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Biomedical subjects

B Colla

Publications and source records attributed to B Colla.

26 records · Page 2Linked to original sources
PubMed1975

[The use of computers in the exercise of electrocardiography (author's transl)].

The use of computers in the exercise of electrocardiography is considered. The problems related to this use concern the choice of leads, the filtration of the signal, the recognition of characteristic segments of ECG, the calculation of various indexes and their statistical evaluation for diagnostic purposes. The authors use a bipolar derivation filtered by averaging and digital filters. The characteristic points of ECG are recognized by the analysis of the curvature. The Tchebycheff coefficients of the S-T tract are evaluated; they appeared to be a very good means for judging positive and negative cases.

Cardiac Output↗
PubMed1975

[The influence of pre-load on myocardial contractility indices. Experimental research (author's transl)].

The behaviour by increasing the ventricular volume of several parameters and indices proposed for measuring the cardiac contractility has been determined in isolated guinea pig hearts beating under isometric conditions. Particularly, V max calculated on the total pressure has been compared with the Vmax calculated on the developed pressure. Whilst the later showed to be independent of preload changes, Vmax was calculated on the total pressure, decreased by changing the ventricular volume. Moreover, it showed itself to be independent of pre-load changes. An index proposed recently obtained from the plot (P, P'), as ratio between the positive portion of the area and the developed sistolic pressure wals also demonstrated.

Animals↗
PubMedDate not supplied

Cardiovascular effects induced by the injection of a new nonionic contrast medium (Iopamidol): experimental study in dogs.

The hemodynamic effects induced by the injection in the pulmonary artery of the new nonionic water soluble contrast medium Iopamidol were compared with those obtained by the injection of two other currently used contrast media (meglumine diatrizoate and sodium iothalamate). The experiments were carried out in nine mongrel dogs. Hemodynamic variables were continuously measured prior to, during, and for 8 minutes after injection of the contrast media. Injections of iopamidol produced significantly smaller decreases in aortic pressure (p less than 0.01), contractile indices (p less than 0.01), and peripheral resistances (p less than 0.01), and changes in heart rate and in cardiac output were less pronounced. At 3-4 minutes after injection, an increase in Vmaxd was observed with all three contrast media, but it was significantly lower after injecting Iopamidol. The role of hyperosmolality in causing cardiovascular changes is discussed. The less significant changes induced by Iopamidol appear to be the result of its lower osmolality, which is about a third that of meglumine diatrizoate or sodium iothalamate.

Animals↗