THE PHYSIOLOGICAL MECHANISMS OF THE PULMONARY VENOUS HYPERTENSION

2018 ◽  
Vol 18 (2) ◽  
pp. 7-18
Author(s):  
V I Evlakhov ◽  
I Z Poyassov ◽  
V I Ovsyannikov

In the review regulatory mechanisms of functions of pulmonary venous vessels have been considered as well as the signifi cance of their impairment in the development of the pulmonary hypertension, caused by the left ventricular cardiac failure. One of the trigger mechanisms of the development of the pulmonary hypertension as a result of the elevation of the left atrial and pulmonary venous pressure is the reflectory constriction of the pulmonary arterioles (Kitayev’s reflex). Further, the development of endothelial dysfunction and pulmonary vessels remodeling with the phenomenon of “arterializations” of the pulmonary veins take place. The exact evaluation of the pulmonary vascular resistance value in the clinical practice is a difficult task. This parameter, being integrated, does not allow to evaluate the resistance values of pulmonary arterial and venous vessels in the conditions of pulmonary hypertension and to give exact characteristics of their changes, as a result. The mechanisms of development of the pulmonary venous hypertension could not be explicated using the simplified model of the pulmonary vasoconstriction, because the main features of the pulmonary circulation are the presence of arteriovenous and bronchopulmonary shunts, and pulsatile character of the blood flow. To understand the exact pathogenesis of this pathology the further fundamental investigation not only on the cell level, but also on organ and system levels are needed.

1980 ◽  
Vol 48 (6) ◽  
pp. 957-964 ◽  
Author(s):  
B. T. Peterson ◽  
S. E. Grauer ◽  
R. W. Hyde ◽  
C. Ortiz ◽  
H. Moosavi ◽  
...  

Brain compression with subdural air causes pulmonary hypertension and noncardiogenic pulmonary edema (A. B. Malik, J. Appl. Physiol.: Respirat. Environ. Exercise Physiol. 42: 335-343, 1977). To see whether air emboli to the lungs rather than brain compression caused these findings, anesthetized dogs received intravenous air infusions, subdural air infusions, or brain compression from balloons inflated in the subdural space. Subdural air and intravenous air resulted in similar vascular responses. Pulmonary artery pressure (Ppa) increased 160% (P less than 0.01) and pulmonary venous pressure transiently rose 13 +/- 5 Torr (P less than 0.05) without an increase in left atrial pressure or cardiac output (Q). The end-tidal PCO2 fell 55% (P less than 0.01) and the postmortem weight of the lungs increased 55% (P less than 0.05). Brain compression with a subdural balloon instead of air only caused a 20% rise in Ppa and Q without pulmonary edema. Thus, pulmonary air emboli rather than brain compression accounts for the edema and pulmonary hypertension caused by subdural air. Catheters in pulmonary veins and the left atrium showed that air emboli cause transient pulmonary venous hypertension as well as a reproducible form of noncardiogenic pulmonary endema.


2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
J Precek ◽  
K Vykoupil ◽  
F Kovacik ◽  
M Hutyra

Abstract Introduction Sleep disordered breathing (SDB) is a group of ventilatory disorders during sleep which includes obstructive sleep apnea (OSA), central sleep apnea (CSA), and sleep related hypoventilation. In patients with SDB, the prevalence of pulmonary hypertension (PH) ranges from 17% to 52%. While SDB is prevalent in the general population with recent estimates of 20% to 30%, in those with cardiovascular disease, particularly left ventricular failure, there is a higher reported prevalence of 47%. Aims The aims of this study were to determine the prevalence and prognostic relevance of sleep apnea in a cohort of patients with newly diagnosed pulmonary arterial hypertension (ESC/WHO Group 1 pulmonary hypertension). Methods We evaluated prospectively 76 patients with the pulmonary arterial hypertension (mean age 54±16 years; 45% male). All patients underwent right heart catheterisation, clinical assessments, sleep study, standard laboratory testing and evaluation of subjective sleepiness by the Epworth Sleepiness Scale. Sleep test was provided with an ApneaLink Plus, consisting of nasal pressure sensor, respiratory effort band, and pulse oximeter worn on the finger. Subjects previously treated for or diagnosed with SDB were excluded from the study. Results Sleep apnea (SA) – defined as apnea-hypopnea index (AHI) ≥5/h – was found in 59 (77.6%) of the pulmonary arterial hypertension (PAH) patients. Mean AHI in the cohort of PAH patients with SA was 26.1±16.6/h. Mean follow-up was 24 months, during which 15 (19.7%) patients died. Characteristics of parameters related to SA in groups of survivors and deceased are in table 1. From the sleep apnea-related parameters, only time with O2Sat <90% – T90 was significantly associated with mortality (AUC 0.856; 95% CI 0.693 – 1.019; p<0.001). Conclusions The presence of sleep apnea in pulmonary arterial hypertension patients is high. The prevalence of sleep apnea is higher in PAH patients than in the general population. The presence of sleep apnea in patients with PAH was not associated with worse prognosis, but noctural hypoxemia (time with O2Sat <90%) was related to poor prognosis. Sleep apnea in patients with PAH should be screened for systematically. Funding Acknowledgement Type of funding source: None


1963 ◽  
Vol 204 (6) ◽  
pp. 987-990 ◽  
Author(s):  
J. Albrecht Koehler ◽  
Theofilos J. Tsagaris ◽  
Hiroshi Kuida ◽  
Hans H. Hecht

The demonstration in a previous study of the effectiveness of an antihistaminic drug in blocking some of the systemic but not the pulmonary vascular effects of endotoxin led to the study of the effect of an inhibitor of serotonin synthesis, alpha-methyl 3,4-dihydroxyphenylalanine (α-m dopa). One group of seven dogs was pretreated with a single dose of 250 mg, and a second group of six animals with three doses of 250 mg, each given at 10-min intervals. Results in these two groups were compared with those in six control animals. Purified E. coli endotoxin, 1 mg/kg, was administered intravenously in all 19 experiments. Intravenous administration of α-m dopa alone had no effect on measured physiologic parameters. Compared with the endotoxin response in control animals, pretreatment with either dose level appeared to have no effect on the magnitude or duration of systemic arterial hypotension, portal venous hypertension, or drop in cardiac output. However, pretreatment with 250-mg and 750-mg doses was associated with significant reduction and abolition, respectively, of pulmonary arterial hypertension. The results are consistent with the interpretation that the pulmonary vasoconstrictive response to endotoxin is mediated through the release of serotonin and that α-m dopa blocks this response by interfering with the synthesis of this intermediary.


2015 ◽  
Vol 24 (138) ◽  
pp. 665-673 ◽  
Author(s):  
Harrison W. Farber ◽  
Simon Gibbs

Pulmonary hypertension (PH) associated with left heart disease (PH-LHD) is the most common type of PH, but its natural history is not well understood. PH-LHD is diagnosed by right heart catheterisation with a mean pulmonary arterial pressure ≥25 mmHg and a pulmonary capillary wedge pressure >15 mmHg. The primary causes of PH-LHD are left ventricular dysfunction of systolic and diastolic origin, and valvular disease. Prognosis is poor and survival rates are low. Limited progress has been made towards specific therapies for PH-LHD, and management focuses on addressing the underlying cause of the disease with supportive therapies, surgery and pharmacological treatments. Clinical trials of therapies for pulmonary arterial hypertension in patients with PH-LHD have thus far been limited and have provided disappointing or conflicting results. Robust, long-term clinical studies in appropriate target populations have the potential to improve the outlook for patients with PH-LHD. Herein, we discuss the knowledge gaps in our understanding of PH-LHD, and describe the current unmet needs and challenges that are faced by clinicians when identifying and managing patients with this disease.


2016 ◽  
Vol 10 ◽  
pp. CMC.S38447
Author(s):  
Valentine N. Amadi ◽  
Olufemi E. Ajayi ◽  
Anthony O. Akintomide ◽  
Olugbenga O. Abiodun ◽  
Olaniyi J. Bamikole ◽  
...  

Background Pulmonary hypertension (PH) is common in heart failure patients. Literature on PH in heart failure is sparse in Nigeria. This study was carried out to determine the prevalence of PH in heart failure patients and ascertain the relationship between left ventricular systolic and diastolic function and the degree of PH. Methods A total of 125 heart failure patients had echocardiography done. PH was diagnosed using tricuspid regurgitation jet and pulmonary ejection jet profile. Results PH was present in 70.4% of heart failure patients. Estimated mean pulmonary arterial pressure increased with increasing severity of systolic and diastolic dysfunction and had significantly negative correlation with ejection fraction, fractional shortening, and early mitral annular tissue diastolic velocity ( E′), but positive correlation with left ventricular end-systolic volume, right ventricular dimension, transmitral E to A ratio, and E/E′ ratio. Conclusion PH is very common in heart failure and has significant relationship with left ventricular function.


2021 ◽  
Vol 36 (Supplement_1) ◽  
Author(s):  
Ekaterina Borodulina ◽  
Alexander M Shutov

Abstract Background and Aims An important predictor of cardiovascular mortality and morbidity in hemodialysis patients is left ventricular hypertrophy. Also, pulmonary hypertension is a risk factor for mortality and cardiovascular events in hemodialysis patients. The aim of this study was to investigate cardiac remodeling and the dynamics of pulmonary arterial pressure during a year-long hemodialysis treatment and to evaluate relationship between pulmonary arterial pressure and blood flow in arteriovenous fistula. Method Hemodialysis patients (n=88; 42 males, 46 females, mean age was 51.7±13.0 years) were studied. Echocardiography and Doppler echocardiography were performed in the beginning of hemodialysis treatment and after a year. Echocardiographic evaluation was carried out on the day after dialysis. Left ventricular mass index (LVMI) was calculated. Left ventricular ejection fraction (LVEF) was measured by the echocardiographic Simpson method. Arteriovenous fistula flow was determined by Doppler echocardiography. Pulmonary hypertension was diagnosed according to criteria of Guidelines for the diagnosis and treatment of pulmonary hypertension of the European Society of Cardiology. Results Pulmonary hypertension was diagnosed in 47 (53.4%) patients. Left ventricular hypertrophy was revealed in 71 (80.7%) patients. Only 2 (2.3%) patients had LVEF<50%. At the beginning of hemodialysis correlation was detected between systolic pulmonary arterial pressure and LVMI (r=0.52; P<0.001). Systolic pulmonary arterial pressure negatively correlated with left ventricular ejection fraction (r=-0.20; P=0.04). After a year of hemodialysis treatment LVMI decreased from 140.49±42.95 to 123.25±39.27 g/m2 (р=0.006) mainly due to a decrease in left ventricular end-diastolic dimension (from 50.23±6.48 to 45.13±5.24 mm, p=0.04) and systolic pulmonary arterial pressure decreased from 44.83±14.53 to 39.14±10.29 mmHg (р=0.002). Correlation wasn’t found between systolic pulmonary arterial pressure and arteriovenous fistula flow (r=0.17; p=0.4). Conclusion Pulmonary hypertension was diagnosed in half of patients at the beginning of hemodialysis treatment. Pulmonary hypertension in hemodialysis patients was associated with left ventricular hypertrophy, systolic left ventricular dysfunction. After a year-long hemodialysis treatment, a regress in left ventricular hypertrophy and a partial decrease in pulmonary arterial pressure were observed. There wasn’t correlation between arteriovenous fistula flow and systolic pulmonary arterial pressure.


1964 ◽  
Vol 207 (6) ◽  
pp. 1314-1318 ◽  
Author(s):  
Benson R. Wilcox ◽  
W. Gerald Austen ◽  
Harvey W. Bender

The mechanism by which the pulmonary artery pressure rises in response to hypoxia has never been clearly demonstrated. This problem was reinvestigated in experiments utilizing separate pulmonary and systemic perfusion systems. These vascular beds were perfused in such a fashion that a change in pulmonary artery pressure could only result from changes in vasomotor tone. Alveolar-pulmonary vein hypoxia was usually associated with a slight fall in pulmonary artery pressure. Systemic hypoxia resulted in elevation of pulmonary arterial pressure in 10 of the 12 animals tested with a constant-flow and constant-pulmonary venous pressure. In addition, all animals with systemic desaturation showed an increased venous return. When the "cardiac output" (pump output) was increased to match this return, the elevation in pulmonary artery pressure increased. It was concluded that the pulmonary arterial pressure elevation seen with hypoxia is the result of active pulmonary vasoconstriction coupled with an increased pulmonary blood flow.


2019 ◽  
Vol 9 (2) ◽  
pp. 204589401984561 ◽  
Author(s):  
Jessica H. Huston ◽  
Robert P. Frantz ◽  
Evan L. Brittain

Pulmonary arterial hypertension (PAH) is a rare disease that carries a poor prognosis. For 45 years, the definition of pulmonary hypertension (PH) has been a mean pulmonary arterial pressure (mPAP) ≥ 25 mmHg, based on expert opinion. Recent data indicate that the mortality risk starts in the mPAP range of 21–24 mmHg, which has recently been reflected in the World Symposium on PH consensus document defining PH as a mPAP > 20 mmHg. The mortality associated with these lower levels of pulmonary pressures suggests that these values reflect a more advanced disease stage than previously recognized. It is unknown whether interventions targeting patients with mPAP values in the range of 21–24 mmHg in the absence of left ventricular or hypoxic lung disease are of clinical benefit. Here we present historical perspective on the hemodynamic definition of PH, discuss recent epidemiologic data, and outline obstacles to enrolling and evaluating response to therapy in mild PAH patients, as well as potentially useful study designs.


2021 ◽  
Vol 8 ◽  
Author(s):  
Yi Zhang ◽  
Qi Jin ◽  
Zhihui Zhao ◽  
Qing Zhao ◽  
Xue Yu ◽  
...  

Background: Emerging evidence has showed that serum carbohydrate antigen 125 (CA 125) levels are associated with the severity and prognosis of heart failure. However, its role in pulmonary hypertension remains unclear. This study aimed to investigate the clinical, echocardiographic, hemodynamic, and prognostic associations of CA 125 in pulmonary hypertension.Methods and Results: We conducted a retrospective cohort study of all idiopathic pulmonary arterial hypertension and chronic thromboembolic pulmonary hypertension patients receiving CA 125 measurement in Fuwai Hospital (January 1, 2014–December 31, 2018). The primary end-point was cumulative 1-year clinical worsening-free survival rate. Linear regression was performed to assess the association between CA 125 and clinical, echocardiographic, and hemodynamic parameters. Cox proportional hazards models were used to assess the association between CA 125 and clinical worsening events. Receiver operating characteristic (ROC) curve analysis was performed to determine the predictive performance of CA 125. A total of 231 patients were included. After adjustment, CA 125 still positively correlated with World Health Organization functional class, NT-proBNP, right ventricular end-diastolic diameter, pericardial effusion, mean right atrial pressure and pulmonary arterial wedge pressure; negatively correlated with 6-min walk distance, left ventricular end-diastolic diameter, mixed venous oxygen saturation, and cardiac index. After adjustment, CA 125 > 35 U/ml was associated with over 2 folds increased risk of 1-year clinical worsening. Further, ROC analysis showed that CA 125 provided additional predictive value in addition to the established pulmonary hypertension biomarker NT-proBNP.Conclusion: CA 125 was associated with functional status, echocardiography, hemodynamics and prognosis of pulmonary hypertension.


1990 ◽  
Vol 29 (06) ◽  
pp. 246-251
Author(s):  
J. C. Böck ◽  
Aileen Lim ◽  
H. Eichstädt ◽  
M. Pollycove ◽  
R. F. Lewis ◽  
...  

To study the effect of septic pulmonary hypertension on right/left ventricular intrapericardial interactions thirteen trauma patients, seven septic and six non-septic controls, were compared. Ventricular volumes were derived from firstpass or gated equilibrium radionuclide angiocardiography, and related to body surface area. Systemic and pulmonary pressures were measured invasively. Pulmonary arterial pressure was significantly increased in the sepsis group. Although right ventricular end-diastolic volumes were higher in sepsis, left ventricular end-diastolic volumes were not decreased. In terms of intrapericardial right/left ventricular interactions these results indicate that the right and left ventricles operate independently in septic pulmonary hypertension.


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