Reproducibility of cardiopulmonary exercise parameters in patients with valvular heart disease.

STUDY OBJECTIVES: To determine the degree of reproducibility of exercise parameters in patients with chronic heart failure. Parameters such as treadmill walking time (TWT), oxygen uptake (Vo2), heart rate, oxygen pulse, minute ventilation (VE) ventilatory equivalents for oxygen uptake (VE/Vo2) and carbon dioxide output (Vco2), and respiratory quotient at both anaerobic threshold (AT) and peak exercise (PE) each were assessed. DESIGN: Using the Naughton-Weber protocol, two repeated cardiopulmonary treadmill exercise tests were performed after detailed instructions prior to the first test and on strict adherence to standardized investigational conditions, viz, at the same time of day and at the same ambient temperature, receiving constant medication, and while in a 12-h fasting state. PATIENTS: The studies were carried out in 17 patients with chronic heart failure due to valvular heart disease considered candidates for intervention because of symptoms. According to Weber's classification of functional capacity, 10 patients were in class A (Vo2 max > 20 mL O2/min/kg), 5 patients were in class B (16 to 20 mL O2/min/kg), and the remaining 2 were in class C (10 to 16 mL O2/min/kg). MEASUREMENTS: Parameters assessed were TWT, Vo2, heart rate, oxygen pulse, VE and ventilatory equivalents for oxygen (VE/Vo2) and carbon dioxide (VE/Vco2) both at AT and at PE. To reflect reproducibility, correlation coefficients (r) were calculated. RESULTS: An excellent reproducibility was found for TWT (r = 0.963, p < 0.0001), Vo2 at AT in percent of predicted Vo2max (r = 0.984, p < 0.0001), Vo2 at PE (r = 0.996, p < 0.0001), heart rate at AT (r = 0.943, p < 0.0001) and at PE (r = 0.928, p < 0.0001), oxygen pulse at AT (r = 0.980, p < 0.001) and at PE (r = 0.991, p < 0.0001), VE at AT (r = 0.949, p < 0.0001) and at PE (r = 0.912, p < 0.0001) as well as VE/Vo2 at AT (r = 0.942, p < 0.0001) and at PE (r = 0.781, p < 0.0002) and VE/Vco2 at AT (r = 0.995, p < 0.0001) and at PE (r = 0.943, p < 0.0001), respectively. CONCLUSIONS: On adherence to standardized conditions, an excellent reproducibility existed for TWT, Vo2 (reflecting cardiac output), ventilation, and heart rate as well as derived parameters, rendering cardiopulmonary exercise testing a reliable means of quantification of heart failure as a prerequisite for enabling diagnostic or therapeutic decisions.

Acute alterations of oxygen uptake and symptom-limited exercise time in patients with mitral stenosis after balloon valvuloplasty.

STUDY OBJECTIVES: To determine the acute influence of improvement in orifice area in mitral stenosis by percutaneous transluminal valvuloplasty (PTVP) on cardiopulmonary exercise capacity, treadmill walking time (TWT), oxygen uptake parameters at maximum exercise as well as at highest comparable workloads and parameters of breathing work were assessed pre- and post-PTVP. PATIENTS AND INTERVENTIONS: PTVP was carried out in 16 patients who had moderately severe mitral stenosis, bringing about an average increase in mitral valve orifice area from 1.0 +/- 0.1 cm2 to 2.2 +/- 0.5 cm2 (p < 0.0005). Based on standardized conditions, the patients (six in functional class A, five in class B, and five in class C according to Weber's classification) underwent symptom-limited treadmill cardiopulmonary exercise testing before as well as 2 days after PTVP. In addition, subgroup analysis (eight patients in sinus rhythm, eight patients in atrial fibrillation) was performed to determine a potential influence of the underlying cardiac rhythm on cardiopulmonary exercise parameters. To rule out a PTVP-independent training effect, a control group of ten patients with mitral stenosis underwent the same kind of cardiopulmonary exercise testing on 2 consecutive days. MEASUREMENTS AND RESULTS: After-PTVP, TWT augmented by 19% (p < 0.0005) in all patients. Maximum oxygen uptake in percent of predicted maximal values at peak exercise and at anaerobic threshold was enhanced by 10% (p < 0.005). Ventilation at highest comparable workload was diminished by 10% (p < 0.025), whereas oxygen uptake and oxygen pulse at highest comparable workload did not differ, reflecting both unaltered cardiac output at comparable workloads and a more economic ventilation, respectively. Furthermore, PTVP-mediated alterations of TWT, but not of oxygen uptake at peak exercise were more pronounced in patients in sinus rhythm than in those in atrial fibrillation, reflecting more effective economization of cardiac work and ventilation in the former subgroup. Except for a statistically significant increase of TWT of 5%, no clinically relevant differences between both exercise tests were found with respect to oxygen uptake in the control group. CONCLUSIONS: Impaired cardiopulmonary fitness in patients with moderately severe mitral stenosis is improved substantially by PTVP immediately after the intervention, mainly the result of acute reduction of pulmonary congestion and subsequent decrease in dead space to tidal volume ratio. Adherence to standardized conditions is considered crucial for comparability of cardiopulmonary data.

[The ionized calcium in the blood of domestic chickens: dependence on age and sex]. / Das ionisierte Calcium im Blut des Haushuhnes: Abhängigkeit von Alter und Geschlecht.

In the present study concentration of ionized calcium and the correlation between total and ionized calcium in blood of domestic fowl and its dependence on age and sex were investigated. Furthermore a possible influence of blood sampling procedure on the measured values was assessed. Leghorn chickens of either sex, aged 3, 9, 25, and 80 weeks, respectively, were used. Blood sampling was performed by vein-puncture and indwelling catheters, respectively, of both ulnaris vein and artery of animals which had been fasting for 12 hours. Determinations of ionized calcium concentration was carried out by use of an ion-selective electrode (ICA1), and of total calcium concentration in plasma using atomic absorption, respectively. After attainment of sexual maturity total calcium in roosters rose from 2.73 to 2.85 mmol/l, whereas ionized calcium fell from 1.45 to 1.40 mmol/l and per cent fraction of ionized/total calcium (extent of ionization) from 53.1 to 49.1%, respectively. After attainment of sexual maturity in hens, the content of total calcium in venous blood rose from 2.78 to 5.78 mmol/l, and of ionized calcium from 1.45 to 1.59 mmol/l, respectively, whereas the extent of ionization was significantly reduced from 52.2 to 27.1%. On comparison of the vein-puncture and indwelling catheter technique a marked influence of the blood sampling procedure on calcium concentrations measured in blood of chicken became evident. On attainment of sexual maturity both the arterial and the venous blood (sampled from indwelling catheters) of hens showed levels of ionized calcium about 8% higher as compared to roosters. The extent of ionization amounted to 39% in sexually mature females as opposed to 51% in males. Concentrations of calcium ions in venous blood averaged 0.07 to 0.08 mmol/l higher compared to arterial blood in either sex. Concentration of ionized calcium did not exhibit any correlation to total calcium in adult animals. However, the concentration of ionized calcium was inversely correlated to blood pH.

[The ionized calcium in the blood of domestic chickens: dependence on the laying cycle]. / Das ionisierte Calcium im Blut des Haushuhnes: Abhängigkeit vom Legezyklus.

In the present study the plasma concentration of both ionized and total calcium in arterial as well as in venous blood of Leghorn hens and its dependence on the ovulatory cycle were investigated. During the ovulatory cycle, the concentration of ionized calcium in blood of hens follows the course of a sine curve. Maximum calcium ion concentrations (1.58 mmol/l in venous blood and 1.48 mmol/l in arterial blood, respectively) were observed 3 to 6 hours after oviposition, and minimum concentrations (1.26 and 1.19 mmol/l, respectively) at 18 to 21 hours after oviposition. Changes in total and ionized calcium concentration went parallel. Six to 9 hours after oviposition maximum values (4.24 and 4.15 mmol/l respectively) and 21 to 24 hours after oviposition minimum values (3.25 and 2.99 mmol/l, respectively) were measured. The arterio-venous difference was -0.22 mmol/l on average.

[The ionized calcium fraction of the blood: dependence on different methodical factors]. / Die ionisierte Calciumfraktion des Blutes: Abhängigkeit von verschiedenen methodischen Faktoren.

In the present study the influence of different methodical factors (analyzer with ion-selective electrodes used, anticoagulation of blood samples with heparin, storing of samples at different temperatures) on the concentration of ionized calcium in blood was investigated. It could be shown that nowadays' systems for analysis of ionized calcium (ORION SS-20, AVL 980, NOVA 2 and 8, ICA 1) yield reproducible values for human as well as canine blood. System-related differences point to a varying degree of interferences on the ion-selective electrodes used. The concentration of ionized calcium is strongly dependent on different preanalytic factors. Heparin leads to a concentration-related reduction of calcium ions in blood. This negative impact of heparin can be overcome by substitution of the solvent for CaCl2 (2.5 mmol.l-1) without meaningful falsification of the measured values. At 4 degrees C blood samples can be stored without detectable changes in Ca++ concentration for 8 hours.

[A contribution to the rate of side-effects of hepatotropic contrast media. A clinical comparative study of iodoxamate (Endomirabil) and ioglycamid (Bilivistan) (author's transl)]. / Beitrag zur Nebenwirkungsrate hepatotroper Kontrastmittel. Klinische Vergleichsuntersuchung von Iodoxamat (Endomirabil) und Ioglycamid (Bilivistan)

The new substance Iodoxamate (Endomirabil) is a hepatotropic contrast medium. In a clinical comparative study, the contrast of the biliary ducts and gall bladder is equivalent compared with Ioglycamid (Bilivistan). Assuming equal conditions of injection and in conformity with animal experimental studies, the rate of side effects of Iodoxamate is distinctly lower than that of the referring substance Iolgycamid (Bilivistan).

The effect of motilin on the electrical activity of rabbit circular duodenal muscle.

The effect of 13-norleucine motilin on electrical activity and membrane resistance of the rabbit circular duodenal muscle was studied with intracellular recording techniques. Electrical slow waves without spikes occurred in Krebs solution made twice hypertonic by addition of sucrose. The slow waves were basic organ specific type rhythm (BOR). Their mean frequency was 18.1.min-1, the mean amplitude from trough to peak was 11.4 mV and mean membrane potential during the trough was -59.1 mV. Motilin (1.10(-7) g/ml) had the following effects: (1) The membrane depolarized by a mean of 10.9 mV. (2) Membrane resistance was reduced. (3) The BOR slow waves were either reduced or abolished. (4) Slow fluctuations of membrane potential characteristic of a minute-type rhythm (MR) appeared. (5) Trains of spikes occurred at the crests of the MR and were associated with contraction of the muscle.

[A comment on the article by Taenzer, V., et al.: Intravenous cholegraphy with Chologram(R), Fortschr. Röntgenstr. 123 (1975) 414]. / Intravenöse Cholegraphie mit Chologram

A comparison of the results published by Taenzer et al. shows: 1. The contrast value of the new hepatotropic substance Iotroxamid (Chologram) in man is of the same order as the previously available contrast media Bilivistan and Biligram (Ioglycamide) 2. The reputedly improved tolerance of the new substance should be confirmed in a more extensive clinical material under the stated conditions. 3. The question whether Chologram permits greater flexibility with regard to the timing of the examination must also remain open for the present.