Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “MITRAL VALVE”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

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

At least 1,441 records · Page 80Linked to original sources
PubMed1981

Mitral valve prolapse and pregnancy.

Mitral valve prolapse (MVP) is the most common congenital heart lesion, and the diagnosis is frequently made in young women of childbearing age. The management of this disorder during pregnancy has not been well studied. Our investigation reviews the outcomes of 42 pregnancies among 25 patients with MVP diagnosed before conception by the characteristic auscultatory and echocardiographic findings. All patients with no other cardiovascular disorder tolerated pregnancy well and developed no remarkable cardiac complications. Furthermore, the incidence of antepartum and intrapartum complications or signs of fetal distress was not greater when compared with pregnant patients with no known cardiac disorder (p greater than 0.05). Congestive heart failure occurred in one case in which premature labor with coexisting toxemia was treated with the combined intravenous administration of a beta adrenergic tocolytic drug, a glucocorticoid drug, and a large volume of fluids.

Adult↗
PubMed1976

Effect of transducer placement on echocardiographic mitral valve systolic motion.

The influence of transducer position and angulation upon the mitral systolic echo was studied in 100 presumably healthy females. Echocardiographic studies were performed from the second, third, fourth and fifth intercostal spaces (ICS). The role of the sound beam's path relative to cardiac motion was assessed by analyzing the recorded mitral valve pattern as a function of transducer orientation, independent of the absolute ICS used. With the transducer directed caudally when both mitral leaflets and left atrium were recorded, holosystolic or midsystolic posterior motion of the mitral valve leaflet echo was seen in 59% of the subjects. These patterns, recorded this way, were not related to phonocardiographic signs suggesting mitral valve prolapse. Best correlation with phonocardiographic findings was obtained when the echocardiographic examination was performed with the transducer either perpendicular to the chest in the sagittal plane, or pointing slightly cephalad ('perpendicular' position). With the transducer in 'perpendicular' position, both holosystolic and midsystolic posterior motion of the mitral systolic echo, deviating more than 2 mm from a line joining the C and D points, were highly related statistically to phonocardiographic findings suggesting mitral valve prolapse. This study demonstrates that transducer position and angulation on the chest wall are important determinants of echocardiographic appearance of mitral valve during systole. Only the 'perpendicular' transducer position should be used when analyzing echocardiograms for the presence of mitral valve prolapse.

Echocardiography↗
PubMed1995

A three-dimensional computational investigation of intraventricular fluid dynamics: examination into the initiation of systolic anterior motion of the mitral valve leaflets.

Systolic anterior motion of the mitral valve leaflets (SAM) is a disease of the left ventricle which results from an abnormal force balance on the mitral valve. The mechanism by which is initiated is poorly understood, and a complete understanding of this mechanism is required for effective treatment of SAM. There are currently two theories for the initiation mechanism of SAM, the Venturi hypothesis and the altered papillary muscle-mitral valve geometry theory (PM-MV). The Venturi hypothesis states that abnormally high ejection velocities create Venturi forces which initiate SAM. The PM-MV theory asserts that SAM is the result of abnormally distributed chordal forces which are incapable of preventing SAM. To investigate the initiation mechanism of SAM, a computer model of early systolic flow in an anatomically-correct human left ventricle was developed using Peskin's immersed boundary algorithm. The computer model was used to determine the effect of chordal force distribution and septal thickness of the intraventricular flow field. The results show that the degree of SAM is inversely proportional to the amount of chordal restraint applied to the central portion of the leaflets. Also, the results support the PM-MV theory and indicate the following: (i) fluid forces capable of initiating SAM as always present in a normal human ventricle; (ii) SAM does not occur normally because of the presence of chordal forces on the central portion of the mitral leaflet; (iii) SAM will occur when these central chordal forces are sufficiently low; (iv) the extent of SAM is inversely proportional to these central chordal forces; and (v) Venturi forces alone can not cause SAM.

Algorithms↗
PubMed1996

Clinical and echocardiographic features of mitral valve prolapse patients in a local population.

Mitral valve prolapse (MVP) is a commonly diagnosed condition with varied clinical presentations but local data is lacking. In our study, we reviewed 98 patients (54 males, 44 females) with echocardiographic mitral valve prolapse diagnosed between 1991 and 1993 to study the clinical profile and echocardiographic features of patients with this condition in our local population. The mean and median age at presentation/detection were 42 years and 38 years respectively. The majority of the patients were asymptomatic (59%); the rest presented with palpitations (21%), congestive heart failure (4%) and infective endocarditis (5%). On clinical examination, 64 patients had mitral regurgitation (13 patients had both mitral regurgitation murmur and a systolic click), while one or more systolic clicks were heard in another 32 patients. Six patients also had associated Marfan syndrome. 2D echo revealed isolated anterior and posterior leaflet involvement in 55 and 19 patients respectively. Another 24 patients had involvement of both leaflets. Mitral regurgitation was detected on colour Doppler study in 78 patients. Nine patients had associated tricuspid valve prolapse. Of the 98 patients, 8 patients developed flail mitral valve. Four were detected at presentation/diagnosis, while the other 4 were diagnosed incidentally on routine follow-up 2D echo. Of these 8 patients, one developed cardiac failure. The patients had been on follow-up for a mean period of 9 months. During this period, mitral regurgitation progressed in 3 patients resulting in valve surgery. Only 20 patients had arrhythmias detected on ambulatory ECG monitoring, most of them were frequent atrial and ventricular premature beats. No patient was found to have haemodynamically significant arrhythmia. In summary, most patients with MVP had anterior mitral valve leaflet prolapse and mitral regurgitation. Although most patients with MVP are asymptomatic or have minor symptoms, it is associated with significant morbidity.

Adult↗
PubMed2001

Left atrial reduction and mitral valve surgery: the "functional-anatomic unit" concept.

The desired outcome for patients undergoing mitral valve surgery includes both good function of the mitral valve, and preservation and restoration of sinus rhythm. To achieve such an outcome, we evolved the concept of the left atrium and mitral valve as a "functional anatomic unit." In this report, we describe a technique for reduction in left atrial size, isolation of the pulmonary veins, and amputation of the left atrial appendage in combination with mitral valve repair. We performed such a procedure in 4 patients, with rheumatic mitral valve disease and chronic atrial fibrillation, with restoration of good valve function and sinus rhythm at 16 to 20 months after surgery.

Adult↗
PubMed1992

Echocardiographic findings and clinical features of left ventricular pseudoaneurysm after mitral valve replacement.

We studied the echocardiographic findings and clinical features of left ventricular pseudoaneurysm after mitral valve replacement. From December 1979 to March 1991, 1050 patients underwent mitral valve replacement at our institute, and eight patients (0.8%) had left ventricular pseudoaneurysm. In all eight patients, left ventricular pseudoaneurysm developed after the second mitral valve replacement. The incidence of left ventricular pseudoaneurysm among 253 patients who had had previous mitral valve surgery was 3.1%. Seven of the eight patients were still alive and were followed up from 5 to 136 months (mean, 57 months) after the development of left ventricular pseudoaneurysm; these patients had no complications. One patient died as a result of low cardiac output after mitral valve replacement in spite of repair of the left ventricular pseudoaneurysm. This patient had a long and wide myocardial laceration near the left ventricular pseudoaneurysm. In the other seven patients, transthoracic echocardiography demonstrated a large extraventricular cavity along the posterobasal left ventricle. In five of these patients, a turbulent flow in the neck of the left ventricular pseudoaneurysm was recorded both in systole and diastole by pulsed and color Doppler echocardiography. Transesophageal echocardiography clearly showed the narrow neck of the left ventricular pseudoaneurysm and an abnormal flow between the left ventricle and the left ventricular pseudoaneurysm. Generally, when left ventricular pseudoaneurysm develops after mitral valve replacement, surgical repair is the first choice of therapy. Our study demonstrated, however, that the development of left ventricular pseudoaneurysm was not always associated with a poor prognosis without surgical intervention.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1996

[The frequency of left atrial spontaneous echo contrast and its clinical significance in mitral valve insufficiency].

The authors investigated the frequency of left atrial spontaneous echo contrast in mitral valve disease. They also tested whether there was any correlation between the presence of left atrial spontaneous echo contrast and the severity of the mitral valve disease. Echocardiographic investigations were performed using both transthoracal and transesophageal echocardiographic methods employing monoplane transducer. The authors carried out 273 transesophageal investigations over a period of 2 years and found left atrial spontaneous echo contrast in 85 patients, who had mitral valve disease. Of this, in 18 cases thrombi were also detected in the left atrium and/or auricula. The diagnoses of mitral stenosis were made in 24 patients, of whom in 12 cases the stenosis were found to be severe, whilst in 12 cases to be moderate. Furthermore insufficiency of the mitral valve was detected in 35 cases. 20 patients had artificial mitral valve implanted, they received long term anticoagulant treatment. 59 patients had no spontaneous echo contrast. 14 patients had previous embolic events of which 9 were cerebral and in other cases arteries of the kidney, eye and extremities were affected. 71 patients had no history of embolism. The authors concluded that mitral valve disease, particularly mitral stenosis is frequently associated with left atrial spontaneous echo contrast. It has been also observed, that the more severe the mitral valve disease, the greater the probability of left atrial spontaneous echo contrast. In all cases where thrombi were found, left atrial echo contrast were demonstrated and the risk of embolism is high. In these cases anticoagulant therapy is suggested.

Adolescent↗
PubMed1976

Morphology and relationship to extensibility curves of human mitral valve chordae tendineae.

Human mitral valve chordae tendineae in which elastic response curves are nonlinear have also been found to exhibit extensibility that increases with chordal size and decreases with chordal age. We used selective enzymatic digestion and scanning transmission electron microscopy to explain these observations. Removal of the outer elastin sheath by enzymatic digestion did not significantly affect the elastic response of this tissue. Scanning electron microscopy revealed that the collagen fibers in the central core of young chordae exhibited a very wavy pattern but the pattern in adult specimens was relatively straight. The increased waviness accounted for the greater extensibility of the young specimens. The collagen fibers from young and old chordae consisted of a network of collagen fibrils that became more collapsed when the tissue was fixed under tension. This network arrangement of the fibrils explains the nonlinearity in the elastic response of the tissue. Transmission electron micrographs showed that the density of collagen fibrils decreased as chordal size increased. The number of fibrils per 10(-8) cm2 of the central core decreased from 182.4 (SE = 1.3) to 131.3 (SE = 1.6) as average chordal cross-sectional area increased from 0.0016 cm2 to 0.0268 cm2. This difference in fibril density provides an explanation for the greater extensibility shown by the thicker chordae. The collagen fibril diameters ranged from 516 A to 552 A.

Adolescent↗
PubMed1999

Relation between QT dispersion and ventricular arrhythmias in uncomplicated isolated mitral valve prolapse.

Complications of mitral valve prolapse (MVP), among which serious ventricular arrhythmia and sudden death are of major importance, affect many individuals due to the high incidence of MVP itself in the community despite the actual low incidence of these complications. The present study investigated the incidence and distribution of ventricular arrhythmias according to their severity and relationship with the QT interval and dispersion of repolarization in uncomplicated isolated MVP (IMVP) cases. Fifty-eight uncomplicated IMVP patients, 33 patients with accompanying tricuspid valve prolapse (TVP), to compare its relationship with ventricular arrhythmia, and 60 age- and sex-matched control subjects were enrolled in the study. Individuals with accompanying cardiac or systemic disease, or who were on drug therapy that could potentially affect QT characteristics, were excluded. The incidence of ventricular arrhythmia was 48% in the IMVP group and 64% in the TVP group; the difference was statistically insignificant. In addition, the differences of the QT and Q peak T values were insignificant, whereas QT dispersion (QTd) and Q peak T dispersion (QpeakTd) values were significantly higher in the patient group (60+/-14, 54+/-14 ms, respectively) compared with the control group (42+/-10, 38+/-10 ms, respectively, p<0.001). Complex ventricular arrhythmias (Lown Grade > or =III) in the IMVP group had a significant relationship with QTd and QpeakTd (p<0.001), but not with QT or QpeakT. As a result of the study, it is concluded that TVP accompanying MVP does not increase the incidence of ventricular arrhythmia, that ventricular arrhythmia is related to QT dispersion rather than QT interval in IMVP, that the QT dispersion is a fairly good marker for identifying the high-risk group for serious ventricular arrhythmia and sudden death, and that QpeakT dispersion measurement is an additional indicator that could be an alternative when QT is difficult to determine in conditions such as high heart rate or the presence of U wave.

Adult↗
PubMed2000

Angiotensin II type 1 receptor gene polymorphism and mitral valve prolapse syndrome.

BACKGROUND: Mitral valve prolapse syndrome (MVPS), a term applied to patients who have a variety of symptoms, has been associated with autonomic or neuroendocrine dysfunction. Recent evidence suggests that effects of angiotensin II mediated by the angiotensin II type 1 (AT(1)) receptor are involved in modulation of cardiovascular autonomic control in human beings. Association of a genetic polymorphism (A-C(1166)) of the AT(1) gene with abnormal vasomotion and low blood pressure related to autonomic control has been reported recently. Because the role of this genetic variant in MVPS has not been studied, we performed a case-control study of the A-C(1166) variant in a group of 76 white subjects with MVPS. METHODS AND RESULTS: All patients were genotyped by use of a mismatch polymerase chain reaction/Afl II restriction fragment length polymorphism analysis. Frequency of the C(1166) allele was 0.4 in patients with MVPS and 0.26 in control patients. The difference in genotype (chi square = 6.5; P <.05) and allele (chi square = 5.9; P =.02) frequencies between the groups was significant. The odds ratio in favor of carrying the C allele was 4 times greater for patients with MVP than for control patients (95% confidence interval 1.4 to 12.1). CONCLUSIONS: The current results indicate that the A-C(1166) polymorphism of the angiotensin II type 1 receptor gene is associated with MVPS in the white population.

Adult↗
PubMed2006

Changes of serum beta-endorphin by programmed exercise training are correlated with improvement of clinical symptoms and quality of life in female mitral valve prolapse syndrome.

BACKGROUND: Mitral valve prolapse (MVP) is a common entity in female population. Although this is a minor disease, it may cause annoying symptoms that impair quality of life (QOL), and no established therapy for this problem. The aim of this study isto examine whether programmed exercise training by treadmill in female MVP syndrome would improve clinical symptoms and QOL. METHODS: An interventional study of 39 females with MVP syndrome with treadmill exercise endurance training for 12 weeks. Every individual received training for 30 min a day, thrice a week for 12 weeks. Baseline and post-exercise at 12 weeks serum beta-endorphins were measured. Symptom improvement was assessed by the MVP symptom checklist questionnaire and the Euro-QOL-5D was used to measure QOL improvement in these females. RESULTS: The mean serum beta-endorphin increased from 0.5 to 1.68 ng/ml (p = 0.001) in the exercise group (n = 18) after 12 weeks exercise, whereas the control group (n = 21) did not show any significant changes (0.44 vs. 0.43 ng/ml). Major symptoms of MVP such as chest pain, palpitation, fatigue were improved significantly by the assessment of MVP symptom checklist. The QOL of the exercised females also showed significant changes. CONCLUSIONS: Through programmed exercise training in these MVP females, the improvement of symptoms and QOL is parallel to the increase of serum beta-endorphin. This result implicates that MVP females should initiate exercise to tackle this annoying problem.

Adult↗
PubMed1991

Altered beta adrenergic receptor function in subjects with symptomatic mitral valve prolapse.

Individuals with mitral valve prolapse (MVP) frequently show symptoms of a hyperadrenergic state. beta adrenergic receptor characteristics were compared in the lymphocytes of subjects with symptomatic MVP and control subjects during rest and exercise. At rest, the proportion of receptors binding agonist with high affinity, as determined from isoproterenol competition for (-)[125I]-iodopindolol binding sites, was greater in MVP subjects than in controls. With exercise, the proportion of high-affinity receptors in MVP subjects decreased to control levels. Isoproterenol stimulation of lymphocyte 3',5'-cyclic adenosine monophosphate (cyclic AMP) also was greater in MVP subjects than in controls at rest, but not during exercise. Plasma catecholamine concentrations in MVP subjects were normal during both rest and exercise. Unlike exercise, isoproterenol infusion elicited clinical manifestations of increased adrenergic responsiveness in MVP subjects. The beta receptor in exercised MVP subjects exhibited unusually high affinity agonist binding (i.e. a lower dissociation constant KH than in either the same subjects at rest or exercised controls) and also abnormal coupling to the stimulatory guanine nucleotide-binding regulatory protein (GS) of adenylate cyclase, as reflected by the inability of guanine nucleotide to convert the receptor to a low-affinity state. These findings suggest that functional alteration of the beta adrenergic receptor, in the absence of abnormal plasma catecholamine levels, might contribute to the hyperadrenergic state of MVP subjects at rest. However, desensitization of high affinity beta receptors or altered receptor-GS coupling might preserve normal adrenergic responsiveness during exercise.

Adult↗
PubMed1996

[Syncopes associated with mitral valve prolapse. Mechanisms].

Prolapsed mitral valve prolapse (PMV) is classically associated with disorders of ventricular excitability whose significance is unclear. However, syncope can suggest the possibility of a serious ventricular arrhythmia. The objective of this study was to try to identify the mechanisms of dizziness and syncope associated with PMV. We report the results of programmed atrial and ventricular stimulation performed under baseline conditions and after administration of Isuprel in 56 patients with PMV: 27 patients had a history of presyncope or syncope (group I), 14 had spontaneous atrial or supraventricular tachycardias without dizziness or syncope (group II) and 15 were asymptomatic and investigated for VEBs or conduction disorders (group III). The following results were obtained: In group I, 6 patients experienced sustained inducible ventricular tachycardia (VT); an atrial tachycardia (atrial tachycardia and/or atrial fibrillation) (AT) was also induced in 5 of them. In another 19 patients, a supraventricular tachycardia (SVT) and/or AT was induced. A total of 24 atrial or junctional tachycardias were triggered in this group. In group II, AT and/or SVT were reproduced in 13 out of 14 cases (93%). In group III, AT was triggered in 3 patients (20%). SVT were induced by Isuprel while AT were triggered prior to administration of Isuprel, under baseline conditions, and 3 of them were reproduced during vagal manoeuvres. A ventricular arrhythmogenic effect was observed in two cases in group II while taking class I antiarrhythmics. In conclusion, spontaneous AT and SVT of PMV are easily inducible with a sensitivity of 93%, but are difficult to induce in asymptomatic subjects. The high incidence of TA and SVT in the case of unexplained presyncope in subjects without documented tachycardia therefore appears to be suggestive of a relationship between these presyncopes and AT or SVT. However, the search for VT should take precedence. SVT appear to be catecholaminergic while AT tend to be vagal.

Adolescent↗
PubMed1993

Mitral valve prolapse: left ventricular hemodynamics in patients with chest pain, dyspnea or both.

Patients with mitral valve prolapse may present with chest pain and dyspnea. Left ventricular hemodynamics as a cause for these symptoms have not been completely evaluated in these patients. The present study was undertaken to investigate left ventricular hemodynamics in symptomatic patients with mitral valve prolapse. One hundred and three patients with mitral valve prolapse (female 72, male 31, age 56 +/- 11 years) had diagnostic cardiac catheterization for evaluation of chest pain (n = 44), dyspnea (n = 10) and for chest pain plus dyspnea (n = 49). All patients had diagnostic auscultatory findings and angiographic documentation of mitral valve prolapse. Patients with coronary artery disease and mitral regurgitation greater than mild were excluded from the study. Left ventricular end diastolic pressures before (chest pain 9.3 +/- 3.7 mmHg; dyspnea 8.2 +/- 4.2 mmHg; chest pain plus dyspnea 9.3 +/- 4.1 mmHg) and after left ventriculography (chest pain 11.6 +/- 5.5 mmHg; dyspnea 10.2 +/- 2.3 mmHg; chest pain plus dyspnea 11.7 +/- 5.6 mmHg) were normal in the majority of patients and similar in all three groups. Likewise, the left ventricular end diastolic volume index (chest pain 72.0 +/- 16 cm3, dyspnea 69.1 +/- 20 cm3, chest pain plus dyspnea 70.0 +/- 16 cm3) and ejection fraction (chest pain 64.0 +/- 8.4%, dyspnea 64.1 +/- 6.1%, chest pain plus dyspnea 64.3 +/- 6.1%) were normal in the majority of patients and similar in the three groups. Symptomatic patients with mitral valve prolapse without significant mitral regurgitation had normal left ventricular hemodynamics, and their symptoms cannot be explained on the basis of hemodynamic abnormalities alone.

Adult↗
PubMed2003

Late outcome of mitral valve surgery for patients with coronary artery disease.

BACKGROUND: We plan to determine whether the cause of mitral valve regurgitation, ischemic or degenerative, affects survival after combined mitral valve repair or replacement and coronary artery bypass grafting (CABG) surgery and to assess the influence of residual mitral regurgitation on late outcome. METHODS: A retrospective study was made of 302 patients having mitral valve repair or replacement and CABG from January 1987 through December 1996. Risk factors for death, for development of New York Heart Association class III or IV congestive heart failure (CHF), and recurrent mitral valve regurgitation were identified by proportional hazards analysis. RESULTS: The cause of mitral regurgitation was ischemic in 137 patients (45%) and degenerative in 165 patients (55%). Valve replacement was performed in 51 patients (17%) and valve repair in 251 patients (83%). Median follow-up was 64 months. Ten-year actuarial survival rates were 33% (95% confidence interval: 22% to 47%) in the ischemic group and 52% (95% confidence interval: 42% to 64%) in the degenerative group. Univariate predictors of death, were entered into a multivariate model. Older age, ejection fraction of 35% or less, three-vessel coronary artery disease, replacement of the mitral valve, and residual mitral regurgitation at dismissal were independent risk factors for death. The cause of mitral valve regurgitation (ischemic or degenerative) was not an independent predictor of long-term survival, class III or IV CHF, or recurrent regurgitation. CONCLUSIONS: Survival after mitral valve surgery and CABG is determined by the extent of coronary disease and ventricular dysfunction and by the success of the valve procedure; etiology of mitral valve regurgitation has relatively little impact on late outcome.

Aged↗
PubMed1976

Dermatoglyphic patterns in patients with mitral valve prolapse: a clue to pathogenesis.

Fingerprints were obtained from 100 patients with mitral valve prolapse and compared with those of 100 control subjects matched for sex and race. Arches were found in 16.8 percent of all digital patterns in patients with mitral valve prolapse but in only 2.5 percent of all digits in the control group. Whereas no patient in the control group had four or more arches, 19 percent of patients with mitral valve prolapse had this finding. In addition, arches were found on 16 and 9 percent, respectively, of digits IV and V in patients with mitral valve prolapse but were not found on these digits in the control group. The finding of four or more arches or arches on digits IV or V may be important supportive evidence of mitral valve prolapse when evaluating patients with atypical chest pain and palpitations. Antenatal factors may be involved in the pathogenesis of mitral valve prolapse since it is possible that a genetic or environmental factor that interferes with the development of the mitral valve may also influence epidermal ridge patterns.

Analysis of Variance↗