velocity Reserve in Two Coronary Arteries During Vasodilator Stress Echocardiography.
Vasodilator stress echocardiography (SE) allows combined evaluation of regional wall motion and Doppler coronary flow velocity reserve (CFVR) of both the left anterior descending coronary artery (LAD) and the right coronary artery (RCA). The aim of this study was to prospectively assess the prognostic correlates of LAD and RCA CFVR on SE. ⋯ Ischemia on SE with high peak wall motion score index identifies a high-risk subset regardless of the underlying CFVR response. Absence of ischemia on SE is associated with intermediate risk, and LAD CFVR is essential to identify a truly low-risk subset. RCA CFVR is less useful than LAD CFVR but may have a role for further risk stratification in patients without ischemia and normal LAD CFVR.
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Randomized Controlled Trial Multicenter Study
Flat-head positioning increases cerebral blood flow in anterior circulation acute ischemic stroke. A cluster randomized phase IIb trial.
Background Whether lying-flat improves blood flow in patients with acute ischemic stroke is unknown. Our aim was to investigate if lying-flat "changes" cerebral blood flow velocities assessed by transcranial Doppler in acute ischemic stroke patients. Methods In a multicenter cluster clinical trial, we randomly assigned patients within 12 h from onset of a neurological deficit due to cerebral ischemia of the anterior circulation to lying-flat or upright head positioning. ⋯ Conclusion The lying-flat head position was associated with a significant increase in cerebral blood flow velocities at one and 24 h within the ipsilateral hemisphere of anterior circulation acute ischemic stroke, without serious safety concerns. Clinical trial registration-URL: http://www.clinicaltrials.gov. Unique identifier: NCT01706094.
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Multicenter Study
Left Ventricular Mass Influences Relationship Between Filling Pressure and Early-Diastolic Ratio of Inflow Velocity to Mitral Annular Velocity (E/e').
Early-diastolic mitral annular velocity (e') and the ratio of early-diastolic left ventricular (LV) inflow velocity (E) to e' (E/e') have been widely used as indexes of LV relaxation and filling pressure, respectively. However, many recent studies have demonstrated that they are not reliable in various clinical settings. We thus investigated the factors influencing these echocardiographic parameters in a multicenter study.Methods and Results:The study group comprised 69 patients, referred for cardiac catheterization, and enrolled in 5 university hospitals. Time constant (τ) and LV mean diastolic pressure (LVMDP) were measured using a micromanometer-tipped catheter. Although e' only weakly correlated with τ (r=-0.35, P<0.01), E/e' modestly correlated with LVMDP (r=0.48, P<0.001). Multivariable analysis revealed that hypertension (β=-0.33, P<0.01) and LV ejection fraction (LVEF) (β=0.44, P<0.001) were the independent determinants of e', and LV mass index (LVMI) (β=0.37, P<0.001) and LVMDP (β=0.47, P<0.001) were those of E/e'. Additionally, E/e' significantly correlated with LVMDP in patients with normal LVMI (r=0.74, P<0.001) but not in those with increased LVMI. ⋯ The coincidence of hypertension and LVEF affected the relationship between LV relaxation and e', whereas LVMI altered the relationship between LV filling pressure and E/e'. Thus, clinical conditions associated with an increase in LVMI, such as LV hypertrophy and LV dilatation, should be considered when estimating the filling pressure from E/e'.
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Randomized Controlled Trial Multicenter Study
Derivation and evaluation of thresholds for core and tissue at risk of infarction using CT perfusion.
Computed tomography perfusion provides information on tissue viability according to proposed thresholds. We evaluated thresholds for ischemic core and tissue at risk and subsequently tested their accuracy in independent datasets. ⋯ Time-based perfusion thresholds perform well as predictors of tissue at risk of infarction with DT the best predictor. Relative CBF was the best predictor of ischemic core. Evaluation in larger populations is needed to confirm the performance of tissue viability thresholds.