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At least 163 records · Page 9Linked to original sources
PubMed1996

[Nonrheumatic calcification of the mitral valve in patients with stenotic calcified bicuspid aortic valve].

The pathogenesis of nonrheumatic calcification of the mitral valve was investigated by analyzing the clinical and echocardiographic characteristics of patients with mitral valvular calcification without any findings suggestive of rheumatic heart disease or infective endocarditis. Calcification of the mitral valve was observed in nine patients, who all had calcified stenotic (aortic valve area < 1 cm2) bicuspid aortic valve. Calcification of the mitral valve was localized to the basal portion of ventricular aspect of the anterior mitral leaflet and contiguous to that of the aortic valve. Mobility and thickness of the mitral leaflet was normal except for the calcified portion. Calcification of the mitral valve was not contiguous to posterior mitral annular calcification nor was related to direction of aortic regurgitant flow. In patients with calcified stenotic bicuspid aortic valve, calcification of the mitral valve was not associated with location of the two aortic cusps, aortic valve area, aortic valvular peak pressure gradient, direction of the left ventricular outflow, end-diastolic left ventricular outflow tract dimension, end-diastolic dimension of the aortic annulus, incidence of aortic regurgitation, calcification of the aortic arch, or risk factors of atherosclerosis. Six patients with mitral valvular calcification had aortic valve replacement. Preoperative coronary angiogram of these patients was normal. Calcification of the aortic valve was on the ventricular and aortic aspects. The calcification of the aortic valve, anterior mitral ring, or anterior mitral leaflet was not rheumatic in these six patients. Rheumatic disease, risk factors of atherosclerosis, mechanical stress by left ventricular outflow or aortic regurgitant flow, or mitral annular calcification did not appear to be related to mitral valvular calcification. The distribution of aortic and mitral valvular calcification suggested that the calcification of the mitral valve was due to progression of calcification of the bicuspid aortic valve.

Aged↗
PubMed1999

The importance of shunt valve position in flow characteristics of the Medtronic PS Medical Delta valve.

This study was conducted to document the extent to which flow depends on valve position in relation to head-pressure reference. Medtronic PS Medical Delta valves (contour model, performance levels 0.5, 1.0, 1.5, and 2.0) were studied in a bench test designed to evaluate flow rates with respect to valve position in relation to the head-pressure reference postion. The valves were connected to an "infinite" reservoir by the standard inlet catheter. An initial head (proximal) pressure was selected for each valve based on package insert data. The position of the inlet catheter tip was fixed at this starting head pressure, thus making the inlet catheter tip position the reference for relative head pressures on the valve assembly. When the valve body is positioned above this level, the effective head pressure is lowered, and when the valve body is positioned below this level, the effective head pressure is raised. Flow was established with the siphon control portion of the valve body located on the same horizontal level as the inlet catheter tip (the reference head pressure or "0" position). A standard silastic catheter was attached to the outlet of the valve, and its length was fixed at 50 cm for all valves (-50 cm H(2)0). The distal end of the outlet catheter was connected to a fraction collector, and 1-minute samples (five replicates) were collected for gravimetric determination of flow rate. The valve assembly was then moved in 1-cm increments through the range of 4 cm above to 8 cm below the head-pressure reference position. Samples were collected from each position (4 cm to -8 cm) relative to the inlet catheter tip. Flow rate, in milliliters/hour, was plotted against both relative position (4 cm to -8 cm) and absolute head pressure (in centimeters of water). Each of the valves tested was shown to have a linear relationship between flow and position relative to the inlet catheter tip (or absolute head pressure). The average increase in flow per centimeter of displacement of valve from catheter tip was 16.5 ml/hr/cm (range 14.4-17.6 ml/hr/cm). Once the inlet catheter tip is fixed in position, it serves as a pressure reference. Movement of the valve above this level results in a net decrease in effective head pressure, and movement below this position results in a net increase in effective head pressure. Thus, the positioning of shunt valves in locations different from this pressure reference position should be performed only with the knowledge that significant increases in outflow rate may occur when the valve body is positioned lower than the inlet catheter tip. This increase in outflow rate is not the result of siphoning or a defect in the antisiphon device but instead the result of a net increase in effective head pressure.

Journal Article↗
PubMed1994

The use of unstented homograft valves for aortic valve reoperations. Review of a twenty-three-year experience.

Unstented homograft valves offer several theoretical advantages when used for patients who have had previous operations on the aortic valve. Between January 1970 and February 1993, 177 patients received unstented homograft valves after previous aortic valve operations. One hundred thirty-four patients had previous aortic valve replacement in the form of homografts (101 patients), mechanical prostheses (24 patients), and bioprostheses (9 patients), and 43 had previous valve repair. The indication for reoperation was deterioration of a noninfected valve (124 patients), infective endocarditis (40 patients), and failure of a noninfected mechanical valve (12 patients). Fresh homograft valves were implanted in 60 patients, homografts preserved in antibiotics were used in 111 patients, and 6 patients received cryopreserved valves. Aortic valve and root replacement was performed in 60 patients, and in 117 the homograft was inserted freehand in the subcoronary position. The early mortality was 5.1%. The actuarial survival at 10 years was 71%. Multivariate analysis demonstrated that patients with previous homograft replacement have a better long-term survival than patients who had previous mechanical valves (p = 0.017). The freedom from valve-related death and reoperation was 70% at 10 years. Fresh homografts faired better than antibiotic-sterilized homografts (p = 0.007). None of the patients had recurrence of endocarditis at 6 months, although 1 patient died of uncontrolled infection despite valve replacement. The freedom from recurrent endocarditis was 88% at 10 years. We conclude that unstented aortic homografts provide good early and long-term results for aortic valve reoperations, particularly in patients with previous homograft replacement. Recurrent endocarditis is uncommon even in patients operated on for prosthetic valve infections.

Adolescent↗
PubMed1985

A 5 1/2 year experience with the St. Jude Medical cardiac valve prosthesis. Early and late results of 737 valve replacements in 671 patients.

Between June 12, 1978, and June 12, 1983, 737 St. Jude Medical valves were implanted in 671 patients (431 males, 240 females) ranging in age from 9 months to 82 years (mean 55 years); 16 of these patients (2.3%) were less than or equal to 15 years and 82 (12.2%) were greater than or equal to 70 years. Associated procedures were performed in 28.2% of the 500 aortic valve replacements, 13.3% of the 105 mitral valve replacements, and 10.6% of the 66 double mitral and aortic valve replacements. Hospital mortality (less than or equal to 30 days) was 3.6% (18/500 patients) for aortic, 4.7% (5/105 patients) for mitral, and 0% for double valve replacement. Only one of these 23 hospital deaths was possibly valve-related. Complete follow-up was achieved during December, 1983, and January, 1984, to provide a minimum follow-up of 6 months. Follow-up has been 100% for a total of 1,619 patient-years, with a mean follow-up of 2 1/2 years. There were 41 late deaths (6.1%): 30 in the aortic group, eight in the mitral group, and three in the double valve replacement group. Fourteen (34.2%) of these late deaths have been considered valve-related. At 5 1/2 years, the actuarial survival rate, hospital mortality excluded, is 91% for aortic, 90% for mitral, and 95% for double valve replacement. Functional improvement of these patients is quite satisfactory: Preoperatively, 60.3% were in Class III or IV of the New York Heart Association, whereas postoperatively, 99.5% of the patients are in Class I or II. As 78 patients (65 aortic, 10 mitral, and three double valve replacement) did not receive anticoagulation therapy for a total period of 84 patient-years, the incidence of valve thrombosis, systemic embolism, and sudden or suspicious deaths in this group was compared with that in a group of 630 patients (including 60 patients from the first group who were given anticoagulants afterwards) subjected to long-term anticoagulation for a total period of 1,535 patient-years. A significantly higher incidence of valve thrombosis and systemic embolism was observed in the absence of anticoagulation. Anticoagulant-related complications occurred in 10 patients, with an incidence of 0.65/100 patient-years. On the basis of this 5 1/2 years of experience, the St. Jude Medical valve appears to be an excellent mechanical prosthesis for cardiac valve replacement, in terms of hemodynamic performance and low thrombogenicity, in patients receiving anticoagulants.

Adolescent↗
PubMed1999

Impact of small prosthetic valve size on operative mortality in elderly patients after aortic valve replacement for aortic stenosis: does gender matter?

OBJECTIVE: Ideal management of the elderly patient with a small aortic root remains controversial. This retrospective analysis was performed to determine whether small prosthetic valve size is related to outcome in patients 70 years of age or older undergoing aortic valve replacement for aortic stenosis. METHODS: Between December 1991 and July 1998, 366 patients 70 years of age or older (median age 77 years, range 73-81 years, 49% male) underwent isolated aortic valve replacement or aortic valve replacement with coronary bypass grafting with standard Carpentier-Edwards bovine pericardial valves (Baxter Healthcare Corp, Edwards Division, Santa Ana, Calif) (n = 277; 76%) or St Jude Medical mechanical valves (St Jude Medical, Inc, St Paul, Minn) (n = 89; 24%). Propensity scoring and multivariable regression models were used to evaluate the risks associated with implantation of 19-mm valves. RESULTS: Operative mortality was 16.7% (17/102) in patients who received 19-mm valves and 3% (8/264) among those receiving >/=21-mm valves (P </=.0005). The univariable odds ratio for operative death for 19-mm versus >/=21-mm valves was 6.4 (95% CI 2.7, 15.4; P </=.0005). In the final multivariable model, receipt of a 19-mm valve alone was not a statistically significant predictor of operative death (odds ratio 2. 1; 95% CI 0.7, 6.4; P =.21). However, the combination of male sex and 19-mm valve resulted in a significant risk of operative death (4/9 patients; odds ratio 17.5; 95% CI 2.2, 139; P =.007). Use of a 19-mm valve was not related to late death in either the univariable (hazard ratio 1.0; 95% CI 0.5, 2.0; P =.95) or the multivariable analysis (hazard ratio 0.7; 95% CI 0.3, 1.8; P =.51). CONCLUSIONS: Implantation of a standard 19-mm aortic valve in elderly men with aortic stenosis may be associated with an increased risk of operative mortality. A higher performance valve and/or a root enlargement procedure should be considered in men with a measured 19-mm anulus.

Aged↗
PubMed2006

40 Years experience in mitral valve replacement using Starr-Edwards, St. Jude Medical and ATS valves.

BACKGROUND: We have used the Starr-Edwards ball (S-E) valve since 1963, the St. Jude Medical (SJM) valve since 1978, and the ATS valve, since 1993 as the first choice of mechanical valve. In this study, the results with each valve during the 40 years were investigated in single mitral valve replacement (MVR) cases. PATIENTS AND METHODS: The mean age for S-E valves was 32.8+/-11.1 years old (y.o.), for SJM it was 47.2+/-12.6 y.o. and for ATS it was 56.3+/-11.4 y.o., indicating the aging of patients over time. The operative mortality decreased over the same time from 10.3% to 5.2% then 1.4% respectively. A significant difference was observed among the 3 groups with regards to the valve-related complication-free rate and cardiac event-free rate. However, there was no significant difference among the 3 groups with the other complications. CONCLUSION: Although there are many cases of valve-related complications with S-E valves, they have a role as an initial stage mechanical valve. In view of the long-term results extending over 20 years, the SJM valves is considered as the most reliable valve. The ATS valve is expected to achieve favorable results in the future because it may improve the quality of life (QOL) of patients and produce fewer valve-related complications.

Adult↗