Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “EXTRASYSTOLE”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 145 records · Page 8Linked to original sources
PubMed1976

[The effect of disopyramide phosphate in extrasystole at rest and on exercise (author's transl)].

The antiarrhythmic action of disopyramide phosphate was compared to placebo in a randomized double blind trial at rest and under physical exertion in two groups each of 10 patients with extrasystoles. The exercise was carried out on the bicycle ergometer in a recumbent posture in stages of 25 watts at 2 minutes each without a break to the limit of the individual. The extrasystoles were counted at fixed registration periods. It was shown that the number of extrasystoles in the disopyramide group was significantly lower in comparison to the placebo group (P less than 0.05).

Adult↗
PubMed1981

[Rhythmographic study of the frequency dependence of extrasystole in ischemic heart disease].

Results are given of the rhythmographic study of the frequency of extrasystole at rest, in the orthostatic position and during exercise in 236 patients with chronic ischaemic disease of the heart. The frequency dependence of extrasystole (the rate dependence of premature beats) was seen in 75.4% of cases. In the absence of the rate dependence of extrasystole, novocainamide, propranolol and atropine exerted marked antiarrhythmic effect less frequently than when such a dependence was present.

Aged↗
PubMed1983

["Critical interval of the dispersion of refractoriness" in the pathogenesis of ventricular extrasystole in the long QT syndrome].

The reentry mechanism (R.M.) has been demonstrated to be relevant in the genesis of experimental extrasystoles. The extrapolation of these observations to the ventricular extrasystoles (V.E.) observed in clinical situations is still debated. However, the V.E. related to the long QT syndromes have been commonly considered to be caused by R.M. In fact an abnormal prolongation of the repolarization time favors the dispersion of the myocardial recovery time. A critical lengthening of the QT interval has been observed by several Authors to underlie the appearance of V.E. That after a further critical prolongation of the QT the V.E. disappear, has not been so far described. We report a patient with long QT syndrome in whom the ECG demonstrated an extreme variability of the QT interval. The V.E. appeared only when the QT interval was greater than 580 msec, whereas they disappeared when the QT interval was greater than 660 msec. Thus, a critical interval of refractoriness dispersion (C.I.R.D.) between 580 and 660 msec was established. We suggest that in our case the V.E. were probably due to R.M., caused by regional lengthening of the repolarization; a further prolongation of repolarization time probably induced either an antegrade block in both limbs of the circuit or a retrograde block in the reentry pathway and consequently the abolition of R.M. The identification of a C.I.R.D. suggest a possible R.M. in the pathogenesis of clinical ventricular extrasystoles.

Aged↗
PubMed1984

Action potentials of the rabbit, guinea pig, dog and albino rat working ventricular myocardium under interpolated extrasystole conditions during postnatal ontogenesis.

Experiments were carried out on the working myocardium of the right heart ventricle of newborn and adult rabbits, guinea-pigs, dogs and albino rats. In the dog, the guinea-pig and the rabbit, after ten action potentials (AP) elicited with 1 Hz frequency we always interpolated an extrasystole at an interval (TE) of 100-900 ms. In albino rats we used a basic frequency of 2 Hz and a TE of 30-370 ms from the last regular AP. Using glass microelectrodes, we recorded the extrasystolic AP (EAP) and the next subsequent AP (2AP). The results were evaluated by constructing graphs of the correlations of the duration of the plateau phase (D0) to TE and of the duration of repolarization to -60 mV level (D60) to the TE. In the myocardium of newborn rabbits, guinea-pigs and dogs, with short TE both D0 and D60 of the EAP are shorter than in the steady state (SS), while for the 2AP the same parameters are influenced only a little. As the TE lengthens, the EAP gradually acquire a length corresponding more to the SS. With TE longer than half the duration of the cycle in the steady state the EAP return to normal, while the 2AP become shorter. The effect of extrasystole on the rat EAP and 2AP diminished with advancing age. In the myocardium of adult rabbits and adult guinea-pigs, and slightly in the myocardium of adult dogs and newborn rats, we observed that the duration of the EAP, with certain TE, was greater than in the steady state.(ABSTRACT TRUNCATED AT 250 WORDS)

Action Potentials↗
PubMed1984

[Comparative study of a slow-release quinidine preparation and flecainide administered in 2 daily doses for the treatment of extrasystole].

The new anti-arrhythmic agent flecainide was compared in a single-blind cross-over study to arabogalactane quinidine sulfate in the treatment of stable chronic extrasystole, using a fixed twice-daily dose protocol. Results were assessed by the Holter method. 12 patients (7 men and 5 women) with an average age of 56.5 were selected on the basis of stable and essentially ventricular extrasystole (VES) in 11 cases, and essentially atrial extrasystole (AES) in the remaining case. All patients however had some VES and 6 had some AES, and 5 patients had bursts of VES. The protocol provided for four sequences lasting one week each: one fixed, for selection, and the other three random, flecainide (375 mg), quinidine (660 mg), or placebo (2 doses). Data on each were recorded for Holter analysis. Statistical comparison of results was performed by studying variances on an equilibrated block. Comparison between the selection and placebo sequences showed the stability of the arrhythmia whatever its type. Against ectopic complexes as a whole, only flecainide had significant activity (p less than 0.01). Against AES, both compounds were active (p less than 0.05), quinidine more than flecainide (-73%/63%: a non-significant difference). Only flecainide was active against VES (-88.5%). Quinidine did not significantly reduce VES (-56%).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1984

[Treatment of chronic ventricular extrasystole with propafenone (Rhythmonorm)].

Peroral treatment with rhythmonorm (Knoll AG--GFR) with 450 to 900 mg daily was carried out to 38 patients with an average age 52,2 +/- 2,34, with chronic ventricular extrasystole. In 89,50 per cent of the cases, complete inhibition of the ventricular extrasystoles was attained or reduction in their number with greater than 80 per cent, and that result, in 55,26 per cent, was attained within the first days of the treatment. The pulse rate was reduced with 10 per cent on the average by the end of the treatment. Significant changes in cardiac conductivity, arterial pressure and severe adverse effects were not observed. The preparation rhythmonorm is an effective, convenient to take and well tolerated agent for the treatment and prophylaxis of ventricular extrasystoles.

Adolescent↗
PubMed1977

[Various aspects of individualization of drug therapy of extrasystole].

The clinical experience of drug therapy of 673 patients with extrasystole of different genesis has demonstrated that the nature of the underlying pathology and the topical characteristics of the extrasystole produce a comparatively moderate effect upon the antiarrhythmic action of Novocainamide, Chinidine, Obsidan, Isoptine, Bellataminal. Of certain importance in this context is the determination of the degree of prematurity of the extrasystole, their stability, as well as the periodic structure of the sinus rhythm as shown by the rhythmogram.

Administration, Oral↗
PubMed1982

Relationship between plasma concentrations and suppression of ventricular extrasystoles by flecainide acetate (R-818), a new antiarrhythmic, in patients.

To assess the relationship between plasma levels of 2,5-bis-(2,2,2-trifluoroethoxy)-N-(2-piperidylmethyl)benz-amide acetate (flecainide acetate), a new antiarrhythmic, and the suppression of ventricular arrhythmias, a decreasing multiple oral dosage regimen (200 mg b.i.d. to 50 mg b.i.d.) was administered over 12 days to eight patients with chronic ventricular extrasystoles. 1-h ECG recordings and blood samples for plasma flecainide measurements were obtained prior to, during each day of dosage, and post-drug. Maximum plasma levels observed with the higher doses range from 413 to 789 ng/ml (mean 637 ng/ml); these levels are well tolerated and are associated with essentially complete (greater than 95%) suppression of arrhythmias. As dose is decreased, plasma levels decline and the arrhythmias progressively return. The lowest plasma levels associated with essentially complete suppression of ventricular extrasystoles on two consecutive days range from 217 to 414 ng/ml (mean 317 ng/ml); levels below about 230 ng/ml are associated with the initial substantial reappearance (less than 70% suppression) of arrhythmias. These data suggest that the minimum therapeutic plasma levels of flecainide for ventricular extrasystoles range from about 200 to 400 ng/ml and that no consequential side effects are associated with plasma levels two-fold higher than these minimum levels.

Anti-Arrhythmia Agents↗
PubMed1994

[Extrasystolic ventricular bigeminy in ventricular tachycardia].

A patient with recent myocardial infarction presented with premature ventricular contractions (PVCs), couplets, and runs of ventricular tachycardia (VT). Two types of ectopic complexes, labeled A and B, were present. Isolated PVCs, as well as the first complex in a couplet, were always type A beats. In contrast, the second beat in a couplet was always a type B beat. Any run of VT was initiated by a type A beat. Monomorphic VT was made only of type B complexes, apart from the first one. Several episodes of VT, however, reflected an alternation of type A and type B complexes with alternating cycle length. This is a manifestation of extrasystolic ventricular bigeminy where any VT impulse (type B) is followed by an extrasystole (type A). In addition, extrasystolic impulses affect the tachycardia, resetting its cycle.

Cardiac Complexes, Premature↗
PubMed1996

[Ventricular extrasystole and arrhythmogenic right ventricular dysplasia. Critical analysis of the diagnostic value of non-invasive tests].

Asymptomatic ventricular extrasystoles were discovered in 2 active sportsmen (32 and 33 years). The cardiology work-up rapidly led to the diagnosis of arrhythmogenic right ventricular dysplasia in one. In the other, the clinical presentation was similar and the initial diagnosis was ventricular extrasystole with a healthy heart. Four years later however, the subject was still asymptomatic but a second evaluation revealed arrhythmogenic right ventricular dysplasia. This delayed diagnosis emphasizes the importance of renewed noninvasive evaluation of patients with asymptomatic ventricular extrasystoles.

Adult↗
PubMed1979

[2 variants of the anti-arrhythmic effect of atropine in extrasystole].

The antiarrhythmic effect of a single intravenous atropine injection (0.02 mg/kg body mass) was studied in 202 patients with extrasystole of various origin by rhythmography. Record of the chronotropic reaction and dynamics of the extrasystole interval suggests that there are two variations of the antiarrhythmic effect of atropine: frequency suppression of extrasystole and a "pure" antiarrhythmic effect. The data obtained are evidence that the mechanism of the antiarrhythmic effect of atropine is heterogeneous and complex.

Adolescent↗
PubMed1979

[New methods for the automatic detection and differentiation of extrasystoles].

Two new methods for automatic detection of extrasystoles are proposed: according to the area described by T wave and changes in the projection of the cardiac EMF vector on different ECG leads when the localization of the excitation focus is changed. Telemetry at an ultrashort distance and a device preventing the recording of extrasystoles when patients move increase the authenticity of the findings in automatic detection of extrasystoles.

Cardiac Complexes, Premature↗
PubMed1979

Influence of post-extrasystolic potentiation on left ventricular function estimated by means of systolic time intervals.

Systolic time intervals were measured in 50 patients with frequent premature ventricular beats. The patients were divided into two groups: group I included those which showed in the beat that preceded an extrasystole a pre-ejection period/left ventricular ejection time (PEP/LVET) ratio greater than or equal to 0.43, and group II with PEP/LVET ratio greater than 0.44. Systolic time intervals recorded during post-extrasystolic potentiation were compared with those measured in the preextrasystolic complex. Also the measured intervals were tested against the hourly rate of premature beats obtained by electrocardiographic telemetric monitoring. The results confirmed the following results of previous reports: a) ventricular premature beats are followed by sinus-potentiated contractions inversely related to the coupling interval and dependent on adequate compensatory pauses; b) potentiated contractions are greater in patients with ventricular dysfunction. No relationship was found between left ventricular performance and the rate of premature beats. It is concluded that the effect of an antiarrhythmic intervention on the left ventricular function might be adequately evaluated by means of systolic time intervals and provoked post-extrasystolic potentiation, with the advantage of using totally non-invasive procedures.

Cardiac Complexes, Premature↗
PubMed1979

Concealed extrasystoles due to Wenckebach conduction delay within the reentry loop.

Long electrocardiographic strips were analyzed from an aged patient whose heart rhythm had periods of unifocal ventricular extrasystoles with fixed coupling intervals. Periods of gradual prolongation of the coupling interval finally led to omission of a ventricular premature beat. This sequence was repetitive and is considered to be the results of reentrant extrasystoles with a 3:2 Wenckebach type of conduction delay within the reentry loop. The mechanism of concealed conduction due to overlong propagation within the reentry loop is discussed.

Aged↗
PubMed2002

Fetal bradycardia in the first trimester: an unusual presentation of atrial extrasystoles.

We report a fetus with fetal bradycardia at 13 weeks of gestation secondary to atrial extrasystoles. The fetus subsequently developed paroxysmal supraventricular tachycardia and hydrops fetalis. The cardiac arrhythmia recovered spontaneously without any medical intervention. This case illustrates that atrial ectopic beats can present in the first trimester with fetal bradycardia. Rapidly evolving hydrops fetalis secondary to supraventricular tachycardia can develop, warranting close monitoring with weekly heart rate assessment. Fetal bradycardia secondary to atrial extrasystole should be differentiated from first trimester sinus bradycardia and those associated with major structural cardiac abnormality, which have a high fetal loss rate.

Adult↗
PubMed1988

Two-dimensional echocardiographic diagnosis of arrhythmogenic right ventricular dysplasia presenting as frequent ventricular extrasystoles in a child.

Two-dimensional echocardiographic investigation of a child with frequent isolated ventricular extrasystoles revealed an area of right ventricular dysplasia. This finding may signify a less favorable prognosis and justifies careful echocardiography in the evaluation of asymptomatic ventricular extrasystoles of left bundle branch block morphology in children.

Bundle-Branch Block↗
PubMed2005

Inotropic response of the myocardium in rats with postinfarction cardiosclerosis exposed to extrasystolic treatment.

The inotropic response of the myocardium to extrasystolic treatment was studied on isolated perfused papillary muscles from rats with postinfarction cardiosclerosis. The development of postinfarction cardiosclerosis was accompanied by a decrease in myocardial excitability. The amplitude of extrasystolic contractions in the remodeled myocardium far surpassed the control. However, the amplitude of postextrasystolic contraction did not surpass that in normal contraction-relaxation cycle. Our results suggest that the ability of the sarcoplasmic reticulum in cardiomyocytes to accumulate Ca2+ is impaired during postinfarction remodeling.

Animals↗
PubMed1983

The repetitive extrasystole as an index of vulnerability to ventricular fibrillation during myocardial ischemia in the canine heart.

The repetitive extrasystole threshold (RET) is a reliable measure of vulnerability to ventricular fibrillation (VF) during diverse interventions in the normal heart. Whether this relationship also holds during varying degrees of myocardial ischemia has not been adequately explored. In 15 chloralose-anesthetized dogs, circumflex coronary blood flow (CBF) was decreased progressively with the use of an externally applied balloon occluder. There was a statistically significant correlation between the RET and ventricular fibrillation threshold (VFT) until left circumflex coronary artery flow was reduced by 90% of control values (r = 0.92). During reductions of CBF of 90% or greater, the VFT fell more than the RET and the RET/VFT ratio was disrupted. Total coronary occlusion, whether performed abruptly or gradually (5 minutes), likewise resulted in a disproportionate decline in VFT. During sustained total coronary occlusion, the VFT recovered to control values within 15 minutes, and the relationship between the RE and VF thresholds was restored. We conclude that the vulnerable period threshold for provoking repetitive extrasystole is a reliable index of vulnerability to VF during myocardial ischemia and remains so until nearly total occlusion of a major coronary vessel.

Animals↗