[The early bicycle ergometry test in drug-stabilized patients with unstable angina pectoris--the correlation with coronary angiography]. / Ranen veloergometrichen test pri medikamentozno stabilizirani bolni ot nestabilna angina pectoris--korelatsiia s koronarnata angiografiia.

The relation between the results of the early submaximal symptom-limited bicycle ergometry [correction of veloergometric] test and coronary angiography were examined in 127 patients with unstable angina pectoris stabilized by medicaments. In 19 (15.0%) patients the test was negative and in 108 (85%) patients the test was positive (angina pectoris and/or ST depression greater than or equal to 0.1 mV at 80 ms after the point J of the ECG). Between the results of the early bicycle ergometry [correction of veloergometric] test and the coronary angiography, performed soon after the test, there was a close correlation. By using strict criteria or a combination of criteria for assessment of residual ischemia the test can with great accuracy differentiate the patients with multivascular from those with monovascular disease or with healthy coronary vessels.

[Prevention of ruminal acidosis during the intensive fattening of weanling lambs]. / Profilaktika na turbukhovata atsidoza pri intenzivno ugoiavane na shileta.

Forty-eight intensely fattened weaned lambs, divided into 2 groups were used to test the prophylactic effect of lasalocid with regard to rumen acidosis. The animals were offered complete mixtures ad libitum, containing 80 per cent concentrates and 20 per cent cut meadow hay. The weaned lambs of the test group were given the preparation "Avatek' (with 15 per cent lasalocid) in the course of 60 days with the feed at the rate of 250 g per ton of the complete mixture. Periodic biochemical and hematologic investigations on the animals of the two groups were carried out, following up their body development. The animals of the test group showed higher level of alkaline reserves, volatile fatty acids, and pH values of the rumen content and lower level of lactic acid in the blood and rumen liquid. By the 45th day of the experiment certain changes in the biochemical indices took place (rise of lactic acid and drop of alkaline reserves) as well as arrest of the weight development in the test animals. The average daily gain of the test group over the entire experimental period was 7.74 per cent higher than that of the control animals.

Influence of acute hemodynamic changes on the peak velocity of contractile element shortening and maximum velocity obtained by the calibrated apex cardiography in dogs.

The effect of various alterations in preload, afterload and inotropic state of the left ventricle on the noninvasive peak velocity of contractile element shortening (Vpm) and maximum velocity of contractile element shortening (Vmax) was studied in the anesthetized dogs in an attempt to test the methods and clarify some of the determinants of these parameters. Calibrated displacement left apex cardiogram obtained with time constant 3 sec and calibrated first derivative of apex cardiogram were recorded simultaneously with left ventricular pressure and its first derivative, electrocardiogram and phonocardiogram. The values of Vpm obtained from catheterization and calibrated apex cardiography were similar in magnitude and standard deviations under various hemodynamic interventions. A highly significant relation was found between these invasive and noninvasive parameters of myocardial contractility. Both Vpm and Vmax were elevated during the administrations of isoprenaline and strophanthin, where only Vpm showed a decrease after extreme volume or pressure load. In conclusion, the results from this study suggest that Vpm and Vmax of the calibrated apex cardiography are a reliable noninvasive tool for assessing left ventricular function; furthermore, Vpm is relatively load independent, whereas Vmax is virtually unchanged over a broad range of loading conditions.

Influence of acute hemodynamic changes on the negative peak of the first derivative of apex cardiogram during ventricular relaxation in dogs.

The effect of various alterations in the preload, the afterload and the inotropic state of the left ventricle on the first derivative of apex cardiogram (dA/dt) was studied in 9 anesthetized dogs to clarify some of the determinants of the negative peak of dA/dt and isovolumic relaxation time. The first derivative of the apex cardiogram was recorded simultaneously with the left (ventricular pressure, conventional left apex cardiogram, first derivative of left ventricular pressure (dP/dt), electrocardiogram and phonocardiogram. Both dA/dt and dP/dt curves were similar in contour and occurred nearly simultaneously. This close relationship was preserved during various acute haemodynamic changes. The maximum negative dA/dt and the isovolumic relaxation period was closely related to the level of afterload. Large rapid augmentation of mean aortic pressure resulted in a significant increase in the negative dA/dt and shortening of the isovolumetric relaxation time, where reduction of afterload had an opposite effect. Isoprenaline acutely augmented minimum dA/dt. It is concluded that measurement of negative peak dA/dt under some conditions is a reliable noninvasive technique for assessing myocardial relaxation.

Influence of acute hemodynamic changes on the negative peak of the first derivative of apex cardiogram during ventricular relaxation in dogs.

The effect of various alterations in preload, afterload and inotropic state of the left ventricle on the first derivative of apex cardiogram (dA/dt) was studied in the anesthetized dogs, in an attempt to clarify some of the determinants of the negative peak of dA/dt and isovolumetric relaxation time. First derivative of apex cardiogram was recorded simultaneously with left ventricular pressure, conventional left apex cardiogram, first derivative of left ventricular pressure, electrocardiogram and phonocardiogram. Both dA/dt and dP/dt curves represent similarity in contour and were found to occur nearly simultaneously. This close relationship was preserved during various acutely hemodynamic changes. Maximum negative dA/dt and isovolumic relaxation period was closely related to the level of afterload. Large rapid augmentation of mean aortic pressure did results in statistically significant increase of negative dA/dt and shortening of isovolumic relaxation time, where reduction of after load had an opposite effect. Another interventions, which acutely augment min dA/dt was nitroprusside and isoprenalin. It is concluded, that negative peak dA/dt under some conditions provides a reliable noninvasive index for assessing myocardial relaxation.

A natural focus of infection with leptospires of the serovar lora in Bulgaria.

A natural focus of infection with leptospira serovar lora (Australis serogroup) was discovered in the Tundga River Valley, South Bulgaria. 1 672 micromammals belonging to seven species were investigated. Serologically and bacteriologically a high incidence of infection was established.

[Effect of pyrogenes on the activity and isoenzyne spectrum of lactate dehydrogenase in tissues and blood serum of guinea pigs].

It is established that 2,4 DNP effect produces no changes in the total activity of lactate dehydrogenase (LDH, EC 1.1.2.3) in the heart, liver and blood serum of guinea pigs. Under the effect of lipopolysaccharide obyained from Bact. alkaligenes faecalis it increases in the liver and heart. A change in the isoenzymic spectrum is characterized bt a decrease in the LDA3, LDH4, LDH5 activity in the blood serum, an increase in the activity LDH1, LDH2 and a decrease in the LDH4, LDH5 in the myocardium, disappearance of LDH, in the liver under the effect of bacterial lipopolysaccharide. Under the effect of 2.4 DNP the activity of LDH3 in the liver increases and that of LDH3 DECREASES.