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At least 451 records · Page 25Linked to original sources
PubMed1996

Severe mitral valve dysfunction due to unsuspected granulomatous myocarditis: successful cardiac transplantation following attempted mitral valve repair.

Granulomatous involvement of the myocardium is a rapidly fatal disease of uncertain aetiology rarely diagnosed premorbidly. We report a patient who presented with mitral valve incompetence and congestive cardiac failure who underwent a successful mitral valve repair but could not be weaned from cardiopulmonary bypass. Urgent heart transplantation was successfully performed and histological studies of the explanted heart revealed granulomatous myocarditis involving the mitral subvalvular apparatus. Endomyocardial biopsy may be necessary in young patients presenting with mitral valve disease of unknown aetiology.

Adult↗
PubMed1991

Acute reduction of mitral valve area after percutaneous balloon mitral valvuloplasty: assessment with Doppler continuity equation method.

Mitral valve areas before and after balloon mitral valvuloplasty were serially determined by the Doppler continuity equation method in 16 patients. Ultrasound examinations were performed before and immediately after balloon inflation and 24 hours, 1 week, and 1 month after valvuloplasty. Mitral valve area determined by the Doppler continuity equation method correlated well with that determined at catheterization by the Gorlin formula, not only before but also immediately after balloon inflation (y = 0.87 x + 0.05, standard error of estimate = 0.22 cm2, r = 0.90). Serial calculation of mitral valve area by the Doppler continuity equation method showed a slight but significant decrease in the valve area at 24 hours after balloon mitral valvuloplasty but no change after that. We conclude that the Doppler continuity equation method provides an accurate estimation of mitral valve area before and even after balloon valvuloplasty. Mitral valve area dilated by balloon inflation is decreased slightly within 24 hours after the procedure, which corroborates valve stretch as one mechanism for increasing mitral valve area with balloon valvuloplasty. Estimation of mitral valve area immediately after balloon mitral valvuloplasty may overestimate the long-term efficacy of the procedure.

Cardiac Catheterization↗
PubMed1986

The association of floppy mitral valve with disjunction of the mitral annulus fibrosus.

Floppy mitral valve is usually attributed to connective-tissue degeneration. However, we have observed several instances in which both a floppy mitral valve and an abnormal mitral annulus fibrosus were present at autopsy. To study this association, we examined 900 hearts (after postmortem arteriography and fixation in distention) from autopsies of adults at The Johns Hopkins Hospital. Twenty-five (3 percent) of the hearts had a morphologically typical floppy mitral valve; in 23 of them (92 percent), the mitral annulus fibrosus showed disjunction--i.e., a separation between the atrial wall-mitral valve junction and the left ventricular attachment. In 42 other hearts (5 percent), which were from significantly younger patients (mean age [+/- SE], 60 +/- 2 years vs. 68 +/- 3; P less than 0.05), there was mitral annulus disjunction but no floppy mitral valve. Two hearts had a floppy mitral valve but no disjunction of the annulus; both of them had old infarcts of the papillary muscle. Our results show that floppy mitral valve is significantly associated with disjunction of the mitral annulus fibrosus (P less than 0.001). We suggest that floppy mitral valve develops from hypermobility of the valve apparatus, and that it is usually secondary to disjunction of the mitral annulus fibrosus, an anatomic variation in the morphology of the annulus.

Age Factors↗
PubMed1980

Mitral valve prolapse.

Mitral valve prolapse (MVP) now is a commonly recognized syndrome with an apparent prevalence of approximately 4-6%. It appears to occur more frequently in females and occasionally it is familial. In most instances, the syndrome is idiopathic, although it occurs in association with many other conditions, particularly Marfan's syndrome, rheumatic heart disease, coronary heart disease, congestive cardiomyopathy, ostium secundum atrial septal defect, Ehlers-Danlos syndrome or abnormalities of the thoracic cage. The majority of patients with the syndrome have minimal, if any, symptoms and have a benign course. When symptoms do occur, more frequently they are palpitations, chest pain, dyspnea on exertion or fatigue. Neuropsychiatric symptoms or even transient ischemic episodes may occur rarely. Very rarely, complications such as severe mitral regurgitation, arrhythmias or infective endocarditis may occur. Characteristically, patients have a midsystolic click, occasionally followed by a systolic murmur. The timing of the click and the onset of the murmur usually is variable, depending on the ventricular volume. The electrocardiogram frequently shows ST-T wave changes. The diagnosis usually can be confirmed by echocardiography or left ventricular angiography. Most patients with MVP require no treatment other than reassurance. If a systolic murmur is present, prophylaxis against infective endocarditis during dental work probably is useful. Patients with palpitations or chest pain usually respond well to treatment with propranolol. Patients with progressive severe mitral regurgitation require mitral valve replacement.

Death, Sudden↗
PubMed1995

Recent developments in the diagnosis and management of mitral valve prolapse.

Mitral valve prolapse (MVP), which occurs in about 3% of adults, is usually a primary, dominantly inherited condition. MVP may be diagnosed by auscultation of a mid-systolic click and late-systolic murmur that move dynamically with postural maneuvers. M-mode echocardiography confirms MVP by demonstrating late-systolic prolapse and two-dimensional echocardiography reveals leaflet billowing into the left atrium. Echocardiography identifies severe forms of MVP by documenting significant mitral regurgitation, enlargement and thickening of the mitral leaflets and annulus, and loss of leaflet apposition. In contrast to early reports, true "MVP syndrome" as revealed by controlled studies consists of low body weight and blood pressure, minor skeletal abnormalities, orthostatic hypotension, palpitations, and mitral regurgitation that is usually mild. Complications of MVP include progressive mitral regurgitation, infective endocarditis, orthostatic syncope, and possible risks of neurologic ischemia and arrhythmic sudden death. Risk factors we have identified for complications among patients with MVP include older age, male gender, the presence of mitral regurgitation, and possibly, higher weight and blood pressure. The cumulative risk of all complications of MVP by age 75 is from 5% to 10% for affected men and 2% to 5% for affected women. Patients with MVP who have neither a murmur nor Doppler evidence of mitral regurgitation may be reassured that their condition is benign. For other patients with MVP we have shown that oral antibiotic prophylaxis is cost-effective. The presence and severity of mitral regurgitation govern the frequency and intensiveness of follow-up.

Adult↗
PubMed1975

A study of the dynamic relations between the mitral valve echogram and phasic mitral flow.

Echocardiographically recorded mitral valve motion was compared with phasic transmitral flow in 17 open chest dogs. The normal mitral valve opening started with the onset of mitral flow and reached its full excursion while flow was still accelerating. Complete valve opening occurred .044 sec (plus or minus .002 sem) before peak flow, during which time an average of 17.6 percent of total mitral filling volume had passed through the valve. In contrast to the opening movement, the closing motion of the anterior mitral valve cusp lagged behind the deceleration of mitral flow. The E-F phase of the mitral valve echogram started while mitral flow was still increasing and resulted from a combined posterior motion of the cusp and the ring. The E-F slope of the normal valve was found to decrease with reduced cardiac output. The amplitude of the anterior cusp excursion did not reflect the amount of mitral flow. Prolonged P-R interval may induce a mid-diastolic reversal of mitral flow which, in turn, may be accompanied by partial or complete valve closure, occurring before the onset of ventricular contraction. Such premature closure of the mitral valve may be accompanied by a certain amount of regurgitant flow.

Animals↗
PubMed1989

Neurologic aspects of mitral valve prolapse.

Mitral valve prolapse (MVP), the most frequently encountered valvular condition in the population, has been reported in an increasing variety of neurologic, muscular, and psychiatric disorders during the last twelve years. Extensive review of reports indicates this has resulted from observations of either (1) inordinate incidence of MVP in well-defined neurologic entities or (2) development of neurologic or ophthalmologic complications attributed to MVP. In the review presented, basis is found for categorizing MVP by its association with (1) well-defined, genetically determined neurologic disorders; (2) disorders characterized by structural abnormalities, many genetically determined, or inflammatory processes of connective tissues; (3) "mechanical" prolapse resulting from disproportion of mitral valve annulus and left ventricular size, which is, at times, reversible; and (4) a generally asymptomatic state that, at times, is associated with ischemic, thrombotic, embolic, and infectious disorders of the brain and eye. The paradox between the large number of persons with MVP in the general population who remain healthy and a subpopulation of patients with complications of MVP (eg, stroke) or other entities has been identified. A second paradox is found between the well-known increased incidence of MVP, especially in young patients with stroke, and the apparent rarity of stroke among patients with both common (eg, migraine) and unusual (eg, myotonic dystrophy) neurologic entities in which an extraordinary high prevalence of MVP is known to exist.

Cerebrovascular Disorders↗
PubMed1977

Mitral valve replacement versus reconstruction. An analysis of indications and results of mitral valve procedures in a consecutive series of 80 patients.

Case histories of 80 patients undergoing mitral valve procedures over a 2 year period were analyzed to determine the preoperative and intraoperative factors favoring reconstruction. Of 34 patients undergoing valve reconstruction, 31 (90 per cent) were women, and the average age of patients undergoing reconstruction was 41 versus 51 for patients who underwent replacement. Absence of calcification on fluoroscopic study and at operation favored reconstruction, as did the finding of good leaflet mobility by preoperative echocardiograms and operative assessment. Pure lesions, i.e., stenosis or insufficiency, favored reconstruction. In this regard, the use of new annuloplasty techniques has facilitated the surgeon's ability to reconstruct regurgitant mitral valves. No operative deaths and excellent functional and clinical results obtained in 80 per cent of patients undergoing mitral reconstruction justify the aggressive application of this technique in properly selected patients.

Adult↗
PubMed1988

Influence of aortic regurgitation on the assessment of the pressure half-time and derived mitral-valve area in patients with mitral stenosis.

The influence of aortic regurgitation on the Doppler assessment of pressure half-time (T1/2) and on the derived calculation of the mitral-valve area has not yet been adequately evaluated in patients with mitral stenosis and associated aortic regurgitation. Therefore this study was undertaken to verify the accuracy of the T1/2 method for the noninvasive estimation of mitral-valve area in patients with mitral stenosis and associated aortic regurgitation. Data were obtained from 31 selected patients who underwent cardiac catheterization within 24 h of the noninvasive examination. From the Doppler velocity curve, T1/2 was calculated as the interval between the peak transmitral velocity and velocity/ square root of 2. Mitral-valve area was measured from the T1/2 with a computerized system using the equation: 220/T1/2, in cm2. Calculation of the mitral-valve area at catheterization was derived applying the modified Gorlin formula. Mean mitral-valve area, as determined at catheterization, ranged from 0.5 to 2.8 cm2 (1.3 +/- 0.6). Mean mitral-valve area, as calculated by continuous-wave Doppler, ranged from 0.7 to 2.7 cm2 (1.5 +/- 0.6). Linear-regression analysis of data revealed a good correlation between Gorlin and Doppler measurements of the mitral-valve area (r = 0.90, SEE = 0.28 cm2, P less than 0.001, y = 1.0x + 0.2). Doppler showed a systematic overestimate of the mitral-valve area (26%) in patients with mitral stenosis and aortic regurgitation as compared to the Gorlin formula. The overestimate of continuous-wave Doppler was even greater (39%) in a subgroup of patients with 2+ or 3+ angiographic aortic regurgitation.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

Gender differences in dehydration-induced mitral valve prolapse.

Mitral valve prolapse (MVP) is a common cardiac valve abnormality that affects women more frequently than men. We have previously shown that mild dehydration induces echocardiographic signs of MVP in approximately 50% of healthy asthenic women with previously normal cardiac findings. The present study was designed to investigate whether dehydration can induce MVP in normal men. Ten healthy male volunteers with a mean body mass index of 24.2 kg/m2, unremarkable history, and normal cardiac findings and echocardiogram were examined after mild diuresis with 20 mg furosemide. Significant decrease in weight, left ventricular end-diastolic dimension, and cardiac output were detected in all subjects after furosemide administration. In 1 (10%) of the 10 subjects echocardiographic MVP developed after furosemide administration. All furosemide-induced changes resolved with hydration. These results demonstrate that dehydration-induced MVP in men without characteristic body habitus of MVP occurs with substantially lower frequency than previously documented in women with the characteristic body habitus of MVP. This study suggests the importance of gender and body habitus in dehydration-induced MVP.

Adult↗
PubMedDate not supplied

Clinical results of mitral valve replacement with and without preservation of the posterior mitral valve leaflet and subvalvular apparatus.

In this study we attempted to investigate the importance of posterior leaflet preservation during mitral valve replacement (MVR). One hundred and forty randomly selected patients with isolated mitral insufficiency were studied, half of whom had MVR with preservation of the posterior leaflet (Group I), whereas in the other half conventional MVR was performed, without preservation of the posterior leaflet (Group II). Within these two groups there were no in hospital deaths, but 5 patients in Group II were admitted to the hospital with congestive heart failure and 3 of them died after approximately 6 months. Long term mortality rate was 4.2% in Group II. Ejection fraction (EF) decreased postoperatively from 56% to 50% in Group I (p less than 0.05), and from 59% to 49% in Group II (p less than 0.05). Fifteen patients in each group and aged below 30 with sinus rhythm and in the first functional capacity according to the New York Heart Association classification (NYHA) were subjected to exercise study, 18 months after the operation. After exercise EF increased from 47% to 64% in Group I and decreased from 51% to 47% in Group II. These findings suggested that MVR with the preservation of the chordae tendineae can be done with a low morbidity and mortality rate in the early and late postoperative period.

Chordae Tendineae↗
PubMed2005

Mitral valve repair for ischemic mitral regurgitation in dilated cardiomyopathy.

Ischemic mitral regurgitation contributes to poor survival in patients with heart failure. The intermediate-term outcome of mitral reconstruction in 15 patients who had ischemic dilated cardiomyopathy with mitral regurgitation requiring surgical intervention was studied. They underwent mitral valve repair along with coronary artery bypass surgery. The mitral valve coaptation depth was considered an important parameter in deciding on repair. Ages ranged from 43 to 72 years. Left ventricular ejection fractions were 15-38% (mean, 26.5% +/- 4.3%). The operative technique in all 15 patients was posterior annuloplasty using Dacron felt. At a mean follow-up of 4.6 +/- 1.2 months (1-8 months), postoperative transesophageal echocardiography revealed mild mitral regurgitation in 2 patients and none in 13. There was a significant improvement in New York Heart Association functional class from 3.9 +/- 1.1 to 1.9 +/- 0.3. Mitral valve repair by posterior felt annuloplasty provides favorable results in the intermediate-term in selected patients with ischemic cardiomyopathy and severe left ventricular dysfunction.

Adult↗
PubMed1994

Onset and progression of calcification in porcine aortic bioprosthetic valves implanted as orthotopic mitral valve replacements in juvenile sheep.

The purpose of this study was to characterize the onset and progression of mineralization in porcine bioprosthetic valves implanted in sheep and to test the hypothesis that such valves simulate calcification that is observed clinically and in other experimental models. Hancock I porcine aortic bioprosthetic valves (Medtronic Heart Valve Division, Irvine, Calif.) were implanted as orthotopic mitral valve replacements in juvenile sheep, retrieved after 1 to 124 days, and analyzed as follows: gross inspection, radiography, light, transmission, and surface scanning electron microscopy, and calcium analysis by absorption spectroscopy. Mineralization increased with increasing time after implantation in both valve cusps and adjacent aortic wall. Mean cuspal calcification was 80 micrograms/mg in valves removed after 3 to 4 months. Nevertheless, considerable variability among valves was apparent in the level of calcification noted at specific time intervals. Virtually all aspects of the morphologic characteristics were identical to those previously noted for clinical explants and experimental specimens, both subcutaneous and circulatory. In particular, ultrastructural examination revealed that the earliest calcific deposits were associated with devitalized cuspal connective tissue cells and their fragments. Collagen calcification was sparse. Both surface scanning and transmission electron microscopy indicated a lack of endothelial or blood-derived cells on the valves at all sampling times. We conclude that porcine bioprosthetic valves implanted as mitral valves in sheep provide a useful calcification model, simulating morphologic and pathobiologic events that occur clinically and in noncirculatory models. However, sufficient specimen replicates must be done to overcome variability in calcification among valves and sampling sites.

Animals↗
PubMed1997

The "proximal isovelocity surface area" method in assessing mitral valve area in patients with mitral stenosis and associated aortic regurgitation.

BACKGROUND: This study compares the mitral valve area determined by Doppler color mapping of the proximal isovelocity surface area (PISA) and by Doppler pressure half-time with that obtained by two-dimensional planimetry in patients affected by mitral stenosis, with and without associated aortic regurgitation. Pressure half-time frequently overestimates the mitral valve area in patients with mitral stenosis and associated aortic regurgitation. PISA is an alternative method for determining mitral valve area in mitral stenosis and is not influenced by regurgitant lesions. METHODS: We studied 76 patients with mitral stenosis; aortic regurgitation > or = 2 was present in 24 patients. The PISA was recorded from the apex and the transmitral maximal flow rate, Q (ml/s), was calculated using the hemispheric equation Q = 2 pi R2 x AV x alpha/180, where R (cm) is the maximal radius of the PISA, AV (cm/s) is the aliasing velocity and alpha/180 is a correction factor accounting for the alpha inflow angle formed by the mitral leaflets. Mitral valve area, A (cm2), was calculated by continuity equation A = Q/V, where V (cm/s) is the peak transmitral flow velocity measured by continuous wave Doppler. RESULTS: The mitral valve area by two-dimensional planimetry (range 0.5-2.4 cm2; mean 1.33 +/- 0.41 cm2) was consistent with both PISA (r = 0.83; SEE 0.23 cm2) and pressure half-time (r = 0.79; SEE 0.25 cm2) methods. Similar agreement was found for the 36 patients with mitral regurgitation and for the 30 patients in atrial fibrillation. However, in patients with aortic regurgitation > or = 2, pressure half-time overestimated two-dimensional and PISA determined mitral valve areas by 0.24 +/- 0.25 cm2 (p < 0.01). CONCLUSIONS: In patients with mitral stenosis and significant aortic regurgitation, the PISA method is more accurate than pressure half-time in assessing mitral valve area. This method may be a reliable alternative when pressure half-time is affected by aortic regurgitation and two-dimensional planimetry images are unsuitable for anatomic evaluation.

Adolescent↗