PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Valves”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources
PubMed1986

Mitral valve stenosis and pure tricuspid valve regurgitation: comparison of necropsy patients having simultaneous mitral and tricuspid valve replacements with necropsy patients having simultaneous mitral valve replacement and tricuspid valve anuloplasty.

Clinical and morphologic observations are described in 30 patients (23 [77%] of whom were in functional class III or IV) who underwent replacement of the mitral valve for mitral stenosis and either simultaneous replacement (13 patients, group I) or anuloplasty (17 patients, group II) of the tricuspid valve for pure tricuspid valve regurgitation. Comparison of the 13 patients in group I with the 17 patients in group II disclosed similar mean ages (55 vs 58 years), similar average preoperative right ventricular systolic pressures (64 vs 61 mm Hg), similar average right atrial mean pressures (10 vs 9 mm Hg), similar average left ventricular systolic pressures (126 vs 120 mm Hg), similar average pulmonary artery wedge-left ventricular mean diastolic pressures (16 vs 18 mm Hg), similar cardiac indexes (2.1 vs 2.0 liters/min/m2), similar mean heart weights (507 vs 535 g), and similar percents with grossly visible foci of left ventricular necrosis (15% vs 12%) and fibrosis (23% vs 12%). Of the 13 patients in group I, 10 (77%) died early (less than or equal to 60 days of tricuspid valve replacement) and 3 (23%) died late (29, 37 and 120 months); of the 17 patients in group II, 14 (82%) died early and 3 (18%) died late (4, 9 and 98 months). The causes of early death in the 2 groups were different: of the 10 patients in group I who died early, the cause was excessive bleeding in 5, low cardiac output of undetermined etiology in 3, dysfunction of both prostheses in 1 and cerebral insult in 1; of the 14 patients in group II who died early, none died from excessive bleeding, 4 from decreased cardiac output of uncertain cause, 5 from left ventricular inflow obstruction (produced by a Starr-Edwards ball-valve prosthesis in 4 and from a Starr-Edwards disc prosthesis in 1), 1 from left ventricular outflow obstruction (by a porcine bioprosthesis), 2 from technical mishaps (incision into left ventricular free wall with rupture in 1 and ligation of the left circumflex coronary artery with resulting acute myocardial infarction in 1) and 2 died suddenly for reasons not determined. Of the 6 patients dying greater than 60 days after operation, 4 died from chronic congestive cardiac failure, 1 from a cerebral embolus and 1 from prosthetic valve endocarditis.

Adult↗
PubMed1992

[Long-term clinical results after aortic valve replacement with mechanical heart valves and mitral valve replacement with porcine valves].

Long-term clinical results of aortic valve replacement (AVR) with mechanical heart valves and mitral valve replacement (MVR) with porcine valves were analysed. Sixty-three patients received isolated AVR and 48 received isolated MVR. Sixty-eight patients with MVR including double or triple valve replacement were also added in order to evaluate the primary tissue failure (PTF). The patients with operative deaths were excluded. Survival rate at 11 years in AVR was 68 +/- 10% and 67 +/- 15% in MVR without statistical difference. At 11 years, 76 +/- 8% of the patients in AVR were free from valve-related complications in contrast with the poor result of 34 +/- 31% in MVR (p less than 0.01). Main cause of this poor result in MVR was PTF as indicated in following event free rates; 83 +/- 9% at 7 years, 61 +/- 25% at 10 years and 49 +/- 31% at 13 years. There was no statistical difference between patients of above 50 years and below 49 years in PTF. Valve-related death event free was 93 +/- 5% in AVR and 86 +/- 11% in MVR at 11 years (not significant), however, there was statistical difference in re-operation event free rate as 94 +/- 5% in AVR and 76 +/- 11% in MVR at 11 years (p less than 0.001). These results suggest that the use of porcine valves in mitral position is confined to the selected patients.

Adult↗
PubMed1986

Intermediate term results of isolated mitral valve replacement with glutaraldehyde-preserved porcine xenograft valve: clinical and hemodynamic comparison between Hancock valve and Angell-Shiley valve.

Clinical and hemodynamic assessments were carried out for 30 cases, who underwent isolated mitral valve replacement with glutaraldehyde-preserved porcine xenograft valve. The cases were divided into two groups, according to the types of prostheses. Group H comprised 23 cases with Hancock 342 valve and group AS, 7 cases with Angell-Shiley valve. Mean (S.D.) follow-up periods were 4.0 +/- 0.7 in group H and 4.6 +/- 0.6 years in group AS. Incidence of valvular malfunction was 3.3 in group H and 9.3% per patient-year in group AS. Cumulative survival and event-free rates were calculated by actuarial method, which revealed 91 and 83% in group H and 70 and 71% in group AS at 6 years after operation. Hemodynamic assessments were carried out in 20 cases, in which complete data at rest and during exercise were obtained. Valvular function deteriorated during exercise in both groups. Parameters showing valvular function in group AS were worse than those in group H. It is concluded from this study that intermediate late results are satisfactory in group H, incidence of valvular malfunction is high in children and in group AS, thromboembolisms are seen even in cases with recourse to anticoagulant, xenograft valves are stenotic especially in high flow state and valvular function of AS valve is inferior to H valve.

Adolescent↗
PubMed1988

Comparison of mitral valve dimensions and motion in mitral valve prolapse with severe mitral regurgitation to uncomplicated mitral valve prolapse and to mitral regurgitation without mitral valve prolapse.

To determine the mitral valve abnormalities associated with hemodynamically important mitral regurgitation (MR) among patients with mitral valve prolapse (MVP), computerized 2-dimensional echocardiographic measurements of mitral leaflet and anular dimensions and motion in 26 patients with MVP and MR were compared to those in 48 subjects with uncomplicated MVP, 16 patients with MR due to etiologies other than MVP (rheumatic in 8) and 35 normal adults. Compared to both uncomplicated MVP and normal subjects, patients with MVP plus MR were older (p less than 0.05), had strikingly large mitral leaflets and anulus (p less than 0.0005) and were more likely to have systolic billowing of mitral leaflets in the parasternal long-axis view (24 of 26 [92%] vs 24 of 48 subjects with uncomplicated MVP [50%], p less than 0.001). Overlap in anular and posterior leaflet dimensions in normal and uncomplicated MVP subjects occurred in the 20 MVP plus MR patients who continue to be followed medically but not in the 6 MVP plus MR patients who underwent mitral valve surgery during 22 +/- 14 months follow-up. Patients with MR due to rheumatic or other non-MVP etiologies had enlargement of mitral leaflets and anulus virtually identical to that in MVP plus MR patients. In conclusion, patients with severe MR due to MVP are older, have striking mitral valve enlargement and more frequently exhibit leaflet billowing compared with subjects with uncomplicated MVP. Similar mitral leaflet enlargement was found in patients with non-MVP etiologies of MR, suggesting that mitral anular and leaflet enlargement may play a more general role in the pathogenesis of MR than is currently appreciated.

Adult↗
PubMed1990

[Long-term results of valve replacement in the right side of the heart in congenital heart disease--comparative study of bioprosthetic valve and mechanical valve].

Valve replacements in the right side of the heart (TVR and PVR) were done on 16 patients with congenital heart disease, mainly tetralogy of Fallot and Ebstein anomaly. Including reoperations, 19 operations were performed on them and 20 artificial valves were inserted. Ten mechanical valves (7 St. Jude Medical valves, 3 Starr-Edwards valves) and 10 bioprosthetic valves (7 Carpentier-Edwards valves, 3 Ionescu-Shiley valves) were used. Age at valve replacement ranged from 9 to 52 years (mean 23.0 years), and the follow-up period was 1.28-19.8 years (mean 5.7 years). Including 2 sudden deaths, late death occurred in 4 patients, on all of whom mechanical valve replacements were done at the primary operation. Five-year survival rate of all patients was 76.4 +/- 12.1%, and 10-year survival rate was 63.6 +/- 15.4%. All the patients who received bioprosthesis at the primary operation survived at the time of this follow-up study. On the contrary, long-term results of mechanical valve was unsatisfactory with the 5-year survival of 62.5 +/- 17.1%. In spite of anti-coagulation therapy with warfarin, three patients with mechanical valve complicated thrombotic valves, which necessitated re-operations. Calcified bioprosthetic valve occurred in one patient with I-S valve 8.5 years after the implantation. Five-year complication-free rate was 87.5 +/- 11.7% for bioprosthesis, whereas it was 50.0 +/- 15.8% for mechanical valve (p less than 0.056). It is concluded that the bioprosthesis is the first choice for the valve replacement in the right side of the heart in congenital heart disease.

Adolescent↗
PubMed1987

Biological versus mechanical valves. Analysis of 1,116 valves inserted in 1,012 adult patients with a 4,818 patient-year and a 5,327 valve-year follow-up.

All surviving patients between 18 and 88 years of age receiving biological or mechanical prosthetic heart valves at the Yale-New Haven Hospital from January 1974 through January 1985 were analyzed for thromboembolism, anticoagulation-related hemorrhage, endocarditis, perivalvular leak, valve failure, need for reoperation, late cardiac death, and valve-related death. The rates of these events were analyzed in linear and actuarial terms over the 11 year period. A total of 533 patients received 606 biological valves (328 aortic, 252 mitral, 24 tricuspid, and two pulmonary, consisting of 482 Carpentier-Edwards, 108 Hancock, 15 Ionescu-Shiley, and one other), with a mean follow-up of 2,571 patient-years and 2,935 valve-years. They were compared with 479 patients with 510 mechanical valves (330 aortic, 175 mitral, and five tricuspid, consisting of 178 Starr-Edwards, 166 St. Jude Medical, 164 Björk-Shiley, and two others), which were implanted for 2,247 patient-years and 2,392 valve-years. We found a significantly increased incidence of thromboembolism (p less than 0.001) and reoperation for perivalvular leak (p less than 0.05) in the mechanical valves compared with the biological valves, but a significantly increased rate of valve failure (p less than 0.001) in the biological valves compared with the mechanical valves. The overall analysis comparing total morbidity and valve-related mortality significantly (p less than 0.01) favored the biological valves in the first 5 years of the study and the mechanical valves (p less than 0.001) in the second 5 years of the study. However, the net 10 year results showed no significant difference between the two types of valves. In summary, we found little direct evidence to strongly support the generalized use of one type of valve over another.

Actuarial Analysis↗
PubMed1976

Comparative study of in vitro flow characteristics between a human aortic valve and a designed aortic valve and six corresponding types of prosthetic heart valves.

A model of a pulsatile cardiovascular system is described including an electronic control, a hydraulic driving unit, a volume storage, a peripheral resistance and measuring equipment. Six different artificial heart valves, a designed aortic valve (Aachen pockett valve II) and a human aortic valve have been tested in the outflow position of the pump. Three of them are presently being used in clinical applications. Measurements of pressure and volume flow have been obtained for different frequencies n, pump volumes Vp and time ratios between pressure and suction phase. From the experimental results a comparative evaluation was deducted for different working conditions. In comparison to natural human aortic valve (NK) large volume flow is verified by the Aachen pocket valve II (AT), the Gott-Dagget value (GD), the Starr-Edwards valve (SE) and the Lillehei-Kaster valve (LK). The Gott-Daggett valve has the smallest back flow volume. The Smeloff-Cutter and in particular the Wada-Cutter valve have the largest regurgitation. This is to be expected since the Cutter valves are purposely so designed that they do not close tightly in order to avoid blood sedimentation. The human aortic valve, the Gott-Daggett valve and the Aachen pocket valve demonstrate the most favourable opening-closing characteristics. The human aortic valve achieves a negligible pressure loss, followed by the Björk-Shiley and the Lillehei-Kaster valve.

Adult↗
PubMed1985

[Continuous wave Doppler assessment of prosthetic valves in the mitral position: comparison of the St. Jude medical mechanical valve and the porcine xenograft valve].

To assess the opening function of prosthetic valves in the mitral position with special reference to the type and size of the valve and the years since replacement, we recorded maximum flow velocity through the mitral orifice using continuous wave Doppler echocardiography for 50 patients with mitral valve replacement and 15 normal subjects. There were 33 patients with St. Jude Medical valves and 17 with porcine xenograft valves. An ultrasonic transducer was placed over the left ventricular apex and the direction of the ultrasonic beam was positioned to be parallel with mitral flow using the Doppler audio signals. A pressure gradient was calculated from continuous wave Doppler flow velocity with a simplified Bernoulli's equation proposed by Hatle et al. The peak and mean maximum flow velocity, mean pressure gradient across the valve and the pressure half time were measured to evaluate the opening function of the prosthetic valve. The results were as follows: All four measurements were significantly larger in patients with valve replacements than in normal subjects, and were significantly increased in patients with porcine xenograft valves compared to those with St. Jude Medical valves. The opening function was well maintained in patients having larger valves than in those having smaller ones in the group of St. Jude Medical valve replacement. In patients who had porcine xenograft valve for four years or more, the opening function was decreased the more years they had been implanted. We conclude that continuous wave Doppler echocardiography is a useful noninvasive method for the quantitative assessment of the diastolic opening function of the prosthetic mitral valve.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

Ten-year experience with the porcine bioprosthetic valve: interrelationship of valve survival and patient survival in 1,050 valve replacements.

The porcine bioprosthetic valve was used in 440 patients having isolated mitral valve replacement (MVR), 522 patients having isolated aortic valve replacement (AVR), and 88 patients having MVR + AVR between 1974 and 1981. Patients with associated surgical procedures were excluded. Mean follow-up was 8.3 years. At 10 years, there was no difference in patient survival between those having AVR and those having MVR. Reoperations were performed on 192 patients. Endocarditis was the reason for reoperation in 3.7% of patients who had MVR and 10.6% of those who had AVR. Structural valve degeneration was the reason for reoperation in 89.7% of MVR patients and 78.8% of AVR patients (p = 0.04). Hospital mortality among patients having valve reoperations was 4.7%. At 10 years, the freedom from valve reoperation for all causes and from structural valve degeneration was significantly better for the AVR group than the MVR group (74% +/- 3% versus 61% +/- 4%, p = 0.004; and 79% +/- 3% versus 63% +/- 4%, p = 0.0006, respectively). For patients in their 60s, the 10-year freedom from reoperation was 92% +/- 2% for AVR and 80% +/- 6% for MVR (p = not significant). At 10 years, freedom from cardiac-related death and valve reoperation was best for both MVR and AVR patients in their 60s. Patients 70 years old or older rarely had reoperation but died before valve failure occurred. The 10-year freedom from all major valve-related events (cardiac-related death, reoperation, thromboembolism, endocarditis, and anticoagulant-related bleeding) was practically the same for both MVR and AVR patients (48% +/- 3% versus 49% +/- 3%, respectively). The porcine bioprosthetic valve is the valve of choice only for patients 60 years old or older. Patients in their 70s have an extremely low rate of reoperation but a high rate of cardiac-related death and do not outlive the prostheses.

Adolescent↗
PubMed1991

Tricuspid valve repair for tricuspid valve endocarditis: tricuspid valve "recycling".

Tricuspid valve endocarditis traditionally has been treated with either valve excision or valve replacement. To avoid implantation of foreign material in an infected field, we have applied the principles of mitral valve repair to 4 patients with tricuspid valve endocarditis. On preoperative echocardiography, all patients had 3 to 4+ tricuspid regurgitation, evidence of progressive right ventricular enlargement, and mobile vegetations. In each case, up to three quarters of the anterior leaflet was excised en bloc with infected chordae and papillary muscle heads. Surgical procedures included standard quadrangular resection, conversion to a bicuspid valve, and pericardial patch replacement of the anterior leaflet with mobilization of basal chordae to replace resected marginal chordae. On postoperative echocardiography, tricuspid regurgitation and right ventricular dimensions were reduced in 2 of 4 patients in spite of loss of leaflet tissue. All excised valve tissue demonstrated bacteria on Gram stain or culture. Nonetheless, all repaired valves were successfully sterilized without recurrent infections. Tricuspid valve repair can allow eradication of infection with potential for improving valve competency in complicated tricuspid valve endocarditis.

Echocardiography↗
PubMed1992

Analysis of left ventricular motion after mitral valve replacement with a technique of preservation of all chordae tendineae. Comparison with conventional mitral valve replacement or mitral valve repair.

The postoperative regional left ventricular motion of 22 patients with a diagnosis of mitral regurgitation, and who underwent mitral valve replacement with preservation of chordae tendineae, were retrospectively analyzed by cineangiography in the early postoperative period and by multiple-gated cardiac blood pool scintigraphy in the mid-to-late postoperative period. The operation consisted of the division of the anterior leaflet into anterior and posterior segments, the shifting and reattachment of the divided segments to the mitral ring of the respective commissural areas, and the use of a low-profile bileaflet prosthetic valve. Control groups consisted of 28 patients with mitral regurgitation who underwent mitral valve replacement with a conventional technique and 16 patients who underwent mitral valve repair. Compared with the conventional mitral valve replacement group, the radial shortening of the left ventricle of the chordae-preserved mitral valve replacement group was greater at the apical septal, inferoapical, anterobasal, and anterolateral portions, whereas the radial shortening of the repair group was greater than that of the chordae-preserved group only at the inferolateral portion. The ejection fraction of the whole left ventricle was statistically greater in the chordae-preserved group, and also regional ejection fraction of the chordae-preserved mitral valve replacement group was greater at the apical septal, inferoapical, inferolateral, anterobasal, and anterolateral portions than that of the conventional mitral valve replacement group at these portions. On the other hand, the postoperative regional and global motion was identical to that of the mitral valve repair group except at the inferolateral portion. The result of this study supports a concept that maintenance of continuity between the mitral anulus and the papillary muscle has a beneficial effect on postoperative left ventricular performance.

Adult↗
PubMed1986

[Surgical indications in mitral valve stenosis, combined mitral valve defect or mitral valve insufficiency. Long-term prognosis of operated or drug-treated patients].

Data obtained from 683 patients with mitral valve disease, NYHA-class III or IV, were retrospectively studied by means of a multivariate Cox regression analysis. Based on symptoms and hemodynamic findings, surgical intervention had been recommended for all patients: closed mitral commissurotomy (n = 361), prosthetic mitral valve replacement (n = 241) and prosthetic mitral valve replacement together with a corrective procedure for the tricuspid valve (n = 81). While the majority of patients underwent surgery during the observation period (n = 528), a substantial number of patients continued on medical treatment (n = 155). The mean observation periods were 52, 49 and 31 months, respectively, in the three collectives. Surgically treated patients in whom closed mitral commissurotomy had been recommended had a better prognosis (p less than 0.0003) than those treated medically (five-year survival rate 89% vs. 63%). Age, clinical severity, previous mitral commissurotomy, pulmonary vascular resistance and right atrial mean pressure had no significant influence on prognosis. In patients in whom prosthetic mitral valve replacement had been recommended, surgical treatment led only to tendencial improvement in prognosis as compared with those treated medically (five-year survival rate 78% vs. 61%). Factors with an unfavorable influence on prognosis were age more than 49 years (p less than 0.05), pure mitral regurgitation (p less than 0.001), NYHA-class IV (p less than 0.02) and right atrial mean pressure in excess of 4 mm Hg (p less than 0.01). In patients in whom prosthetic mitral valve replacement together with a corrective procedure for the tricuspid valve had been considered necessary, surgical treatment had no significant influence on prognosis as compared with those treated medically (five-year survival rate 57% vs. 53%). Patients in whom previous mitral commissurotomy had been performed had an extremely poor prognosis (p less than 0.001). Pulmonary vascular resistance was significantly reduced both after mitral commissurotomy as well as after prosthetic mitral valve replacement; this was associated with a significant decrease in right atrial mean pressure and increase in right ventricular ejection fraction. The indication for closed mitral commissurotomy, thus, appears established in patients with symptoms of class III or IV clinical severity. The indication can be established generously since the surgical mortality is low and long-term prognosis is good.(ABSTRACT TRUNCATED AT 400 WORDS)

Anti-Bacterial Agents↗
PubMed1985

Hemodynamic evaluation of stenotic cardiac valves: II. Modification of the simplified valve formula for mitral and aortic valve area calculation.

Since the introduction by Gorlin and Gorlin of the hydraulic formulae for calculating valve area, it has become the best parameter for quantitating valve stenosis. Recently Hakki et al proposed a simplified formula for valve area calculation that does not take into account either heart rate (HR) or left ventricular filling or ejection time. The purpose of this study was to analyze the validity of Hakki's formulae under different physiological conditions and to propose an easy correction to improve its accuracy. Our study suggests: (1) that an easy correction for heart rate in certain cases, dividing by 1.35 when HR less than 75 beats per min in mitral stenosis and when HR greater than 90 beats per min in aortic stenosis, significantly improves the accuracy and validity of Hakki's formulae (p less than 0.02 and p less than 0.05); (2) the instantaneous valve gradients (peak gradient for aortic stenosis and average of instantaneous early, middle, and late diastolic gradients for mitral stenosis) are as valid as mean planimetric gradients for valve area calculation. Thus the simplified formulae proposed in this study allow mitral and aortic valve area calculations by means of instantaneous gradients, cardiac output, and heart rate.

Adolescent↗