The influence of heart rate and age on diastolic blood flow velocity in the left ventricular inflow tract

1989 ◽  
Vol 17 (5) ◽  
pp. 339-344 ◽  
Author(s):  
Ina van Dam ◽  
Ben Delemarre ◽  
Jeroen Hopman ◽  
Theo de Boo ◽  
Cuno Uiterwaal ◽  
...  
1990 ◽  
Vol 68 (5) ◽  
pp. 2208-2213 ◽  
Author(s):  
K. H. McKeever ◽  
M. G. Skidmore ◽  
L. C. Keil ◽  
H. Sandler

Eight rhesus monkeys were used to study responses of radial artery blood flow velocity (RABFV) and heart rate (HR) to low (0 to -20 mmHg) and high (0 to -60 mmHg) ramp exposures during supine lower body negative pressure (LBNP). These levels were chosen to separate peripheral vascular responses associated with stimulation of low- and high-pressure baroreceptors. Four monkeys had efferent and afferent cardiac denervation by use of the Randall procedure with pharmacological (phenylephrine and atropine) verification. Animals were studied 3 wk after surgery to avoid reinnervation. Findings were compared with those of four identically treated intact animals. Denervated animals showed no change in RABFV or HR during low-level LBNP; however, HR increased significantly (P less than 0.05) when LBNP reached -50 mmHg and blood flow velocity also fell (P less than 0.05) starting at -30 mmHg pressure. In contrast, intact animals showed steady decreases in RABFV during both high- and low-pressure protocols, with HR showing a 6-beat/min increase (P less than 0.05) starting at -20 mmHg pressure. As with denervated animals, intact animals showed a more pronounced increase in HR after reaching a level of -60 mmHg suction. Cardiac output (electromagnetic flowmeter, ascending aorta) fell significantly in both groups starting at -30 mmHg pressure. Left ventricular pressure (Konigsberg pressure cell) in three intact animals showed a progressive fall in systolic pressure starting at -10 mmHg suction, which became significant at -55 mmHg pressure. These results demonstrate that cardiac denervation by use of the Randall technique significantly affects RABFV and HR responses to LBNP in rhesus monkeys. The lack of RABFV change during LBNP in denervated animals suggests that these changes coupled with HR response can be used as an effective method to verify the completeness of denervation of low-pressure baroreceptors in animals that have undergone intrapericardial denervation.


Circulation ◽  
2020 ◽  
Vol 142 (Suppl_3) ◽  
Author(s):  
Wangde Dai ◽  
Jianru Shi ◽  
Juan Carreno ◽  
Lifu zhao ◽  
Michael T Kleinman ◽  
...  

Background: We investigated the effects of chronic electronic cigarettes with nicotine (E-Cig) exposure on cardiovascular function in rats. Methods: Adult Sprague Dawley rats were exposed to either pure air (n=10) or E-Cig (n=14) for 12 weeks. After 12 weeks of exposure, flow-mediated vasodilation was measured in anesthetized rats with ultrasound to measure femoral artery diameter. Femoral artery flow velocity was measured before and 5 minutes after reperfusion of a 5-minute femoral artery occlusion. Cardiac function was assessed by echocardiogram. A Millar catheter was used to record systemic arterial and LV pressures. Cardiac output was measured using a themodilution catheter. Results: The femoral artery internal diameter and blood flow velocity were comparable between the 2 groups before and after artery occlusion. However, in the E-cig group, blood flow velocity significantly decreased from 55.5 ± 5.2 cm/s prior to occlusion to 41.3 ± 4.1 cm/s after reperfusion (p = 0.005); it remained similar prior to (47.8 ± 3.4 cm/s) and after (47.8 ± 5.5 cm/s) occlusion in the air group. There were no statistically significant differences in left ventricular diastolic and systolic dimensions, LV fractional shortening, heart rate or mean blood pressure (80 ± 3 mmHg in air and 79 ± 5 mmHg in E-cig group) , LV end-diastolic pressure (Ped), end-systolic pressure (Pes), peak -dP/dt, Tau, or cardiac output (48.3 ± 3.3 ml/min in air and 47.6 ± 3.9 ml/min in E-cig group) between the E-Cig and the pure air group. There was a trend toward a reduction in peak LV +dP /dt in the E-Cig group (5574 ± 341 mmHg/s) compared to the air group (6166 ± 238 mmHg/s). LV weight and wall thickness were similar between groups. Conclusions: Twelve weeks of E-Cig exposure did not affect heart rate or blood pressure; but did tend to reduce contractility. E-cigarette exposure slowed the flow-mediated blood flow velocity probably at a microvascular level, possibly by altering endothelial function.


Inventions ◽  
2019 ◽  
Vol 4 (4) ◽  
pp. 65 ◽  
Author(s):  
Fiorency Santoso ◽  
Bonifasius Putera Sampurna ◽  
Yu-Heng Lai ◽  
Sung-Tzu Liang ◽  
Erwei Hao ◽  
...  

This study aimed to develop a simple and cost-effective method to measure blood flow in zebrafish by using an image-based approach. Three days post fertilization (dpf) zebrafish embryos were mounted with methylcellulose and subjected to video recording for tracking blood flow under an inverted microscope equipped with a high-speed CCD camera. In addition, Hoffman lens was used to enhance the blood cell contrast. The red blood cell movement was tracked by using the TrackMate plug-in in the ImageJ image processing program. Moreover, Stack Difference and Time Series Analyzer plug-in were used to detect dynamic pixel changes over time to calculate the blood flow rate. In addition to blood flow velocity and heart rate, the effect of drug treatments on other cardiovascular function parameters, such as stroke volume and cardiac output remains to be explored. Therefore, by using this method, the potential side effects on the cardiovascular performance of ethyl 3-aminobenzoate methanesulfonate (MS222) and 3-isobutyl-1-methylxanthine (IBMX) were evaluated. MS222 is a common anesthetic, while IBMX is a naturally occurring methylxanthine. Compared to normal embryos, MS222- and IBMX-treated embryos had a reduced blood flow velocity by approximately 72% and 58%, respectively. This study showed that MS222 significantly decreased the heart rate, whereas IBMX increased the heart rate. Moreover, it also demonstrated that MS222 treatment reduced 50% of the stroke volume and cardiac output. While IBMX decreased the stroke volume only. The results are in line with previous studies that used expensive instruments and complicated software analysis to assess cardiovascular function. In conclusion, a simple and low-cost method can be used to study blood flow in zebrafish embryos for compound screening. Furthermore, it could provide a precise measurement of clinically relevant cardiac functions, specifically heart rate, stroke volume, and cardiac output.


1973 ◽  
Vol 85 (3) ◽  
pp. 294-301 ◽  
Author(s):  
Alberto Benchimol ◽  
Kenneth B. Desser ◽  
John L. Gartlan

1993 ◽  
Vol 1 (2) ◽  
pp. 145
Author(s):  
Chong Hun Park ◽  
Eun Seok Jeon ◽  
Ki Nam Park ◽  
Byeng Su Kwak ◽  
Seung Sik Kang ◽  
...  

1991 ◽  
Vol 261 (5) ◽  
pp. H1585-H1596 ◽  
Author(s):  
F. J. Miller ◽  
M. L. Marcus ◽  
M. J. Brody ◽  
D. D. Gutterman

A role for parabrachial nucleus in cardiovascular regulation is suggested by evidence that electrical stimulation in this region elicits increase in heart rate and arterial pressure. We hypothesized that parabrachial nucleus may also be involved in control of coronary vasomotor tone. After beta-adrenergic receptor blockade in anesthetized cats, electrical stimulation in the region of parabrachial nucleus produced no change in heart rate, an increase in arterial pressure (34 +/- 6 mmHg), and a transient reduction in coronary blood flow velocity (-21 +/- 2%). Coronary resistance (72 +/- 9%) and femoral resistance (189 +/- 31%) increased markedly. The decrease in coronary blood flow velocity was abolished by stellate ganglionectomy or alpha 1-adrenergic blockade without altering pressor or femoral responses. Injection of the neurotransmitter L-glutamate or kainic acid into parabrachial nucleus also elicited coronary vasoconstriction. We conclude that electrical or chemical activation in the region of parabrachial nucleus elicits coronary vasoconstriction as part of a generalized sympathetic activation. The fact that the coronary response is elicited by chemical activation suggests that cell bodies in the region of medial parabrachial nucleus and subceruleus, as opposed to fibers of passage, are involved in this central neural coronary vasoconstriction.


2019 ◽  
pp. 120-124
Author(s):  
Peter Novak

Small fiber neuropathy is associated with adrenergic failure. Anxiety is common and occasionally can be identified as a transient elevation of heart rate, blood pressure, and cerebral blood flow velocity.


Sign in / Sign up

Export Citation Format

Share Document