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Biomedical subjects

J Vidal

Publications and source records attributed to J Vidal.

At least 415 records · Page 23Linked to original sources
PubMedDate not supplied

[Electrophysiological studies in permanent atrial paralysis].

Permanent atrial paralysis is a very rare entity characterized by absence of electrical and mechanical activity of the atria which persists for months or years. We present a patient with congestive cardiomyopathy and chronic atrial paralysis. The phonomechanocardiographic study confirmed the absence of mechanical contraction of the atrium and did not show atrial electrical activity in the superficial electrocardiogram nor in the intracavitary tracing. In the electrophysiological study of the biopsy of the atrial myocardium an unexcitable tissue was found with an important diastolic despolarization of 30 mv. The histologic and ultrastructural studies showed nonspecific changes, with the replacement of the myocardial cells by fibrous tissue.

Heart Atria↗
PubMedDate not supplied

[Mechanisms of conduction disorders in digitalis poisoning].

Ever since the first papers on the mechanism of the arrhythmias of digitalis were first published, during the first two decades of this century, the issue has been a controversial one. Since the automaticity induced by digitalis intoxication has different characteristics when compared to normal automaticity, it has been suggested that probably the mechanisms for these two types of spontaneous activity are different. It has been recently proposed that the automaticity induced by digitalis intoxication could be secondary to the after potential oscillations described in isolated conducting fibers. In order to test this hypothesis we used two experimental models which allow for a careful analysis of the ectopic activity, without the interference of the sinus rhythm. These studies were done in two groups of animals: one, with electrically isolated atria, was used to analyze supraventricular arrhythmias. The other, with chromic atrioventricular block, was used to study ventricular arrhythmias. The results obtained from these experiments show: 1. High therapeutic doses of digitalis enhance the postpacing inhibition of normal pacemakers; 2. When the ectopic rhythms of digitalis intoxication appear, they show postpacing stimulation; 3. Ectopic activity shows a direct relationship with the rate of the conditioning stimulation, and both the coupling period and the number of premature beats depend on this rate. In view of the similarity between the behavior of these arrhythmias and that of the after potential oscillations, we conclude that these oscillations are responsible for the ectopic automaticity of digitalis intoxication.

Animals↗
PubMedDate not supplied

[Helicoid ventricular tachycardia, torsade de pointes, in acute myocardial infarction].

Helicoidal ventricular tachycardia (Torsades de Pointe), (HVT) is an arrhythmia with peculiar characteristics and therefore should be individualized. The occurrence of HVT during acute myocardial evolution has been denied by many authors. In this paper, the possibility that this association may be not only coincidental is analyzed. A group of 1,307 patients with acute myocardial infarction was studied, in 29 of them this arrhythmia was detected in the first 72 hours and these patients didn't have an associated disease and/or treatment related to HVT. This represents an incidence of 2.22% in this group. The helicoidal ventricular tachycardia had a peculiar behavior, different to the one found in HVT of other etiologies. It was triggered by early premature ventricular beats, it was found even in cases with supraventricular tachycardia and acute atrio--ventricular heart block, very seldom is autolimited and usually degenerates into ventricular fibrillation, the most important factor in association with this arrhythmia is QT prolongation. Intracavitary pacing is the treatment of choice.

Adult↗
PubMedDate not supplied

[Effect of hypoxia on atrio-ventricular conduction in severe respiratory insufficiency].

The role of hipoxia on A-V conduction was studied in the patients with severe respiratory insufficiency. Intervals of A-V conduction were measured under basal conditions, breathing room air and with increasing atrial rates. Results are compared with those obtained after the administration of 99% oxygen. A-V conduction times were normal in all the patients while breathing room air and in response to atrial pacing. With oxygen administration most patients had a decrease in A-V conduction at the expense of a prolonged A-H time, without significant alteration of the other time intervals. A-V conduction in chronic hipoxia with a PaO2 above 28 mm Hg is not delayed. Intranodal conduction delay with oxygen administration may be due to a decrease in sympathetic nerve stimulation.

Aged↗
PubMedDate not supplied

Surgical reduction of spondylolisthesis using a posterior approach.

In 26 cases, spondylolisthesis was reduced and stabilized by an intervertebral graft in a new one-step surgical procedure. A critical review of various techniques presently in use illustrates the evolution of the one-stage operation. A most recent modification of the operation is open reduction and internal fixation by a combination of Harrington instrumentation and the posterior intervertebral arthrodesis of Cloward.

Arthrodesis↗
PubMedDate not supplied

Intracavernous pharmacotherapy for management of erectile dysfunction in multiple sclerosis patients.

Intracavernous self-injection of vasoactive drugs is a well accepted therapy for the management of erectile dysfunction in neurogenic disorders. We present the results of a self-injection program in seven MS patients who were admitted in Institut Guttmann of Barcelona and who presented with an insufficient erection. All patients showed an excellent erectile response and had penile rigidity sufficient for sexual intercourse during acceptable time, with minimal complications. A patient reported improvement of erectile capacity so as not to need another cavernously injection for 2-3 months.

Adult↗