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Biomedical subjects

C Luca

Publications and source records attributed to C Luca.

At least 37 records · Page 2Linked to original sources
PubMed1976

Ventricular activity during atrial fibrillation. Studies with His bundle electrography.

His bundle electrograms were recorded in 12 patients with atrial fibrillation. In all cases but one, the dominant rhythm was atrial fibrillation. In 1 case the dominant rhythm was fascicular tachycardia due probably to digitalis overdosage. However ventricular, fascicular and junctional beats could be often recognized on His bundle tracings, even when QRS configuration was similar to supraventricular conducted beats due to atrial fibrillation. In the patients in whom sinus rhythm occurred, the H-V interval was unchanged. Although it is admitted that during atrial fibrillation the zone of concealment of A-V conduction is in the A-V nodal area, concealed penetration of atrial impulses in the fascicular system may be encountered in patients not treated with digitalis.

Adult↗
PubMed1976

Recurrent ventricular tachycardia due to reentry within the bundle branches.

A case of recurrent ventricular paroxysmal tachycardia in a young man without obvious heart disease is described. Posttachycardiac T-wave inversion followed the arrhythmic episodes. Programmed stimulation of the heart in association with intracardiac recordings showed evidence in favor of reentry within the bundle branches and its divisions during tachycardia. A critical prolongation of the H2-V3 interval preceded each paroxysm of tachycardia.

Adolescent↗
PubMed1976

[Effects of lidocaine on supraventricular arrhythmias (author's transl)].

Using Lidocaine intravenously in 99 patients with atrial arrhythmias, it was observed that the drug has a regularising effect in 41 from 45 atrial arrhythmia, atrial tachycardia with block and accelerated ectopic supraventricular tachycardia, where the enhanced focal activity should be taken into account. No effect was observed in functional supraventricular tachycardia, paroxysmal atrial flutter and fibrillation and tachyarrhythmia in WPW syndrome, where the re-entry mechanism plays the major role. The effect of the drug is short lived, but may be prolonged by using the drug in perfusion or repeatedly with an intramuscular method. Lidocaine acts by depressing the enhanced atrial focal activity, and therefore may be of value in the treatment of these kinds of arrhythmias.

Adolescent↗
PubMed1976

Monophasic action potentials of the right atrium during atrial fibrillation in man.

In 28 patients with established atrial fibrillation [AF], right atrial monophasic action potentials [MAP] were recorded before DC shock. A close correlation was found between the atrial rate and MAP duration of the fibrillatory waves [FW]. The duration of MAPs ranged between 1 and 6 mV. The atrial rate ranged between 311 and 578 per minute, the highest rates were found during lone AF. In two patients in whom cardioversion failed, a prolongation of right atrial MAP duration of the FW was noted. The efficacy of DC shock and the maintenance of sinus rhythm after cardioversion was greater in patients with AF having a slower rate and a longer MAP.

Adult↗
PubMed1976

Bidirectional tachycardia a study of five cases.

Five patients with bidirectional tachycardia due to digitalis toxicity associated with severe organic heart disease were studied. The origin of the abnormal rhythm was established with the aid of His bundle recordings in three cases and by indirect clues in the others two. In three cases the origin of bidirectional tachycardia was suprahisian while in two patients it was infrahisian. In one patient the transition from junctional to ventricular tachycardia could be observed. Bidirectional tachycardia appears to be a complex arrhythmia in which similar electrocardiographic configuration can be due to different mechanism. Digitalis toxicity was often a causal factor.

Aged↗
PubMed1976

Pseudo-retrograde conduction in complete A-V heart block due to ectopic His bundle activity.

A case with complete A-V heart block in whom retrograde P- waves following some of the ventricular complexes were due to an ectopic junctional activity with the characteristics of parasystole is reported. His bundle electrogram showed an infrahisian block. After administration of 1 mg atropine intravenously the retrograde P- waves were detached from the ventricular automatic complexes and an H' deflection preceded each inverted P- wave with an H'-A' interval of 40 msec.

Adult↗
PubMed1975

Right atrium monophasic action potentials during atrial flutter and fibrillation in man.

Monophasic action potentials recorded in two patients with atrial flutter and one patient with atrial fibrillation showed a nonuniform depolarization of the right atrial wall. In each of the two patients with atrial flutter, there was a site where two separate action potential deflections were recorded for each flutter wave. It was supposed that this was the site of re-entry for a cycling wavelet subsidiary to the main flutter wave. In the patient with atrial fibrillation, three types of electric atrial activity were found: regular activity at 180 per minute similar to that found in flutter, small irregular activity at a rate of 400 per minute, and a mixed type of the former two. The significance of these findings for the mechanism of atrial flutter and fibrillation is discussed.

Action Potentials↗
PubMed1974

Ventriculo-atrial conduction associated with ventricular premature beats. Study with his bundle electrography.

In a group of eight patients with ventricular premature beats, ventriculoatrial conduction, with retrograde activation of the His bundle and the atria could be demonstrated by His bundle electrograms in four subjects. All had early ventricular premature beats with coupling indices between 210 and 350 msec. In the other four cases, concealed retrograde conduction could be demonstrated in the A-V nodal area. The ventricular ectopic beats were late, and depending upon the refractory period of the A-V node these extrasystoles were interpolated or followed by compensatory pauses.

Adult↗