Idiopathic mitral valve prolapse-analysis by real-time two-dimensional echocardiography

Mitral valve prolapse is diagnosed in real-time two-dimensional echocardiograms when there are discrepancies in the coaptation zone of the anterior mitral leaflet and the posterior mitral leaflet. Out of the 100 cases of mitral valve prolapse diagnosed in this way, 65 had prolapsed anterior mitral leaflets, 28 prolapsed posterior mitral leaflets and 7 prolapses of both the anterior and posterior mitral leaflets. In addition to the cases with mitral valve prolapse 23 cases of ruptured chordae tendineae of the mitral valve, including 15 cases which had undergone surgery, were investigated. The frequent site of mitral valve prolapse was the posteromedial commissure in the anterior leaflet and the posteromedial and anterolateral commissures in the posterior leaflet. These sites coincide with those where rupture of the chordae tendineae of the mitral valve was apt to occur. An investigation of the relation between age and mitral valve prolapse showed that the number of cases of prolapsed anterior leaflet did not increase with age, but there was an age-related increase in the number of cases of prolapsed posterior leaflets. It was also found that the degree of the prolapse progressed with age. Many of the cases of ruptured chordae tendineae of the mitral valve were in their forties or fifties, and there appeared to be some relation between the progress of the prolapse and age. Mitral regurgitant murmurs were recorded on phonocardiograms, and the severer the degree, the wider the range of the prolapse. Mitral regurgitation was more likely to occur in cases of prolapsed posterior leaflets than in those with prolapsed anterior leaflets, even if the degree and the range of the prolapse were mild.     

Mitral annulus size in isolated mitral stenosis

M-mode and two-dimensional echocardiographic images were obtained using the planimeter method in the short axis view and calculated by Doppler-derived pressure half-time in 24 patients with mitral stenosis before and after surgical commissurotomy and posterior annuloplasty. The diameter of the mitral valve annulus was measured in the standard long axis view and in the apical four-chamber view using two-dimensional echocardiography. Preoperatively, the mitral annulus was dilated in all patients as a consequence of left atrial dilation. This could be one of the factors causing residual regurgitation after surgical mitral commissurotomy. However, more data are needed to demonstrate that annuloplasty can prevent the development of mitral regurgitation after surgery.     

Diagnosis of endocardial cushion defect with cross-sectional and M-mode scanning echocardiography. Differentiation from secundum atrial septal defect

Twelve cases of endocardial cushion defect were studied before and after operation with ultrasono-cardiotomography (tomography) cross-sectional echocardiography, two-dimensional echocardiography, B-scan echocardiography) and M-mode scan along a horizontal section of the heart. For comparison, 20 healthy subjects, 18 cases of mitral valvular disease, 4 cases of congestive cardiomyopathy, 1 case of partial anomalous pulmonary venous drainage, and 25 cases of atrial septal defect of secundum type were also examined with the same technique. In cases without cardiac malformation, the echo of the anterior mitral valve was usually continuous medially with that of the interatrial septum in the horizontal plane at the level of the membranous septum. This feature was clearly recorded in all cases with right heart enlargement. In ostium secundum atrial septal defect the echo of the anterior mitral valve continued into that of the interatrial septum. An echo interruption was shown, indicating the defect itself to be in the middle part of the interatrial septum. In all the cases of endocardial cushion defect which we examined discontinuity was shown between the echo of the anterior mitral valve and that of the interatrial septum. This discontinuity was interpreted as indicating the defect itself. The mitral valve ring echo was close to the basal end of that of the interventricular septum, possibly reflecting an abnormal attachment of the mitral valve. In all cases, after operation, the echo of the artificial interatrial septum was recorded, continuous with that of the anterior mitral valve. The features of the echocardiographic sweep from the anterior mitral valve to the interatrial septum were thus different in the three groups. These echocardiographic differences are thought to correspond to the anatomical differences between the normal, atrial septal defect of secundum type, and endocardial cushion defect, and are essential features differentiating them from each other.     

Newer advances in the diagnosis and treatment of mitral stenosis

There have been significant changes in presentation, diagnosis, and therapy of patients with mitral stenosis. Both the prevalence of mitral stenosis, as well as the type of patient now with mitral stenosis, have changed significantly over the past few decades. In patients with mitral stenosis two-dimensional and Doppler echocardiography have become the diagnostic modalities of choice. The advent of percutaneous mitral balloon valvotomy now provides a nonsurgical approach for the treatment of selected patients with mitral stenosis.     

Three-dimensional transesophageal echocardiographic assessment for prosthetic valves

We evaluated three-dimensional transesophageal echocardiographic assessment of the implanted mechanical valves by rotational scanning method. Patients were 7 mitral valve replacement and one aortic valve replacement, 2 mitral and aortic valve replacement. In 2 cases of 7 mitral valve replacement, the prosthetic valve regurgitation was evaluated using by color Doppler echocardiography. In this study, multiplane transesophageal probe was used. It rotated at 2-degree intervals from 0 to 180 degrees and the three-dimensional reconstruction was performed by echo scan workstation system (TOMTEC Inc, Munich, Germany). In mitral valve replacement cases, the valve motion of bileaflet valve (St. Jude Medical valve and ATS valve) were showed very clearly. The struts was easily recognized in the St. Jude Medical valve (SJM valve) cases. In one of SJM valve cases, the pannus formation was revealed, but it did not disturb valve motion. The prosthetic valve regurgitation can be seen accurately. However, aortic valve and ball valve cases cannot be reconstructed because of artifact from prosthetic valve and ultrasonic direction. The prosthetic valve regurgitation, pannus formation which was difficult to be showed in two-dimensional echocardiography and relationship between annulus and sewing cuff can be evaluated by this three-dimensional echocardiography. In this study, this system has some problems, for example real-time evaluation is impossible, aortic valve and ball valve cases cannot be reconstructed. However, we think that this new technology is suitable for evaluating valve thrombus, valve dysfunction and paravalvular leakage. In conclusion, the three-dimensional echo-cardiography demonstrated, reliable and accurate examination, and it can evaluate various complications of prosthetic valve.     

Three-dimensional echocardiography. Principles and applications

Three-dimensional echocardiography is based on two methods of retrospective reconstruction from two-dimensional echocardiographic images. The acquisition of the two-dimensional images may be free or imposed, the transducer either carrying an emission-reception system or fixed to an articulated support providing data about its position. In the first system, manual tracing of the contours of the region of interest performed on each frame are superimposed after time sequencing (using the ECG) and spatial repositioning, so enabling three-dimensional visualisation of the contours of the cardiac structures: this approach provides reliable quantitative information (volumes, mass and ejection fractions) and has led to the redefinition of the echocardiographic criteria of mitral valve prolapse. The second system is based on equidistant sections obtained by progressive, controlled two-dimensional scanning (parallel, arc of a circle and rotational) of the structure of interest: a value of grey scale is assigned to the space between two adjacent pixels, enabling the formation of voxels which, when superimposed, give the required effects of volume and surface for three-dimensional imaging. It is then possible to obtain any section of the volume and simulate surgical views of the beating heart. This approach may significantly improve diagnostic accuracy compared with two-dimensional echocardiography and provides access to new quantitative and qualitative parameters.     

Noninvasive estimation of regurgitant flow rate and volume in patients with mitral regurgitation by Doppler color mapping of accelerating flow field

OBJECTIVES: This study was designed to examine the accuracy of proximal accelerating flow calculations in estimating regurgitant flow rate or volume in patients with different types of mitral valve disease. BACKGROUND: Flow acceleration proximal to a regurgitant orifice, observed with Doppler color flow mapping, is constituted by isovelocity surfaces centered at the orifice. By conservation of mass, the flow rate through each isovelocity surface equals the flow rate through the regurgitant orifice. METHODS: Forty-six adults with mitral regurgitation of angiographic grades I to IV were studied. The proximal accelerating flow rate (Q) was calculated by: Q = 2 pi r2.Vn, where pi r2 is the area of the hemisphere and Vn is the Nyquist velocity. Radius of the hemisphere (r) was measured from two-dimensional or M-mode Doppler color recording. From the M-mode color study, integration of accelerating flow rate throughout systole yielded stroke accelerating flow volume and mean flow rate. Mitral regurgitant flow rate and stroke regurgitant volume were measured by using a combination of pulsed wave Doppler and two-dimensional echocardiographic measurements of aortic forward flow and mitral inflow. RESULTS: The proximal accelerating flow region was observed in 42 of 46 patients. Maximal accelerating flow measured from either two-dimensional (372 +/- 389 ml/s) or M-mode (406 +/- 421 ml/s) Doppler color study tended to overestimate the mean regurgitant flow rate (306 +/- 253 ml/s, p < 0.05). Mean Doppler accelerating flow rate correlated well with mean regurgitant flow rate (r = 0.95, p < 0.001), although there was a tendency toward slight overestimation of mean regurgitant flow by mean accelerating flow in severe mitral regurgitation. However, there was no significant difference between the mean accelerating flow rate (318 +/- 304 ml/s) and the mean regurgitant flow rate (306 +/- 253 ml/s, p = NS) for all patients. A similar relation was found between accelerating flow stroke volume (78.27 +/- 62.72 ml) and regurgitant flow stroke volume (76.06 +/- 59.76 ml) (r = 0.95, p < 0.001). The etiology of mitral regurgitation did not appear to affect the relation between accelerating flow and regurgitant flow. CONCLUSIONS: Proximal accelerating flow rate calculated by the hemispheric model of the isovelocity surface was applicable and accurate in most patients with mitral regurgitation of a variety of causes. There was slight overestimation of regurgitant flow rate by accelerating flow rate when the regurgitant lesion was more severe.     

A case report of mitral valve papillary fibroelastoma leading to embolic stroke

A 39-year-old man presented with acute onset of left arm and left side face weakness, and mild expressive aphasia. He was referred for two-dimensional echocardiography, which demonstrated a 13 mm diameter pedunculated, mobile, echodense mass attached to the anterior leaflet of the mitral valve. At operation, the tumor was a 10 x 10 x 15 mm, rounded, and yellow-whitish mass with a short stalk arising from rough zone of the anterior leaflet of the mitral valve. The surface appeared to be sean anemone. The mitral valve with this tumor was excised and replaced with a 29 mm St Jude Medical mechanical valve. The pathological findings are typical of a papillary fibroelastoma.     

Accurate localization of mitral regurgitant defects using multiplane transesophageal echocardiography

BACKGROUND: Appropriate patient selection for surgical repair of the mitral valve depends on the specific location and mechanism of regurgitation, which, in turn, has necessitated a more detailed method to accurately describe mitral pathology. This study tests a strategy of using multiplane transesophageal echocardiography to systematically localize mitral regurgitant defects and compares these results with the surgical findings. METHODS: Fifty patients with mitral regurgitation underwent intraoperative transesophageal echocardiography for the evaluation of mitral pathology and potential repair. Mitral regurgitant defects were localized using a systematic strategy and a simple nomenclature that divides each mitral valve into six sections (three sections per leaflet) and each prosthetic sewing ring into six sections (60 radial degrees = one section). RESULTS: Thirty-nine patients with native mitral valves were studied, for a total of 234 sections evaluated. Eighty-seven of these sections contained regurgitant defects by transesophageal echocardiography (mean number of regurgitant defects per valve, 2.2; range, 1 through 6). There was agreement between the transesophageal echocardiographic and surgical localizations in 96% (224/234; p < 0.0001) of the sections. Eleven patients with prosthetic mitral valves were studied, for a total of 66 sections evaluated. Twenty-three of these sections contained paravalvular leaks by transesophageal echocardiography (mean number of leaks per prosthesis, 2.1; range, 1 through 6). There was agreement between the transesophageal echocardiographic and surgical localizations in 88% (58/66; p < 0.001) of the sections. CONCLUSIONS: This transesophageal echocardiographic strategy provides a systematic method to accurately localize mitral regurgitant lesions and has the potential to improve the preoperative assessment of patients with significant mitral regurgitation.     

Massive pulmonary hemorrhage complicating mitral prosthetic valve obstruction

A case is reported of prosthetic mitral valve obstruction in a patient who had had three hospital admissions with massive hemoptysis. A diagnosis was finally made after two-dimensional echocardiography with Doppler and cardiac catheterization were performed. The patient was successfully treated with re-replacement of the valve. Any new pulmonary or cardiac symptom in a patient with a prosthetic valve requires prompt evaluation and treatment.     

Zinc dependent activation of cAMP-specific phosphodiesterase (PDE4A)

OBJECTIVES: This study was undertaken to determine whether the presence of calcium in the mitral valve commissures, as demonstrated echocardiographically, could predict outcome and to compare this with an established echocardiographic scoring system. BACKGROUND: Percutaneous mitral balloon valvotomy is an effective form of treatment for mitral valve stenosis. It is important to identify patients who would benefit from this procedure. Commissural splitting is the dominant mechanism by which mitral valve stenosis is relieved by this technique, and thus commissural morphology may predict outcome. METHODS: One hundred forty-nine consecutive patients who underwent percutaneous mitral balloon valvotomy at the Mayo Clinic were evaluated retrospectively. The morphology of the mitral valve apparatus on the baseline echocardiograms was scored in blinded manner using a semiquantitative grading system of leaflet thickening, mobility, calcification and subvalvular thickening (Abascal score). Additionally, each of the medial and lateral commissures was graded for the presence or absence of calcification. End points were death, New York Heart Association functional class, repeat percutaneous mitral balloon valvotomy and mitral valve replacement at follow-up. RESULTS: The mean follow-up period was 1.8 years (maximum 7.9 years). Univariate predictors of death and all events combined included age, the use of a double-balloon technique, the presence of calcium in a commissure and the Abascal score, as continuous variables. Patients with an Abascal score < or = 8 showed a trend toward improved survival at 36 months free of death, repeat percutaneous mitral balloon valvotomy or mitral valve replacement (78 +/- 6% vs. 67 +/- 8%, p = 0.07) and free of all events combined (75 +/- 6% vs. 64 +/- 8%, p = 0.07) versus those patients with a score > 8. However, survival at 36 months free of death, repeat percutaneous mitral balloon valvotomy or mitral valve replacement (86 +/- 4% vs. 40 +/- 4%) and free of all events combined (82 +/- 5% vs. 38 +/- 10%) at follow-up was significantly different between patients without commissural calcium and those with commissural calcium (p < 0.001). In a Cox regression model with Abascal score and commissural calcium and their interaction, calcification emerged as the only significant variable (p < 0.01). CONCLUSIONS: The presence of commissural calcium is a strong predictor of outcome after percutaneous mitral balloon valvotomy. Patients with evidence of calcium in a commissure have a lower survival rate and a higher incidence of mitral valve replacement and all end points combined. Thus, the simple presence or absence of commissural calcification assessed by two-dimensional echocardiography can be used to predict outcome.     

Two-dimensional echocardiography with a wide angle (60 degrees) sector scanner

A wide angle (60 degrees) sector scanner producing a real-time two-dimensional echocardiogram has been used to examine healthy infants, children, and adults. Its method of use is described and findings from longitudinal and transverse scans are presented. The points of difference between the various types of electronic and mechanical two-dimensional scanning systems are discussed. This equipment minimises problems of chest contact and rib and lung interference and, by providing echocardiograms of high line density from a wide angle, is a suitable real-time two-dimensional scanning system for examining patients of all ages.     

Improved posterobasal segment function after thrombolysis is associated with decreased incidence of significant mitral regurgitation in a first inferior myocardial infarction

OBJECTIVES: This study was designed to investigate the association between wall motion abnormalities and the occurrence of ischemic mitral regurgitation in patients with a first inferior or posterior myocardial infarction and to reassess the role of thrombolytic treatment in these patients. BACKGROUND: We previously demonstrated that thrombolytic therapy reduces the incidence of significant mitral regurgitation in patients with a first inferior myocardial infarction, but the mechanisms responsible for this decrease were not clear. METHODS: Wall motion score on two-dimensional echocardiography (16 segments) and mitral regurgitation grade (0 to 3) on Doppler color flow imaging were assessed in 95 patients (in 47 after thrombolysis) at 24 h, 7 to 10 days and 1 month after myocardial infarction. Significant mitral regurgitation was defined as moderate or severe (grade 2 or 3). RESULTS: Multivariate analysis revealed that the presence of an advanced wall motion abnormality of the posterobasal segment of the left ventricle was the most significant independent variable associated with significant mitral regurgitation: odds ratio (OR) 15.0, 90% confidence interval (CI) 1.4 to 165.6 at 24 h; OR 2.8, CI 0.9 to 9.3 at 7 to 10 days; OR 4.2, CI 1.2 to 11.4 at 1 month. Thrombolysis reduced the prevalence of advanced wall motion abnormalities in the posterobasal segment at 24 h (55% vs. 75%, OR 0.5, CI 0.2 to 0.99), 7 to 10 days (44% vs. 73%, OR 0.3, CI 0.1 to 0.7) and 1 month (36% vs. 56%, OR 0.4, CI 0.2 to 0.9). CONCLUSIONS: There is a strong association between advanced wall motion abnormalities in the posterobasal segment and significant mitral regurgitation. In this study group, thrombolysis reduced the prevalence of advanced wall motion abnormalities in the posterobasal segment and thereby reduced the incidence of significant mitral regurgitation.     

Failure of neural tube closure in the loop-tail (Lp) mutant mouse: analysis of the embryonic mechanism

Three-Dimensional (3D) echocardiography was performed during routine transesophageal examinations in 100 patients to identify the most promising applications. The approach used was based on the integration of multiple two-dimensional images recorded with a multiplane probe to achieve 3D reconstruction. A series of 90 cardiac cycles was recorded from a fixed position during computer-controlled rotation of the transducer. The images were digitized, then reorganized according to their spatial and temporal location. The cardiac structures were then represented dynamically in three dimensions. In 100 patients referred for transesophageal echocardiography, the 3D reconstruction provided good quality images, under new angles, such as the view of the atrial aspect of the mitral valve as seen from the roof of the left atrium. This method was particularly well suited to assess mitral valve prolapse or stenosis. The spatial extent, direction and number of jets of mitral regurgitation were easily appreciated throughout systole, as were the regurgitant jets of mechanical prosthetic valves. However, the sensitivity of the 3D method was not as good as 2D echocardiography for detecting bacterial vegetations in cases of infective endocarditis. On the other hand, the determination of the precise localization of infectious, degenerative and tumoral lesions and their size were facilitated by 3D reconstruction. The authors conclude that 3D echocardiography is applicable in routine practice and the complementary information provided in certain cardiac diseases should help management of these patients.     

Analysis of coccal cell formation by Campylobacter jejuni using continuous culture techniques, and the importance of oxidative stress

OBJECTIVES: We tested the hypothesis that patients with incomplete systolic mitral leaflet closure (IMLC: apically displaced coaptation) also have restricted diastolic leaflet opening that is independent of mitral inflow volume and provides evidence supporting increased leaflet tethering. BACKGROUND: Competing hypotheses for functional mitral regurgitation (MR) with IMLC include global left ventricular (LV) dysfunction per se (reduced leaflet closing force) versus geometric distortion of the mitral apparatus by LV dilation (augmented leaflet tethering). These are inseparable in systole, but restricted leaflet motion has also been observed in diastole, and attributed to reduced mitral inflow. METHODS: Diastolic mitral leaflet excursion and orifice area were measured by two-dimensional echocardiography in 58 patients with global LV dysfunction, 36 with and 22 without IMLC, compared with 21 normal subjects. The biplane Simpson's method was used to calculate LV ejection volume, which equals mitral inflow volume in the absence of aortic regurgitation. RESULTS: The diastolic mitral leaflet excursion angle was markedly reduced in patients with IMLC compared with those without IMLC, whose ventricles were smaller, and normal subjects (17 +/- 10 degrees vs. 58 +/- 13 degrees vs. 67 +/- 8 degrees, p < 0.0001). Excursion angle was dissociated from mitral inflow volume (r2 = 0.04); excursion was reduced in patients with IMLC despite a normal inflow volume in the larger ventricles with MR (60 +/- 25 vs. 61 +/- 12 ml in normal subjects, p = NS), and excursion was nearly normal in patients without IMLC despite reduced inflow volume (40 +/- 10 ml, p < 0.001 vs. normal subjects). The anterior leaflet when maximally open coincided well with the line connecting its attachments to the anterior annulus and papillary muscle tip (angular difference = 3 +/- 7 degrees vs. 25 +/- 9 degrees vs. 32 +/- 10 degrees in patients with and without IMLC vs. normal subjects, p < 0.0001). In patients with IMLC, the leaflet tip orifice was smaller in an anteroposterior direction but wider than in the other groups, giving a normal total area (6.8 +/- 1.8 vs. 7.1 +/- 1.2 vs. 6.9 +/- 0.8 cm2, p = NS). CONCLUSIONS: Patients with LV dysfunction and systolic IMLC also have restricted diastolic leaflet excursion that is independent of inflow volume, coincides with the tethering line connecting the annulus and papillary muscle and reflects limitation of anterior motion relative to the posteriorly placed papillary muscles without a decrease in total orifice area. These observations are consistent with increased tethering by displaced mitral leaflet attachments in the dilated ventricles of patients with IMLC that can restrict both diastolic opening and systolic closure.     

Early surgery in patients with mitral regurgitation due to flail leaflets: a long-term outcome study

BACKGROUND: The optimal timing for surgery in patients with mitral regurgitation is disputed. Because of the frequency of left ventricular dysfunction, which is difficult to predict, early surgery has been recommended, but its potential benefits have not been demonstrated. METHODS AND RESULTS: The outcomes of 221 patients (mean age, 65 +/- 13 years; 71% males) with flail leaflets diagnosed with two-dimensional echocardiography between 1980 and 1989 who were eligible for operation were analyzed. Group I comprised 63 patients who had early mitral valve surgery (within 1 month after diagnosis). Group II comprised 158 patients initially treated conservatively (80 of whom were operated on later). Group I patients were younger (P=.009), had more symptoms (P<.0001), and were more frequently in atrial fibrillation (P=.023) than group II patients. There was no difference in ejection fraction between the groups. The early surgery strategy was followed by an improved overall survival rate (P=.028) and a lower incidence of cardiovascular deaths (P=.025), congestive heart failure (P=.046), and new chronic atrial fibrillation (P=.032), as confirmed by multivariate analysis (adjusted risk ratios of 0.31, 0.18, 0.38, and 0.05, respectively; all P<.02). CONCLUSIONS: In patients with mitral regurgitation due to flail leaflets, the strategy of early surgery versus conservative management is associated with an improved long-term survival rate, decreased cardiac mortality, and decreased morbidity after diagnosis. This outcome advantage suggests that early surgery is a reasonable treatment option to be considered in low-risk candidates with repairable valves and severe mitral regurgitation.     

The effect of exercise training on the severity and duration of a viral upper respiratory illness

OBJECTIVE: The purpose of this study was to assess whether joint hypermobility syndrome is more frequent in patients with panic disorder, agoraphobia, or both than in control subjects and, if so, to determine whether mitral valve prolapse modifies or accounts in part for the association. METHOD: A case-control study was conducted in a general teaching hospital outpatient clinic. Subjects were 99 patients, newly diagnosed and untreated, with panic disorder, agoraphobia, or both and two groups of age- and sex-matched control subjects: 99 psychiatric patients and 64 medical patients who had never suffered from any anxiety disorder. Measures consisted of the Structured Clinical Interview for DSM-III-R, Beighton's criteria for joint hypermobility syndrome, and two-dimensional and M-mode echocardiogram. The presence of mitral valve prolapse and joint hypermobility syndrome was explored by raters who were blind to subjects' psychiatric status. RESULTS: Joint hypermobility syndrome was found in 67.7% of patients with anxiety disorder but in only 10.1% of psychiatric and 12.5% of medical control subjects. On the basis of statistical analysis, patients with anxiety disorder were over 16 times more likely than control subjects to have joint laxity. These findings were not altered after the presence of mitral valve prolapse was taken into account. Of the patients with anxiety disorder, those who had joint hypermobility syndrome were younger and more often women and had an earlier onset of the disorder than those without joint hypermobility syndrome. CONCLUSIONS: Joint laxity is highly prevalent in patients with panic disorder, agoraphobia, or both and may reflect a constitutional disposition to suffer from anxiety. Mitral valve prolapse plays a secondary role in the association between joint hypermobility and anxiety.     

Combined one- and two-dimensional ultrasound system for monitoring fetal breathing movements

A combined one- and two-dimensional ultrasonic system for monitoring respiratory movements in the human fetus has been developed. A real-time cross-sectional image of the fetal chest at the level of the fetal heart can be obtained, and a time motion recording of fetal respiratory movements can then be written on a strip-chart recorder. Combining the features of one-dimensional and two-dimensional systems produces an accurate means of investigating fetal breathing movements.     

Two-Dimensional Transient Temperature Field of Finish Rolling Section in Hot Tandem Rolling

Comprehensively considering the factors such as descaling cooling, air cooling, watercooling, frictional heat and deformation heat in gap of every stand, heat conduction betweenwork roll and strip etc, a model of two-dimensional transient temperature field of finish rollingsection in hot tandem rolling was built with finite difference method to calculate the temperaturefields of strip and work roll. So two-dimensional accurate analysis and calculation of strip tem-perature were realized, and the theoretical basis for predicting and controlling strip temperaturewas provided. The simulated results show that the model is practical and reliable.     

Lambl's excrescence: an uncommon cause of cerebral embolism

A 31 year old right handed woman presented with acute onset of aphasia which cleared over two days. CT-scan showed a left middle cerebral artery infarct within Wernicke area. Initial transesophageal two-dimensional echocardiography disclosed a mitral valve lesion suggesting a thrombus. She was discharged on oral anticoagulant treatment. A second stroke occurred ten months later involving left lenticulo-striate arteries area. Echocardiography remain unchanged. Subsequently, giant Lambl's excrescences of mitral valve was confirmed by operation and pathologic examination. The majority of patients with Lambl's excrescences are asymptomatic. However surface thrombus is common with this tumors which reposant a potential us for cerebral embolization. These tumors should be operated since complete excision is the only definitive means of eliminating the source of recurrent embolization.