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Biomedical subjects

F Fillette

Publications and source records attributed to F Fillette.

35 records · Page 2Linked to original sources
PubMed1985

[Action of betaxolol on ventricular arrhythmias. Control of efficacy and tolerance by repetitive Holter recordings].

The ventricular anti-arrhythmic action of 20 mg of betaxolol per day was evaluated in 14 patients treated in monotherapy for a fortnight, by means of repeated Holter recordings. A significant decrease in the number of ischemic ventricular extrasystoles was observed during the diurnal and nocturnal periods. Repetitive ventricular events were also reduced. Betaxolol therefore appears to have a direct anti-arrhythmic action which is not related to its action on the heart rate. The other effects of beta-blocker treatment were also observed: a decrease in the systolic and diastolic blood pressure and sinus bradycardia.

Adrenergic beta-Antagonists↗
PubMed1985

[Electric activation of the heart using laser spectrometry. 1. Study of transmembrane action potentials using optical technics].

The action potentials of the contractile myocardium and conduction cells are usually recorded by intracellular glass microelectrodes but they call also be obtained at a distance and without physical contact by optical techniques. The myocardial fragment must be stained with a dye which, when illuminated by a laser beam, emits a fluorescence whose wave length is related to the transmembrane potential. The responses obtained were checked by microelectrode and optical techniques on several types of preparation (sheep myocardium, sheep Purkinje cells, mouse myocardium). The morphology of the action potential was identical by both methods; the beginning of phase 0 in particular was identical with both methods, eliminating any mechanical activity. Contraction appeared later, during the plateau phase of the action potential with a measurable interval corresponding to the excitation- contraction coupling time. Remote recordings of action potentials without physical contact with the preparation, should enable very accurate myocardium activation mapping using CCD video techniques.

Action Potentials↗
PubMed1984

[Elementary changes in the duration of successive sinus cycles; the concept of sinus extrasystole].

The authors studied the duration of successive sinus cycles in 35 patients confined to bed using a computerized system to trace graphs of heart rate (tachograms) with a resolution greater than +/- 2,5 ms due to precise detection of the upstroke of the R wave. A coupled visualization system excluded variations due to changes in the PR interval. Several types of modification were demonstrated: 1) slow fluctuations of high amplitude of the heart rate probably related to the autonomic nervous system or circulating catecholamines, 2) smaller variations of heart rate, from cycle to cycle with different forms of distribution: progressive increment or decrement over 3 to 4 cycles in 10 ms steps. This may be a system of intrasinus regulation for controlling variations of periods of 10 ms from one cycle to another. In both forms of distribution, the total amplitude of variation for a complete period of 3 to 4 cycles ranged from 30 to 75 ms. In some cases, sinus complexes were recorded with a prematurity of about 50 ms with respect to the preceding cycle and followed by an equivalent compensatory pause with respect to the last non-extrasystolic cycle. When the coupling interval of these premature complexes varied, the compensatory pauses remained unchanged. These results suggest a very precise system of control over the sinus rhythm, the mechanisms of which could be very varied: either cyclical variations of intrasinus conduction time from the same zone of automaticity to the atrium, or a sequential system of automaticity of slightly different frequencies obeying an unknown law; or again, electronic variations between two or more pacemakers of comparable frequency within the sinus node.(ABSTRACT TRUNCATED AT 250 WORDS)

Cardiac Complexes, Premature↗
PubMed1983

[Retrospective analysis of a series of 330 Holter recordings. Diagnostic value of the method and correlation with symptomology].

We have studied a series of 330 Holter recordings (HR) (including 5 double observations) 189 men and 136 women, mean age 58,4 years Old. The analysis of this series shows that: --105 HR were performed on patients with focal ischemia attacks of suputed embolic origin; the HRT was positive in 35 patients (33 p. 100) with 25 supraventricular arrhythmias (SVA) 16 ventricular arrhythmias, associated in 9 cases, and 3 conduction blocks second degrees type 2. These arrhythmias are rare in patients under 40, increasing with age, and reaching 53 p. 100 in patients greater than 70 years. --86 HR were performed in ischemic heart disease (IHD): 52 HR for ST segment analysis, positive in 5 cases, and coexisting with chest pain in 4 cases; 34 HR for detecting arrhythmias in IHD, positive in 18 cases with 14 VA and 4 SVA. In 83 p. 100 the arrhythmias occur without IHD. They were positive in 70 cases, with 49 SVA, 34 VA, associated in 17 cases, and 4 blocks second degrees type 2. --10 cardiomyopathies were recorded; the HR was positive in 6, with 4 SVA, 3 VA associated in 1 case. --8 mitral valve prolapses were recorded with 5 VA and 1 SVA. In conclusion, the HR was positive in 45 p. 100 of the cases, and show especially the great incidence of asymptomatic VA in patients with IHD.

Adolescent↗
PubMed1983

[Torsades de pointes initiated by slow ventricular stimulation].

The authors report a case of isolated and probably congenital complete heart block with spontaneous torsades de pointes preceded by an increase in the QT interval. During positioning of a temporary pacing catheter mechanically induced extrasystoles were observed, which seem to favor ventricular extrasystoles and unsustained runs of torsades de pointes. When the basal rhythm showed no extrasystoles, electrical stimulation delivered late in diastole captured the ventricle normally and was then followed in reproducible fashion by episodes of torsades de pointes or minor equivalents. The mechanism of this phenomenon is thought to be related to a concealed phase 4 intramyocardial block. It may have important practical consequences in paced patients predisposed to torsades de pointes. If the pacemaker is programmed at too slow a rate, with stimulation falling late in diastole, torsades de pointes could occur, some attacks of which are known to degenerate to true ventricular fibrillation.

Cardiac Pacing, Artificial↗
PubMed1982

[Arrhythmogenic right ventricular dysplasia and Uhl's disease].

Ventricular tachycardia with left bundle branch block appearance in adults without coronary artery disease may be due to arrhythmogenic right ventricular dysplasia. This condition forms part of a spectrum with the complete form of Uhl's anomaly at one end and arrhythmogenic right ventricular dysplasia at the other. Both conditions have similar histological appearances representing the same congenital defect but the macroscopic appearances are quite different. Arrhythmogenic right ventricular dysplasia seems to be a slowly progressive condition with one or more localisations in the right ventricle where the myocardium is replaced by adipose tissue with progression of lesions from the epicardium towards the endocardium. The subepicardial layers resemble a plexiform structure of partially degenerated myocardial fibres within fibro-adipose tissue. These fibres may be the site of slowing of activation and the anatomical basis of intraventricular reentry phenomena. A similar appearance is also found in UHl's anomaly, but the severe dilatation of the ventricle and almost complete absence of muscle fibres only leaves a few zones with surviving, partially degenerated myocardial fibres. Clinically, a cardiothoracic index of over 0.60 is more common in Uhl's anomaly whilst arrhythmogenic right ventricular dysplasia is usually associated with a normal cardiac silhouette or only slight cardiomegaly. The differential diagnosis is important if surgery is being considered. An appropriate technique must be chosen to avoid supraventricular arrhythmias which can lethal in patients with Uhl's anomaly.

Adolescent↗
PubMedDate not supplied

[Holter monitoring in patients with focal cerebral ischaemic attacks (author's transl)].

One hundred patients with focal cerebral ischaemic attacks of suspected embolic origin were investigated by Holter monitoring to determine whether paroxysmal arrhythmia may have been responsible for the episodes. There were 57 men and 43 women aged from 16 to 79 years (mean 50 years). Ninety-seven had residual focal neurological deficits and 3 had transient ischaemic attacks. The neurological lesions were verified by cerebral angiography in 68. Twenty-one had arterial hypertension and 9 had old myocardial infarction or angina. Nine had a history of palpitations. None had cardiac valve disease. All patients were in sinus rhythm, 4 had ventricular extrasystoles on routine ECG, and 4 had supraventricular extrasystoles. None of the patients were receiving anti-arrythmic drugs at the time of investigation. Holter monitoring was performed for 18 hours in 91 cases and for 24-54 hours in the remaining ones. The interval between the cerebral ischaemic attack and the monitoring was less than one month (mean 20 days) for 50 patients and longer for the others. Cardiac arrythmias were found in 36 patients. Sixteen had more than 10 supraventricular extrasystoles per hour, 13 had runs of 3 to 8 beats of supraventricular tachycardia, 1 had an episode of atrial fibrillation. Eighteen subjects had more than 5 ventricular extrasystoles per hour, 1 had accelerated ventricular rhythm, 2 had runs of 4 to 7 beats of ventricular tachycardia. Two patients had second degree A.V. block. None had palpitations during monitoring. Arrythmias were increasingly frequent with age. Our findings are similar to those obtained with monitoring in ambulatory asympatomatic subjects of the same age without apparent heart diseases reported by other authors. On the other hand, the frequency of arrythmia was unrelated to the time elapsed between the ischaemic attack and Holter monitoring. In conclusion, Holter monitoring performed several weeks after suspected cerebral embolism failed to reveal arrythmias likely to be responsible for a focal cerebral ischaemic attack.

Adolescent↗
PubMedDate not supplied

[Ventricular response in atrial fibrillation : normal conduction, consequences of conduction disorders and preexcitation syndromes. Therapeutic implications].

Atrial fibrillation is the most common arrhythmia in man. It is characterized by: 1) a rapid and irregular atrial electrical activity, 2) an irregular ventricular response which follows complex laws in the absence of advanced disorder of atrio-ventricular conduction. The study of these laws of complex transformation which govern the ventricular response can be approached by histograms of the RR interval: the shortest interval between two QRS complexes corresponds approximately to the functional refractory period of the atrio-ventricular conduction pathways--the longest interval corresponds to the maximal intranodal hidden conduction in the central part of the node. Depending on the values obtained and the morphological type of the distribution, we can diagnose all degrees of atrio-ventricular conduction disorders. This has great practical significance in patients receiving or about to receive cardiotonics or antiarrhythmics. In the same way, in cases of pre-excitation syndrome, this method can be used to evaluate the refractory period of the accessory pathway and to guide treatment.

Atrial Fibrillation↗