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Biomedical subjects

G Ferro

Publications and source records attributed to G Ferro.

At least 109 records · Page 6Linked to original sources
PubMed1979

[Anti-arrhythmic effect of magnesium cations. Protection against ventricular excitability during cardiotonic therapy].

This study showed the effectiveness of magnesium sulphate during digitalis therapy complicated by ventricular hyperexcitability. 28 patients with cardiac disease and ventricular arrhythmias in heart failure were studied. Magnesium sulphate was given by slow intravenous infusion (30--50 mg/min) twice daily. The anti-arrhytmic action allowed treatment with digitalis until improvement in cardiac function was observed. The mechanism of the action of magnesium sulphate in digitalis--induced arrhythmias is discussed.

Anti-Arrhythmia Agents↗
PubMed1978

Relation between cholinergic and histaminergic components in reflex vasodilatation in the dog.

Previous studies have shown that phentolamine is able to reverse the reflex vasodilatation produced by transitory baroreceptor stimulation by blocking sympathetic, histaminergic, and cholinergic components. A direct anticholinergic action of phentolamine has never been described; however, since it is known that this drug is capable of inhibiting histamine release during the reflex vasodilatation, it is possible that its ability to block the cholinergic component of the reflex is related to the latter property. Therefore, this study was undertaken in an attempt to identify possible relationships between cholinergic and histaminergic components of the reflex vasodilatation. Accordingly, in mongrel dogs the gracilis muscle was isolated and perfused and then loaded with 14C-labeled histamine. A transitory systemic hypertension was induced by intravenous injection of norepinephrine; this produced a reflex vasodilatation, shown by the fall in perfusion pressure, which was accompanied by an increase of histamine release from the muscle. Vagal block induced by atropine pretreatment reduced the fall in perfusion pressure induced by the systemic hypertension and produced a reduction of histamine release during the vasodilatation. In another group of animals a vasodilatation in the perfused muscle was induced by injection of acetylcholine. This response was accompanied by an increase in histamine release from the gracilis muscle. Alpha-receptor blockade, which has been shown to inhibit histamine release, reduced this acetyl-choline-induced vasodilatation. These results, while confirming the participation of the cholinergic system in the reflex vasodilatation elicited by transitory stimulation of the arterial baroreceptors, seem to demonstrate that this component is mediated almost exclusively by histamine release.

Acetylcholine↗
PubMed1978

Correlation between systolic time intervals and roentgen findings in normal subjects and cardiopathic patients.

This study was designed to evaluate the usefulness of non-invasive parameters in the follow-up of cardiopathic patients without valvular cardiac diseases. In 49 patients suffering from heart disease we have studied the changes of radiologic cardiac measurements and systolic time intervals (STI) in the 4 functional classes of the NYHA classification, investigating also the existence of any relationship between these different parameters. Only the patients in the 3rd and the 4th functional classes showed significant changes in STI and radiologic measurements, as compared with the control group. Moreover, significant negative correlations have been observed between relative heart volume and LVET (r = 0.69, P less than 0.001) and LVETc (r = 0.82, P less than 0.001) and positive correlations between relative heart volume and PEP (r = 0.59, P less than 0.01) and PEP/LVET ratio (r = 0.75, P less than 0.001). These results, while confirming the close correlation between STI and cardiac performance, seem to demonstrate that relative heart volumetry is a fairly accurate index of the cardiac conditions in non-valvular heart diseases.

Adult↗
PubMed1978

[The short PR syndrome: sino-atrial block with preservation of sino-nodal conduction].

From among the theories which have been advanced to explain the finding on ECG of a shorter than normal PR interval, in addition to the short circuit theory we should mention the explanation given by Condorelli before the first publication on the "short PR-normal QRS" syndrome appeared. While studying the mechanism of conduction of a stimulus in the atrial myocardium, he showed that a short PR may result from a conduction defect in the sino-atrial pathways, while sino-nodal conduction remains normal. In this report there is an example which supports the validity of Condorelli's hypothesis. It involves a female patient with mitral valve disease beginning to affect the tricuspid. Her rheumatic disease had just relapsed, and after this there was a long period of attacks of tachycardia with arrhythmia during the course of which the surface electrocardiogram showed a short PR and normal QRS. Electrophysiological investigations allowed us to interpret these findings in the light of Condorelli's hypothesis (sino-atrial block with normal sino-nodal conduction). This study suggests that it is useful to separate off those cases with a short PR and normal QRS to a clinical entity of their own, as this syndrome may have a different pathogenesis. Therefore, if there is no electrocardiographic evidence of an accessory pathway, far from indicating accelerated conduction, the short PR may be due to an isolated defect of conduction in the atrial myocardium, as Condorelli suggested. It is also correct that this author should be given credit for describing the first cases. To him also should go credit for first describing the short PR.

Adult↗
PubMed1978

[Permanent atrial paralysis].

A case is described of permanent atrial paralysis in a 68 year old female with diabetes and cirrhosis of the liver. Absence of electrical atrial activity was expected on the standard electrocardiogram, and confirmed by intracavitary electrophysiological investigation which showed the ineffectiveness of stimulation of both the right atrium and the coronary sinus. Recording of the His potentials showed that the resultant rhythm was of supra-ventricular origin. The absence of mechanical atrial activity was confirmed radiographically, on the jugular venogram, on the apexogram, and on the tracings of right atrial and pulmonary capillary pressure. A search was made for muscular or neuromuscular dystrophy which has often been found in association with this arrhythmia, but none was found. There may be an etio-pathological relationship between carbohydrate metabolism and atrial paralysis, as certain authors have suggested.

Aged↗
PubMed1978

[Usefulness of x-ray parameters in the functional evaluation of patients with nonvalvular cardiopathies].

In 49 patients suffering of heart diseases we have studied the changes of radiologic cardiac measurements and systolic time intervals (STI) in the four functional classes of the New York Heart Association (NYHA) classification, investigating also the existence of any relationship between these different parameters. Only the patients in functional classes 3rd and 4th showed significant changes in STI and radiologic measurements as compared to the control group. Moreover, a significant negative correlation has been observed between relative heart volume and left ventricular ejection time (LVET) (r = 0.69, P less than 0.001) and LVETc (r = 0.82, P less than 0.001) and a positive correlation between relative heart volume and pre-ejection period (PEP) (r = 0.59, P less than 0.01) and PEP/LVET ratio (r = 0.75, P less than 0.001). These results seem to demonstrate that relative heart volumetry is a fairly accurate index of the cardiac conditions in non valvular heart diseases.

Adult↗
PubMed1977

Myocardial contractility after injection of prolonged infusion of magnesium sulphate.

The effect of magnesium sulphate administration on myocardial inotropism has been evaluated by means of the noninvasive indexes of myocardium contractility in 18 patients affected by myocardiosclerosis associated with signs of cardiac impairment of different degree. Magnesium has been administered via either a prolonged infusion (30-50 mg/min) or a single injection (2.5 g/30 sec). It is emphasized that the influence of this agent on systolic time intervals (STI) is dependent upon its route of administration. Thus, prolonged infusion does not modify significantly these parameters, whereas a single injection induces marked variations, i.e., decrease of LVET, increase of PEP, ICT and PEP/LVET ratio, which are all more marked in cases of severe cardiac impairment. In view of the strict correlation established between the STI and the invasive indexes of myocardial contractility, it is suggested that administration of magnesium sulphate via prolonged infusion does not induce a decrease of cardiac performance, while a single injection of this agent leads to this effect.

Arrhythmias, Cardiac↗