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Biomedical subjects

H Dittrich

Publications and source records attributed to H Dittrich.

At least 55 records · Page 3Linked to original sources
PubMed1989

The Omni design: evolution of a valve.

The Lillehei-Kaster prosthesis has been the subject of an engineering evolution to close the gap between engineering expectations and clinical performance. Advanced engineering development in response to users has narrowed this gap with the Omni design (Omniscience titanium and omnicarbon Pyrolite cages). Our studies on mitral Omniscience valves demonstrated that because anatomic and surgical variations, the anterior orientation was more forgiving than the posterior orientation, resulting in lower thrombotic complications (0.5% versus 3.3% patient-year). A subsequent thicker cuff was used to reduce the probability of anatomic interference and incomplete opening after cardiac recovery. Such findings were also incorporated in the Omnicarbon design. Five European centers implanted 354 patients (198 atrial valve replacement, 115 mitral valve replacement, and 41 double valve replacement with Omniscience valves between August 1984 and January 1986. No restrictive patient selection criteria were used. As of June 1987, 96% of the patients at risk were accounted for. Average follow-up was 1.7 +/- 0.4 years (range, 0.3 to 2.8 years), with a total follow-up of 555 years. There were no cases of structural failure or clinically significant hemolysis. Ninety-one percent of the patients improved one or more functional classes. Actuarial analysis of survival probability at 3 years is 92.5% for atrial valve replacement, 97.9% for mitral valve replacement, and 93.6% overall. There were no late deaths from valve thrombosis or thromboembolism. The actuarial freedom from all thromboembolic events (valve thrombosis, thromboembolism, and transient ischemia) is 97.8% at 2 1/2 years. Through close rapport between user surgeons and designers, the evolution of a valve with improved performance becomes a reality.

Actuarial Analysis↗
PubMed1988

[Congenital alcoholic cardiomyopathy in 3 children].

Three cases of congenital alcoholic cardiomyopathy and cardiac defects in children are described. The mothers were heavy spirits drinkers. One child had a ventricular septal defect, two had Fallot's tetralogy, all requiring operation. At open-heart surgery left-ventricular myocardial biopsies were obtained in all three children. Histological and electronmicroscopic examination revealed primary toxic and hypotrophic changes, which differed from those seen in alcoholic cardiomyopathy of the adult. The cells, their nuclei and the myofibrils had reduced diameters. The mitochondria were damaged to differing extent. The myofibrils were arranged in parallel and some had contraction bands and ruptures. The sarcoplasmic reticulum was dilated and had vacuoles. The cell surface penetrated into the interstitial tissue. All these changes could have resulted from inhibited embryofetal cell growth and cytotoxic damage by alcohol during pregnancy. It would seem that alcoholic cardiomyopathy occurs only in extreme forms of alcohol abuse during pregnancy. The prognosis is as yet unknown.

Cardiomyopathy, Alcoholic↗
PubMed1988

Acute myocardial infarction in women: influence of gender on mortality and prognostic variables.

The contention that mortality after acute myocardial infarction (AMI) is increased in women compared with men has been controversial, with findings in a recent multicenter study suggesting that gender plays an important prognostic role. To assess whether or not early and late mortality after AMI is greater in women, 2,089 patients (1,551 men, 538 women) were followed for 1 year after AMI. In the hospital, women had an increased mortality compared to men (17.5 vs 12.3%, p less than 0.003) and were on average 7 years older, whereas after hospital discharge and up to 1 year no difference in mortality was observed. Multivariate analyses of historical, clinical and laboratory features demonstrated that gender had no independent predictive value when variables that included age, congestive heart failure in the hospital, history of congestive failure, prior AMI and diabetes mellitus were considered. Moreover, when age stratification was performed, the significant difference of in-hospital mortality between genders was no longer present. Causes of death in the hospital and during 1 year after hospital discharge were similar between men and women, whether or not age stratification was performed. Several baseline clinical characteristics were different between men and women; a history of systemic hypertension and congestive heart failure occurred more frequently in women and previous AMI and smoking occurred more commonly in men. Also, the value of several other important prognostic indicators after AMI, such as the ejection fraction, was found to differ between men and women.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1988

Influence on prognosis and morbidity of left ventricular ejection fraction with and without signs of left ventricular failure after acute myocardial infarction.

The left ventricular (LV) ejection fraction (EF) is known to be an independent predictor of late prognosis after acute myocardial infarction. Despite a previous report that early heart failure (evidenced only by advanced pulmonary rales in the hospital) can predict prognosis in the absence of severe depression of the LVEF at hospital discharge, the potentially strong influence of various measures of in-hospital heart failure on the predictive ability of LVEF has not been generally appreciated. Accordingly, in 972 patients with acute myocardial infarction the effect on late mortality of the presence or absence in-hospital of both clinical and radiographic signs of LV failure in subgroups of patients with normal, moderately or severely depressed LVEF was examined and measured close to hospital discharge. Patients were divided into 3 groups according to LVEF: group I LVEF less than or equal to 40, n = 265; group II LVEF 0.41 to 0.50, n = 241 and group III LVEF greater than or equal to 0.51, n = 466. When clinical signs of LV failure were present at any time during the coronary care unit period, the 1-year mortality rate after hospital discharge in groups I, II and III was 26, 19 and 8%, compared with 12% (p less than 0.01), 6% (p less than 0.01) and 3% (p less than 0.02), respectively, when signs of LV failure were absent.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1988

First myocardial infarction: age and ejection fraction identify a low-risk group.

This study examines patients with a first myocardial infarction (MI) (about 70% of the population, n = 2089), and identifies factors associated with 1-year cardiac mortality in patients discharged alive. With the use of multivarate analysis of variables observed at hospital discharge in patients with a first MI, age was the most important predictor, followed by left ventricular ejection fraction (LVEF) (determined in 56%) and other variables. Based on this finding, age subsets (less than or equal to 50, 51 to 70, greater than 70 years) were related to LVEF groups (less than or equal to 0.40, 0.41 to 0.50, greater than 0.50). Patients with a first MI who were less than 50 years of age with LVEF greater than 0.40 and patients between 51 and 70 years of age with LVEF greater than 0.50 had a very low risk for 1-year cardiac death, 1.2 +/- 1.1% (95% confidence interval). Such patients comprised 47% of individuals with a first MI having an LVEF determination. Mortality in the remaining patients less than 70 years was 7.4 +/- 3.5%. Mortality for patients greater than 70 years was high, 22.2 +/- 6.6%. Thus with LVEF as the only predischarge test, a sizable low risk group can be identified among patients with a first MI.

Age Factors↗
PubMed1988

Evaluation of Björk-Shiley prosthetic valves by real-time two-dimensional Doppler echocardiographic flow mapping.

We studied the value of two-dimensional Doppler echocardiographic color flow mapping for identifying normal transvalve flow profiles and valve malfunction in 20 patients with Björk-Shiley prosthetic valves. Seven patients had Björk-Shiley prosthetic valves in the aortic position alone, seven in the mitral position, and six had prosthetic valves in both the aortic and mitral positions. In 10 patients with normally functioning mitral valves, the ratios of the maximal major and minor Doppler-imaged orifice flow diameters to the valve ring diameters were 25 +/- 3% (mean +/- SD) and 24 +/- 3%, respectively, similar to values reported in in vitro studies. No mitral regurgitation was found in these patients by two-dimensional Doppler echocardiographic flow mapping or by spectral Doppler. Of the 10 clinically normal aortic Björk-Shiley valves, no valvular regurgitation was found by color flow mapping, whereas mild aortic regurgitation was found in two patients with the use of spectral Doppler. Malfunction of six valves was documented in five patients and was confirmed by cardiac catheterization and/or surgery. These included one case of focal fibrous ingrowth involving primarily the minor orifice of a mitral prosthetic valve, one case of mitral valve prosthetic thrombosis with decreased major and minor orifice flow diameters and valvular regurgitation, and four cases of paravalvular regurgitation involving prosthetic valves in the aortic position (three patients) and the mitral position (one patient). Two-dimensional Doppler echocardiographic flow mapping provides new observations that may aid in identifying Björk-Shiley prosthetic valve malfunction. By localizing precisely the site of prosthetic stenosis or regurgitation, it may also assist in defining the cause of valve malfunction.

Adolescent↗
PubMed1988

Late clinical outcome in patients with early ventricular fibrillation after myocardial infarction.

Whether ventricular fibrillation occurring within 48 h after acute myocardial infarction is associated with particular clinical features and poor prognosis, especially in patients with anterior myocardial infarction, is still debated. Therefore, clinical variables and in-hospital and 1 year mortality rates were analyzed in 2,088 patients, aged 18 to 95 years (mean +/- SD 64 +/- 12), admitted to the hospital with acute myocardial infarction between 1979 and mid 1984. One hundred forty-seven patients (7%) had at least one episode of ventricular fibrillation occurring within 48 h of hospital admission. Of these, 25% died during their initial hospitalization compared with 13% of patients without early ventricular fibrillation (p less than 0.001). In greater than 50% of patients with early ventricular fibrillation, the immediate cause of death was left ventricular failure or cardiogenic shock. In contrast, the 1 year mortality rate after hospital discharge was not significantly greater in patients with than in those without early ventricular fibrillation (15 versus 11%, respectively), particularly in the subgroup of patients with anterior myocardial infarction in which the mortality rate tended to be lower in patients with early ventricular fibrillation (8 versus 14%, respectively). Similar mortality results were found when only primary (not associated with left ventricular failure) ventricular fibrillation was analyzed. The left ventricular ejection fraction and the incidence of complex ventricular arrhythmias from 24 h ambulatory electrocardiographic monitoring obtained at hospital discharge were not different in survivors with or without early ventricular fibrillation (0.45 +/- 0.13 versus 0.49 +/- 0.14 and 41 versus 41%, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1988

Long-term outcome in patients with inferior myocardial infarction and complete atrioventricular block.

Some studies have reported increased short-term mortality and higher incidence of multivessel coronary artery disease in patients with inferior myocardial infarction and complete heart block, but information is lacking on clinical outcome after hospital discharge. Therefore, data were obtained and analyzed in 749 patients who were admitted with inferior myocardial infarction to four different centers and followed up for 1 year. Six hundred fifty-four patients (Group 1) did not have complete heart block and 95 (Group 2) had complete heart block during their hospital stay (incidence rate 12.8%). Compared with Group 1, Group 2 patients were older (66 versus 61 years, p less than 0.01), more often had signs of left ventricular failure (p less than 0.001) and had higher peak creatine kinase values (1,840 versus 1,322 IU/liter, p less than 0.001). The in-hospital mortality rate was higher in Group 2 than in Group 1 (24.2 versus 6.3%, p less than 0.001). However, at discharge there was no difference between Group 1 and Group 2 in clinical characteristics, left ventricular ejection fraction (0.52 +/- 0.12 versus 0.52 +/- 0.11) or incidence of complex ventricular arrhythmias on ambulatory electrocardiographic monitoring. Furthermore, during the year after hospital discharge, patients in Groups 1 and 2 did not have significantly different mortality rates (6.4 versus 10.1%, p = NS). The incidence rate of reinfarction (4%) was the same in Groups 1 and 2. The incidence of coronary artery bypass surgery was slightly but not significantly higher in Group 1 compared with Group 2 (11 versus 4%).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1987

Zinc, cadmium and selenium concentrations in separated epithelium and stroma from prostatic tissues of different histology.

The concentration of Zn, Cd and Se in unseparated tissues and epithelial and stromal fractions of normal prostate gland, BPH and prostatic carcinomas of different histological grading were determined by flameless AAS. There were distinct differences in the content of Zn, Cd and Se in the epithelial and stromal fractions depending on histology. In all cases the concentration of these elements in the epithelial fractions was higher than in stromal fractions. These differences are discussed.

Cadmium↗
PubMed1987

Pulmonary angiography in severe chronic pulmonary hypertension.

We have analyzed the safety of doing pulmonary angiography in 67 consecutive patients with moderate-to-severe primary pulmonary hypertension or hypertension secondary to chronic thromboembolic occlusions of the pulmonary arteries. The average (+/- SD) pulmonary arterial systolic and diastolic pressures were 74 +/- 19 and 34 +/- 10 mm Hg, respectively. Fourteen patients had a right ventricular end-diastolic pressure of 20 mm Hg or more. Selective left and right main pulmonary artery injections were done using ionic contrast agents in 56 patients and nonionic contrast agents in 11. No major rhythm disturbances or systemic hypotension requiring therapy occurred, and there were no deaths. Thrombotic occlusions of the pulmonary arteries were identified in 52 patients and confirmed in all 42 of those who had a thromboendarterectomy. At autopsy, 3 of the 15 patients who had normal angiograms were found not to have had thrombotic occlusions. We conclude that pulmonary angiography can be done safely despite the presence of severe pulmonary hypertension and right ventricular failure, and that the procedure leads to the identification of chronic, major-vessel thromboembolic pulmonary hypertension that may be alleviated by thromboendarterectomy.

Adolescent↗