Medtronic-Hall prosthesis: valve related deaths and complications

The purpose of this retrospective study was to assess the clinical performance of the Medtronic-Hall prosthesis based on a review of all valve related complications over a period of nine years. From January 1978 until December 1986, 502 prostheses were implanted in 450 patients. There were 200 aortic valve replacements, 198 mitral valve replacements and 52 double valve replacements. There were 234 associated procedures performed, the most frequent being coronary grafting in 129 patients and tricuspid annuloplasty in 35 patients. The mean age of the patients (230 men and 220 women) was 54.08 +/- 11.7 years. Preoperatively, 92.2% were in NYHA class III or IV. Early mortality was 7.1% and late mortality 16.7%. The follow-up totalled 1733 patient-years (mean 49.8 +/- 31.7 months). Over a period of nine years, the valve related complication rate was 4.4% per patient-year. Thromboembolic events occurred in 37 patients (2.1% per patient-year), anticoagulant related hemorrhage in 23 patients (1.3% per patient-year), endocarditis in 11 patients (0.6% per patient-year), perivalvular leak in six patients (0.3% per patient-year) and death and reoperation in 28 patients (1.6% per patient-year). At eight and one-half years, the survival rate was 71.28 +/- 2.7% for the whole group. The actuarial rate of patients free from all valve related complications was 75.92 +/- 2.7%, rate of freedom from thromboembolism was 86.01 +/- 2.4%, freedom from anticoagulant related hemorrhage was 92.7 +/- 1.6%, freedom from endocarditis was 97.17 +/- 0.8%, freedom from perivalvular leak was 98.27 +/- 0.7% and freedom from death and reoperation was 90.70 +/- 1.9%.(ABSTRACT TRUNCATED AT 250 WORDS)     

Study of dilated cardiomyopathies using gallium 67 myocardial scintigraphy

Twenty-seven patients were diagnosed as having dilated cardiomyopathies, based on increases in the cardiothoracic index greater than 0.50, in the diastolic and systolic diameters of the left ventricle, and in the telediastolic volume of the left ventricle, which was indexed by body surface determined by contrast ventriculography. They underwent gallium 67 scintigraphic examination of the myocardium, in order to non-invasively detect the presence of an inflammatory infiltrate. Fifteen of them also had endomyocardial biopsies and all had virology check-up. The results were disappointing. Only in one case was the scintigraphic image undeniably positive; in 20 other patients the findings were dubious or negative. This technique did not demonstrate the presence of an inflammatory infiltrate and thus we could not establish an association between myocarditis and dilated cardiomyopathy.     

Prenatal diagnosis of cystic fibrosis: microvillar enzymes and DNA analysis compared

We have established reference ranges for three microvillar intestinal enzymes--alkaline phosphatase (EC 3.1.3.1), gamma-glutamyltransferase (EC 2.3.2.1), and leucine aminopeptidase (EC 3.4.1.1)--measured in amniotic fluid in a reference population of 1875 women presenting for routine amniocentesis. These data were derived for use in prenatal diagnostic studies in a population at risk (1:4) for cystic fibrosis. False-positive or indeterminate results were noted for fewer than 3.5% of all low-risk cases for each enzyme evaluated. Total alkaline phosphatase and its isoenzymes and leucine amino-peptidase and gamma-glutamyltransferase were measured in amniotic fluid sampled between the 15th and 19th weeks of gestation. Restriction fragment length polymorphism analysis of DNA was also performed when possible. In 52 cases examined for cystic fibrosis thus far, 46 were diagnosed on the basis of DNA analysis and (or) by sweat testing; for the other six cases, only abnormal enzyme results were obtained before termination of pregnancy. Predictions based on microvillar enzyme results were falsely negative in three cases. In only one case was there a discrepancy between enzyme results and DNA analysis. Diagnostic accuracy was highest during the 17th and 18th week of gestation. Preliminary results suggest the false-negative rate of this diagnostic strategy may be greater than or equal to 10%.     

The Medtronic-Hall cardiac valve: 7 1/2 years' clinical experience

Clinical information on the Medtronic-Hall valve prosthesis was obtained by reviewing the records of 379 patients, 164 of whom had aortic valve replacement (AVR), 163 of whom had mitral valve replacement (MVR), and 52 of whom had double valve replacement over 90 months (1,225 patient-years) (mean follow-up, 42.01 +/- 1.3 months [+/- standard error]). Mean age was 53.8 +/- 12 years. One hundred ninety-three patients (50.9%) had some type of concomitant operation, such as tricuspid annuloplasty, coronary artery bypass grafting, or resection of ascending aortic aneurysm. Ninety-one percent were in New York Heart Association (NYHA) Functional Class III or IV preoperatively. Early mortality and late mortality were 7.7% (29 patients) and 13.5% (51 patients), respectively. The actuarial survival at 7 1/2 years was 74.1 +/- 2.7% for the total group and 69.0 +/- 4.5% for those having AVR, 81.0 +/- 3.2% for those having MVR, and 67.0 +/- 8.9% for those having double valve replacement. All patients but 2 were maintained on a regimen of chronic anticoagulation with warfarin sodium. Twenty-six thromboembolic episodes occurred (2.1/100 patient-years): 13 after MVR (2.3/100 patient-years), 11 after AVR (2.1/100 patient-years), and 2 after double valve replacement (1.4/100 patient-years). Four thromboembolic episodes were fatal; no valve thrombosis occurred. There were no structural failures. Of the 350 late survivors, 92% were in NYHA Functional Classes I and II. Total valve-related complications have been minimal.(ABSTRACT TRUNCATED AT 250 WORDS)     

Reinnervation of dopamine neurons by regenerating serotonin axons in the rat medial zona incerta

Summary Cellular relationships between serotonin (5-HT) axons and tyrosine hydroxylase (TH)-containing neurons were examined by combined (³H)5-HT uptake radioautography and TH immunocytochemistry in the medial zona incerta (ZI) of adult rats, 7 and 50 days after an intracerebral injection of 5,7-Dihydroxytryptamine (5,7-DHT). Seven days post-lesion, only rare, scattered (³H)5-HT-labeled axon terminals were apparent in the zone of the medial ZI accessible to intraventricularly injected (³H)5-HT. In contrast, in sham-injected animals (³H)5-HT-labeled varicosities were numerous and often observed adjacent to TH-immunoreactive perikarya and dendrites. Fifty days post 5,7-DHT injection, the density of (³H)5-HT-labeled terminals approximated that seen in sham-treated animals. At the ultrastructural level, these regenerated 5-HT axons were similar in size, shape and content to those observed in sham-operated rats. Also, as in sham, some of the (³H)5-HT-labeled axons were directly apposed to TH-immunopositive labeled profiles. The latter included large dendritic shafts and dendritic spines, but only rare perikarya. In both sham- and 5,7-DHT-treated animals a few of the contacts between (³H)5-HT-labeled and TH-immunoreactive profiles exhibited an asymmetric synaptic differentiation. These results indicate that 5-HT fibers in the medial ZI, following regeneration, can reestablish normal relationships and even synapses with a given population of chemically identified cells.     

研究诊断准确性的论著的质量:STARD公布后无改变——STARD公布前后的比较研究

目的确定对诊断准确性进行研究的论著的规范(STARD)公布前、后该类论著的质量改善情况,并比较执行STARD和未执行STARD的杂志的该类论著质量有无差