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W Kottmann

Publications and source records attributed to W Kottmann.

6 recordsLinked to original sources
PubMed1997

The effects of simulated akinetic and dyskinetic aneurysms on left ventricular systolic function: clinical implications.

OBJECTIVE: Scant attention has been directed towards quantifying the degree of mechanical disadvantage produced by akinetic and dyskinetic aneurysms. The purpose of this study was to evaluate the mechanical disadvantages of simulated akinetic and dyskinetic aneurysms on left ventricular function. METHODS: An elaborate experimental apparatus consisting of a computer-controlled water pressure chamber in which is suspended a model rubber ventricle was developed. The system has been shown to reproduce accurately the ventricular and aortic pressures found in vivo. In this study, a procedure was designed to simulate akinetic and dyskinetic aneurysms of various sizes on ventricular function. RESULTS: The results indicated that an akinetic aneurysm produces little or no mechanical disadvantage with respect to ventricular pressure since systolic paradox is minimal. However, a dyskinetic aneurysm, irrespective of size, will usually compromise ventricular function due to paradoxical systolic expansion in the bulging aneurysmic sac. In vivo, other factors, such as blood coagulation and rhythm disturbances, may influence these results. CONCLUSIONS: An akinetic aneurysm causes little or no mechanical disadvantage while the dyskinetic aneurysm, irrespective of size. will restrict ventricular function. The experimental simulation system, notwithstanding its limitations, thus provides a unique procedure to quantify akinetic and dyskinetic aneurysms.

Heart Aneurysm↗
PubMed1991

[Special aspects of physical training during the rehabilitation stage of coronary patients].

Practical aspects: Physical exercise is a basic component of the rehabilitation program for patients recuperating from myocardial infarction or bypass surgery. The aim of exercise is to enhance physical performance by improving coordination, flexibility, strength, speed and endurance. The training concept is matched to the individual capability, which is determined by an exercise test at the beginning of the rehabilitation program. On the basis of this test, an "exercise heart rate" is calculated with the aim of protecting the patient from overstrenuous activity. Depending on their physical fitness, the patients are divided into two groups: those with a capability of less, and those with a capability of more than 1 watt/kg. Most elderly patients are no longer active participants in sports, so that guidance through flexibility and coordination exercise is offered. Usually, patients perform a daily program of 15 minutes of physical activity in their individual groups, and spend 45 minutes walking and relaxing. In addition, they have opportunities for swimming, jogging and cycling. Decreased left-ventricular function: The effects of a four-week training program in myocardial infarction (MI) patients with moderate-to-severe left-ventricular dysfunction were investigated in two distinct studies. In neither study was a deterioration in the ejection fraction at rest or during exercise observed. In the second study, an additional parameter was provided by the Swan-Ganz catheter. Neither pulmonary wedge pressure (PWP) nor cardiac output indicated any deterioration in response to dosed training. However, in this second study, four patients in the training group with a resting ejection fraction (EF) less than 30% developed complications. All these patients had a pathological PWP at rest. Nevertheless, five patients with an EF less than 30% but with a normal PWP at rest completed the training program without complications. The long-term prognosis for training post-MI patients with severe left-ventricular dysfunction would appear to be no worse than for controls. Results of the first study: During the four-week training program, no complications occurred. No major changes in the EF at rest and during training were seen. In the training group the EF at rest increased slightly to 40 +/- 10%. The EF during exercise improved to 39 +/- 10%. Delta EF showed a decrease of 3 +/- 8%. After the four-week training period the decrease was 1 +/- 9%. In the control group, a major increase in the EF at rest to 41 +/- 10% was seen. The EF during exercise, however, showed only a small increase to 43 +/- 15%.(ABSTRACT TRUNCATED AT 400 WORDS)

Coronary Disease↗
PubMed1988

[Filling pressures (pulmonary capillary pressure, indwelling catheter) in combined static (handgrip) and dynamic (bicycle ergometer) stress in postinfarct patients].

79 male post-MI patients (mean age 50 years) underwent Swan-Ganz catheterization using handgrip (1.5 min using both hands at 1/3 of the maximum voluntary capacity), bicycle ergometry and a combination of both: handgrip added after 4 min of ergometry at each level of ergometry, a mean of 3 months after MI. Our aim was to determine to which level of dynamic exercise the chosen handgrip exercise could be compared; furthermore, to examine the left ventricular reaction (PCP) under these combined conditions, because it mimics daily life situations. Using this combination of tests, it should be possible to identify patients who should avoid static work. Our findings were as follows: 48 of the 79 patients showed pathological PCPs. Comparing the same level of double product, no significant differences of PCP were found between dynamic and combined static + dynamic exercise. Our handgrip exercise can replace dynamic exercise of 40 W. 19 patients showed highly pathological PCP reactions with delta PCP greater than or equal to 10 mm Hg following handgrip exercise. This extreme PCP reaction did not correlate with the appearance of ST-segment depression in the exercise ECG, nor with either infarction scar size nor heart volume as estimated by X-ray. These findings demonstrate the importance of a staticdynamic exercise combination in evaluating PCP reactions in post-MI patients. The test allows one to select those MI patients who should avoid isometric work.

Cardiac Catheterization↗
PubMedDate not supplied

[Experimental simulation of dyskinetic heart wall aneurysms].

A mechanical model for the quantitative investigation of the loss of performance of a ventricle caused by aneurysms of different sizes is described. The model permits an accurate simulation of the geometry of both the ventricle and the aneurysm, as well as the mechanical flow situation as expressed by the changing pattern of the intraventricular pressure. Investigations are limited to a determination of the loss of ventricular performance brought about by the dyskinetic motion of the aneurysm.

Blood Pressure↗