Pulmonary hypertension in mitral valve disease: 56 surgical patients reviewed.

Manners, John M.; Monro, James L.; Ross, John

doi:10.1136/thx.32.6.691

Cited by 10 publications

(10 citation statements)

References 39 publications

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“…We also examined the difference in mechanical properties of MV tissues between individuals with and without hypertension. Hypertension has been shown to alter the structure and function of valve leaflets to accommodate an increase in blood pressure and consequently correlates with valvular disease such as degenerative and calcification . We found that MV leaflets from hypertensive hearts exhibited a higher stiffness and lower extensibility values as compared to that of normotensive hearts.…”

Section: Discussionmentioning

confidence: 67%

“…Hypertension has been shown to alter the structure and function of valve leaflets to accommodate an increase in blood pressure and consequently correlates with valvular disease such as degenerative and calcification. [57][58][59][60] We found that MV leaflets from hypertensive hearts exhibited a higher stiffness and lower extensibility values as compared to that of normotensive hearts. Yap et al 61 studied the dynamic deformation of aortic valve during hypertensive loading conditions and showed that valves experienced an increased diastolic stretch with high pressure conditions.…”

Section: Valve Microstructurementioning

confidence: 69%

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Material properties of aged human mitral valve leaflets

Pham

Sun

2013

J Biomedical Materials Res

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Objective To characterize the mechanical properties of aged human anterior (AML) and posterior (PML) mitral leaflets. Materials and Methods The AML and PML samples from explanted human hearts (n = 21, mean age of 82.62 ± 8.77 years old) were subjected to planar biaxial mechanical tests. The material stiffness, extensibility and degree of anisotropy of the leaflet samples were quantified. The microstructure of the samples was assessed through histology. Results Both the AML and PML samples exhibited a nonlinear and anisotropic behavior with the circumferential direction being stiffer than the radial direction. The AML samples were significantly stiffer than the PML samples in both directions, suggesting that they should be modeled with separate sets of material properties in computational studies. Histological analysis indicated the changes in the tissue elastic constituents, including the fragmented and disorganized elastin network, the presence of fibrosis and proteoglycan/glycosaminoglycan infiltration and calcification, suggesting possible valvular degenerative characteristics in the aged human leaflet samples. Overall, stiffness increased and areal strain decreased with calcification severity. In addition, leaflet tissues from hypertensive individuals also exhibited a higher stiffness and low areal strain than normotensive individuals. Conclusion There are significant differences in the mechanical properties of the two human mitral valve leaflets from this advanced age group. The morphologic changes in the tissue composition and structure also infer the structural and functional difference between aged human valves and those of animals.

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Section: Discussionmentioning

confidence: 67%

Section: Valve Microstructurementioning

confidence: 69%

Material properties of aged human mitral valve leaflets

Pham

Sun

2013

J Biomedical Materials Res

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“…There is not a consensus in the literature about the reversibility of severe PAH; some authors showed a significant short term or long term regression in the mean PAP after MVR in patients with severe PAH [9][10][11][12][13][14][15][16][17][18][19] while some others failed to confirmed this. [3][4][5][6][7][8] In patients with mild PAH, the mean PAP showed an increase immediately after MVR, but it decreased significantly from 40.4 ± 7.3 to 32.5 ± 3.9 mmHg over the first 24 hours.…”

Section: Figmentioning

confidence: 99%

“…However, there is no consensus about the outcome of patients with PAH after MVR in the literature, some studies have revealed that severe PAH is associated with poorer outcome and higher mortality rate [3][4][5][6][7][8] while some others do not agree with this and believed that severe PAH do not imply the greater risk in corrective surgery; [9][10][11][12][13][14][15][16][17][18][19] but the point is that the definition of PAH varies across studies, pulmonary artery pressure >40, 50, 70 and 110 have been considered as severe PAH in various studies. [9][10][11][12][13][14][15][16][17][18][19] To our knowledge, there is no related study about this issue in Iran, and most of the previous, related works are not so recent [5][6][7][8][12][13][14][15][16][17][18][19] and had been conducted with a small sample size.…”

Section: Introductionmentioning

confidence: 99%

“…[9][10][11][12][13][14][15][16][17][18][19] To our knowledge, there is no related study about this issue in Iran, and most of the previous, related works are not so recent [5][6][7][8][12][13][14][15][16][17][18][19] and had been conducted with a small sample size. A major proportion of related studies has assessed the late outcome of MVR in patients with severe PAH.…”

Section: Introductionmentioning

confidence: 99%

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Early Hemodynamic Changes after Mitral Valve Replacement in Patients with Severe and Mild Pulmonary Artery Hypertension

Bayat¹,

Aghdaii

Farivar³

et al. 2013

ATCS

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Purpose: to assess the early hemodynamic changes after elective mitral valve replacement (MVR) in patients with severe and mild pulmonary arterial hypertension (PAH). Methods: a total of 45 consecutive patients, who were candidate for elective MVR, were enrolled in this prospective observational study. Patients were divided into two groups based on the absence (group A, 20 patients) or presence (group B, 25 patients) of severe pulmonary artery hypertension (PAH) defined as systolic pulmonary artery pressure ≥50 mmHg measuring by catheterization. MVR was performed using standard cardiopulmonary bypass (CBD) technique. The hemodynamic and arterial blood gas assessments were carried out at baseline before the induction of general anesthesia, in the operating room immediately after MVR, and then continued after stabilization of hemodynamic status with 2 hr interval up to 24 hours. Results: The mean CPB and aortic cross-clamp times were similar in two groups (95.3 ± 49.5 and 61.8 ± 36.3 minutes in group A and 103.1 ± 34.7and 61.9 ± 20.0 minutes in group B). In group A, the mean PAP showed an increase immediately after the operation (from 40.4 ± 7.3 to 43.10 ± 6.2 mmHg) and then decreased significantly to 32.5 ± 3.9 mmHg (P <0.05). In group B, the mean PAP showed no significant reduction immediately after MVR, but it decreased significantly below the range of severe PAP over the first 24 hours. Conclusion: MVR is safe and effective even in patients with severe PAH. The anesthetic technique and postoperative cares can be useful in improving the outcome in such patients.

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