scholarly journals The diastolic pressure-volume relationship of the left ventricle -Studied by canine isovolumetric contracting left ventricle-.

1982 ◽  
Vol 46 (1) ◽  
pp. 84-91 ◽  
Author(s):  
SANYA SAKAMOTO ◽  
HISAKAZU YASUDA ◽  
RINJI MURAKAMI ◽  
MASANOBU ANDO ◽  
TITSUO NISHINO
2017 ◽  
Vol 07 (02) ◽  
pp. e86-e92 ◽  
Author(s):  
Kathleen Antony ◽  
Diana Racusin ◽  
Michael Belfort ◽  
Gary Dildy

Objective Uterine tamponade by fluid-filled balloons is now an accepted method of controlling postpartum hemorrhage. Available tamponade balloons vary in design and material, which affects the filling attributes and volume at which they rupture. We aimed to characterize the filling capacity and pressure-volume relationship of various tamponade balloons. Study Design Balloons were filled with water ex vivo. Intraluminal pressure was measured incrementally (every 10 mL for the Foley balloons and every 50 mL for all other balloons). Balloons were filled until they ruptured or until 5,000 mL was reached. Results The Foley balloons had higher intraluminal pressures than the larger-volume balloons. The intraluminal pressure of the Sengstaken-Blakemore tube (gastric balloon) was initially high, but it decreased until shortly before rupture occurred. The Bakri intraluminal pressure steadily increased until rupture occurred at 2,850 mL. The condom catheter, BT-Cath, and ebb all had low intraluminal pressures. Both the BT-Cath and the ebb remained unruptured at 5,000 mL. Conclusion In the setting of acute hemorrhage, expeditious management is critical. Balloons that have a low intraluminal pressure-volume ratio may fill more rapidly, more easily, and to greater volumes. We found that the BT-Cath, the ebb, and the condom catheter all had low intraluminal pressures throughout filling.


1978 ◽  
Vol 42 (3) ◽  
pp. 433-441 ◽  
Author(s):  
S A Glantz ◽  
G A Misbach ◽  
W Y Moores ◽  
D G Mathey ◽  
J Lekven ◽  
...  

1992 ◽  
Vol 263 (1) ◽  
pp. H88-H95
Author(s):  
J. Kikuchi ◽  
Y. Koiwa ◽  
T. Takagi ◽  
H. Honda ◽  
N. Hoshi ◽  
...  

To examine the effect of mechanical vibration on ventricular relaxation and diastolic chamber stiffness under global ischemia, we studied eight coronary perfused, isolated, isovolumic canine left ventricles (LV). To produce varying degrees of impaired relaxation, graded coronary flow reduction and paced tachycardia were imposed. A mechanical 50-Hz, 2-mm-amplitude vibration was applied during diastole and was turned off during systole. Without diastolic vibration, the relaxation time constant of LV pressure (tau) increased with the severity of ischemia. The chamber stiffness index (K) from the diastolic pressure-volume relationship showed a slight increase during ischemia; tau decreased with diastolic vibration. The change in tau with vibration increased with ischemia and was dependent on vibration amplitude but not heart rate. The ratio of tau to the diastolic interval (DI, the time from peak negative rate of LV pressure change to end diastole) always decreased with vibration and was linearly correlated with K (r = 0.93; P less than 0.01). K decreased with vibration when tau/DI was greater than 0.3. We conclude that diastolic vibration improves impaired relaxation and chamber stiffness under myocardial ischemia.


1980 ◽  
Vol 239 (2) ◽  
pp. H189-H198 ◽  
Author(s):  
H. S. Goldberg

Static and dynamic properties governing the fluid movement into the pulmonary interstitium were examined in isolated canine lobes. The system was driven by altering intravascular presure (Piv) when the lobe was isogravimetric (change in weight (W) = 0) and allowing the lobe to become isogravimetric again. By making use of an analogy to charging a capacitor across a resistor, calculation of the filtration coefficient for transvascular fluid movement (KF) and determination of the pressure-volume relationship of the pulmonary interstitial space (Pis-Vis), with a minimum of untested assumptions, was possible. KF was found to be the same for fluid moving out of or into the intravascular space, and when the relationship between Piv and alveolar pressure (PAlv) was constant, KF was independent of transpulmonary pressure (PL). When PAlv exceeded Piv, changes in Piv did not influence KF, suggesting no significant change in either surface area available for fluid transudation or vascular permeability. The Pis-Vis curve for increasing values of Vis and Pis is best described by an exponential relationhip and is independent of PL. However, the Pis-Vis curve with decreasing values of Vis and Pis is dependent on PL.


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