From Feb. 1989 to May 1996, 170 patients underwent valve replacement with bileaflet heart valve prosthesis. There were 13 early deaths (mortality of 7-65% ), and 6 late deaths. The Preoperative cardiac function (NYHA)...From Feb. 1989 to May 1996, 170 patients underwent valve replacement with bileaflet heart valve prosthesis. There were 13 early deaths (mortality of 7-65% ), and 6 late deaths. The Preoperative cardiac function (NYHA) was grade Ⅱ in 96 cases, Ⅳ in 35 cases and Ⅲ to Ⅳ in 77. 1%.Follow-up of the survivors from 3 to 87 (average 39) months showed that most of them could do light and moderate physical labor, and cardiac function was restored to grade Ⅰ～ Ⅱ in 96. 4%. Anti-coagulating bleeding is a common complicaion. However, severe embolism and valve dysfunction had not been found- The authors analysed the causes of death and follow-up data, then emphasized that it was necessary that valve replacement be performed as early as possible, and bileaflet heart valve substitute was the best choice. Furthermore, therapy of little dose anti-coagulating drug(warfarin 1.5～3- 0mg/d) is safe and dependable to most of the patients.展开更多
The objective was to evaluate the practice of self-care of patients with mechanical heart valve prosthesis. A descriptive, cross-sectional study developed in two outpatient valvopathies of teaching hospitals of Fortal...The objective was to evaluate the practice of self-care of patients with mechanical heart valve prosthesis. A descriptive, cross-sectional study developed in two outpatient valvopathies of teaching hospitals of Fortaleza/CE, from October 2013 to January 2014. The sample consisted of 127 patients with mechanical heart valve prosthesis. It was held an interview using instrument based on the Theory of Orem’s Self-Care and Brazilian Guidelines for Valvular Heart Diseases. The data were presented in tables and charts. Results: Universal self-care practices of larger adhesion: body hygiene (97.6% washed-haired, daily-bath 92.1%);oral hygiene (brushing teeth before sleeping, 87.4%);fluid intake (drinking-water 95.2%);food intake (salt intake ≤ 2 g/day, 92.1%, fruit and vegetable consumption 79.5%);intestinal eliminations (without blood or mucus—96%, non-parasitic 94.4%);urinary elimination (no blood nor pus-96.8%, urination 4 to 6 times a day, 96%). As self-care developmental requirements predominated: never used illegal drugs, tobacco, alcohol, or stopped at the discovery of the disease (70%). As self-care health deviation requirements we have: making use of certain medication at the right dose (95.2%);attending medical appointments (cardiologist—92.1%;nursing—84.2%);INR control (identifies signs of bleeding— 85.8%). We conclude that patients did not perform all recommended self-care practices, being necessary to establish strategies to reduce the self-care deficit.展开更多
It has been hypothesized that leaflet substrates with a trilayer structure and anisotropicmechanical properties could be useful for the production of functional and long-lasting tissue-engineered leaflets.To investiga...It has been hypothesized that leaflet substrates with a trilayer structure and anisotropicmechanical properties could be useful for the production of functional and long-lasting tissue-engineered leaflets.To investigate the influence of the anisotropic structural and mechanical characteristics of a substrate on cells,in this study,we electrospun trilayer anisotropic fibrous substrates and randomly oriented isotropic fibrous substrates(used as controls)from polycaprolactone polymers.Consequently,the random substrates had higher radial and lower circumferential tensile properties than the trilayer substrates;however,they had similar flexural properties.Porcine valvular interstitial cells cultured on both substrates produced random and trilayer cell-cultured constructs,respectively.The trilayer cell-cultured constructs had more anisotropic mechanical properties,17%higher cellular proliferation,14%more extracellular matrix(i.e.,collagen and glycosaminoglycan)production,and superior gene and protein expression,suggesting that more cells were in a growth state in the trilayer constructs than in the random constructs.Furthermore,the random and radial layers of the trilayer constructs had more vimentin,collagen,transforming growth factor-beta 1(TGF-ß1),transforming growth factor-beta 3(TGF-ß3)gene expression than in the circumferential layer of the constructs.This study verifies that the differences in structural,tensile,and anisotropic properties of the trilayer and random substrates influence the characteristics of the cells and ECM in the constructs.展开更多
Background: Isolated tricuspid valve disease remains a controversial indication for surgical intervention. Many patients referred for surgery already have a poor clinical condition and an advanced New York Heart Assoc...Background: Isolated tricuspid valve disease remains a controversial indication for surgical intervention. Many patients referred for surgery already have a poor clinical condition and an advanced New York Heart Association functional class. There is no consensus on the optimal surgical technique for this condition, including on whether to perform the procedure on a beating or an arrested heart and whether to perform valve repair or replacement. Methods: We analyzed four case series between 2015 and 2022 in which patients with secondary tricuspid regurgitation (TR) underwent valve repair on a beating heart and right atrial plication for a dilated right atrium. The TRI-SCORE was calculated for each patient. Results: All patients experienced a favorable postoperative course with significant improvements in heart failure symptoms. TR was markedly reduced;however, in one patient with concomitant mitral regurgitation (MR) and a high TRI-SCORE, MR worsened postoperatively. This patient later died from unknown causes due to multiple comorbidities in the late phase. Conclusions: Tricuspid valve repair on a beating heart was effective for improving the cardiac function, and the TRI-SCORE proved useful as a preoperative risk assessment tool. The underlying mechanism by which TR exacerbates MR requires further investigation.展开更多
Valves are widely used in various working conditions for their flow control functions,and the cavitation inside valves has been investigated owing to its harm to the valve itself and the connecting downstream parts.Th...Valves are widely used in various working conditions for their flow control functions,and the cavitation inside valves has been investigated owing to its harm to the valve itself and the connecting downstream parts.This paper presents a comprehensive review of the progress that has been achieved in the past years about cavitation in valves including both mechanical heart valves and control valves.The review is divided in the following parts,namely the location where there is a high possibility of the occurrence of cavitation,the parameters that affect cavitation intensity,and the methods to minimize cavitation intensity.It should be noticed that although simulation has been widely used,advanced experiments are still needed in order to obtain accurate analysis of cavitation in valves and the cavitation model still needs to be improved.展开更多
Jiuling bileaflet prosthetic heart valve is manufactured in compliance with the national standard of P.R.C. GB12279 90. This mechanical heart valve substitute is constructed entirely of solid low temperature pyrolytic...Jiuling bileaflet prosthetic heart valve is manufactured in compliance with the national standard of P.R.C. GB12279 90. This mechanical heart valve substitute is constructed entirely of solid low temperature pyrolytic carbon. There is no graphite substrate within the leaflets or orifice. This prosthesis presents with satisfactory histocompatibility and induces little hemocoagulation around it. Objective: This study aimed to assess the hydrodynamic function of the newly China made Jiuling bileaflet heart valve prostheses. Methods: Jiuling valve has been tested in a pulsatile flow simulator in the aortic position. The testing condition was set at the pulsatile frequency of 55, 75, and 100 beats/min and a constant cardiac output of 4 L/min. The mean pressure differences, leakage volumes and closing volumes across each valve, and the effective orifice areas have been analyzed. Results: The Jiuling heart valves prosthesis had the lowest pressure difference at any given tissue annulus diameter. The mean pressure difference of all the Jiuling valves decreases with increasing the tissue annulus diameter or pulse frequency, and is in the range of below 10 mmHg. CarboMedics (CarboMedics, Inc., Austin, Tex.) is similar to that of the 21 mm and 23 mm Jiuling heart valves at the given pulse rate under 4 L/min. C L tilting disc valve (Lanzhou CarboMedics Inc., China) is similar to that of the 23 mm Jiuling heart valve. The effective orifice area of the Jiuling mechanical valve increases with increasing the tissue annulus diameter or pulse frequency. CarboMedics and C L tilting disc valve is similar to that of the 21 mm and 23 mm Jiuling heart valves. The Closing volume of the Jiuling prosthetic cardiac valves increases with increasing the tissue annulus diameter, but decreases with increasing the pulse frequency, and is in the range of below 11% (normalized by stroke volume). CarboMedics is below 16.5% of stroke volume; and C L tilting disc valve is below 7.5%. The leakage volume of the Jiuling prosthetic cardiac valves increases with increasing the tissue annulus diameter, but decreases with increasing the pulse frequency, and are in the range of below 28.9% (normalized by stroke volume). The leakage volume of CarboMedics is higher than that of the same sized 25 mm Jiuling valve, and the C L tilting disc valve is also higher than that of Jiuling valve at 4 L/min. Conclusion: For a given tissue diameter, the Jiuling valve showed significantly better hemodynamic characteristics. The material used in the construction is biocompatible, durable, and thromboresistant. The design permits light weight, low profile, and high ratio of flow area to tissue annulus diameter.展开更多
Objective: To validate the hypothesis that camel pericardium could be more protected than bovine pericardium against calcification process according to the huge difference in their respective lifestyle and lifetime. M...Objective: To validate the hypothesis that camel pericardium could be more protected than bovine pericardium against calcification process according to the huge difference in their respective lifestyle and lifetime. Methods: Glutaraldehyde (GA) fixed bovine and camel pericardium samples (BP and CP respectively) were both implanted in 30 New Zealand white rats (2 BP and 2 CP matched specimens in each animal) and explanted after 60 days. Unimplanted GA-fixed samples of both species served as control. Matched implanted samples and unimplanted samples were randomly submitted to elemental analysis by spectroscopy, phospholipid extraction, macroscopic and X-ray examination and histology. Results: At 60 days, calcium and phosphorus content were respectively 9.54% ± 3.1% and 4.79% ± 1.4% of tissue dry weight in BP, and 12.52% ± 2.7% and 6.14% ± 1.3% of tissue dry weight in CP (ns). In X-ray analysis, the calcification score was 1.28 ± 0.45 and 2.14 ± 0.98 in BP and CP samples respectively without significant difference (p < 0.08). In histology, calcifications were lower in BP than in CP: 1.37 ± 0.85 vs 2.28 ± 0.83 (ns);collagen fibers were better conserved in BP than in CP: 2.4 ± 0.48 vs 1.87 ± 0.78 (ns), and less disoriented: 25% vs 62% (ns). In unimplanted samples, there was a higher but not significant rate of extracted lipids in CP: 5.7 ± 1.8 vs 9.5 ± 3.8 nanomoles in PS fraction and 11.3 ± 3.7 vs 19 ± 7.7 nanomoles in total fatty acids, in BP and CP samples respectively. All results were in conjunction and demonstrated a higher but not significant rate of mineralization in camel pericardium after implantation, which could be related to a higher but not significant basic rate of phospholipid and fatty acids. Conclusion: This experiment study in a subcutaneous rat model has failed to valid our hypothesis. Because the differences observed between bovine and camel pericardium did not reach the significance, at the best, there is no difference between both species and at the worst, camel pericardium has a higher rate of the phosphatidylserine fraction of phospholipid, and is more sensitive and prompt to calcification.展开更多
Regurgitation in the heart diastolic phase represents a critical flow condition associated with many heart valve design considerations. The finite volume method, the Low-Reynolds-Number k-ω turbulent model and slidin...Regurgitation in the heart diastolic phase represents a critical flow condition associated with many heart valve design considerations. The finite volume method, the Low-Reynolds-Number k-ω turbulent model and sliding mesh model are employed to solve and compare the complex flow field and the torque in each case. The end results expected from a cardiovascular CFD analysis are not limited only to the flowfield investigations. More importantly, it needs an evaluation criterion to judge if the design is acceptable as considered from a broader blood cell damage or activation perspective. In this study, blood cell damage index developed based on stress-time empirical rule and Lagrangian particle tracking is introduced to assess the viscous and turbulence-induced stresses effect to the blood cells.展开更多
Objective: To explore the changes of coagulation activity and the characters of anticoagulation early after mechanical heart valve replacement. Methods: All patients only took warfarin orally for anticoagulation. The ...Objective: To explore the changes of coagulation activity and the characters of anticoagulation early after mechanical heart valve replacement. Methods: All patients only took warfarin orally for anticoagulation. The predicted international normalized ratio (INR) was 1.5 to 2.0. Several coagulation markers were monitored early after valve replacement. Complications associated with anticoagulation were recorded and analyzed. The patients were divided into three groups based on the number and position of mechanical valve prothesis, including group M (mitral valve replacement), group A (aortic valve replacement) and group D (mitral and aortic valve replacement).Comparison was made between the three groups. Results: Three events of mild cerebral embolism and five events of mild bleeding occurred during the early postoperative period. One patient suffered from mild cerebral embolism on the 4th day after operation, accompanied by large volume of pericardial drainage. Two patients with bleeding had lower INRs than predicted range. However, INR in one patient with mild cerebral embolism was in the predicted range. There was no significant difference in thrombo time (TT), activated partial thromboplastin time (APTT) and INR on the 3rd day after operation compared to those before operation; meanwhile, plasma fibrinogen (FIB) concentration was higher than that before operation (P<0.05). INR had no significant changes on the 2nd day after the beginning of anticoagulation compared to that before operation; however, INR was significantly elevated on the 4th day (P<0.05). Warfarin doses and INRs were similar among the three groups, but FIB concentrations in plasma were higher in groups M and D than in group A (P<0.01). Conclusion: Hypercoagulabale state exists early after mechanical heart valve replacement. When anticoagulation begins is determined by the change of coagulation markers, not by the volume of chest or pericardial drainage. INR can not accurately reflect the coagulation state sometimes, especially during the first 3 days after anticoagulation. The number and position of mechanical valve prothesis could affect coagulation state. Therefore, anticoagulation therapy should be regulated accordingly.展开更多
The purpose of this study was to fabricate decelluarized valve scaffold modified with polyethylene glycol nanoparticles loaded with transforming growth factor-β1(TGF-β1),by which to improve the extracellular matrix ...The purpose of this study was to fabricate decelluarized valve scaffold modified with polyethylene glycol nanoparticles loaded with transforming growth factor-β1(TGF-β1),by which to improve the extracellular matrix microenvironment for heart valve tissue engineering in vitro.Polyethylene glycol nanoparticles were obtained by an emulsion-crosslinking method,and their morphology was observed under a scanning electron microscope.Decelluarized valve scaffolds,prepared by using trypsinase and TritonX-100,were modified with nanoparticles by carbodiimide,and then TGF-β1 was loaded into them by adsorption.The TGF-β1 delivery of the fabricated scaffold was measured by asing enzyme-linked immunosorbent assay.Whether unseeded or reseeded with myofibroblast from rats,the morphologic,biochemical and biomechanical characteristics of hybrid scaffolds were tested and compared with decelluarized scaffolds under the same conditions.The enzyme-linked immunosorbent assay revealed a typical delivery of nanoparticles.The morphologic observations and biological data analysis indicated that fabricated scaffolds possessed advantageous biocompatibility and biomechanical property beyond decelluarized scaffolds.Altogether this study proved that it was feasible to fabricate the hybrid scaffold and effective to improve extracellular matrix microenvironment,which is beneficial for an application in heart valve tissue engineering.展开更多
Transition from non-surgical heart valve defects repair from bench to bedside is a reality.Some biological material-based designs for transcatheter aortic valve implantation are ready for use.Their drawback,however is...Transition from non-surgical heart valve defects repair from bench to bedside is a reality.Some biological material-based designs for transcatheter aortic valve implantation are ready for use.Their drawback,however is their unknown functional as well as structural durability.Moreover,research on new non-biological materials is essential to replace classical animal-derived sources of human heart valve prostheses.展开更多
Currently-used mechanical and biological heart valve prostheses have a satisfactory short-term performance, but may exhibit several major drawbacks on the long-term. Mechanical prostheses, based on carbon, metallic an...Currently-used mechanical and biological heart valve prostheses have a satisfactory short-term performance, but may exhibit several major drawbacks on the long-term. Mechanical prostheses, based on carbon, metallic and polymeric components, require permanent anticoagulation treatment, and their usage often leads to adverse reactions, e.g. thromboembolic complications and endocarditis. In recent years, there is a need for a heart valve prosthesis that can grow, repair and remodel. The concept of tissue engineering offers good prospects into the development of such a device. An ideal scaffold should mimic the structural and purposeful profile of materials found in the natural extracellular matrix (ECM) architecture. The goal of this study was to develop cellulose acetate scaffolds (CA) for valve tissue regeneration. After their thorough physicochemical and biological characterization, a biofunctionalization process was made to increase the cell proliferation. Especially, the surface of scaffolds was amplified with functional molecules, such as RGD peptides (Arg-Gly-Asp) and YIGSRG laminins (Tyrosine-Isoleucine-Glycine-Serine-Arginine-Glycine) which immobilized through biotin-streptavidin bond, the strongest non-covalent bond in nature. Last step was to successfully coat an aortic metallic valve with CA biofunctionallized nanoscaffolds and cultivate cells in order to create an anatomical structure comparable to the native valve. Promising results have been obtained with CA-based nanoscaffolds. We found that cells grown successfully on the biofunctionalized valve surface thereby scaffolds that resemble the native tissues, elaborated with bioactive factors such as RGD peptides and laminins not only make the valve’s surface biocompatible but also they could promote endothyliazation of cardiac valves causing an anti-coagulant effect展开更多
Data from 736 patients undergoing prosthetic heart valve replacement surgery and concomitant surgery (combined surgery) from January 1998 to January 2004 at Union Hospital were retrospectively reviewed. Univariate log...Data from 736 patients undergoing prosthetic heart valve replacement surgery and concomitant surgery (combined surgery) from January 1998 to January 2004 at Union Hospital were retrospectively reviewed. Univariate logistic regression analyses were conducted to identify risk factors for prolonged mechanical ventilation. The results showed that prolonged cardiopulmonary bypass duration, prolonged aortic cross clamp time and low ejection fraction less than 50 percent (50 %) were found to be independent predictors for prolonged mechanical ventilation. Meanwhile age, weight, and preoperative hospital stay (days) were not found to be associated with prolonged mechanical ventilation. It was concluded that, for age and weight, this might be due to the lower number of old age patients (70 years and above) included in our study and genetic body structure of majority Chinese population that favor them to be in normal weight, respectively.展开更多
BACKGROUND Aortic stenosis is one of the rare valvular complications in a transplanted heart.Over the past 8 years,transcatheter approach for aortic valve replacement(TAVR)has been slowly evolving to be the preferred ...BACKGROUND Aortic stenosis is one of the rare valvular complications in a transplanted heart.Over the past 8 years,transcatheter approach for aortic valve replacement(TAVR)has been slowly evolving to be the preferred approach in these patient population when compared to the surgical approach.We report a second case in the United States with successful transfemoral minimal approach with minimal sedation for TAVR in a heart transplant recipient 19 years post transplantation for severe symptomatic calcified aortic stenosis.CASE SUMMARY We present a case of 73-year-old male who has undergone successful minimal approach transcatheter aortic valve replacement in an allograft heart.Patient had received orthotopic heart transplantation 19 years ago for non-ischemic cardiomyopathy.Follow up transthoracic echocardiograms as per routine protocol did not show any aortic valve disease until 15 years post transplantation.Aortic valve was noted to be mildly sclerotic at that time and gradually progressed to severe symptomatic aortic stenosis over the next 4 years.Patient had complaints of worsening shortness of breath that limited his functional capacity.Overall his post heart transplantation period has been mostly uneventful except for allograft non occlusive vasculopathy and aortic stenosis.His Society of Thoracic Surgery risk score was 12.205%and he was considered to be a high-risk surgical candidate by surgeon.Decision was made to undergo transcatheter aortic valve replacement.CONCLUSION With the improved survival of these patients,we think it is time to look intopathophysiology of valvular disease in transplant heart recipients.Some other unanswered questions include,underlying donor and recipient risk factors for valvular diseases in heart transplant recipients.展开更多
The analysis of 10 normal and 51 mitral valve pathology making a total of 61 heart sound signals that were obtained with Littmann 4100 Digital Stethoscope were conducted in this study.Following the recorded sound sign...The analysis of 10 normal and 51 mitral valve pathology making a total of 61 heart sound signals that were obtained with Littmann 4100 Digital Stethoscope were conducted in this study.Following the recorded sound signals were denoised by using wavelet filters,the signals were applied bicoherence analysis that is an high order spectral analysis method.It has been demonstrated that varieties of mitral valve pathology could be determined by three-dimensional surfaces of bicoherence and maximum bicoherence values.展开更多
Patient-prosthesis mismatch(PPM) should be recognized in patients with elevated transprosthetic gradients but without leaflet immobility, since the treatment strategy may differ in either etiology. However, thrombus a...Patient-prosthesis mismatch(PPM) should be recognized in patients with elevated transprosthetic gradients but without leaflet immobility, since the treatment strategy may differ in either etiology. However, thrombus and/or pannus formation should be excluded before a diagnosis of PPM is made. Particularly, pannus formation may not be diagnosed with 2-dimensional transesophageal echocardiography. Electrocardiographically gated 64-section multidetector computed tomography(MDCT) may be a promising tool in diagnosing or excluding pannus formation. Our report underlines the utility of MDCT in this regard and also emphasizes the importance of recognition of PPM as a differential diagnosis in such patients.展开更多
Management of warfarin-induced major bleeding in patients with mechanical heart valves is challenging.There is vast controversy and confusion in the type of treatment required to reverse anticoagulation and stop bleed...Management of warfarin-induced major bleeding in patients with mechanical heart valves is challenging.There is vast controversy and confusion in the type of treatment required to reverse anticoagulation and stop bleeding as well as the ideal time to restart warfarin therapy safely without recurrence of bleeding and/or thromboembolism.Presently,the treatments available to reverse warfarin-induced bleeding are vitamin K,fresh frozen plasma,prothrombin complex concentrates and recombinant activated factor Ⅶa.Currently,vitamin K and fresh frozen plasma are the recommended treatments in patients with mechanical heart valves and warfarin-induced major bleeding.The safe use of prothrombin complex concentrates and recombinant activated factor Ⅶa in patients with mechanical heart valves is controversial and needs well-designed clinical studies.With regard to restarting anticoagulation in patients with warfarin-induced major bleeding and mechanical heart valves,the safe period varies from 7-14 d after the onset of bleeding for patients with intracranial bleed and 48-72 h for patients with extra-cranial bleed.In this review article,we present relevant literature about these controversies and suggest recommendations for management of patients with warfarin-induced bleeding and a mechanical heart valve.Furthermore,there is an urgent need for separate specific guidelines from major associations/professional societies with regard to mechanical heart valves and warfarin-induced bleeding.展开更多
Cardiac valve replacement is an effective method to treat valvular heart disease.Artificial valves used routinely in clinic still have defects.In our study,we explored a novel method to modify the performance of Decel...Cardiac valve replacement is an effective method to treat valvular heart disease.Artificial valves used routinely in clinic still have defects.In our study,we explored a novel method to modify the performance of Decellularized Heart Valve(DHV)scaffold.The decellularized porcine aortic valve was prepared using sequential hydrophile and lipophile solubilization method.The sericin was extracted from silk fibroin-deficient silkworm cocoon by lithium bromide method.First,DHV was immersed in sericin solution to produce the sericin–DHV composite scaffold.Then,we modified the DHV by making a Polydopamine(PDA)coating on the DHV first and then binding the sericin.The physical properties and biological compatibility of our composite scaffold were assessed in vitro and in vivo.Sericin were successfully prepared,combined to DHV and improved its biocompatibility.PDA coating further promoted the combination of sericin on DHV and improved the physical properties of scaffolds.The decay rate of our modified valve scaffold was decreased in vivo and it showed good compatibility with blood.In conclusion,our modification improved the physical properties and biocompatibility of the valve scaffold.The combination of PDA and sericin promoted the recellularization of decellularized valves,showing great potential to be a novel artificial valve.展开更多
文摘From Feb. 1989 to May 1996, 170 patients underwent valve replacement with bileaflet heart valve prosthesis. There were 13 early deaths (mortality of 7-65% ), and 6 late deaths. The Preoperative cardiac function (NYHA) was grade Ⅱ in 96 cases, Ⅳ in 35 cases and Ⅲ to Ⅳ in 77. 1%.Follow-up of the survivors from 3 to 87 (average 39) months showed that most of them could do light and moderate physical labor, and cardiac function was restored to grade Ⅰ～ Ⅱ in 96. 4%. Anti-coagulating bleeding is a common complicaion. However, severe embolism and valve dysfunction had not been found- The authors analysed the causes of death and follow-up data, then emphasized that it was necessary that valve replacement be performed as early as possible, and bileaflet heart valve substitute was the best choice. Furthermore, therapy of little dose anti-coagulating drug(warfarin 1.5～3- 0mg/d) is safe and dependable to most of the patients.
文摘The objective was to evaluate the practice of self-care of patients with mechanical heart valve prosthesis. A descriptive, cross-sectional study developed in two outpatient valvopathies of teaching hospitals of Fortaleza/CE, from October 2013 to January 2014. The sample consisted of 127 patients with mechanical heart valve prosthesis. It was held an interview using instrument based on the Theory of Orem’s Self-Care and Brazilian Guidelines for Valvular Heart Diseases. The data were presented in tables and charts. Results: Universal self-care practices of larger adhesion: body hygiene (97.6% washed-haired, daily-bath 92.1%);oral hygiene (brushing teeth before sleeping, 87.4%);fluid intake (drinking-water 95.2%);food intake (salt intake ≤ 2 g/day, 92.1%, fruit and vegetable consumption 79.5%);intestinal eliminations (without blood or mucus—96%, non-parasitic 94.4%);urinary elimination (no blood nor pus-96.8%, urination 4 to 6 times a day, 96%). As self-care developmental requirements predominated: never used illegal drugs, tobacco, alcohol, or stopped at the discovery of the disease (70%). As self-care health deviation requirements we have: making use of certain medication at the right dose (95.2%);attending medical appointments (cardiologist—92.1%;nursing—84.2%);INR control (identifies signs of bleeding— 85.8%). We conclude that patients did not perform all recommended self-care practices, being necessary to establish strategies to reduce the self-care deficit.
基金supported by the National Institute of Health(No.NIH R00HL134823).
文摘It has been hypothesized that leaflet substrates with a trilayer structure and anisotropicmechanical properties could be useful for the production of functional and long-lasting tissue-engineered leaflets.To investigate the influence of the anisotropic structural and mechanical characteristics of a substrate on cells,in this study,we electrospun trilayer anisotropic fibrous substrates and randomly oriented isotropic fibrous substrates(used as controls)from polycaprolactone polymers.Consequently,the random substrates had higher radial and lower circumferential tensile properties than the trilayer substrates;however,they had similar flexural properties.Porcine valvular interstitial cells cultured on both substrates produced random and trilayer cell-cultured constructs,respectively.The trilayer cell-cultured constructs had more anisotropic mechanical properties,17%higher cellular proliferation,14%more extracellular matrix(i.e.,collagen and glycosaminoglycan)production,and superior gene and protein expression,suggesting that more cells were in a growth state in the trilayer constructs than in the random constructs.Furthermore,the random and radial layers of the trilayer constructs had more vimentin,collagen,transforming growth factor-beta 1(TGF-ß1),transforming growth factor-beta 3(TGF-ß3)gene expression than in the circumferential layer of the constructs.This study verifies that the differences in structural,tensile,and anisotropic properties of the trilayer and random substrates influence the characteristics of the cells and ECM in the constructs.
文摘Background: Isolated tricuspid valve disease remains a controversial indication for surgical intervention. Many patients referred for surgery already have a poor clinical condition and an advanced New York Heart Association functional class. There is no consensus on the optimal surgical technique for this condition, including on whether to perform the procedure on a beating or an arrested heart and whether to perform valve repair or replacement. Methods: We analyzed four case series between 2015 and 2022 in which patients with secondary tricuspid regurgitation (TR) underwent valve repair on a beating heart and right atrial plication for a dilated right atrium. The TRI-SCORE was calculated for each patient. Results: All patients experienced a favorable postoperative course with significant improvements in heart failure symptoms. TR was markedly reduced;however, in one patient with concomitant mitral regurgitation (MR) and a high TRI-SCORE, MR worsened postoperatively. This patient later died from unknown causes due to multiple comorbidities in the late phase. Conclusions: Tricuspid valve repair on a beating heart was effective for improving the cardiac function, and the TRI-SCORE proved useful as a preoperative risk assessment tool. The underlying mechanism by which TR exacerbates MR requires further investigation.
基金the National Natural Science Foundation of China through Grant No.51805470the Fundamental Research Funds for the Central Universities through Grant No.2018QNA4013the Youth Funds of the State Key Laboratory of Fluid Power and Mechatronic Systems(Zhejiang University)through Grant No.SKLoFP-QN-1801.
文摘Valves are widely used in various working conditions for their flow control functions,and the cavitation inside valves has been investigated owing to its harm to the valve itself and the connecting downstream parts.This paper presents a comprehensive review of the progress that has been achieved in the past years about cavitation in valves including both mechanical heart valves and control valves.The review is divided in the following parts,namely the location where there is a high possibility of the occurrence of cavitation,the parameters that affect cavitation intensity,and the methods to minimize cavitation intensity.It should be noticed that although simulation has been widely used,advanced experiments are still needed in order to obtain accurate analysis of cavitation in valves and the cavitation model still needs to be improved.
文摘Jiuling bileaflet prosthetic heart valve is manufactured in compliance with the national standard of P.R.C. GB12279 90. This mechanical heart valve substitute is constructed entirely of solid low temperature pyrolytic carbon. There is no graphite substrate within the leaflets or orifice. This prosthesis presents with satisfactory histocompatibility and induces little hemocoagulation around it. Objective: This study aimed to assess the hydrodynamic function of the newly China made Jiuling bileaflet heart valve prostheses. Methods: Jiuling valve has been tested in a pulsatile flow simulator in the aortic position. The testing condition was set at the pulsatile frequency of 55, 75, and 100 beats/min and a constant cardiac output of 4 L/min. The mean pressure differences, leakage volumes and closing volumes across each valve, and the effective orifice areas have been analyzed. Results: The Jiuling heart valves prosthesis had the lowest pressure difference at any given tissue annulus diameter. The mean pressure difference of all the Jiuling valves decreases with increasing the tissue annulus diameter or pulse frequency, and is in the range of below 10 mmHg. CarboMedics (CarboMedics, Inc., Austin, Tex.) is similar to that of the 21 mm and 23 mm Jiuling heart valves at the given pulse rate under 4 L/min. C L tilting disc valve (Lanzhou CarboMedics Inc., China) is similar to that of the 23 mm Jiuling heart valve. The effective orifice area of the Jiuling mechanical valve increases with increasing the tissue annulus diameter or pulse frequency. CarboMedics and C L tilting disc valve is similar to that of the 21 mm and 23 mm Jiuling heart valves. The Closing volume of the Jiuling prosthetic cardiac valves increases with increasing the tissue annulus diameter, but decreases with increasing the pulse frequency, and is in the range of below 11% (normalized by stroke volume). CarboMedics is below 16.5% of stroke volume; and C L tilting disc valve is below 7.5%. The leakage volume of the Jiuling prosthetic cardiac valves increases with increasing the tissue annulus diameter, but decreases with increasing the pulse frequency, and are in the range of below 28.9% (normalized by stroke volume). The leakage volume of CarboMedics is higher than that of the same sized 25 mm Jiuling valve, and the C L tilting disc valve is also higher than that of Jiuling valve at 4 L/min. Conclusion: For a given tissue diameter, the Jiuling valve showed significantly better hemodynamic characteristics. The material used in the construction is biocompatible, durable, and thromboresistant. The design permits light weight, low profile, and high ratio of flow area to tissue annulus diameter.
文摘Objective: To validate the hypothesis that camel pericardium could be more protected than bovine pericardium against calcification process according to the huge difference in their respective lifestyle and lifetime. Methods: Glutaraldehyde (GA) fixed bovine and camel pericardium samples (BP and CP respectively) were both implanted in 30 New Zealand white rats (2 BP and 2 CP matched specimens in each animal) and explanted after 60 days. Unimplanted GA-fixed samples of both species served as control. Matched implanted samples and unimplanted samples were randomly submitted to elemental analysis by spectroscopy, phospholipid extraction, macroscopic and X-ray examination and histology. Results: At 60 days, calcium and phosphorus content were respectively 9.54% ± 3.1% and 4.79% ± 1.4% of tissue dry weight in BP, and 12.52% ± 2.7% and 6.14% ± 1.3% of tissue dry weight in CP (ns). In X-ray analysis, the calcification score was 1.28 ± 0.45 and 2.14 ± 0.98 in BP and CP samples respectively without significant difference (p < 0.08). In histology, calcifications were lower in BP than in CP: 1.37 ± 0.85 vs 2.28 ± 0.83 (ns);collagen fibers were better conserved in BP than in CP: 2.4 ± 0.48 vs 1.87 ± 0.78 (ns), and less disoriented: 25% vs 62% (ns). In unimplanted samples, there was a higher but not significant rate of extracted lipids in CP: 5.7 ± 1.8 vs 9.5 ± 3.8 nanomoles in PS fraction and 11.3 ± 3.7 vs 19 ± 7.7 nanomoles in total fatty acids, in BP and CP samples respectively. All results were in conjunction and demonstrated a higher but not significant rate of mineralization in camel pericardium after implantation, which could be related to a higher but not significant basic rate of phospholipid and fatty acids. Conclusion: This experiment study in a subcutaneous rat model has failed to valid our hypothesis. Because the differences observed between bovine and camel pericardium did not reach the significance, at the best, there is no difference between both species and at the worst, camel pericardium has a higher rate of the phosphatidylserine fraction of phospholipid, and is more sensitive and prompt to calcification.
文摘Regurgitation in the heart diastolic phase represents a critical flow condition associated with many heart valve design considerations. The finite volume method, the Low-Reynolds-Number k-ω turbulent model and sliding mesh model are employed to solve and compare the complex flow field and the torque in each case. The end results expected from a cardiovascular CFD analysis are not limited only to the flowfield investigations. More importantly, it needs an evaluation criterion to judge if the design is acceptable as considered from a broader blood cell damage or activation perspective. In this study, blood cell damage index developed based on stress-time empirical rule and Lagrangian particle tracking is introduced to assess the viscous and turbulence-induced stresses effect to the blood cells.
文摘Objective: To explore the changes of coagulation activity and the characters of anticoagulation early after mechanical heart valve replacement. Methods: All patients only took warfarin orally for anticoagulation. The predicted international normalized ratio (INR) was 1.5 to 2.0. Several coagulation markers were monitored early after valve replacement. Complications associated with anticoagulation were recorded and analyzed. The patients were divided into three groups based on the number and position of mechanical valve prothesis, including group M (mitral valve replacement), group A (aortic valve replacement) and group D (mitral and aortic valve replacement).Comparison was made between the three groups. Results: Three events of mild cerebral embolism and five events of mild bleeding occurred during the early postoperative period. One patient suffered from mild cerebral embolism on the 4th day after operation, accompanied by large volume of pericardial drainage. Two patients with bleeding had lower INRs than predicted range. However, INR in one patient with mild cerebral embolism was in the predicted range. There was no significant difference in thrombo time (TT), activated partial thromboplastin time (APTT) and INR on the 3rd day after operation compared to those before operation; meanwhile, plasma fibrinogen (FIB) concentration was higher than that before operation (P<0.05). INR had no significant changes on the 2nd day after the beginning of anticoagulation compared to that before operation; however, INR was significantly elevated on the 4th day (P<0.05). Warfarin doses and INRs were similar among the three groups, but FIB concentrations in plasma were higher in groups M and D than in group A (P<0.01). Conclusion: Hypercoagulabale state exists early after mechanical heart valve replacement. When anticoagulation begins is determined by the change of coagulation markers, not by the volume of chest or pericardial drainage. INR can not accurately reflect the coagulation state sometimes, especially during the first 3 days after anticoagulation. The number and position of mechanical valve prothesis could affect coagulation state. Therefore, anticoagulation therapy should be regulated accordingly.
基金supported by grants from the National Natural Sciences Foundation of China (No. 30571839, No. 30600608,No. 30872540)the National High Technology Research and Development Program of China (863 Program) (No. 2009AA03Z420)
文摘The purpose of this study was to fabricate decelluarized valve scaffold modified with polyethylene glycol nanoparticles loaded with transforming growth factor-β1(TGF-β1),by which to improve the extracellular matrix microenvironment for heart valve tissue engineering in vitro.Polyethylene glycol nanoparticles were obtained by an emulsion-crosslinking method,and their morphology was observed under a scanning electron microscope.Decelluarized valve scaffolds,prepared by using trypsinase and TritonX-100,were modified with nanoparticles by carbodiimide,and then TGF-β1 was loaded into them by adsorption.The TGF-β1 delivery of the fabricated scaffold was measured by asing enzyme-linked immunosorbent assay.Whether unseeded or reseeded with myofibroblast from rats,the morphologic,biochemical and biomechanical characteristics of hybrid scaffolds were tested and compared with decelluarized scaffolds under the same conditions.The enzyme-linked immunosorbent assay revealed a typical delivery of nanoparticles.The morphologic observations and biological data analysis indicated that fabricated scaffolds possessed advantageous biocompatibility and biomechanical property beyond decelluarized scaffolds.Altogether this study proved that it was feasible to fabricate the hybrid scaffold and effective to improve extracellular matrix microenvironment,which is beneficial for an application in heart valve tissue engineering.
基金Supported by IKEM Research Grant G973 (research project No.#000233001 awarded by the Ministry of Health,CZ)
文摘Transition from non-surgical heart valve defects repair from bench to bedside is a reality.Some biological material-based designs for transcatheter aortic valve implantation are ready for use.Their drawback,however is their unknown functional as well as structural durability.Moreover,research on new non-biological materials is essential to replace classical animal-derived sources of human heart valve prostheses.
文摘Currently-used mechanical and biological heart valve prostheses have a satisfactory short-term performance, but may exhibit several major drawbacks on the long-term. Mechanical prostheses, based on carbon, metallic and polymeric components, require permanent anticoagulation treatment, and their usage often leads to adverse reactions, e.g. thromboembolic complications and endocarditis. In recent years, there is a need for a heart valve prosthesis that can grow, repair and remodel. The concept of tissue engineering offers good prospects into the development of such a device. An ideal scaffold should mimic the structural and purposeful profile of materials found in the natural extracellular matrix (ECM) architecture. The goal of this study was to develop cellulose acetate scaffolds (CA) for valve tissue regeneration. After their thorough physicochemical and biological characterization, a biofunctionalization process was made to increase the cell proliferation. Especially, the surface of scaffolds was amplified with functional molecules, such as RGD peptides (Arg-Gly-Asp) and YIGSRG laminins (Tyrosine-Isoleucine-Glycine-Serine-Arginine-Glycine) which immobilized through biotin-streptavidin bond, the strongest non-covalent bond in nature. Last step was to successfully coat an aortic metallic valve with CA biofunctionallized nanoscaffolds and cultivate cells in order to create an anatomical structure comparable to the native valve. Promising results have been obtained with CA-based nanoscaffolds. We found that cells grown successfully on the biofunctionalized valve surface thereby scaffolds that resemble the native tissues, elaborated with bioactive factors such as RGD peptides and laminins not only make the valve’s surface biocompatible but also they could promote endothyliazation of cardiac valves causing an anti-coagulant effect
文摘Data from 736 patients undergoing prosthetic heart valve replacement surgery and concomitant surgery (combined surgery) from January 1998 to January 2004 at Union Hospital were retrospectively reviewed. Univariate logistic regression analyses were conducted to identify risk factors for prolonged mechanical ventilation. The results showed that prolonged cardiopulmonary bypass duration, prolonged aortic cross clamp time and low ejection fraction less than 50 percent (50 %) were found to be independent predictors for prolonged mechanical ventilation. Meanwhile age, weight, and preoperative hospital stay (days) were not found to be associated with prolonged mechanical ventilation. It was concluded that, for age and weight, this might be due to the lower number of old age patients (70 years and above) included in our study and genetic body structure of majority Chinese population that favor them to be in normal weight, respectively.
文摘BACKGROUND Aortic stenosis is one of the rare valvular complications in a transplanted heart.Over the past 8 years,transcatheter approach for aortic valve replacement(TAVR)has been slowly evolving to be the preferred approach in these patient population when compared to the surgical approach.We report a second case in the United States with successful transfemoral minimal approach with minimal sedation for TAVR in a heart transplant recipient 19 years post transplantation for severe symptomatic calcified aortic stenosis.CASE SUMMARY We present a case of 73-year-old male who has undergone successful minimal approach transcatheter aortic valve replacement in an allograft heart.Patient had received orthotopic heart transplantation 19 years ago for non-ischemic cardiomyopathy.Follow up transthoracic echocardiograms as per routine protocol did not show any aortic valve disease until 15 years post transplantation.Aortic valve was noted to be mildly sclerotic at that time and gradually progressed to severe symptomatic aortic stenosis over the next 4 years.Patient had complaints of worsening shortness of breath that limited his functional capacity.Overall his post heart transplantation period has been mostly uneventful except for allograft non occlusive vasculopathy and aortic stenosis.His Society of Thoracic Surgery risk score was 12.205%and he was considered to be a high-risk surgical candidate by surgeon.Decision was made to undergo transcatheter aortic valve replacement.CONCLUSION With the improved survival of these patients,we think it is time to look intopathophysiology of valvular disease in transplant heart recipients.Some other unanswered questions include,underlying donor and recipient risk factors for valvular diseases in heart transplant recipients.
文摘The analysis of 10 normal and 51 mitral valve pathology making a total of 61 heart sound signals that were obtained with Littmann 4100 Digital Stethoscope were conducted in this study.Following the recorded sound signals were denoised by using wavelet filters,the signals were applied bicoherence analysis that is an high order spectral analysis method.It has been demonstrated that varieties of mitral valve pathology could be determined by three-dimensional surfaces of bicoherence and maximum bicoherence values.
文摘Patient-prosthesis mismatch(PPM) should be recognized in patients with elevated transprosthetic gradients but without leaflet immobility, since the treatment strategy may differ in either etiology. However, thrombus and/or pannus formation should be excluded before a diagnosis of PPM is made. Particularly, pannus formation may not be diagnosed with 2-dimensional transesophageal echocardiography. Electrocardiographically gated 64-section multidetector computed tomography(MDCT) may be a promising tool in diagnosing or excluding pannus formation. Our report underlines the utility of MDCT in this regard and also emphasizes the importance of recognition of PPM as a differential diagnosis in such patients.
文摘Management of warfarin-induced major bleeding in patients with mechanical heart valves is challenging.There is vast controversy and confusion in the type of treatment required to reverse anticoagulation and stop bleeding as well as the ideal time to restart warfarin therapy safely without recurrence of bleeding and/or thromboembolism.Presently,the treatments available to reverse warfarin-induced bleeding are vitamin K,fresh frozen plasma,prothrombin complex concentrates and recombinant activated factor Ⅶa.Currently,vitamin K and fresh frozen plasma are the recommended treatments in patients with mechanical heart valves and warfarin-induced major bleeding.The safe use of prothrombin complex concentrates and recombinant activated factor Ⅶa in patients with mechanical heart valves is controversial and needs well-designed clinical studies.With regard to restarting anticoagulation in patients with warfarin-induced major bleeding and mechanical heart valves,the safe period varies from 7-14 d after the onset of bleeding for patients with intracranial bleed and 48-72 h for patients with extra-cranial bleed.In this review article,we present relevant literature about these controversies and suggest recommendations for management of patients with warfarin-induced bleeding and a mechanical heart valve.Furthermore,there is an urgent need for separate specific guidelines from major associations/professional societies with regard to mechanical heart valves and warfarin-induced bleeding.
基金supported by the National Key Research and Development Program of China Stem Cell and Translational Research(2016YFA0101103)the National Natural Science Foundation of China(grant numbers 81930052,81901904,82000367,82001701).
文摘Cardiac valve replacement is an effective method to treat valvular heart disease.Artificial valves used routinely in clinic still have defects.In our study,we explored a novel method to modify the performance of Decellularized Heart Valve(DHV)scaffold.The decellularized porcine aortic valve was prepared using sequential hydrophile and lipophile solubilization method.The sericin was extracted from silk fibroin-deficient silkworm cocoon by lithium bromide method.First,DHV was immersed in sericin solution to produce the sericin–DHV composite scaffold.Then,we modified the DHV by making a Polydopamine(PDA)coating on the DHV first and then binding the sericin.The physical properties and biological compatibility of our composite scaffold were assessed in vitro and in vivo.Sericin were successfully prepared,combined to DHV and improved its biocompatibility.PDA coating further promoted the combination of sericin on DHV and improved the physical properties of scaffolds.The decay rate of our modified valve scaffold was decreased in vivo and it showed good compatibility with blood.In conclusion,our modification improved the physical properties and biocompatibility of the valve scaffold.The combination of PDA and sericin promoted the recellularization of decellularized valves,showing great potential to be a novel artificial valve.
