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Biomedical subjects

P G Berge

Publications and source records attributed to P G Berge.

11 recordsLinked to original sources

[Cardiopulmonary capacity in patients before and after prosthetic valve replacement].

In this study we wanted to investigate if noninvasive cardiopulmonary exercise testing can be securely, accurately applied in patients with acquired cardiac valve disease pre- and postoperatively with any convenience. Furthermore, we looked if the cardiopulmonary exercise capacity (anaerobic threshold, etc.) was improved postoperatively (3 and 6 months) in 15 patients suffering from severe mitral valve disease as compared to the preoperative condition. The symptom-limited cardiopulmonary exercise testing was performed on a bike in a semi-supine position using a ramp program (+20 W/min). The following parameters were continuously monitored, and the breath-by-breath gas exchange values documented: cardiocirculatory parameters (heart rate; blood pressure; surface ECG; exercise capacity in Watts); gas-exchange parameters (O2-uptake VO2; CO2-production VCO2; respiratory anaerobic threshold VO2 AT; gas-exchange ratio VCO2/VO2; O2-pulse VO2/HR; aerobic capacity delta VO2/delta WR) and ventilatory parameters (respiratory rate; tidal volume Vt; minute ventilation VE; equivalent for O2: VE/VO2 and CO2: VE/VCO2). The 155 cardio-pulmonary exercise tests in 115 patients were practicable, safe (no emergency case) and accurate. In 100 patients late postoperatively (68.3 +/- 53.0 -102.9 +/- 41.2 months) after aortic or mitral valve replacement or both without signs of significant hemolysis or prosthetic valve dysfunction the NYHA classification was too imprecise to characterize the actual exercise capacity of the patients (e.g., NYHA class II: Weber class B to E). Patients with aortic valve prosthesis had a significantly better anaerobic threshold (57.4 +/- 19.1% pred. value max. VO2) as compared to those with mitral valve replacement (mean: 35.9% pred. value max. VO2).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

[Methodologic aspects of modern, computerized ergospirometry (CPX): ramp program, constant workload test and CO2 rebreathing method].

The cardiopulmonary exercise testing (CPX) is a non-invasive method for the evaluation of the cardiopulmonary exercise capacity. Based upon the recent technical progress in gas analysers and personal computers today it is possible to perform CPX with acceptable time consumption, high practicability and high reproducibility of the results in many clinical areas. CPX is realized on a bike or on a treadmill. In bicycle CPX a ramp program (increase of x watts per minute) or a constant workload test (p.e. with 75% of the watts at anaerobic threshold) are performed. Furthermore, an estimation of the cardiac output using CO2-rebreathing method can be realized during a ramp program or a constant workload test. In this paper, also the CPX parameters of the ramp program, the constant workload test and the CO2-rebreathing method are defined and explained. The normal values of CPX are dependent of age, sex, body weight and exercise program. This should be kept in mind in interpreting the measured CPX data. Additionally, the performance of a routine CPX will be reported. Furthermore, the accuracy of the CPX parameters and the potential influences on the data will be discussed. Finally, problems during measurements and their analysis will be clarified.

Carbon Dioxide↗

[Cardiopulmonary exercise capacity in VVI stimulation in patients with high grade AV block].

VVI-pacemaker patients with high-grade atrioventricular block were subjected to cardiopulmonary exercise testing. An interindividual comparison was made between patients with intermittent intrinsic rhythm (n = 9) and patients with permanent VVI-stimulation (n = 15). Patients with intermittent sinus rhythm on exercise had no significant increase in exercise capacity as quantified by the O2-uptake at the anaerobic threshold. An intermittent sinus rhythm is of no relevance to therapeutic decisions, such as choosing the appropriate pacing mode. Exercise capacity is determined by multiple, partly peripheral factors.

Adult↗

[Methodologic and clinical comparison of four different ergospirometry systems].

The clinician who uses cardio-pulmonary exercise testing (CPX) systems relies on the technical informations from the device producers. In this paper, the practicability, the accuracy and the safety of four different, available CPX systems are compared in the clinical area, using clinically orientated criteria. The exercise tests were performed in healthy subjects, in patients with cardiac and/or pulmonary disease as well as in young or old people. The comparison study showed, that there were partially large differences in device design and measurement accuracy. Furthermore, our investigation demonstrated that beneath repetitive calibrations of the CPX systems a frequent validation of the devices by means of a metabolic simulator is necessary. Problems in calibration can be caused by an inadequate performance or by unclean calibration gases. Problems in validation can be due to incompatibility of the CPX device and the validator. The comparison study of the four different systems showed that in the future standards for CPX testing should be defined.

Adult↗

[Cardiopulmonary capacity in patients with coronary heart disease].

Cardiopulmonary exercise testing (CPX) allows a non-invasive control of the cardiopulmonary exercise capacity. In this study, we wanted to investigate if the CPX can be securely, practicably, and accurately performed in patients with invasively documented coronary heart disease (CHD). Furthermore, we wanted to find out the clinical value of CPX in CHD diagnosis. The CPX measurements (symptom-limited; ramp program with 20 Watts increase/min; semi-supine position; continuous registration of the cardio-circulatory parameters (HR, RR, ECG), of the gas exchange parameters (O2, CO2) and of the ventilation) in 101 patients have shown that CPX is secure, accurate, and practicable. The day-to-day reproducibility is high (r > 0.8). The respiratory anaerobic threshold can be manually evaluated by means of the PET O2 criterion in 95% of the cases. The CCS-classification of angina pectoris could not accurately describe the cardiopulmonary exercise capacity as compared to the Weber-classification. The disadvantage of the Weber-classification is that it does not respect the age-, sex- and weight-dependent differences of the normal values. Our own data and results from the literature demonstrate that the anaerobic threshold, the maximum VO2 and the maximum O2-pulse are the more reduced the more coronary arteries are involved, the more reduced the left ventricular function is. But, nevertheless, the range of values shows large overlaps so that an exact differentiation, based upon these parameters, is not possible. Patients with similar functional results or degree of reduced exercise capacity have different morphological alterations. Most patients demonstrated typical ischemic cascade with anaerobic threshold, ST-segment alterations, angina pectoris and, finally, reduced max. VO2. In conclusion, CPX does not replace the traditional methods of non-invasive and invasive ischemia detection, but enables secure, practicable, and accurate measurements of the individual cardiopulmonary exercise capacity and the interaction between muscles, heart, circulation, and lungs. Possibly, CPX can be used in the near future for identifying CHD patients with low, medium or high risk.

Adult↗

[Effect of a single blood donation on ergo-spirometrically determined cardiopulmonary performance capacity of young healthy probands].

Autologous blood donation is an established method for an effective reduction of the blood-transfusion-associated infectious diseases (hepatitis, HIV infections, etc.) in elective surgical procedures. The aim of the study was to investigate the effects of a blood donation of 450 ml on the cardiopulmonary exercise capacity in 16 apparently healthy young subjects. The 24 cardiopulmonary exercise tests were performed on a bicycle ergometer (Ergoline 900) in a semisupine position, using a ramp program (+20 watt/min) 1-7 days before and 2 days after blood donation. By means of continuous breath-by-breath measurements of the gas exchange (VO2, VCO2) and ventilation parameters (minute ventilation VE), as well as of the routine parameters (heart rate, blood pressure, work rate) during incremental exercise the respiratory anaerobic threshold VO2AT, the maximum VO2 (VO2max and the maximal working capacity (max. WR) were determined. Serum hemoglobin concentration was significantly (p < 0.0005) reduced from 14.5 +/- 1.0 to 13.0 +/- 1.4 g/dl after blood donation. The ventilatory anaerobic threshold (before: 68.5 +/- 17.0; after: 52.0 +/- 20.3% pred. max. VO2), the max. VO2 (before: 124.2 +/- 21.3; after: 110.2 +/- 23.2% pred. max. VO2) and max. WR (before: 287.1 +/- 75.6; after 265.5 +/- 76.2 watt) fell significantly (VO2AT: p < 0.0005; max. VO2: p < 0.0005; max. WR: p < 0.025). Heart rate and minute ventilation showed a steeper increase (dHR/dWR: before: 0.31 +/- 0.06; after: 0.34 +/- 0.05 beats/min/watt; dVE/dWR: before: 0.29 +/- 0.05; after: 0.31 +/- 0.05 l/watt) in relation to the increase in WR after blood donation as compared to the test before.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

[Local vascular complications in heart catheter studies].

Over a period of 30 months (1. 1. 89-30. 6. 91) 3516 patients who had either a diagnostic (2718) or therapeutic (798) heart catheterization were followed for local vascular complications. 774 patients were investigated prospectively. The following complications were observed in declining frequency: 1. relevant haematoma, 2. pseudoaneurysm, 3. arteriovenous fistula, 4. arterial thrombosis/dissection, 5. venous thrombosis, 6. rupture of the vessel, 7. local infection. The total complication rate was 2.22%. With prospective investigation it was significantly higher (3.23%) than with retrospective investigation (1.93%). The complication rate was also significantly higher in therapeutical procedures (3.76%) than in diagnostic catheterizations (1.76%). Factors associated with a significantly higher incidence of local vascular complications were age (p < 0.01), female gender (p < 0.025), manifest arterial hypertension (p < 0.005), aortic regurgitation (p < 0.1), peri-interventional medication with acetylsalicylic acid and full dose heparin (p < 0.001), full dose heparin alone (p < 0.001) or fibrinolysis-therapy (p < 0.025). Relevant technical factors were: duration of the procedure, duration of the placement of the catheter-sheath, French size of the catheter, left femoral access, arterial and venous access at one extremity. In about half of the cases the treatment of the complications was conservative, in the other half it was surgical (51%). In relation to all surgically treated patients the percentage of emergency operations was 25%, the percentage of reoperations was 15%.

Adult↗

Sialyltransferase activity in tumor tissues.

Sialyltransferase (ST) activity was examined in tumor and control tissues. Within each group of control tissues a wide variation in the levels of ST activity was observed. Only in 20% of the tumors was the ST activity above the range of enzyme activity of the corresponding group of control tissues. Compared with its corresponding normal counterpart from the same individual, ST was elevated in tumor tissue by a factor of 2.1 on average. The distribution function indicates an increase in enzyme activity in 74% of the tumors. Other tumor markers were also determined for comparison. The ratio of the lactate dehydrogenase (LDH) subunits (M/H) was increased in tumors by a factor of 1.3 on average; the frequency of increase was 75%. From the distribution function of our data it follows that a decrease in the ratio of the creatine kinase (CK) subunits (B/M) occurs in 56% of tumors, the average factor being 0.8. The Regan isoenzyme of the alkaline phosphatase (AP) could be demonstrated in 13% of the tumors. In serum and in tissues ST was found to be composed of multiple forms. However, an isoenzyme of higher tumor specificity has not yet been established.

Alkaline Phosphatase↗

Serum-sialyltransferase activity in cancer patients.

Serum-sialyltransferase activity was measured in serum samples of 116 patients with malignant tumors of various origins and different clinical stages using asialo-fetuin as the acceptor and cytidine-5'-mono-phospho[14C]sialic acid as the donor. Only patients with metastatic tumors had significantly elevated serum-sialyltransferase levels. Increased enzyme activity was also associated with rheumatoid arthritis and with acute hepatitis, whereas no significant alteration of enzyme activity was observed in cystic fibrosis patients. In a group of tumor patients, various additional tumor markers were determined (carcinoembryonic antigen, alkaline phosphatase: Regan isoenzyme, creatinekinase: BB-isoenzyme, lactatedehydrogenase: isoenzyme 5) and the data compared to the clinical diagnoses. The sensitivity and specificity of serum-sialyltransferase as a tumor marker is assessed.

Alkaline Phosphatase↗

[Analysis of sialyltransferase activity in human serum (author's transl)].

The activity of sialyltransferase in human serum was determined by a radiochemical assay with desialylized fetuin as acceptor. The precision of this method proved to be low. The effect of storage, temperature, concentration of hydrogen ions and other substances was investigated. As at least 5 pH-optima were found, multiple forms of sialyltransferase may well exist in serum.

Blood Preservation↗