DOPPLER ECHOCARDIOGRAPHY IN THE NORMAL DOG: PART II. Factors Influencing Blood Flow Velocities And a Comparison between Left and Right Heart Blood Flow

1992 ◽  
Vol 33 (6) ◽  
pp. 380-386 ◽  
Author(s):  
Robert M. Kirberger ◽  
Paul Bland-vanden Berg ◽  
Richard J. Grimbeek
2019 ◽  
Vol 6 (4) ◽  
pp. 79 ◽  
Author(s):  
Legler ◽  
Koy ◽  
Kummerfeld ◽  
Fehr

The ventricular filling velocities during diastole and the influence of isoflurane anesthesia on these blood flow velocities of the racing pigeon (n = 43) are evaluated by pulsed-wave (PW) Doppler sonography. Sonographic examination demonstrates an early passive ventricular (E wave) and late active (A wave) ventricular filling. The results indicate differences between the two heart ventricles. Especially, the E wave velocity of the right heart is significantly lower than in the left heart, which is explained by the crescent-shaped cavity of the right ventricle around the left ventricle. The faster active filling velocities are significantly influenced by heart rate in conscious birds. Anesthesia with isoflurane leads to a significant decrease of the diastolic blood flow velocities, and the A wave velocities of both ventricles are especially influenced. Anesthesia with isoflurane induces a high incidence of insufficiencies of the left atrioventricular valve in the preejection period. These observations indicate that a contraction of the left ventricle myocardium is important for a complete valvular closure and for normal functioning of this heart valve. The effective closure of the right atrioventricular muscle valve in anesthetized pigeons supports the observation of the fast innervation of this muscle valve via a direct connection to the right atrium.


2008 ◽  
Vol 22 (2) ◽  
pp. 81-90 ◽  
Author(s):  
Natalie Werner ◽  
Neval Kapan ◽  
Gustavo A. Reyes del Paso

The present study explored modulations in cerebral blood flow and systemic hemodynamics during the execution of a mental calculation task in 41 healthy subjects. Time course and lateralization of blood flow velocities in the medial cerebral arteries of both hemispheres were assessed using functional transcranial Doppler sonography. Indices of systemic hemodynamics were obtained using continuous blood pressure recordings. Doppler sonography revealed a biphasic left dominant rise in cerebral blood flow velocities during task execution. Systemic blood pressure increased, whereas heart period, heart period variability, and baroreflex sensitivity declined. Blood pressure and heart period proved predictive of the magnitude of the cerebral blood flow response, particularly of its initial component. Various physiological mechanisms may be assumed to be involved in cardiovascular adjustment to cognitive demands. While specific contributions of the sympathetic and parasympathetic systems may account for the observed pattern of systemic hemodynamics, flow metabolism coupling, fast neurogenic vasodilation, and cerebral autoregulation may be involved in mediating cerebral blood flow modulations. Furthermore, during conditions of high cardiovascular reactivity, systemic hemodynamic changes exert a marked influence on cerebral blood perfusion.


Anaesthesia ◽  
2012 ◽  
Vol 67 (8) ◽  
pp. 936-936 ◽  
Author(s):  
P. Kundra ◽  
J. Velraj ◽  
U. Amirthalingam ◽  
S. Habeebullah ◽  
K. Yuvaraj ◽  
...  

1999 ◽  
Vol 9 (4) ◽  
pp. 198-200 ◽  
Author(s):  
Olaf Hoffmann ◽  
Markus Weih ◽  
Thomas von Münster ◽  
Stephan Schreiber ◽  
Karl Max Einhäupl ◽  
...  

2018 ◽  
Vol 2018 ◽  
pp. 1-6
Author(s):  
Marion Bienert ◽  
Niklas Plange ◽  
Andreas Remky ◽  
Kay Oliver Arend ◽  
David Kuerten

Purpose.Ischemic ocular disorders may be treated by hypervolemic hemodilution. The presumed therapeutic benefit is based on a volume effect and improved rheological factors. The aim was to investigate the acute effect of intravenous hydroxyethyl starch on retrobulbar hemodynamics in patients with nonarteritic anterior ischemic optic neuropathy (NAION).Methods.24 patients with acute NAION were included. Retrobulbar hemodynamics were measured using color Doppler imaging before and 15 min after intravenous infusion of 250 cc 10% hydroxyethyl starch (HES). Peak systolic velocity (PSV), end diastolic velocity (EDV), and Pourcelot’s resistive index (RI) were measured in the ophthalmic artery (OA), central retinal artery (CRA), and short posterior ciliary arteries (PCAs).Results.After infusion of HES blood flow velocities significantly increased in the CRA (PSV from7.53±2.33to8.32±2.51  (p<0.001); EDV from2.16±0.56to2.34±0.55  (p<0.05)) and in the PCAs (PSV from7.18±1.62to7.56±1.55  (p<0.01); EDV from2.48±0.55to2.66±0.6 cm/sec (p<0.01)). The RI of all retrobulbar vessels remained unaffected. Blood pressure and heart rate remained unchanged.Conclusions.Hypervolemic hemodilution has an acute effect on blood flow velocities in the CRA and PCAs in NAION patients. Increased blood flow in the arteries supplying the optic nerve head may lead to a better perfusion in NAION patients. This trial is registered withDRKS00012603.


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