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PubMed1989

Comparison of transthoracic and transesophageal color Doppler flow imaging in patients with mechanical prostheses in the mitral valve position.

This study determined the relative value of transthoracic and transesophageal color Doppler flow imaging to systolic flow patterns in the left atrium in different types of mechanical prostheses in the mitral valve. Thirty-nine patients were investigated. Based on clinical findings, 36 of 39 patients had normal prosthetic valve function. Seventeen patients were interrogated within a few days after surgery. Systolic regurgitant jets in the left atrium were absent in all patients by both transthoracic pulsed and color Doppler flow imaging. Using transthoracic continuous wave Doppler, however, jets were demonstrated in 8 of 39 patients (21%). Transesophageal color Doppler flow imaging demonstrated systolic regurgitant jets originating from the prosthesis in all patients. Tilting disc valves showed jets during the entire systole (closure and leakage backflow). Each type of prosthesis generated a specific jet pattern. Pathologic regurgitant jets were crescent-shaped, more extensive and turbulent than jets caused by normal closure and leakage backflow. Thus, transthoracic color Doppler flow imaging is not sensitive for detecting regurgitant jets in mechanical prostheses in the mitral valve. All mechanical prostheses show a specific jet pattern, which should be helpful when transesophageal echocardiography is used to identify pathologic backflow.

Adult↗
PubMed1995

Doppler echocardiographic comparison of small (19 mm) bileaflet and pericardial heart valve prostheses in aortic position.

The resting haemodynamics of five types of small (19 mm) aortic valve prosthesis (2 bileaflet, 3 pericardial) were evaluated with Doppler echocardiography in 43 patients. Two received St Jude Medical and six CarboMedics bileaflet valves and 35 were given bioprostheses--16 Ionescu-Shiley, four Mitroflow and 15 Labcor-Santiago. No significant differences in peak or mean transvalvular pressure drop or in effective valve area were found between the bileaflet and the pericardial valves or among the three types of bioprosthesis. All but one of the bileaflet prostheses showed a characteristic regurgitation pattern, with two lateral and one central jet, and 16 (46%) of the bioprostheses showed central regurgitation, but in no case were these jets haemodynamically significant. Thus the 19 mm bileaflet and the studied pericardial prostheses all have satisfactory resting haemodynamics, and all are suitable for implanting in small aortic roots.

Adult↗
PubMed1999

Intravascular hemolysis after mitral and aortic valve replacement with different types of mechanical prostheses.

Heart valve replacement with mechanical prosthesis is associated with mild intravascular hemolysis. In this study we evaluated the incidence of hemolysis in patients with different combinations of two mechanical valves. Between 1974 and 1996, 680 patients underwent mitral and aortic valve replacement with mechanical prostheses; we selected 90 patients, divided into six groups according to the prosthetic model (Group A, ball and tilting disc; Group B, ball and bileaflet; Group C, tilting disc and tilting disc; Group D, tilting disc and bileaflet; Group E, bileaflet and tilting disc; Group F, bileaflet and bileaflet; respectively, in mitral and aortic position). Blood tests were performed to check blood hemoglobin, serum lactic dehydrogenase, percent-correlated reticulocyte fraction, serum haptoglobin, and schistocytes. Chi square test was performed for categorical data. ANOVA and Bonferroni tests were performed in order to evaluate significant statistical differences between media and variance of the hematological data. A mild degree of intravascular hemolysis was observed in 30% of patients with double mechanical prostheses. LDH values were above the normal values in all groups, although a significant difference was found only between Group B versus Groups C and D. Reticulocytes and schistocytes and serum haptoglobin values were within the normal range and no differences were found between the groups. Low levels of blood hemoglobin were found in Groups D and F. The difference was statistically significant when compared with Groups A and E. In conclusion, hemolysis is frequent but never severe in patients with mitral and aortic mechanical prostheses. A higher incidence of subclinical hemolysis was found in patients with bileaflet valves regardless of the position of the implant.

Analysis of Variance↗
PubMed1997

[Late reopening of patent ductus arteriosus after complete closure with the Rashkind prosthesis. Possible traumatic origin].

We report the case of a symptomatic adult with an occluded persistent duct with a transcatheter proceeding using a Rashkind prosthesis. After a month of follow up the color-coded Doppler-flow echocardiogram did not show residual shunt, posteriorly the patient's symptoms disappeared and the left ventricular dimensions were reduced. At the thirteen month of follow-up, the patient had an accident while working, falling down from a scaffold. Afterwards, a ductal jet was observed in the echocardiogram with an increased size of the left ventricle, symptoms also appeared. A cardiac catheterism was then performed showing a pulmonary/systemic flow rate of 2 and a 3 mm flow jet at the superior border of the prosthesis. A second prosthesis was implanted with no residual shunts.

Accidental Falls↗
PubMed2002

Effect of surface conditions on the color of dental resin composites.

The objectives of this study were to evaluate the effect of surface conditions of dental resin composites on the measured color depending on the measuring geometry (SCE, SCI), and to determine the color difference (DeltaE*) caused by varied surface conditions. Color and surface roughness (Ra) of five brands of resin composites of A2 shade were measured after polymerization and polishing with 600-, 1000-, or 1500-grit SiC paper. Color was measured according to the CIE L*a*b* color scale. DeltaE* between different surface conditions was calculated by the equation DeltaE* = [(DeltaL*)(2) + (Deltaa*)(2) + (Deltab*)(2)](1/2). Before polishing, CIE L* values with the SCE were significantly lower than those measured with the SCI. Before polishing, DeltaE* values depending on the measuring geometry were very high (3.78-5.93). However, those after polishing were lower than 1.61. CIE L* values increased after polishing (p < 0.05) with the SCE; however, they were not changed with the SCI. DeltaE* values between Mylar-covered and 600-grit polished specimens were 4.20-5.99 with the SCE and 0.27-1.46 with the SCI. Measurement with the SCE geometry may result in accurate color determination, which reflects the surface conditions of dental restorative materials. DeltaE* values measured with the SCE between the specimens of different surface conditions were significantly higher than those with the SCI (p < 0.05).

Biocompatible Materials↗
PubMedDate not supplied

Refractory hemolytic anemia secondary to perivalvular leak diagnosed by transesophageal echocardiography.

Transesophageal echocardiography (TEE) has become increasingly important in the assessment of mitral valve prosthetic dysfunction. We report on three patients who developed medically refractory hemolytic anemia after St. Jude mitral valve replacement secondary to perivalvular mitral prosthetic regurgitation. Two of the three cases had corrective surgical intervention that resolved the hemolytic process. Careful transesophageal echocardiographic evaluations of the perivalvular area proved diagnostic and resulted in appropriate management decisions.

Adult↗
PubMed1995

Aortic valve replacement: is the stentless xenograft an alternative to the homograft? Early results of a randomized study.

From November 1992 to October 1993 we randomized 101 patients over 60 years of age undergoing elective aortic valve replacement, with or without concomitant coronary artery bypass grafting, to receive either a cryopreserved aortic or pulmonary homograft (n = 38) or a stentless porcine aortic valve xenograft (Edwards Prima 2500) (n = 63). The majority of all valves (92%) were inserted freehand in the subcoronary position. Six homografts (16%) were implanted as a free-root replacement and two xenografts (3%) were used as a mini root. There were four in-hospital deaths (4%), three in the homograft group and one in the xenograft group (homograft, 7.9% versus xenograft, 1.6%; p = not significant). Forty-one patients were followed at 3- to 6-month intervals for 9 +/- 2 months (3 to 14 months) and valve pathology was assessed routinely by means of color flow Doppler echocardiography. Two patients in the homograft group developed new aortic insufficiency grade II; all others remained with trivial or no valve incompetence. The mean gradient remained unchanged to immediate postoperative measurements (homograft, 5 +/- 1 mm Hg versus xenograft, 11 +/- 4 mm Hg; p < 0.001). Despite a slightly higher transvalvular gradient, xenografts achieved excellent initial results when compared to homografts. Ease of implantation and freedom from thromboembolism indicate that xenografts can be an acceptable alternative to homografts, particularly in older patients with small aortic annuli. Long-term studies assessing the durability of the xenograft are necessary for final evaluation.

Aged↗
PubMed1992

Effects of environmental factors on maxillofacial elastomers: Part IV--Optical properties.

The optical properties of four currently used and two recently introduced maxillofacial prosthetic materials were evaluated after the materials were subjected to the following seven environmental variables: natural weathering; normal aging; two types of adhesives; two types of cleaning agents; and cosmetics. Optical density and color changes were evaluated. The currently used silicones Silastic 4-4210 and Silastic 4-4515, Medical Adhesive type A material, and polyurethane all showed more changes in color and optical density than the newly introduced silicone A-102 material.

Analysis of Variance↗
PubMed1997

Improvement in mitral regurgitation after aortic valve replacement.

This study sought to determine whether there is a quantitative improvement in mitral regurgitation (MR) after aortic valve replacement (AVR) for aortic stenosis (AS) and, if so, the mechanisms for this change. MR frequently accompanies AS. The addition of mitral valve replacement to AVR significantly increases the risk of surgery. Although previous studies have suggested a qualitative improvement in MR severity after AVR, semiquantitative analysis of this improvement has not been documented nor have the underlying mechanisms been examined. We evaluated 28 patients who had undergone 2-dimensional echo and color flow Doppler imaging an average of 1.5 +/- 2.5 months before and 2.5 +/- 4.2 months after AVR. Maximum MR area, MR percentage (MR area/left atrial area), mitral annular area, left atrial area, aortic gradient, and parameters of left ventricular geometry were measured to evaluate MR severity and to assess functional mechanisms for improvement in MR. There was a significant decrease in MR area (5.5 +/- 2.8 cm2 vs 2.5 +/- 1.9 cm2, p < or =0.0001) and MR percentage (25 +/- 11% vs 12 +/- 10% after operation, p < or =0.0001) between preoperative and postoperative studies. There was a significant reduction in aortic gradient, mitral annular area, left atrial area, and left ventricular length postoperatively. In univariate analysis, MR improvement was related to the lower preoperative left ventricular fractional area change (p = 0.027) and to the changes in fractional area change (p = 0.001) and left ventricular systolic area (p = 0.001). Thus, improvement in MR after AVR is related to changes in left ventricular function postoperatively. These data suggest that reduction in MR is due not only to decreased intraventricular pressure, but also to changes in ventricular morphology.

Aged↗
PubMed2000

Clinical features and management of isolated cleft mitral valve in childhood.

OBJECTIVES: We reviewed an institutional experience of isolated cleft mitral valve (ICMV), its clinical features, and management in a pediatric population. BACKGROUND: As ICMV is relatively uncommon, earlier reports highlighted its anatomical and echocardiographic features. Few studies have collated their clinical features with their outcome. METHODS: All patients with ICMV were retrospectively reviewed. Patients who were considered to have an atrioventricular septal defect or variant were excluded. RESULTS: Twenty patients (9 male, 11 female) were diagnosed with ICMV. Seven patients had associated cardiac lesions. The median age of diagnosis was 5.2 years (range 0.4 to 13.6 years). Echocardiography aided by color Doppler demonstrated the ICMV in all patients. However, an incomplete diagnosis was made in 4 of 20 patients before surgery. The severity of the mitral regurgitation (MR) at presentation was mild in 11, moderate in 8, and severe in 1 patient. In the 13 patients without associated cardiac lesions, 5 underwent mitral valve (MV) repair at median age of 5.2 years (range 1.2 to 7.7 years) for moderate to severe MR, 4 being symptomatic. The severity of the MR in seven of the eight unoperated patients has remained unchanged over the follow-up period (median 8.3 years, range 0.7 to 14.4 years). In total, 10 patients underwent MV repair (median 6.4, range 0.4 to 13.8 years). No patient required MV replacement. None of the 10 patients had more than mild MR over the follow-up period (median 0.6, range 0.2 to 11.0 years). CONCLUSIONS: Now readily diagnosable by echocardiography, ICMV is a correctable cause of MR with a good outcome. Surgery is indicated in those patients with moderate to severe MR and probably should be done early following diagnosis.

Adolescent↗
PubMed1998

[Aortic rupture after blunt chest trauma. Rapid diagnosis using transesophageal echocardiography when radiographic and computed tomographic findings are unclear].

HISTORY AND CLINICAL FINDINGS: A 37-year-old woman who was not wearing a seat-belt while driving a car had a head-on collision at 70 km/h. On arrival of the emergency physician she was awake and responsive but complained of pain with bruising over the sternum and the epigastrium. Pressure on the sternum was painful. Arterial pressure was 95/60 mm Hg, heart rate 112/min. On admission the heart sounds were unremarkable and peripheral pulses normal. Vesicular sounds were heard over both lungs. In addition to multiple facial abrasions voluntary movements were impaired and the right knee-joint was swollen. INVESTIGATIONS: The ECG showed sinus tachycardia (103 beats/min) with left axis deviation, but was otherwise unremarkable. Initially the haemoglobin was 12.6 g/dl with normal white cell and platelet counts. Clotting tests, serum transaminases, creatine kinase, lactate dehydrogenase and other routine laboratory tests were within normal limits. TREATMENT AND COURSE: Because the haemoglobin level had fallen to 7.7 g/dl within the first 4 hours erythrocytes concentrate was infused. The chest radiogram and subsequent computed tomography showed a mediastinal and paraaortic haematoma of unclear origin. Transoesophageal echocardiography (TEE) demonstrated rupture of the descending aorta with free floating intraluminal parts of the intima in the isthmal region, just distal to the origin of the left subclavian artery, which was not occluded. Colour Doppler echocardiography revealed abnormal flow into mediastinal and paraaortic tissues. At operation the echocardiographic findings were confirmed and part of the descending aorta was replaced by a 3 cm dacron tube during an aortic crossclamping time of 37 min. The patient was discharged after a postoperative stay of average length, during which her other injuries were treated. CONCLUSION: After blunt thoracic or deceleration trauma earliest possible TEE is indicated, because it can at once provide details of extent and degree of injury to heart and/or aorta.

Accidents, Traffic↗