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At least 235 records · Page 13Linked to original sources
PubMed1982

Factors affecting performance and thromboembolism after porcine xenograft cardiac valve replacement.

Long-term durability and the need for anticoagulation in conjunction with the use of porcine valves remain questionable. We analyzed valve dysfunction and thromboembolism in 325 adult (older than 20 years) and 31 pediatric survivors who received 407 porcine xenograft valves from June, 1974, to September, 1980 (46% of all valve replacements). Valves at risk in the adults were 216 aortic, 138 mitral, and 22 tricuspid; in children, 14 aortic, eight mitral, seven pulmonary, and two tricuspid. Mean follow-up was 38 (9 to 85) months. Twenty-seven valved conduits also were followed up for 9 to 85 (mean 52) months. Two late deaths in children resulted from dysfunction and another from endocarditis. One late death in an adult was caused by embolism. The other 36 deaths in the entire group were not valve related. Dysfunction requiring reoperation at 12 to 37 months occurred in eight of 325 adults (six mitral, one aortic, and one tricuspid). Dysfunction was due to recurrent endocarditis in six and to primary tissue failure in two (both older than 35 years of age); all survived reoperation. However, in children, severe dysfunction due to primary tissue failure occurred in seven (23%) cardiac valves, necessitating replacement at 21 to 48 months, and three of 27 conduits had to be replaced at 39 to 70 months. Thromboembolism occurred in six adults with mitral xenografts but none with aortic or tricuspid valve. Four of the patients with thromboemboli (one of whom died) were among 16 who had atrial fibrillation and no warfarin, but aspirin and persantine (11.7%/patient-year) and two were among 14 with sinus rhythm on no medication. No thromboembolism occurred in patients with mitral xenografts who were in sinus rhythm and receiving antiplatelet agents or in those with atrial fibrillation receiving warfarin. This experience indicates a high incidence of relatively early failure of porcine xenograft cardiac valves in children and young adults but excellent medium and long-term performance in older adults, in whom severe dysfunction occurred mainly with recurrent endocarditis. Thromboembolism occurred primarily in patients with mitral replacement especially with atrial fibrillation and no anticoagulants.

Adult↗
PubMed2004

[Clinical analysis of ten primary cardiac valve tumors].

OBJECTIVE: To investigate the clinical characteristics of primary valve tumors and the late surgical results of their resection. METHODS: We reviewed our clinical experience with the surgical treatment of ten primary valve tumors at Fuwai Hospital between November 1983 and November 2002. RESULTS: In this series, cardiac valve tumors constituted 2.65% (10/378) of all primary cardiac tumors, and the incidence of primary valve tumors was roughly one in 4000 cardiac operations. There were 5 male and 5 female patients aged 2 to 66 years (mean age, 30 years). The clinical presentations included exertional dyspnea in 7 patients, neurological symptoms in 2, and cyanosis at rest in 1 patient. The diagnosis was established by preoperative echocardiography in 8 patients, and in the other 2, it was confirmed by the findings at operation. All of the tumors were resected. Eight of the ten tumors were benign, and two were malignant. All patients survived the operation and recovered eventfully. Late outcomes were known for all patients. There were three late deaths. One patient with a benign tricuspid valve died 2 months postoperatively of an electrolyte disorder. The other 2 patients with a malignant mitral valve tumor died within 1 year postoperatively. The 7 survivors, all with a benign valve tumor, were followed up for an average of 5.7 years (range, 8 months to 19 years), and all were in functional Class I. Exercise tolerance improved to normal levels. The latest follow-up echocardiography showed no evidences of the local recurrence in any patients. CONCLUSION: Excellent early and late surgical results can be obtained in patients with benign valve tumors. The prognosis for the patients with a malignant valve tumor is poor.

Adolescent↗
PubMed2005

[Effects of low-dose pergolide therapy on cardiac valves in patients with Parkinson's disease].

BACKGROUND: Pergolide mesilate is widely used to treat Parkinson's disease in both the USA and Japan, but the maintenance dose is distinctly different between the USA (usually more than 1.5 mg/day) and Japan (usually less than 1.5 mg/day). Although several reports from the USA have suggested that mitral, aortic, and tricuspid valvular lesions were caused by pergolide, it is unclear whether low-dose pergolide therapy causes such valvular lesions. OBJECTIVES: The effects of low-dose pergolide therapy on cardiac valves were studied in Japanese patients with Parkinson's disease. METHODS: One hundred and five consecutive patients with Parkinson's disease approved for our protocol were enrolled in this study. Forty patients were treated with low-dose pergolide (0.05-1.5 mg/day for 2-115 months), and were included in the pergolide group (mean age 71 +/- 6 years). The other 44 patients received no ergot-derived dopamine receptor agonists, and 32 patients acted as age-matched controls (mean age 71 +/- 7 years). Both groups of patients underwent echocardiographic examination to detect organic lesions in cardiac valves such as thickening of the leaflet, annular calcification, restriction of valve motion and valvular tenting, and valvular regurgitation greater than 2 + on the 4-point scale. RESULTS: No significant difference was observed in the incidence of aortic, mitral and pulmonic valve lesions between the pergolide group and the control group. Although no organic lesions were detected in the tricuspid valve, the incidence of tricuspid regurgitation was significantly higher in the pergolide group than in the control group (p < 0.05). CONCLUSIONS: Although low-dose pergolide of less than 1.5 mg/day does not cause serious damage in the left-sided valves, it may induce tricuspid regurgitation.

Aged↗
PubMed1995

Adenine nucleotide depletion in cryopreserved human cardiac valves: the "stunned" leaflet interstitial cell population.

Preparation protocols for human cardiac valves are intended to minimize cytotoxicity because it has been thought that viable leaflet interstitial cells may enhance homograft durability. Preimplantation factors influencing the status of these cells at the time of transplantation include ischemia, disinfection, and cryopreservation freezing programs. In these experiments, adenine nucleotide quantitation was undertaken to assess metabolic consequences of preparation; preharvest ischemia served as an independent variable to examine the relationship between time of procurement (postmortem) and high-energy phosphate status of the cryopreserved leaflets at thaw. Nucleotides were measured using high-performance liquid chromatography performed on extracts of semilunar cusps from 25 cryopreserved human valves with documented ischemic times. Results indicate total adenine nucleotides (TAN; [ATP] + [ADP] + [AMP], in nmol TAN/mg leaflet protein) are higher (P < 0.05) after < 2 h of harvest ischemia (1.16 +/- 0.36) than with ischemic times of 3-6 h (undetected), 7-12 h (0.18 +/- 0.07), and 13-20 h (0.06 +/- 0.06). Depletion of ATP was similar, with many leaflets devoid of detectable levels. Net utilization of leaflet energy stores demonstrates time dependency when assayed after completed processing. However, relatively elevated catabolites, even with brief ischemia, and infrequently identified ATP, ADP, and AMP, suggest a consumption so accelerated that the following cryopreservation it is virtually independent of procurement-associated ischemia. We conclude resumption of a functional cell population obligates significant de novo phosphoanhydride boned reformation or a repopulation of dead/dying interstitial cells from a subset surviving the apparently severe rigors of valve preparation.

Adenine Nucleotides↗
PubMed2001

Effect of coronary bypass and cardiac valve surgery on systemic endothelial function.

Seventeen patients scheduled for a cardiac procedure necessitating cardiopulmonary bypass underwent serial perioperative assessment of brachial artery flow-mediated dilation. Patients who underwent coronary bypass surgery had a sustained systemic endothelial dysfunction in the perioperative period, whereas those undergoing cardiac valve surgery experienced transient postoperative systemic endothelial dysfunction.

Adult↗
PubMed1990

The utility of transesophageal echocardiography and Doppler color flow imaging in patients undergoing cardiac valve surgery.

To assess the value of intraoperative transesophageal echocardiography during cardiac valve surgery, 154 consecutive patients who had a valve operation in conjunction with pre- and postcardiopulmonary bypass transesophageal imaging were studied. Prebypass imaging yielded unsuspected findings that either assisted or changed the planned operation in 29 (19%) of the 154 patients. Imaging immediately after bypass revealed unsatisfactory operative results that necessitated immediate further surgery in 10 (6%) of the 154 patients. Postbypass left ventricular dysfunction, prompting administration of inotropic agents, was identified in 13 patients (8%). Transesophageal echocardiography proved most useful when both two-dimensional and Doppler color flow imaging were employed in patients undergoing a mitral valve operation, where surgical decisions based on echocardiographic results were made in 26 (41%) of 64 cases. Postbypass echocardiographic findings identified patients at risk for an adverse postoperative outcome. Of 123 patients whose postbypass valve function was judged to be satisfactory, 18 (15%) had a major postoperative complication and 6 (5%) died, whereas of 7 patients with moderate residual valve dysfunction, 6 (86%) had a postoperative complication and 3 (43%) died (p less than 0.05 for both). Likewise, of 131 patients with preserved postbypass left ventricular function, 12 (9%) had a major complication and 7 (5%) died, whereas of 23 patients with reduced ventricular function, 17 (73%) had a postoperative complication and 6 (26%) died (p less than 0.05 for both). These data indicate that intraoperative transesophageal echocardiography is useful in formulating the surgical plan, assessing immediate operative results and identifying patients with unsatisfactory results who are at increased risk for postoperative complications.

Cardiopulmonary Bypass↗
PubMed1987

The long-term risk of warfarin sodium therapy and the incidence of thromboembolism in children after prosthetic cardiac valve replacement.

Thirty children less than 18 years of age underwent cardiac valve replacement with a prosthetic valve between 1967 and 1984 and have been followed up for a mean of 6 years (range 1 to 17 years). Their mean age at the time of operation was 13 years (range 6 to 17 years). All patients were begun on a regimen of warfarin before hospital discharge. One major and four minor bleeding episodes occurred in 211 patient-years of warfarin therapy, an incidence of 2.3 per 100 patient-years. Three of those five episodes occurred in patients who were receiving excessively anticoagulation or who were participating in physical activities inappropriate for a patient on warfarin therapy. Thus, the majority of the bleeding episodes were preventable. There were five thromboembolic events in 211 patient-years, an incidence of 2.3 per 100 patient-years. Three of those five patients had intentionally stopped their warfarin therapy. The majority of thromboembolic episodes, like the bleeding episodes, were preventable. Eight teenage patients were noncompliant with the warfarin therapy. More than one third of that group experienced a thromboembolic event, an incidence of 5.5 per 100 patient-years (55 patient-years). Twenty-two patients adhered to the warfarin regimen and only two (9%) of them had a thromboembolic event, an incidence of 1.3 per 100 patient-years (156 patient-years). Warfarin therapy presented no greater risk of serious bleeding to this pediatric age group than it does to an adult age group. The incidence of thromboembolism among these patients was less than that which is generally reported for adult patients. Discontinuation of or noncompliance with warfarin therapy substantially increased the risk of thromboembolism. Continuous warfarin therapy is recommended for every child after prosthetic valve replacement.

Adolescent↗
PubMed1978

Clinical evaluation of porcine heterograft cardiac valves in 200 patients.

Of 200 patients who received porcine heterograft cardiac valves, the first 100 did not receive postoperative anticoagulant therapy. In the second 100 patients anticoagulant measures were used when thrombogenic factors not related to the prosthesis were evident. Anticoagulation should be employed following mitral valve replacement while factors contributing to thromboembolism prevail. The conditions that tend to induce vascular stasis in the left atrium followed by embolism are chronic atrial fibrillation, a large dilated left atrium and a calcified left atrial wall. The results of our study provide assurance of the continued use of the porcine bioprosthesis.

Adolescent↗
PubMed1984

Pregnancy in patients with prosthetic cardiac valves.

Thirty-seven pregnancies in 33 patients who had prosthetic cardiac valves inserted at Baragwanath Hospital are reviewed. The patients were divided into three groups, as determined by fetal and maternal outcome. There were 31 live births, and the patients seemed to deal well with the haemodynamic stresses of pregnancy. There were 2 maternal deaths, and 6 patients required a second valve replacement during the pregnancy under review. The problem of longterm anticoagulant therapy and its management is discussed.

Abortion, Spontaneous↗
PubMed2002

Catheter pericardiocentesis for delayed tamponade after cardiac valve operation.

BACKGROUND: Late tamponade is a rare cause of morbidity and mortality after cardiac valve operation. We describe our recent experience with this entity. METHODS: This is a single institution, procedure-matched, retrospective review of patients undergoing pericardiocentesis more than 7 days after cardiac operation, during a 7-year period. RESULTS: Pericardiocentesis for delayed tamponade was performed in 43 of 9,612 patients. Although isolated valve operation accounted for 17% of all patients overall, 76% of patients undergoing pericardiocentesis (33 of 43) had undergone isolated valve operation. The average age in this group was 58 years, compared to an average of 68 years in all patients. Patients presented with tamponade an average of 18 days after operation. Positive predictors included elevated prothrombin time on presentation. Of the patient cohort 75% presented with dyspnea, 61% with inability to diurese, and 61% with hypotension. Echocardiography detected effusions in all patients, but specific echocardiographic signs of tamponade were present in only 30%. Of the patients, 97% were successfully treated by pericardiocentesis. All were safely restarted on warfarin. One patient required pericardial window. CONCLUSIONS: Delayed cardiac tamponade is more common after isolated valve operation, as opposed to coronary artery bypass grafting and valve/coronary artery bypass grafting. It tends to occur in the third postoperative week in younger patients who are aggressively anticoagulated. Pericardiocentesis with catheter placement is highly effective, and patients can be reanticoagulated safely. This series underestimates the incidence of late tamponade, as some patients may present to outside facilities. The diagnosis is aided by a high degree of suspicion.

Adult↗
PubMed1999

The anatomical aspects of minimally invasive cardiac valve operations.

Cadaveric dissections were carried out to examine the relationship of the cardiac valve structures to the surface anatomy of the chest as it relates to our approaches to minimally invasive valvular operations. The techniques of upper hemisternotomy and lower hemisternotomy as used at our institution are described.

Cardiac Surgical Procedures↗
PubMed2000

Cardiac valve replacement: a bioengineering approach.

The second most common major heart operation in the western world is valve replacement. Any one of the four heart valves may become either so stenotic or regurgitant that it needs to be replaced in order to restore normal heart function. Although replacement surgery of dysfunctional heart valves has a very high success rate, it can provide the surgeon with a difficult decision regarding the choice of a suitable prosthesis for the individual patient. Over the years many different types of artificial heart valves have been devised. Surgeons typically deal with a heart valve replacement by installing a mechanical prosthesis or by using a bioprosthetic valve, hand-crafted from animal tissue. Least commonly, valves can be taken from human organ donors. Mechanical valve substitutes have a long fatigue life but the central flow occluders often induce blood cell trauma. Tissue substitutes have an unimpeded central orifice when open, cause minimal cell damage but have a relatively short fatigue life, especially in children where calcification may be a major problem. More recently alternative materials, such as polyurethane, have been used in artificial heart valve design while the new concept of tissue-engineering has enhanced the prospects towards an ideal cardiac valve replacement. Today's artificial valves are designed with a better understanding of the cardiovascular system with the aid of computers. Advances in computer software have allowed simulations of fluid flows through valve substitutes, both in cardiac flow simulators and the heart itself.

Animals↗
PubMed1987

Advances in the hemodynamic assessment of stenotic cardiac valves.

In 1951 Gorlin and Gorlin (Am Heart J 1951;41:1-29) published their formula for calculating the area of a stenotic cardiac valve from hemodynamic data. The important concept implicit in this formula is that the hemodynamic evaluation of a stenotic valve requires that the pressure gradient across that valve be examined in light of the cardiac output passing through the orifice. The concept asserts that if an accurately obtained pressure gradient can be related to an accurate cardiac output by an accurate formula, valve area can be determined. However, recent studies have demonstrated flaws in current practices for obtaining transvalvular gradients and cardiac outputs. Further, new data are available regarding the validation and possible changes in the Gorlin formula, validation and changes that the Gorlins noted might be necessary to make. These new data concerning the three basic requirements of an accurate valve area determination are the subject of this review.

Heart Valve Diseases↗
PubMed1998

Cardiac valve calcification in haemodialysis patients: role of calcium-phosphate metabolism.

BACKGROUND: Cardiac valve calcification (VC) has been detected with increased frequency in haemodialysis (HD) patients, making it necessary to determine the potential pathogenic factors in uraemic patients. METHODS: A total of 92 chronic HD patients (39 female, 53 male) and 92 age and gender-matched nondialysis control subjects were evaluated by echocardiography and a severity score for VC was determined. Calcium phosphate metabolism was evaluated at the beginning of haemodialysis. RESULTS: We found a greater prevalence of VC in dialysis patients than in normal patients (mitral annulus 44.5% vs 10%, P = 0.02; aortic annulus 52% vs 4.3%, P = 0.01). HD patients with mitral calcification were found to be older than patients without calcification, were on long-term renal replacement therapy, had longer duration of predialysis arterial hypertension, had greater values of the highest value of mean calcium phosphate product in 6 successive months (CaxP) and the highest absolute value of calcium-phosphate product (CaxPmax). We also found a positive correlation between calcification score, age, and CaxP. No correlation was found between actual VC and arterial hypertension or parathyroid hormone. Multiple stepwise regression analysis selected age and CaxP as the most predictive parameters for mitral calcification (r = 0.47). Mitral calcification was associated more frequently with rhythm and cardiac conduction defects, valvular insufficiency and with peripheral vascular calcification. Aortic calcification was correlated with age (r = 0.42) and longer duration of predialysis arterial hypertension. CONCLUSION: Our study confirmed an increased prevalence of VC in HD patients and selected age and calcium phosphate product as the most predictive parameters. These findings support careful monitoring of calcium metabolism beginning at the early stages of end-stage renal failure to reduce the risk of heart disease.

Aged↗
PubMed1976

Prosthetic valve endocarditis: clinicopathologic analysis of 22 necropsy patients with comparison observations in 74 necropsy patients with active infective endocarditis involving natural left-sided cardiac valves.

Clinical and morphologic features are described in 22 necropsy patients with endocarditis involving rigid-framed prosthetic valves: aortic in 15 patients and mitral in 7. The interval from valve replacement to onset of symptoms of prosthetic valve endocarditis was less than 2 months in 8 patients and longer than 2 months in 14 patients. The most frequent infecting organism was the Staphylococcus (13 patients). In each of the 22 patients the infection was located behind the site of attachment of the prosthesis to the valve ring, and the infection spread to adjacent structures in 13 patients, 11 of whom had aortic prostheses. Prosthetic detachment causing severe regurgitation occurred in 12 of the 15 patients with an infected aortic valve prosthesis, and in 2 of the 7 with an infected mitral valve prosthesis. Prosthetic obstruction by vegetative material occurred in 5 of 7 patients with prosthetic mitral infection and in only 1 of 15 with prosthetic aortic infection. High degrees of conduction defects developed in seven patients with aortic prosthetic valve endocarditis: complete heart block in five, and complete left bundle branch block in two. Comparison of observations in the 22 patients with prosthetic valve endocarditis with those in 74 patients with active infective endocarditis involving natural left-sided cardiac valves revealed significant (P less than 0.05) differences in the percent with ring abscess, hemodynamic consequences of the endocarditis (valve stenosis), frequency of Staphylococcus as the causative organism and percent with complete heart block or left bundle branch block. No significant differences were observed between the two groups when comparing age, sex, type of underlying valve disease or frequency of organ infarcts of splenomegaly.

Abscess↗
PubMed2004

Ephrin-B2 reverse signaling is required for axon pathfinding and cardiac valve formation but not early vascular development.

Vascular development begins with the formation of a primary vascular plexus that is rapidly remodeled by angiogenesis into the interconnected branched patterns characteristic of mature vasculature. Several receptor tyrosine kinases and their ligands have been implicated to control early development of the vascular system. These include the vascular endothelial growth factor receptors (VEGFR-1 and VEGFR-2) that bind VEGF, the Tie-1 and Tie-2 receptors that bind the angiopoietins, and the EphB4 receptor that binds the membrane-anchored ligand ephrin-B2. Targeted mutations in the mouse germline have revealed essential functions for these molecules in vascular development. In particular, protein-null mutations that delete either EphB4 or ephrin-B2 from the mouse have been shown to result in early embryonic lethality due to failed angiogenic remodeling. The venous expression of EphB4 and arterial expression of ephrin-B2 has lead to the speculation that the interaction of these two molecules leads to bidirectional signaling into both the receptor-expressing cell and the ligand-expressing cell, and that both forward and reverse signals are required for proper development of blood vessels in the embryo. Indeed, targeted removal of the ephrin-B2 carboxy-terminal cytoplasmic tail by another group was shown to perturb vascular development and result in the same early embryonic lethality as the null mutation, leading the authors to propose that ephrin-B2 reverse signaling directs early angiogenic remodeling of the primary vascular plexus [Cell 104 (2001) 57]. However, we show here that the carboxy-terminal cytoplasmic domain of ephrin-B2, and hence reverse signaling, is not required during early vascular development, but it is necessary for neonatal survival and functions later in cardiovascular development in the maturation of cardiac valve leaflets. We further show that ephrin-B2 reverse signaling is required for the pathfinding of axons that form the posterior tract of the anterior commissure. Our results thus indicate that ephrin-B2 functions in the early embryo as a typical instructive ligand to stimulate EphB4 receptor forward signaling during angiogenic remodeling and that later in embryonic development ephrin-B2 functions as a receptor to transduce reverse signals involved in cardiac valve maturation and axon pathfinding.

Animals↗