Effects of altered hematocrit on pulmonary artery pressure-flow characteristics in canine pulmonary embolism

1990 ◽  
Vol 5 (1) ◽  
pp. 35-41
Author(s):  
John Ducas ◽  
Robert Kischuk ◽  
Usha Schick ◽  
Richard M. Prewitt
2018 ◽  
Vol 57 (5) ◽  
pp. 647-654
Author(s):  
Masaomi Gohbara ◽  
Keigo Hayakawa ◽  
Azusa Hayakawa ◽  
Yusuke Akazawa ◽  
Yukihiro Yamaguchi ◽  
...  

1977 ◽  
Author(s):  
M.H. Todd ◽  
J.B. Forrest ◽  
J. Hirsh

Embolisation of the pulmonary vasculature with microspheres releases prostaglandin-1ike substances, PGLS (Piper and Vane, N.Y. Acad. Sei. 180: 363, 1971) but the capacity of autologous blood clots (ABC) to release pulmonary vasoactive substances is disputed. Ten normal mongrel dogs were anesthetised with pentobarbitone sodium and instrumented. Pulmonary venous blood was continuously superfused over isolated tissues for bioassay and then returned to the animal. Injection of ABC into the right atrium increased pulmonary artery pressure from 21 ± 6.5 mm Hg to 38 ± 15 mm Hg (mean ± S.D.), increased arterial pCO2 and decreased arterial pO2. No significant changes in heart rate, systemic arterial blood pressure or cardiac output occurred. In three animals contractions of the blood superfused assay tissues occurred following embolism. This effect was produced in normal assay tissues and those pretreated with antagonists of ACh, Serotonin, Histamine and Catecholamines and could therefore be attributed to PGLS. No cardiovascular or assay tissue tension changes were observed when equivalent volumes of saline or clot lysate were injected into the right atrium.Therefore, pulmonary embolism with ABC can release PGLS which may contribute to the pulmonary artery pressure rise. Vasoactive substances may normally be inactivated in the lung but in some animals appear in pulmonary venous blood.(Supported by the Ontario Heart Foundation)


1991 ◽  
Vol 21 (2) ◽  
pp. 248
Author(s):  
Kwang Kon Koh ◽  
Myung A Kim ◽  
Joo Hee Cho ◽  
Myoung Mook Lee ◽  
Young Bae Park ◽  
...  

2020 ◽  
Author(s):  
Mahsa Behnemoon ◽  
Elham Laleh ◽  
Amin Sedokani ◽  
Ayatay Bahrami

Abstract Background: Pulmonary embolism (PE) is a relatively common health problem and the third most common cause of cardiovascular death with a 15-20 percent mortality rate. Severe pulmonary arterial hypertension is not common in acute forms of the disease, and we usually expect only mild to moderate degrees of PAH in these patients. However, we have encountered numerous cases of severe pulmonary hypertension after acute PE in our practice. In this study, we aimed to evaluate the echocardiographic findings of patients admitted with documented PE in a 5 years study of two heart centers of Urmia.Methods: In this retrospective study, the data of 183 patients with a definitive diagnosis of acute pulmonary embolism based on pulmonary CT angiography have entered the study.Results: Of the 183 cases diagnosed with pulmonary embolism with an average age of 61.15 years, 45.4% were male and 54.6% were female. Shortness of breath, chest pain, and hemoptysis were seen in 88%, 49.2%, and 13.1% of patients, respectively. Tachypnea and tachycardia were the most common clinical findings with a frequency of 54.1%. Echocardiographic findings of right ventricular enlargement and right ventricular dysfunction were observed in 66.7% and 67.8% of patients, respectively and 42.1% of patients had severe pulmonary hypertension. We found a significant relationship between pulmonary artery pressure severity and shock state as well as in-hospital mortality. While only 3 patients out of 64 cases (4%) with normal or mildly elevated pulmonary artery pressure died in their hospital stay period, the mortality rate was 28.5% in patients with moderate or severe pulmonary artery hypertension (p-value=0.002).Conclusion: we found a relatively high frequency of severe pulmonary artery hypertension in patients admitted with the definite diagnosis of acute pulmonary embolism and there was a significant correlation between pulmonary artery pressure severity and shock state, as well as in-hospital mortality. So, echocardiographic findings including right ventricular systolic pressure and TR velocity may have additional prognostic value in the decision making of acute PE patients and could be helpful in reducing in-hospital mortality of this complex illness provided being included in prognostic models of acute PE, based on future studies.


1988 ◽  
Vol 255 (1) ◽  
pp. H19-H25 ◽  
Author(s):  
J. Ducas ◽  
U. Schick ◽  
L. Girling ◽  
R. M. Prewitt

We studied the effects of changes in pulmonary capillary wedge pressure (PCWP) on the slope (incremental resistance) and the extrapolated pressure intercept (PI) of the mean pulmonary artery pressure (PAP)-cardiac output (CO) relationship. Multipoint plots of PAP against CO were obtained in intact anesthetized dogs. Group 1 consisted of six dogs entirely in West zone 3 and group 2 of four dogs with mixed West zone 2-3. The four conditions studied were the following: 1) fixed low PCWP, 2) fixed high PCWP, 3) variable PCWP, and 4) time-control repeat of condition 1. The PI significantly exceeded PCWP at fixed low PCWP (group 1, 9.3 vs. 11.1 mmHg, group 2, 6.6 vs. 3.9 mmHg). PI became identical to PCWP only at fixed high PCWP in group 1 (19 +/- 2.0 vs. 19 +/- 1.1 mmHg). Thus PCWP reflects the effective vascular outflow pressure when PCWP is fixed and high. For both groups of dogs in condition 3, when PCWP was varied with CO, the slope of the resulting PAP-CO plot was significantly greater than when PCWP was constant. Also in 9 of 10 dogs, PI was less than PCWP when PCWP was varied. These findings demonstrate that when changes in PCWP are allowed to occur during the generation of a pulmonary artery pressure-flow plot, the resulting slope and intercept, as defined by a Starling resistor model, do not accurately represent the incremental resistance and outflow pressure of the pulmonary vasculature.


2018 ◽  
Vol 23 (2) ◽  
pp. 134-138
Author(s):  
Edwin A Takahashi ◽  
Christopher J Reisenauer ◽  
Andrew H Stockland ◽  
Haraldur Bjarnason ◽  
Melissa J Neisen ◽  
...  

This study examined the potential correlation between pulmonary embolism (PE) attenuation on computed tomography pulmonary angiography (CTPA) and pulmonary artery hemodynamic response to catheter-directed thrombolysis (CDT) in 10 patients with submassive PE. Treatment parameters, PE attenuation, clot burden, computed tomography signs of right ventricle dysfunction and right ventricular systolic pressure at echocardiography were retrospectively analyzed to determine correlation with pulmonary artery pressure improvement using Spearman correlation. A single reader, blinded to the treatment results, measured PE attenuation of all patients. There was a significant positive correlation between PE attenuation and absolute pulmonary artery pressure improvement with a Spearman correlation of 0.741, p=0.014. When attenuation was greater than or equal to the median (44.5 HU, n=5), CDT was associated with significantly better pulmonary artery pressure improvement ( p=0.037). Clot attenuation at CTPA may be a potential imaging biomarker for predicting pulmonary artery pressure improvement after CDT.


Author(s):  
Mona Lichtblau ◽  
Stéphanie Saxer ◽  
Patrick Bader ◽  
Paula Appenzeller ◽  
Philipp Scheiwiller ◽  
...  

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