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At least 91 records · Page 5Linked to original sources
PubMed1991

[The prevalence and clinical features of pathologically abnormal mitral valve leaflets (myxomatous mitral valve) in the mitral valve prolapse syndrome: an echocardiographic and pathological comparative study].

We studied the prevalence and clinical features of pathologically abnormal mitral valve leaflets (myxomatous mitral valve: MMV) in consecutive 142 patients with the mitral valve prolapse syndrome (MVP). Our echocardiographic criteria for MMV were 1) thick leaflets 3 mm or greater, 2) redundant leaflet-motion, and 3) echo-density lower than that of the aortic walls. The echocardiographic measurements of left ventricular diastolic dimensions (LVDd), percent fractional shortening (%FS), mitral annular diameter (MAD), and LV mass were compared between MMV and non-MMV groups. Twelve patients (8%) were referred for surgery because of congestive heart failure, and two patients died during the observation periods. Gross morphology of the MMV was characterized by increased surface area, dome formation of the leaflet-body, and non-uniform leaflets in thickness, and histologic findings of the MMV were the infiltration of spongiosa layer into the fibrosa layer. The diagnostic accuracy of echocardiography for the MMV was examined in 14 patients underwent either surgery or autopsy, and it was high (78% in sensitivity and 80% in specificity). The progression of mitral regurgitation (MR) from mild to moderate grade or mild to severe grade was found in five of 26 patients during follow-up studies over 12 months (mean = 36 months). All of the five patients were aged 50 years and older. While, MR completely disappeared in a 17-year-old boy with marked physical development within three years of the observation period. Mitral annular diameter significantly increased in MMV with MR when compared to non-MMV with MR (4.1 +/- 0.7 vs 3.5 +/- 0.4). But no significant changes were noted in LVDd and LV mass between non-MMV with MR and MMV with MR. Of the 142 patients with MVP, 96 patients were non-MMV and 46 patients were MMV. Ruptured chordae tendineae were associated in 5/96 patients (5%) with non-MMV and 22/46 patients (48%) with MMV. Intracardiac vegetations were seen in four of the 96 patients (4%) with non-MMV. The prevalence of MMV in MVP was greater in older patients, and it reached nearly as high as 50% of MVP patients aged 60 years and older. In conclusion, the echocardiographic diagnostic criteria for MMV are reliable with high sensitivity and specificity, and are useful to predict the high risk patients in the MVP syndrome. MMV may be a potential etiology causing aggravation of mitral regurgitation and/or ruptured chordae tendineae.

Adolescent↗
PubMed1996

[The problem of 19 mm St. Jude Medical valve prosthesis in the small aortic annuls--19 mm St. Jude Medical valve vs 23 mm St. Jude Medical valve].

We compared the results of 19 mm SJM aortic valve replacements with those of 23 mm SJM aortic valve replacements conducted the same period. [Material & Method] The subjects were 21 patients who underwent valve replacement with a 19 mm SJM prosthesis (the SJM19A group). The age ranged among 16 and 65-year-old, mean of 51. The body surface area was 1.24 to 1.76 m2, mean of 1.48 m2. The post-operative follow-up period was 156 months at maximum and 44 months on average. We compared the SJM19A group with the SJM23A group by chest X-ray and echocardiography. [Results] Two patients in the SJM19A group died soon after surgery. Of the other patient, 19 were categorized NYHA I and one in NYHA II classification in their late phase. Arrhythmia of Lown IVa developed in one patient. The cardio-thoracic ratio decreased from preoperative 60% in the late phase after surgery (p < 0.002) in the SJM19A group, although there was no significant difference with that in the SJM23A group. Echocardiographic improvement in left ventricular hypertrophy was considerable between before and late after surgery in the SJM19A group, while it was not significantly different between the SJM19A and SJM23A group. The mean value of aorta-left ventricle pressure difference in the late stage was 32 mmHg in the SJM19A group and significantly different from the value in the SJM23A group (p < 0.001). This pressure difference tended to be greater as the follow-up period was progressed, while the percentage decrease in the myocardial mass of the left ventricle tended to decreased with longer follow-up period. This data suggests that an increasing level of aorta-left ventricle pressure difference should raise little problem in the mid-term late stage after surgery but possibly cause a serious problem in the long term. Clinical observation should be continued over a long period of time after surgery.

Adolescent↗
PubMed1999

Echocardiographic predictors of left ventricular outflow tract obstruction and systolic anterior motion of the mitral valve after mitral valve reconstruction for myxomatous valve disease.

OBJECTIVE: To determine predictors of systolic anterior motion and left ventricular outflow tract obstruction (SAM/LVOTO) after mitral valve repair (MVRep) in patients with myxomatous mitral valve disease. BACKGROUND: Mechanisms for the development of SAM/LVOTO after MVRep have been described; however, predictors of this complication have not been explored. We hypothesize that pre-MVRep transesophageal echocardiography (TEE) can predict postrepair SAM/ LVOTO. METHODS: Using TEE, the lengths of the coapted anterior (AL) and posterior (PL) leaflets and the distance from the coaptation point to the septum (C-Sept) were measured before and after MVRep in 33 patients, including 11 who developed SAM/LVOTO (Group 1) and 22 who did not (Group 2). RESULTS: Group 1 patients had smaller AL/PL ratios (0.99 vs. 1.95, p < 0.0001) and C-Sept distances (2.53 vs. 3.01 cm, p = 0.012) prior to MVRep than those in Group 2. Resolution of SAM/LVOTO was associated with increases in AL/PL ratio and C-Sept distance. This reflects a more anterior position of the coaptation point in those who developed SAM/ LVOTO. CONCLUSIONS: These data suggest that TEE analysis of the mitral apparatus can identify patients likely to develop SAM/LVOTO after MVRep for myxomatous valve disease. The findings are consistent with the concept that SAM of mitral leaflets is due to anterior malposition of slack mitral leaflet portions into the LVOT. The position of the coaptation point of the mitral leaflets is dynamic and a potential target and end point for surgical designs to prevent SAM/LVOTO post MVRep.

Aged↗
PubMed1976

Clinical and hemodynamic findings following prosthetic valve replacement for mitral valve disease. A study of patients with the new Björk-Shiley tilting disc valve.

Clinical and hemodynamic results have been evaluated 12--24 months after mitral valve replacement with the new Björk-Shiley tilting disc valve prosthesis. After operation, most patients were improved symptomatically and were classified as I-II (N.Y.H.A.). No patient became worse. Hemodynamic status at rest showed significant reduction in pulmonary capillary venous pressure, pulmonary artial pressure and significant increase in cardiac output when compared with the preoperative values, but postoperative hemodynamic abnormalities remained. Exercise produced a rise in pressures in the pulmonary circuit and in cardiac output. The increase in cardiac output was less than expected from the increase in oxygen consumption, with a few exceptions. Apparently, there was no close relationship between the symptomatic improvement and the hemodynamic results. Thus, the present study points to the importance of hemodynamic data in the objective assessment of the results of cardiac surgery.

Adult↗
PubMed1979

Intravascular haemolysis after valve replacement: comparative study between Starr-Edwards (ball valve) and Björk-Shiley (disc valve) prosthesis.

Seventy-four patients with single prosthetic valves (Björk-Shiley or Starr-Edwards) in the mitral or aortic position and 18 controls with rheumatic valvar heart disease were investigated for evidence of intravascular haemolysis. Serum lactate dehydrogenase (LDH) was used as the most sensitive indicator of haemolysis. Raised concentrations were found in a third of 39 patients with Björk-Shiley prostheses (mean 281 IU/l) and in all 35 patients with Starr-Edwards prostheses (mean 859 IU/l. Values were considerably higher in patients with Starr-Edwards prostheses and particularly in those with aortic prostheses (mean 927 IU/l). Eight out of 12 patients with haemosiderinuria had Starr-Edwards valves. Intravascular haemolysis was of little clinical significance in patients with Björk-Shiley prostheses, but some patients with Starr-Edwards prostheses became iron deficient as a result.

Aortic Valve↗
PubMed1993

Surgical intervention for tricuspid valve endocarditis: vegetectomy, valve excision, or valve replacement?

Illegal drug use predisposes the intravenous drug abuser to bacterial endocarditis, primarily of the tricuspid valve. The prevalence and clinical symptomatology of tricuspid valve endocarditis is reviewed, as are surgical options available to these patients. Nursing care issues that are discussed include postoperative hemodynamic monitoring, fluid resuscitation, and the psychosocial elements surrounding these patients.

Cardiac Surgical Procedures↗
PubMed2000

[Efficacy of aortic valve replacement with freestyle stentless valve in patients with aortic valve disease].

Stentless porcine aortic bioprosthesis has several potential advantages over conventional stented bioprosthesis. The Medtronic Freestyle aortic bioprosthesis, a stentless design analogous to an aortic allograft, has zero-pressure-fixed leaflets treated with an antimineralization agent, and has been shown to have benefits of superior effective orifice area, excellent flow characteristics and durability. To evaluate the early results for its efficacy in view of post-operative performance. The valve was implanted using the cylinder method, with subcoronary, root-inclusion techniques or full root techniques. No patients experienced any significant valvular regurgitation on echocardiography. The post-operative data of EDVI, ESVI and LVPWD decreased significantly as compared with the pre-operative data while ejection fraction remained unchanged. The average peak pressure gradient was 16.5 mmHg, and the average effective orifice area was 2.45 cm2. In conclusion, Freestyle stentless aortic bioprosthesis showed excellent hemodynamic function. It seems to be suited for the older patient with a small aortic annulus.

Aged↗
PubMed2004

Is the mitral valve passive flap theory overstated? An active valve is hypothesized.

The concept that the mitral valve of the heart is a passive flap that opens and closes like a barn door has been emphasized for decades by medical and biology professors to their students. But experimental findings, which are outlined in this report, support the theory of an active valve. We hypothesize that the two leaflets of the mitral valve are actively contractile; that physical forces generated in the valve itself may stabilize and add precision to the sum of forces that regulate valve movement. This precision could be of critical significance both in the moments preceding, and during, valve opening and closing. Evidence supporting our active valve hypothesis includes the profuse innervation of motor and sensory nerves that are present in the mitral valves of all animals studied. In addition, multiple contractile cell types have been found in the mitral valve, including cardiac muscle cells, smooth muscle cells, and cardiac valvular interstitial cells. In vitro work in our laboratories using the rat mitral valve shows that not only are the valves capable of contraction and relaxation, but that the contractions and relaxations are nerve-mediated. We theorize that the rich innervation and contractile cells in the mitral valve work together to modulate fine-tuning of valve movements and tone, thereby ensuring the integrity of the valve seal. Other investigators have reported that the mitral valve demonstrates contractile activity and that denervation localized to the mitral valve affects valve competence. The evidence for an active mitral valve presented by these and other experimental studies warrant a reexamination of the validity of the passive valve concept. An accurate and full understanding of the precise movements of the valve leaflets and the mechanisms that regulate these movements is likely to provide the information needed to understand and develop treatments for many different cardiac valve problems, including mitral valve diseases such as prolapse and myxomatous degeneration. In view of the available experimental evidence, the concept that the mitral valve functions only as a passive structure is challenged by numerous anomalies. A reinterpretation of the concept of valve function that incorporates active as well as passive roles for the valve leaflets and other components of the valve apparatus would have significant implications both for the directions taken in research involving the cardiac valves and for the approaches to treatment.

Animals↗
PubMed2006

In vitro comparison of aortic valve movement after valve-preserving aortic replacement.

OBJECTIVE: In aortic valve regurgitation and aortic dilatation, preservation of the aortic valve is possible by means of root remodeling (Yacoub procedure) or valve reimplantation (David procedure). In vivo studies suggest that reimplantation might substantially influence aortic valve-motion characteristics. Evaluation of aortic valve movement in vivo, however, is technically limited and is difficult to standardize. We evaluated the aortic valve-motion pattern echocardiographically in vitro after reimplantation and remodeling. METHODS: By using aortic roots of house pigs (aortoventricular diameter, 22 mm) a Yacoub procedure (22-mm graft; group Y, n = 5) or a David I procedure (24-mm graft; group D, n = 5) was performed. Roots after supracommissural replacement (22-mm graft; group C, n = 5) served as control valves. In an electrohydraulic, computer-controlled pulse duplicator the valves were tested at flows of 2, 4, 7, and 9 L/min. Echocardiographically assessed parameters were rapid valve-opening velocity, slow valve-closing velocity, rapid valve-closing velocity, rapid valve-opening time, rapid valve-closing time, ejection time, maximum valve opening, slow valve-closing displacement, and maximum flow velocity. RESULTS: Mean rapid valve-opening velocity and mean rapid valve-closing velocity at a cardiac output of 2 to 9 L/min were fastest in group D (rapid valve-opening velocity: 69 +/- 10 cm/s [group D] vs 39 +/- 4 cm/s [group Y] vs 42 +/- 4 cm/s [group C], P = .0041; rapid valve-closing velocity: 22 +/- 2 cm/s [group D] vs 16 +/- 2 cm/s [group Y] vs 17 +/- 1 cm/s [group C], P = .0272), and slow valve-closing velocity was slowest in group D (0.2 +/- 0.1 cm/s [group D] vs 1.0 +/- 0.3 cm/s [group Y] vs 0.6 +/- 0.1 cm/s [group C], P = .0063). With increasing cardiac output, the difference in rapid valve-opening velocity between the groups increased, the difference in slow valve-closing velocity remained unchanged, and the difference in rapid valve-closing velocity decreased. CONCLUSIONS: In this standardized experimental setting remodeling of the aortic valve provides significantly smoother valve movements. This might contribute to preservation of a better valve performance during long-term follow-up.

Animals↗
PubMed1995

[Comparison of long-term clinical results of the three models of the Björk-Shiley valve prosthesis and the Omnicarbon valve prosthesis].

A multi-institutional cooperative study, that was a comparison of long-term results of the replacement of the four models of the oblique disc valve prosthesis which had been implanted on aortic and mitral position alone or double from December 1976 to September 1992 in the eight national hospitals in Japan was performed. Seven hundred and thirty-four patients and 765 prostheses that consisted of 582 patients and 610 prostheses of the Björk-Shiley (BS) valve, including 326 patients of the Spherical disc (SP) valve (49 aortic, 259 mitral, and 18 double aortic-mitral), 103 patients of the Convexoconcave disc (CC) valve (45, 51, 7) and 153 patients of the Monostrut (MS) valve (101, 49, 3), and of 152 patients (71, 78, 3) and 155 prostheses of the Omnicarbon (OC) valve were compared with their mortality and morbidity in every valve position respectively according to the approval by STS-guideline. The MS valve and the OC valve showed 0% to 11.3% of operative mortality, 0.3%/py to 1.8%/py of valve related mortality, 85.5% +/- 5.6% to 98.4% +/- 1.6% of actuarial survival rate at 10 years, and 58.5% +/- 6.4% to 82.7% +/- 5.7% of actuarial free rate of all mortality and morbidity at 10 years in every valve position. Structural deteriorations occurred in two patients of the CC valve in the mitral position only, and its rate of all valve positions showed 0.04%/py. Significant differences were seen in actuarial survival rate at 10 years after aortic valve replacement, and in operative mortality rate, improved degree of NYHA class, structural deterioration rate and actuarial free rate of all mortality and morbidity after mitral valve replacement between the group of the MS and OC valve and the group of the SP and CC valve. Therefore the MS valve or the OC valve should be selected to implant rather than the SP valve or the CC valve, and the patient who had been implanted with the CC valve should be treated considering valve position, valve position, valve size, age and activity of the patient and the manufactured date of the prosthesis.

Bioprosthesis↗
PubMed1999

The natural history of aortic valve disease after mitral valve surgery.

OBJECTIVES: The present study evaluates the long-term course of aortic valve disease and the need for aortic valve surgery in patients with rheumatic mitral valve disease who underwent mitral valve surgery. BACKGROUND: Little is known about the natural history of aortic valve disease in patients undergoing mitral valve surgery for rheumatic mitral valve disease. In addition there is no firm policy regarding the appropriate treatment of mild aortic valve disease while replacing the mitral valve. METHODS: One-hundred thirty-one patients (44 male, 87 female; mean age 61+/-13 yr, range 35 to 89) were followed after mitral valve surgery for a mean period of 13+/-7 years. All patients had rheumatic heart disease. Aortic valve function was assessed preoperatively by cardiac catheterization and during follow-up by transthoracic echocardiography. RESULTS: At the time of mitral valve surgery, 59 patients (45%) had mild aortic valve disease: 7 (5%) aortic stenosis (AS), 58 (44%) aortic regurgitation (AR). At the end of follow-up, 96 patients (73%) had aortic valve disease: 33 AS (mild or moderate except in two cases) and 90 AR (mild or moderate except in one case). Among patients without aortic valve disease at the time of the mitral valve surgery, only three patients developed significant aortic valve disease after 25 years of follow-up procedures. Disease progression was noted in three of the seven patients with AS (2 to severe) and in six of the fifty eight with AR (1 to severe). Fifty two (90%) with mild AR remained stable after a mean follow-up period of 16 years. In only three patients (2%) the aortic valve disease progressed significantly after 9, 17 and 22 years. In only six patients of the entire cohort (5%), aortic valve replacement was needed after a mean period of 21 years (range 15 to 33). In four of them the primary indication for the second surgery was dysfunction of the prosthetic mitral valve. CONCLUSIONS: Our findings indicate that, among patients with rheumatic heart disease, a considerable number of patients have mild aortic valve disease at the time of mitral valve surgery. Yet most do not progress to severe disease, and aortic valve replacement is rarely needed after a long follow-up period. Thus, prophylactic valve replacement is not indicated in these cases.

Adolescent↗
PubMed1999

Aortic valve replacement with stentless porcine aortic valve: a pioneer series.

Durability of stentless porcine aortic valves is determined by the resistance of the cusps to mechanical fatigue and reactions by the host. This study examines the role of mismatch between the size of the valve and the diameter of the sinotubular junction on durability of the valve. A custom-made stentless porcine aortic valve designed for implantation in the subcoronary position was used for aortic valve replacement in 29 patients. There were 15 men and 14 women, with a mean age of 58 years (range 26 to 72 years). In addition to aortic valve replacement, 6 patients had mitral valve surgery, 10 patients had coronary artery bypass graft, 1 patient had closure of an atrial septal defect, and 1 had concomitant aortobi-iliac bypass graft. Follow-up time extended from 10.3 to 11.5 years and was complete. The selection of size of valve implanted was based solely on the diameter of the aortic annulus. Because the diameter of the sinotubular junction plays an important role in leaflet motion and valve competence, the size of valves was compared with the diameter of the sinotubular junction of the aortic roots where they were implanted. There was one operative death and five late deaths. There were no valve-related deaths. The actuarial survival at 10 years was 76%+/-5%. There were only two transient ischemic attacks and no strokes. One patient developed endocarditis 4 years' postoperatively and was successfully treated with aortic valve re-replacement. One patient with cardiomyopathy had heart transplantation. Thus, the stentless valve was at risk of failure in 21 patients. Nine patients developed echocardiographic evidence of valve dysfunction: seven had aortic valve re-replacement and two continue to be observed because the dysfunction is not severe. The function of the stentless valve remained normal in 12 patients. Patients with bioprosthetic valve dysfunction had a sinotubular junction 3.2+/-1.3 mm larger than the size of the valve, whereas patients with normal bioprosthetic valve function had a sinotubular junction 0.8+/-1.2 mm larger than the size of the valve (P = .01). The durability of stentless porcine aortic valve implanted in the subcoronary position is affected by discrepancies in diameters between the xenograft valve and the sinotubular junction of the aortic root. Sinotubular junction greater than the size of the stentless valve probably increases mechanical stress on the cusps and causes premature valve failure.

Adult↗
PubMed1993

Late results of valve replacement with the Björk-Shiley valve (1973 to 1982)

Cardiac valve replacement with use of only the Björk-Shiley prosthesis was performed in 1253 patients between January 1973 and December 1982. There were 828 patients having aortic valve replacement, 280 patients having mitral valve replacement, and 145 patients having double valve replacement with aortic and mitral valve prostheses. Patient outcome was stratified according to multiple variables, including valve position and valve model (spherical versus convexo-concave discs). No valve failure due to strut fracture was identified in 26 high-risk patients (mitral valve replacement with greater than or equal to 29 mm implanted in patients less than or equal to 50 years of age) followed up for a mean of 10 years postoperatively. Fifteen patients had late thrombosis of their Björk-Shiley prosthesis (0.28 per 100 patient-years), but there was no significant difference in risk of valve thrombosis comparing the spherical and convexo-concave discs (0.27 per 100 patient-years versus 0.27 per 100 patient-years). One hundred two patients had 128 thromboembolic episodes; rates of thromboembolism after aortic valve replacement, mitral valve replacement, and double valve replacement were 2.1, 4.3, and 4.6 per 100 patient-years, respectively. Percentages of patients free from thromboemboli after aortic valve replacement, mitral valve replacement, and double valve replacement were 93% +/- 1%, 86% +/- 2%, and 89% +/- 3% at 5 years postoperatively and 87% +/- 2%, 79% +/- 5%, and 77% +/- 8% 10 years postoperatively. There was no significant difference in the rates of thromboemboli for spherical and convexo-concave discs for all patients and for each of the subgroups. Ten-year actuarial survival estimates for patients dismissed alive from the hospital after aortic valve replacement, mitral valve replacement, and double valve replacement with the Björk-Shiley valve were 65% +/- 4%, 63% +/- 5%, and 55% +/- 8%, respectively. Overall event-free survival (freedom from death, thromboembolism, anticoagulant-related bleeding, endocarditis, and reoperation) was similar for the three patient groups. Performance of the Björk-Shiley valve as judged by late patient follow-up is similar to other mechanical valves, and modifications in disc design do not appear to have reduced the threat of late valve thrombosis and thromboemboli. Evidence does not support elective explantation of this prosthesis.

Adolescent↗