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Biomedical subjects

J Manthey

Publications and source records attributed to J Manthey.

At least 55 records · Page 3Linked to original sources
PubMed1982

The effect of aortic valve replacement on survival.

We retrospectively studied 252 operated and 47 unoperated patients with isolated aortic valve disease. Aortic valve replacement (AVR) was recommended to all patients based on clinical and hemodynamic data. Preoperative hemodynamic and angiographic data were similar in operated and unoperated cohorts. Seventy-one percent of patients received a Björk-Shiley prosthesis. Operative mortality was 7% for the entire surgical series. For patients with predominant aortic stenosis (AS), survival at 3 years was 87% in operated and 21% in unoperated patients (p less than 0.001). For patients with predominant aortic insufficiency (AI), the 5-year survival rate was 86% in operated and 87% in unoperated patients (NS). AVR improved long-term survival in patients with AS who had normal or impaired left ventricular (LV) function. In patients with AI and normal LV function, survival was not improved after AVR, but those with LV dysfunction who were operated on tended to survive longer (NS). Long-term survival of unoperated patients with AI was better than that in unoperated patients with AS. We conclude that AVR improves long-term survival in patients with AS who were normal or abnormal LV function, and that AVR does not change long-term survival in patients with AI, although those with LV dysfunction tended to survive longer.

Adult↗
PubMed1981

[The effect of tricuspid insufficiency on right ventricular performance in patients with valvular heart disease (author's transl)].

The hemodynamic effect of tricuspid insufficiency on right ventricular function was studied in 25 patients with rheumatic heart valve disease. 10 patients had mixed valve disease without tricuspid insufficiency (group A), and 15 patients had mixed mitral valve disease with tricuspid insufficiency (group B). Mitral valve area (1.76 vs. 1.66 cm2) and mitral regurgitant fraction (55 vs. 45%) were not significantly (p greater than 0.05) different between groups. Patients of group B revealed higher right atrial and right ventricular end-diastolic pressures than patients of group A. Right ventricular ejection fraction was lower in group B as compared to group A (44 vs. 52%, p less than 0.05). During ergometric exercise right atrial pressure was higher in group B as compared to group A (19 vs. 14 mm Hg, p less than 0.05), but mean pulmonary artery pressure (48 vs. 51 mm Hg, p greater than 0.05), cardiac index (3.3 vs. 3.31/min . mi2, p greater than 0.05) and stroke index (27 vs. 25 ml/m2, p greater than 0.05) were not significantly different. In mixed mitral valve disease associated with tricuspid regurgitation, right ventricular function is impaired when compared to mixed mitral valve disease of equal severity but without tricuspid regurgitation. Exercise induces a further augmentation of right atrial pressure in these patients with tricuspid regurgitation. We conclude, right atrial pressure elevation is not only the consequence of tricuspid regurgitation in group B but also the consequence of impaired right ventricular function. Impairment of right ventricular function is further augmented during exercise.

Adult↗
PubMed1981

[Effect of intracoronary fibrinolysis on left ventricular diastolic function in patients with acute myocardial infarction (author's transl)].

In 22 patients with acute myocardial infarction, intracoronary infusion of streptokinase was begun 3.2 +/- 1.4 hours after the onset of symptoms. In 71% of patients recanalization of a completely occluded artery could be achieved. In 12 successfully treated patients left ventricular hemodynamics (left ventricular diastolic compliance and regional wall motion) were compared before and 4 weeks after recanalization. 4 weeks after intracoronary fibrinolysis left ventricular end-diastolic pressure had fallen (from 20 to 15 mm Hg, p less than 0.05), diastolic compliance had improved (p less than 0.05) and infarct size was reduced (p less than 0.05) compared to the acute stage of myocardial infarction. Left ventricular hemodynamics of 16 patients without heart disease (group A) and 22 patients with chronic myocardial infarction treated medically (group B) were compared to the findings of patients with acute myocardial infarction (group C). Group B and C showed reduced diastolic compliance as compared to group A (p less than 0.001). When group B and c were compared with identical size of akinesis (as measured by the number of asynergic hemiaxes), there was no significant difference of diastolic compliance. Reduction of diastolic compliance correlated linearly with infarct size (r = 0.73, r = 0.78). The results indicate that successful early reperfusion of acute myocardial infarction leads to a reduction of infarct size.

Adult↗
PubMed1976

Functional significance of collateral blood flow in working skeletal muscle of the dog.

The semitendinosus muscle of the dog is supplied by two separate arteries and drained by two corresponding veins. In the muscles used in this study no blood entering via the distal artery was found to leave via the proximal vein during perfusion through both arteries (orthograde perfusion). Therefore, collateral flow (CF) could be determined as proximal venous outflow during occlusion of the proximal artery. During orthograde perfusion total blood flow averaged 12 ml x min-1 x 100 g-1 at rest and 58.4 ml x min-1 x 100 g-1 during exercise. CF was found to average 6.2 ml x min-1 x 100 g-1 at rest and increased to 9.2 ml x min-1 x 100 g-1 during exercise. CF was sufficient to cover the metabolic demand of resting muscle. During exercise the O2-uptake (VO2) of the distal muscle portion was increased 13.4 fold in comparison to a 3.1 fold increase in the proximal muscle portion. The average contractile power decreased by 46%. Additional infusion of adenosine into the distal artery resulted in an increase of CF to 11.4 ml x min-1 x 100 g-1 and of orthograde flow to 71 ml x min-1 x 100 g-1. The average contractile power of the muscle increased by 13%. Both orthograde flow and CF were found to decrease with increasing muscle load. But this decrease was significantly more pronounced in the case of CF especially at a lower range of loads. It is concluded that after acute occlusion of orthograde flow, CF is limited by the number, the size and the dilatory capacity of precapillary network vessels. Furthermore, CF is influenced considerably by changes of extravascular support.

Adenosine↗
PubMed1975

[Chemical induction of lysogeny of Staphylococcus aureus (author's transl)].

Concerning the chemical induction of lysogeny of Staphylococcus aureus only little is known. Therefore, we performed induction experiments on 43 Staph, aureus strains using nine mutagenic substances and 15 chemotherapeutics. Only three of the nine mutagenic substances (beta-propiolacton, nitrosoguanidin and mitomycin C) and six of the 15 chemotherapeutics (penicillin G, ampicillin, cephalothin, nebacetin, novobiocin and nalidixie acid) showed inducing effects. Our results demonstrated furtheron that the lysogeny inducing ability is dependent on strains and substances used.

Anti-Bacterial Agents↗
PubMedDate not supplied

End-systolic pressure-volume and end-systolic stress-volume relationships in patients with aortic stenosis and with normal valvular function.

In order to study the effect of left ventricular hypertrophy on the endsystolic pressure-volume relationship, three left ventricular angiograms were performed in ten patients with normal valvular function but with varying left ventricular function (group 1) after 0.15 mg/kg propranolol and 1 mg atropine: at rest, after isosorbide-dinitrate at a decreased afterload and after methoxamine at an enhanced afterload. In eight patients with aortic stenosis (group 2) two left ventricular angiograms were performed: at rest and after isosorbide-dinitrate. Heart rate was kept constant by atrial pacing. Left ventricular mass in group 1 was 89 g/m2 and in group 2 180 g/m2. In group 1 the slope k of the end-systolic pressure-volume relation was related to the ejection fraction (EF) at rest: k = 0.024 . e0.072 EF; r = 0.93. In group 2 this relation was shifted to the left (P less than 0.001): k = 0.135 . e0.057 EF; r = 0.81. The relations, however, between the slope k of the end-systolic stress-volume relation and the ejection fraction were close together in group 1 and in group 2 and crossed at an ejection fraction of 67%. It is concluded: 1. In patients with aortic stenosis the end-systolic pressure-volume relation is steeper than in patients without valvular dysfunction at a given ejection fraction, so the relation between the slope k and the ejection fraction is shifted to the left. 2. The end-systolic stress-volume relationship is not altered in patients with aortic stenosis and seems to be advantageous for the evaluation of left ventricles with substantial hypertrophy due to pressure load.

Adult↗