scholarly journals The isobaric pulmonary arterial compliance in pulmonary hypertension

2021 ◽  
pp. 00941-2020
Author(s):  
Denis Chemla ◽  
Emmanuelle Berthelot ◽  
Jason Weatherald ◽  
Edmund M. T. Lau ◽  
Laurent Savale ◽  
...  

Pulmonary hypertension (PH) is associated with stiffening of pulmonary arteries which increases right ventricular pulsatile loading. High pulmonary artery wedge pressure (PAWP) in postcapillary PH (Pc-PH) further decreases PA compliance (PAC) at a given pulmonary vascular resistance (PVR) compared to precapillary PH, thus responsible for a higher total arterial load. In all other vascular beds, arterial compliance is considered as mainly determined by the distending pressure, due to non-linear stress-strain behaviour of arteries. We tested the applicability, advantages and drawbacks of two comparison methods of PAC depending on the level of mean PA pressure mPAP (isobaric PAC) or PVR.Right heart catheterisation data including PAC (stroke volume/pulse pressure) were obtained in 112Pc-PH (of whom 61 had combined postcapillary and precapillary PH) and 719 idiopathic pulmonary arterial hypertension (iPAH).PAC could be compared over the same mPAP range (25–66 mmHg) in 792/831 patients (95.3%) and over the same PVR range (3–10.7 WU) in only 520/831 patients (62.6%). The main assumption underlying comparisons at a given PVR was not verified as the PVR×PAC product (RC-time) was not constant but on the contrary more variable than mPAP. In the 788/831 (94.8%) patients studied over the same PAC range (0.62–6.5 mL·mmHg−1), PVR and thus total arterial load tended to be higher in iPAH.Our study favours comparing PAC at fixed mPAP level (isobaric PAC) rather than at fixed PVR. A reappraisal of the effects of PAWP on the pulsatile and total arterial load put on the right heart is needed, and this point deserves further studies.

2015 ◽  
Vol 46 (4) ◽  
pp. 1178-1189 ◽  
Author(s):  
Denis Chemla ◽  
Edmund M.T. Lau ◽  
Yves Papelier ◽  
Pierre Attal ◽  
Philippe Hervé

Right ventricular adaptation to the increased pulmonary arterial load is a key determinant of outcomes in pulmonary hypertension (PH). Pulmonary vascular resistance (PVR) and total arterial compliance (C) quantify resistive and elastic properties of pulmonary arteries that modulate the steady and pulsatile components of pulmonary arterial load, respectively. PVR is commonly calculated as transpulmonary pressure gradient over pulmonary flow and total arterial compliance as stroke volume over pulmonary arterial pulse pressure (SV/PApp). Assuming that there is an inverse, hyperbolic relationship between PVR and C, recent studies have popularised the concept that their product (RC-time of the pulmonary circulation, in seconds) is “constant” in health and diseases. However, emerging evidence suggests that this concept should be challenged, with shortened RC-times documented in post-capillary PH and normotensive subjects. Furthermore, reported RC-times in the literature have consistently demonstrated significant scatter around the mean. In precapillary PH, the true PVR can be overestimated if one uses the standard PVR equation because the zero-flow pressure may be significantly higher than pulmonary arterial wedge pressure. Furthermore, SV/PApp may also overestimate true C. Further studies are needed to clarify some of the inconsistencies of pulmonary RC-time, as this has major implications for our understanding of the arterial load in diseases of the pulmonary circulation.


2015 ◽  
Vol 24 (138) ◽  
pp. 642-652 ◽  
Author(s):  
Stephan Rosenkranz ◽  
Ioana R. Preston

Right heart catheterisation (RHC) plays a central role in identifying pulmonary hypertension (PH) disorders, and is required to definitively diagnose pulmonary arterial hypertension (PAH). Despite widespread acceptance, there is a lack of guidance regarding the best practice for performing RHC in clinical practice. In order to ensure the correct evaluation of haemodynamic parameters directly measured or calculated from RHC, attention should be drawn to standardising procedures such as the position of the pressure transducer and catheter balloon inflation volume. Measurement of pulmonary arterial wedge pressure, in particular, is vulnerable to over- or under-wedging, which can give rise to false readings. In turn, errors in RHC measurement and data interpretation can complicate the differentiation of PAH from other PH disorders and lead to misdiagnosis. In addition to diagnosis, the role of RHC in conjunction with noninvasive tests is widening rapidly to encompass monitoring of treatment response and establishing prognosis of patients diagnosed with PAH. However, further standardisation of RHC is warranted to ensure optimal use in routine clinical practice.


2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
S Tanyeri ◽  
B Keskin ◽  
O Y Akbal ◽  
A Hakgor ◽  
A Karagoz ◽  
...  

Abstract Background and aim In this study we evaluated the impact of the updated pulmonary hypertension (PH) definitive criteria proposed in 6th World PH Symposium (WSPH) on numbers and frequencies of and pre- versus post-capillary PH as compared to those in European Society of Cardiology (ESC) 2015 PH Guidelines. Methods Study group comprised the retrospectively evaluated 1299 patients (pts) (age 53.1±18.8 years, female 807, 62.1%) who underwent right heart catheterisation (RHC) with different indications between 2006 and 2018. For ESC and WSPH PH definitions, pulmonary arterial mean pressure (PAMP) ≥25 mmHg (definition-A) and PAMP >20 mmHg (definition-B) RHC criteria were used, respectively. For pre-capillary PH definitions, pulmonary artery wedge pressure (PAWP) ≤15 mmHg and pulmonary vascular resistance (PVR) ≥3 Wood units criteria were included in the both definitions. Results In RHC assessments, PAMP ≥25 mmHg and >20 mmHg were noted in 891 (68.6%) and 1051 (80.9%) of overall pts, respectively. Moreover, pre-capillary PH was diagnosed in 284 (21.8%) and 298 (22.9%) with definition-A and B, respectively. Although updated WSPH definition was associated with a net 12.3% and a relative 18% increase in the overall PH diagnosis, net and relative changes in the frequency of the pre-capillary PH were only 1% and 4.9%. Increase in the overall PH with updated WSPH criterias compared to previous ESC definitions was associated with increase in the number of pre-capillary PH (n=298, 22.9%) but not in the overall frequency of post-capillary PH (688, 52.9%). Because PVR was the product of the transpulmonary gradient (PAMP minus PAWP) divided by cardiac output, this measure was found to keep specificity for distinction between pre- versus post-capillary PH even after lowering thetreshold diagnostic for PAMP from 25 to 20 mmHg. Conclusions Although updated WSPH definition was associated with net 12.3% and relative 18% increase in the overall PH diagnosis, its impact on frequencies of pre- versus post-capillary PH within overall PH population was negligible.These seem to be due to critical role of PVR ensuring specificity in pre-capillary PH diagnosis even after lowering the definitive PAMP treshold to 20 mmHg.


1963 ◽  
Vol 204 (4) ◽  
pp. 619-625 ◽  
Author(s):  
John W. Hyland ◽  
George T. Smith ◽  
Lockhart B. McGuire ◽  
Donald C. Harrison ◽  
Florence W. Haynes ◽  
...  

Pulmonary embolism was produced in 30 closed-chest 8-kg dogs with polystyrene spheres, glass beads, or blood clots of precise graded size. The sizes matched selectively the internal diameter of pulmonary arteries from lobar branches (5–6 mm) down to atrial arteries (0.17 mm). Emboli were injected into the right atrium until the pressure in the pulmonary artery rose 5–10 mm Hg. The number of emboli of a given size required to produce this incipient pulmonary hypertension was compared with the number of vessels of that same size as determined from the literature as well as by postmortem injection with Schlesinger mass. The number of emboli bore a constant relation to the number of vessels of that same size. With each size, the majority of vessels had to be occluded before pulmonary hypertension appeared. This was true even in the absence of anesthesia. The results support the thesis that mechanical blockade rather than vasoconstriction is the mechanism by which pulmonary hypertension is produced by emboli occluding pulmonary arterial (as opposed to arteriolar) vessels.


1991 ◽  
Vol 70 (2) ◽  
pp. 859-868 ◽  
Author(s):  
B. D. Zuckerman ◽  
E. C. Orton ◽  
K. R. Stenmark ◽  
J. A. Trapp ◽  
J. R. Murphy ◽  
...  

We compared main pulmonary arterial elasticity and global pulmonary arterial compliance in control and high-altitude (HA) calves to determine whether 1) changes in pulmonary arterial elasticity are contributing to an increase in the oscillatory load of the right ventricle in this model of pulmonary hypertension and 2) measured changes in stiffness of the HA calves' arterial wall are the result of both an increase in pressure and an alteration of the material properties of the HA calves' arterial wall. Newborn calves were placed at 4,300 m simulated altitude for 14 days, and control calves were kept at 1,500 m. The HA calves were then reacclimatized to 1,500 m for 24 h so that baseline pressures of the two groups were similar. Open-chest main pulmonary arterial and right ventricular micromanometric pressures, ultrasonic main pulmonary arterial diameter, and green dye flow were measured under baseline conditions and then under moderate and severely hypoxic conditions to make measurements at both baseline and increased pulmonary pressures. At elevated pressures, the pressure-diameter relationship was noted to be nonlinear, and a characteristic late systolic peaking of the right ventricular pressure waveform was seen. The Peterson pressure-strain modulus, pulse wave velocity, characteristic impedance, and global compliance (3 element windkessel) were calculated. The calculated variables were all shown to be pressure dependent, and no intrinsic differences in stiffness were seen between the control and HA animals when mean pressure was taken into account. Pulmonary arterial histology demonstrated, however, a characteristic increase in wall thickness in the HA animals. Thus, in this model of pulmonary hypertension, major changes in elasticity and pulsatile load are primarily due to an increase in pulmonary pressure. The structural changes present in the HA calves' arterial wall did not separately produce any measurable changes in arterial distensibility or the oscillatory load.


2019 ◽  
Vol 53 (1) ◽  
pp. 1801900 ◽  
Author(s):  
Anton Vonk Noordegraaf ◽  
Kelly Marie Chin ◽  
François Haddad ◽  
Paul M. Hassoun ◽  
Anna R. Hemnes ◽  
...  

The function of the right ventricle determines the fate of patients with pulmonary hypertension. Since right heart failure is the consequence of increased afterload, a full physiological description of the cardiopulmonary unit consisting of both the right ventricle and pulmonary vascular system is required to interpret clinical data correctly. Here, we provide such a description of the unit and its components, including the functional interactions between the right ventricle and its load. This physiological description is used to provide a framework for the interpretation of right heart catheterisation data as well as imaging data of the right ventricle obtained by echocardiography or magnetic resonance imaging. Finally, an update is provided on the latest insights in the pathobiology of right ventricular failure, including key pathways of molecular adaptation of the pressure overloaded right ventricle. Based on these outcomes, future directions for research are proposed.


2014 ◽  
Vol 23 (134) ◽  
pp. 476-487 ◽  
Author(s):  
Robert Naeije ◽  
Alessandra Manes

Pulmonary arterial hypertension (PAH) is a right heart failure syndrome. In early-stage PAH, the right ventricle tends to remain adapted to afterload with increased contractility and little or no increase in right heart chamber dimensions. However, less than optimal right ventricular (RV)–arterial coupling may already cause a decreased aerobic exercise capacity by limiting maximum cardiac output. In more advanced stages, RV systolic function cannot remain matched to afterload and dilatation of the right heart chamber progressively develops. In addition, diastolic dysfunction occurs due to myocardial fibrosis and sarcomeric stiffening. All these changes lead to limitation of RV flow output, increased right-sided filling pressures and under-filling of the left ventricle, with eventual decrease in systemic blood pressure and altered systolic ventricular interaction. These pathophysiological changes account for exertional dyspnoea and systemic venous congestion typical of PAH. Complete evaluation of RV failure requires echocardiographic or magnetic resonance imaging, and right heart catheterisation measurements. Treatment of RV failure in PAH relies on: decreasing afterload with drugs targeting pulmonary circulation; fluid management to optimise ventricular diastolic interactions; and inotropic interventions to reverse cardiogenic shock. To date, there has been no report of the efficacy of drug treatments that specifically target the right ventricle.


2021 ◽  
Vol 162 (37) ◽  
pp. 1485-1493
Author(s):  
Györgyi Csósza ◽  
Zsófia Lázár ◽  
Zsolt Rozgonyi ◽  
Hajnalka Vágó ◽  
György Losonczy ◽  
...  

Összefoglaló. Pulmonalis artériás hypertoniában (PAH) a tüdőartériák falának átépülése az elsődleges patofiziológiai eltérés, amely a pulmonalis vascularis rezisztencia (PVR) és a pulmonalis nyomás progresszív emelkedéséhez vezet. Ez a nyomásemelkedés a jobb szívfélben az afterload fokozódásához vezet, ami hosszú távon jobbkamra-diszfunkciót és jobbszívfél-elégtelenséget okoz. Az egyre növekvő PVR mellett kialakuló cardialis adaptáció pontos patomechanizmusa nem ismert, de egyes betegek esetén nagyon eltérő lehet az adaptáció mértéke és kialakulásának üteme. A kialakuló myocardium-hypertrophia és -dilatáció mértéke nagyban függ a PAH etiológiájától, de emellett egyéb tényezők – mint az életkor, a neurohumoralis aktiváció mértéke, genetikai és epigenetikai faktorok – is jelentősen befolyásolják. Minél kevésbé képes a jobb kamra megtartani funkcióját az egyre növekvő ellenállással szemben, annál gyorsabban alakul ki a jobbszívfél-elégtelenség, és annál rosszabbak a beteg életkilátásai. Ezen folyamatok jobb megismerése klinikai jelentőséggel bír, mivel a jobb kamrai adaptáció elősegítése javíthatja a betegség kimenetelét. Orv Hetil. 2021; 162(37): 1485–1493. Summary. Remodeling of the pulmonary artery wall is the primary pathophysiological abnormality in pulmonary arterial hypertension leading to a progressive increase in pulmonary vascular resistance (PVR) and pulmonary arterial pressure. The elevation of pressure increases the afterload in the right heart, causing right ventricular dysfunction and right heart failure in the long term. The exact pathomechanism of cardiac adaptation with increasing PVR is unknown, but the degree and rate of adaptation may be very different in patients suffering from pulmonary hypertension. The development of myocardial hypertrophy and dilatation is highly dependent on the etiology of pulmonary hypertension, but is also significantly influenced by other factors such as age, degree of neurohumoral activation, and genetic and epigenetic factors. Right heart failure develops and life expectancy shortens if the right ventricle is unable to maintain its function in the face of increasing resistance. Orv Hetil. 2021; 162(37): 1485–1493.


2021 ◽  
Vol 9 (3) ◽  
pp. 247-254
Author(s):  
Mahya Mobinikhaledi ◽  
◽  
Ali Arjmand Shabestari ◽  
Yazdan Ghandi ◽  
◽  
...  

Introduction: The primary concern about Familial Pulmonary Arterial Hypertension (FPAH) is the development of right heart failure, which ultimately leads to sudden death. Despite recent advances in pharmacological therapy, the mortality rate in children is still high, emphasizing the importance of novel treatments. Moreover, there is still no definitive treatment for children with severe pulmonary hypertension. The consequences of right heart failure led to the proposal of a surgical approach, the Potts shunt, to decompress the right ventricle, providing shunting of deoxygenated blood to lower extremities and improving overall cardiac output. This surgical technique creates an anastomosis between the left pulmonary artery and the descending aorta, providing a palliative treatment to off-load the right ventricle. Case Presentation: We report an 11-year-old girl with familial pulmonary arterial hypertension and right ventricular failure who benefited from a Potts shunt with good mid-term results. The patient was diagnosed at the age of 5 when she had a history of fainting and persistent syncope. The patient was under medical treatment therapy with bosentan, sildenafil, acetylsalicylic acid, and warfarin for six years. The results of molecular genetic testing, which was confirmed with direct sequencing of the Bone Morphogenetic Protein Receptor Type 2 (BMPR2) gene, revealed a heterozygous pathogenic mutation. Since she was diagnosed with Pulmonary Arterial Hypertension (PAH), she lost her grandmother, an aunt, and father because of PAH. Her 14-year-old sister also had mutated the BMPR2 gene without developing FPAH. Conclusions: The Potts shunt provides an interventional step for palliation of patients with familial pulmonary hypertension and severe right heart failure refractory to medical treatment. It opens the door to the possibility of lung transplantation in the future. We did not see any complications within 6 years after placing the Potts shunt.


2018 ◽  
Vol 5 (3) ◽  
pp. G11-G24 ◽  
Author(s):  
Daniel X Augustine ◽  
Lindsay D Coates-Bradshaw ◽  
James Willis ◽  
Allan Harkness ◽  
Liam Ring ◽  
...  

Pulmonary hypertension is defined as a mean arterial pressure of ≥25 mmHg as confirmed on right heart catheterisation. Traditionally, the pulmonary arterial systolic pressure has been estimated on echo by utilising the simplified Bernoulli equation from the peak tricuspid regurgitant velocity and adding this to an estimate of right atrial pressure. Previous studies have demonstrated a correlation between this estimate of pulmonary arterial systolic pressure and that obtained from invasive measurement across a cohort of patients. However, for an individual patient significant overestimation and underestimation can occur and the levels of agreement between the two is poor. Recent guidance has suggested that echocardiographic assessment of pulmonary hypertension should be limited to determining the probability of pulmonary hypertension being present rather than estimating the pulmonary artery pressure. In those patients in whom the presence of pulmonary hypertension requires confirmation, this should be done with right heart catheterisation when indicated. This guideline protocol from the British Society of Echocardiography aims to outline a practical approach to assessing the probability of pulmonary hypertension using echocardiography and should be used in conjunction with the previously published minimum dataset for a standard transthoracic echocardiogram.


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