Functional Characteristics of Intramyocardial Capacitance Vessels and Their Effects on Coronary Arterial Inflow and Venous Outflow

1990 ◽  
pp. 89-97 ◽  
Author(s):  
Katsuhiko Tsujioka ◽  
Masami Goto ◽  
Osamu Hiramatsu ◽  
Yoshifumi Wada ◽  
Yasuo Ogasawara ◽  
...  
Keyword(s):  
Functional Characteristics ◽  
Venous Outflow ◽  
Arterial Inflow ◽  
Capacitance Vessels

MECHANICAL CHARACTERISTICS OF CORONARY CIRCULATION

2001 ◽  
Vol 01 (02) ◽  
pp. 67-77 ◽  
Author(s):  
FUMIHIKO KAJIYA ◽  
OSAMU HIRAMATSU ◽  
MASAMI GOTO ◽  
YASUO OGASAWARA
Keyword(s):  
Blood Volume ◽  
Mechanical Characteristics ◽  
Venous Outflow ◽  
Venous Flow ◽  
Unstressed Volume ◽  
Arterial Inflow ◽  
Capacitance Vessels ◽  
Unsaturated Condition ◽  
Functional Components ◽  
Interesting Analogy

The phase opposition of velocity waveforms between coronary arteries (predominantly diastolic) and veins (systolic) is the most prominent characteristic of coronary hemodynamics. The phase opposition indicates the importance of intramyocardial capacitance vessels, as a determinant of phasic coronary arterial and venous flows. To investigate the functional characteristics of the intramyocardial capacitance vessels and its physiological significance, we analyzed the change in venous flow following changes in coronary arterial inflow. It was shown that during diastole the intramyocardial capacitance vessels have two functional components, unstressed volume and ordinary capacitance. Unstressed volume is defined as the volume of blood in a vessel at zero transmural pressure, and it was ~5% of the volume of the myocardium. The systolic coronary venous outflow showed a significant, positive correlation with the total displaceable blood volume stored in the intramyocardial unstressed volume and ordinary capacitance. When the unstressed volume was saturated, the coronary inflow was decreased significantly, compared with that for the unsaturated condition. Thus, the increase in intramyocardial blood volume decreases the coronary arterial inflow, whereas it enhances coronary venous outflow. The latter is an interesting analogy to the Starling's law of the heart.

Functional diameters of alveolar microvessels at high lung volume in zone II

1998 ◽  
Vol 85 (1) ◽  
pp. 47-52 ◽  
Author(s):  
Robert L. Conhaim ◽  
Lance A. Rodenkirch
Keyword(s):  
Flow Cytometry ◽  
Confocal Microscopy ◽  
Lung Volume ◽  
Left Atrial ◽  
Venous Outflow ◽  
Latex Particles ◽  
Arterial Inflow ◽  
Pulmonary Arterial ◽  
Zone Ii ◽  
Isolated Rat

To estimate the functional diameter of alveolar microvessels, we perfused isolated rat lungs with fluorescent latex particles (1 diameter/lung) at inflation, pulmonary arterial, and left atrial pressures of 25, 30, and 0 cmH2O, respectively. We used confocal microscopy to count latex particles within septal microvessels and flow cytometry to count particle concentrations in venous outflow. We found 1-, 2-, and 4-μm-diameter particles within septal vessels of 45 ± 12, 31 ± 12, and 25 ± 9%, respectively, of examined alveoli. Particles of 5-μm diameter were absent from septal vessels but were present within a small percentage of corner vessels. Particle concentrations in the venous outflow for 1-, 2-, 4-, and 5-μm-diameter particles were 54 ± 28, 67 ± 32, 2.2 ± 0.3, and 0.4 ± 0.3%, respectively, of the arterial inflow. Particles with diameters of 6 or 10 μm were absent from venous outflow. Our results suggest that, under these conditions, the functional diameter of the septal microvessels is ∼4 μm and that the diameter of the adjacent corner vessels is slightly larger but <6 μm.

Tissue pressure and critical closing pressure in the isolated denervated dog foreleg

1959 ◽  
Vol 196 (3) ◽  
pp. 489-494 ◽  
Author(s):  
Lerner B. Hinshaw ◽  
Stacey B. Day
Keyword(s):  
Pressure Difference ◽  
Null Point ◽  
Homologous Blood ◽  
Venous Outflow ◽  
Tissue Pressure ◽  
Tissue Edema ◽  
Critical Closing Pressure ◽  
Arterial Inflow ◽  
Low Pressures ◽  
Closing Pressure

Experiments designed to obtain very low pressures and flows in the isolated leg were performed on the weighed, denervated dog foreleg perfused with homologous blood. Continuous strain gauge recordings of pressure decay curves and rates of weight loss (venous outflow) were obtained after arrest of the arterial inflow. In some instances tissue pressures were measured by a ‘null-point’ procedure. The results provide no evidence for a generalized critical closing pressure in the denervated, blood-perfused, nonedematous leg. After occlusion of arterial inflow the arteriovenous pressure difference fell to zero (0.0 mm Hg) as venous outflow approached zero. Evidence was obtained showing that if a pressure difference is found at zero flow in the isolated leg, it is produced by the existing tissue pressure. An elevated closing pressure is readily obtained in the dog foreleg when the tissue pressure is increased, and its magnitude is directly related to the extent of tissue edema.

Phasic characteristics of arterial inflow and venous outflow of right ventricular myocardium in dogs

1992 ◽  
Vol 262 (5) ◽  
pp. H1422-H1427 ◽  
Author(s):  
O. Hiramatsu ◽  
A. Kimura ◽  
T. Yada ◽  
T. Yamamoto ◽  
Y. Ogasawara ◽  
...  
Keyword(s):  
Coronary Artery ◽  
Right Ventricular ◽  
Right Coronary Artery ◽  
Pulmonary Stenosis ◽  
Systolic Pressure ◽  
Laser Doppler Velocimeter ◽  
Venous Outflow ◽  
Coronary Veins ◽  
Arterial Inflow ◽  
The Right

To clarify the characteristics and causes of phasic blood flow in coronary circulation of the right ventricle we measured blood velocities in peripheral portions of the right coronary artery and vein in dogs under three conditions: control, transient pulmonary stenosis, and isoproterenol administration. An optical fiber sensor of a laser Doppler velocimeter was fixed onto the vessels (150-500 microns OD) with cyanoacrylate. The phasic pattern of distal arterial velocity was compared with the proximal velocity in the right coronary artery measured with an ultrasound pulsed Doppler velocimeter. Systolic-to-total velocity area ratio in the small epicardial artery [0.38 +/- 0.03 (SE)] was found to be smaller than in the large epicardial artery (0.51 +/- 0.02, P less than 0.01), indicating a capacitive filling of the epicardial artery during systole. The velocity waveform in small right coronary veins was predominantly systolic; i.e., it increased with a rise of right ventricular pressure and decreased with right ventricular relaxation. Comparison of the waveforms during isoproterenol infusion and pulmonary stenosis indicates that contraction of the ventricle is more important than right ventricular systolic pressure in retarding arterial inflow and accelerating venous outflow.

scholarly journals Functional characteristics of intramyocardial capacitance vessels during diastole in the dog.

1986 ◽  
Vol 58 (4) ◽  
pp. 476-485 ◽  
Author(s):  
F Kajiya ◽  
K Tsujioka ◽  
M Goto ◽  
Y Wada ◽  
X L Chen ◽  
...  
Keyword(s):  
Functional Characteristics ◽  
Capacitance Vessels

Cardiovascular function in nonarteriosclerotic versus arteriosclerotic rats

1975 ◽  
Vol 229 (1) ◽  
pp. 18-22 ◽  
Author(s):  
HT Colfer ◽  
SG Iams ◽  
BC Wexler
Keyword(s):  
Venous Blood ◽  
Cardiovascular Function ◽  
Gracilis Muscle ◽  
Heavy Exercise ◽  
Venous Outflow ◽  
Contracting Muscle ◽  
Vasodilator Activity ◽  
Exercise Hyperemia ◽  
Arterial Inflow ◽  
Resting Muscle

Cardiovascular function of arteriosclerotic (breeders) and nonarteriosclerotic (virgins) male am exercise was examined in the denervated gracilis muscle of the anesthetized dog. The data show that 1) on initiation of heavy exercise, the effluent blood PO2 and pH fall markedly and then rise slowly but remain depressed relative to control during 60 min of exercise hyperemia, while the initial increases in [K+] and osmolality rapidly approach and eventually reach preexercise levels. 2) The enhanced vasodilator activity of venous blood from exercising muscle is attenuated when effluent blood PO2 or pH is corrected to preexercise levels; it is completely abolished when both are corrected. 3) Induced reduction of PO2 or pH in the arterial inflow, and thus venous outflow, of resting muscle produces a fall in resistance; simultaneous reductions of both to levels seen in heavy exercise produce a fally in resistance to near that observed during exercise. Since the enhanced vasodilator activity of venous blood from the contracting muscle was abolished by simultaneous correction of the PO2 and pH, it seems likely that these factors, acting directly or indirectly, are the prinicipal chemicals responsible for the maintenance of the vasodilation seen in canine skeletal muscle during heavy exercise.

Interaction of O2 and CO2 in sustained exercise hyperemia of canine skeletal muscle

1975 ◽  
Vol 229 (1) ◽  
pp. 28-33 ◽  
Author(s):  
DF Stowe ◽  
TL Owen ◽  
DK Anderson ◽  
FJ Haddy ◽  
JB Scott
Keyword(s):  
Skeletal Muscle ◽  
Venous Blood ◽  
Heavy Exercise ◽  
Venous Outflow ◽  
Relative Contribution ◽  
Vasodilator Activity ◽  
Exercise Hyperemia ◽  
Arterial Inflow ◽  
Resting Muscle

The relative contribution of O2 and CO2 to the metabolic control of blood flow in long-term exercise was examined in the denervated gracilis muscle of the anesthetized dog. The data show that 1) on initiation of heavy exercise, the effluent blood PO2 and pH fall markedly and then rise slowly but remain depressed relative to control during 60 min of exercise hyperemia, while the initial increases in [K+] and osmolality rapidly approach and eventually reach preexercise levels. 2) The enhanced vasodilator activity of venous blood from exercising muscle is attenuated when effluent blood PO2 or pH is corrected to preexercise levels; it is completely abolished when both are corrected. 3) Induced reduction PO2 or pH in the arterial inflow, and thus venous outflow, of resting muscle produces a fall in resistance; simultaneous reductions of both to levels seen in heavy exercise produce a fall in resistance to near that observed during exercise. Since the enhanced vasodilator activity of venous blood from the contracting muscle was abolished by simultaneous correction of the PO2 and pH, it seems likely that these factors, acting directly or indirectly, are the principal chemicals responsible for the maintenance of the vasodilation seen in canine skeletal muscle during heavy exercise.

Vacuum-assisted mechanical thrombectomy in extensively occlusive thrombosis of dialysis arteriovenous grafts with indigo system

2020 ◽  
Vol 21 (5) ◽  
pp. 673-679
Author(s):  
Filippo Piacentino ◽  
Andrea Coppola ◽  
Andrea Zaghetto ◽  
Edoardo Macchi ◽  
Giuseppe De Marchi ◽  
...  
Keyword(s):  
Mechanical Thrombectomy ◽  
Clinical Success ◽  
Primary Patency ◽  
Secondary Patency ◽  
Technical Failure ◽  
Arteriovenous Graft ◽  
Venous Outflow ◽  
Percutaneous Mechanical Thrombectomy ◽  
Arterial Inflow ◽  
Surgical Thrombectomy

Purpose: To present a selected series of extensively occlusive thrombosis of arteriovenous graft treated with the Penumbra’s Indigo System. Materials and Methods: Ten patients with acute (within 72 h) extensively occlusive thrombosis of arteriovenous graft (mean extension = 30.1 (range = 15–45) cm) were treated at our institution with the Indigo System. Of the 10 cases, thrombosis was extended to venous outflow in 7 cases and to both arterial inflow and venous outflow in 3 cases. Results: Both anatomic and clinical success were achieved in 8 of the 10 procedures (80.0%). In the 2 cases of technical failure, the patients underwent surgical thrombectomy with the finding of arteriovenous graft exhaustion, which was then replaced. The 6-month primary patency, primary-assisted patency, and secondary patency rates were 37.5% (3/8), 50.0% (4/8), and 62.5% (5/8). We reported 2 complications (one minor and one major adverse event). Conclusion: Percutaneous mechanical thrombectomy aspiration with Indigo System is a relatively safe and effective procedure and can be used even in extensively thrombosed arteriovenous graft.

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