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PubMed1987

[Propafenone in ventricular extrasystole in elderly patients. Tolerance and efficacy].

The tolerance and efficacy of propafenone were studied in cases of chronic ventricular extrasystoles of the elderly (age greater than 70 years). Only patients presenting more than 1,000 extrasystoles per day and requiring a treatment, were included in this study. Patients presenting non-compensated cardiac insufficiency, hypotensive patients, patients with conduction disorders without pacemakers as well as patients presenting a severe renal or hepatic insufficiency, were excluded. After making sure that the rhythm disorder was chronic, a control Holter was performed, then, 600 mg of propafenone per day, in 3 doses were prescribed for 5 days. On the 5th day, a Holter was performed as well as a blood propafenone level. Some patients received then 900 mg per day with a new Holter and plasma propafenone titration on the 10th day. 11 patients were studied in this fashion. The tolerance to 600 mg was good in 10 out of 11 cases. The efficacy, appreciated by the decrease of the number of isolated ventricular extrasystoles (-69%), doublets (-95%), triplets (-98%) and salvos of ventricular tachycardias (-100%), was excellent in 6 cases, average in 2 cases and mediocre in 3 cases. Increase of the dosage to 900 mg does not improve significantly the anti-arrhythmic efficacy while the side effects seem more frequent. It is not possible to establish a relationship between plasma concentrations and efficacy. At a dosage of 600 mg per day, propafenone is therefore effective in the treatment of ventricular extrasystoles in elderly patients and its tolerance is good. Higher doses are not advisable as they seem much less well tolerated without any additional advantage.

Aged↗
PubMed1989

[Anti-arrhythmic effectiveness and hemodynamic effect of ethacizine in middle-aged and elderly patients with ischemic heart disease and extrasystole].

The anti-arrhythmic effectiveness of ethacizine (diethylamine ethmozine analogue) was studied in extrasystolic arrhythmia in 40 IHD patients aged 60-85 and its effect on the autonomic cardiac rhythm regulation, intracardiac and central hemodynamics in acute oral load (75 mg) and in the process of course monotherapy (150 mg/24 h). In monotherapy of ventricular extrasystole ethacizine (150 mg/24 h) is effective in 80 per cent and in supraventricular extrasystole in 66 per cent of the cases. The drug produced no significant negative inotropic action but caused delay of atrioventricular and intraventricular conduction and weakening of parasympathetic cardiac tone. Side effects were found in 20 per cent of the patients. Ethacizine can be a preparation of choice in a long-term therapy of ventricular extrasystole in elderly patients.

Age Factors↗
PubMed1975

[Prognosis of the effect of cardiac glycosides on the extrasystole in ischemic heart disease].

The results of a single intravenous injections of strophanthin or digoxin and of a course-wise medication with cardiac glycosides in acute and chronic ischemic heart disease are contrasted. Investigations were carried out in 64 patients under cardiomonitoring with an automatic extrasystoles count. In the absence of extrasystoles or infrequent ones the cardiac glycosides provoked frequent extrasystoles in 10 per cent of the patients. The antiarrhythmic effect was recorded in 1/3 of the patients with infrequent extrasystoles. In cases of frequent extra systoles the positive result of the glycoside test justifies anticipating a beneficial influence of digitalization on the heart rate. In all the cases the results of the glycoside test determine in a large measure the individual prognosis.

Administration, Oral↗
PubMed1982

[Ventricular extrasystoles in the convalescence phase of myocardial infarction. Relation to angiographic data].

A series of 80 patients hospitalised for recent myocardial infarction underwent: --three continuous ambulatory 24 hour recordings (Holter method) on the 15th, 22nd days, and 6 months after infarction; --selective coronary angiography with left ventriculography, with a study of left ventricular performance and analysis of segmental contractility (Leighton's method). Five patients died over a mean follow-up period of 16 months. At the third week when physical activities were reintroduced 72,3 p. 100 of patients had frequent ventricular extrasystoles (Lown's Class II) or repeated ventricular extrasystoles (Classes III, IV, V). Holter monitoring gave reproducible results with a tendency to aggravation between the Ist and the 6th month (repetitive ventricular activity increasing from 35 to 45 p. 100). 55 p. 100 of posterior infarcts had few extrasystoles whilst 47 p. 100 of anterior infarcts had severe arrhythmias (Classes III, IV and V). There was a significant correlation between the presence of multivessel disease and severe ventricular extrasystoles 60 p. 100 of patients with multiple vessel lesions had repetitive ventricular activity (p less than 0,02). Positive correlations were established between: severe ventricular arrhythmias and a reduction in ventricular ejection fraction (p less than 0,01), dyskinesia in the infarcted zone (p less than 0,01) and reduction in wall motion of the non infarcted zones. The presence of incomplete occlusion of early revascularisation by collateral circulation in the infarcted zone seemed to favour severe ventricular arrhythmias. Five patients died (arrhythmias or cardiac failure): the association of severe hypokinesia and reduced left ventricular performance with repetitive ventricular activity was demonstrated. It is concluded from the correlations obtained between ventriculography and continuous electrocardiographic monitoring that repetitive ventricular activity is associated with severe reduction in left ventricular performance. The immediate gravity and poor prognosis of the ventricular arrhythmias are the result of the extent of the myocardial damage.

Cardiac Complexes, Premature↗
PubMed1982

Part of the autonomous nervous system in the development of chaotic post-extrasystolic pictures. Electrophysiological and pharmacological studies of 49 cases.

The interpretation of post-extrasystolic parameters and their significance is discussed. Programmed extrastimulation according to Strauss was carried out in 49 cases, before and after atropine and propranolol administration. The result was a computable sinoauricular conduction time (SACT), a chaotic picture, or an ascending line without plateau. The patients were selected on basis of their intrinsic heart rates (IHR). If the total SACT exceeded 250 ms, the chaotic post-extrasystolic picture and the ascending 1st phase without plateau were considered pathologic, then after drug testing the ratio of pathologic parameters decreased from 54 to 22% in cases with normal IHR. Including cases with pathologic IHR the ratio increased from 55 to 90%, especially in asynchronous chaotic pictures. After drug testing the chaotic forms were always replaced by a plateau in cases with normal IHR, but in pathologic ones the chaotic picture appeared to be a dominant electrophysiological parameter. It follows that the autonomous nervous system has its part in the development of chaotic post-extrasystolic pictures. A plateau in the post-extrasystolic curve could mean a functional organization and synchronism rather than a conduction disturbance; to the latter a high-level plateau would correspond.

Atropine↗
PubMed1983

[Hyperbaric oxygenation in paroxysmal and extrasystolic disorders of cardiac rhythm].

Hyperbaric oxygenation (HBO) was used as part of combined treatment in 102 patients with frequent paroxysms of atrial fibrillation and supraventricular tachycardia, and extrasystoles associated with coronary disease in 74 and neurogenic disturbances in 28 patients. HBO was indicated where anti-arrhythmic drugs had proved inefficient. Electrocardiographic, hemodynamic (rheographic), spirographic parameters and blood catecholamines were examined. Extrasystoles became less frequent or disappeared altogether for varying intervals in 75% of coronary patients, the duration of disappearance depending on the duration of their former presence. Stable disappearance of extrasystoles for 6-12 months was noted in 50% of coronary patients with less than two years' existence of extrasystole. In atrial fibrillation paroxysms due to coronary disease, HBO-incorporating combined treatment eliminated paroxysms for 4 to 10 months. In addition to normalizing cardiac rhythm, HBO increased formerly low cardiac output, reduced hyperventilation, eliminated respiratory arrhythmias and brought down blood catecholamine levels.

Arrhythmias, Cardiac↗
PubMed1983

Electromechanical relationships of rabbit papillary muscle under interpolated extrasystole conditions and after a pause.

The aim of the study was to describe and attempt to explain certain specific features of electromechanical coupling in the rabbit myocardium. Electromechanical correlations in the papillary muscles of the right ventricle of adult rabbit hearts were studied by a programmed stimulation technique. The duration of action potentials (AP) was measured in the plateau phase (Do, ms) and at -80 mV level (D80, ms), together with the intensity of the corresponding isometric contractions (MG, arbitrary units). After twenty AP of 1 Hz frequency, we interpolated an extrasystole with a variable interval (TE = 100-900 ms) and measured D0 and MG of the premature AP and the first AP of the subsequent cycle. When a steady state at 1 Hz frequency had been reached, we interpolated pauses (Tp) of 5 to 600 s and read D80 and MG of the first to the tenth contraction after the pause. The extrasystole D0 attained the maximum at TE = 260 ms and then fell abruptly. The MG of extrasystoles with a longer TE grew from the lowest value (0.3), attained 1 at TE = 700 ms and then remained stable. The first contraction after extrasystole displayed distinct postextrasystolic potentiation (MG = 2), while D0 was unwontedly short. Prolongation of TE was accompanied by an increase in its D0 value and by a steep drop in MG (to as little as 0.2). D80 of the first AP evoked after the pause fell proportionally to log Tp and then, from Tp = 60 s, gradually rose. The MG value of the first contraction after the pause fell proportionally to log Tp. The AP recovered much more rapidly than contractility from the effect of the pause. In the discussion, an attempt is made to explain the found correlations on the basis of differences in the behaviour of the calcium current channel system in the rabbit myocardium and a commentary on electromechanical correlations is based on the hypothesis that the free sarcoplasmic calcium level determines both membrane electrogenesis and the inotropic state.

Action Potentials↗
PubMed1978

[Relationship between ventricular extrasystole and parasystole].

Monomorphic ventricular extrasystoles, no less than 30 within an hour, were revealed in 89 of 300 patients with chronic ischemic heart disease during continuous 24-hour ECG recording on magnetic tape. A fixed type of the linkage interval (oscillations of no more than 0.1 sec) was established in 58 (62%) and the variable tupe (oscillations of more than 0.1 sec) in 31 (38%) patients. Oscillations in the linkage interval of more than 0.1 sec gave grounds to suspect parasystole. A deeper analysis revealed parasystole in 8 cases (2.6% of the total number of patients), the remaining cases were included in the group of extrasystoles with a variable non-parasystolic type of the linkage interval. This group of extrasystoles occupies an intermediate position between para- and extrasystole. The large number of transitional forms between extra- and parasystole suggests their common origin.

Aged↗
PubMed1976

Lidocaine and His bundle extrasystoles. His bundle discharge conducted with functional right of left bundle-branch block, or blocked entirely (concealed).

In this patient, discharge from the bundle of His either conducted normally, conducted with functional right or functional left bundle-branch block, or blocked entirely (concealed), depending on the preceding cycle length and the coupling interval of the premature His bundle depolarization. The presence of both functional right and left bundle-branch block may have been attributable to differences in effective and functional refractory periods between the two bundle branches. Concealed His bundle extrasystoles mimicked first-degree, and types I and II second-degree AV block, according to the interval between His bundle discharge and the subsequent P wave. Lidocaine eliminated His bundle extrasystoles that blocked entirely (concealed) or conducted with functional left bundle-branch block by improving His-Purkinje conduction and by lengthening the coupling interval of the premature His bundle extrasystole. Lidocaine had no effect on AV nodal conduction time. This patient has been known to have concealed His bundle discharge for at least three years and has not required permanent pacemaker insertion.

Bundle of His↗
PubMed1977

Pseudo A-V block secondary to concealed junctional extrasystoles. Case report and review of the literature.

A 23 year old woman, convalescing from a motorcycle accident was noted to have a complex arrhythmia. Short bursts of apparent ventricular tachycardia, sudden P-R delays, and Mobitz I and Mobitz II block were observed as well as frequent junctional premature systoles. Careful analysis revealed that the rhythm disturbances were caused entirely by manifest and concealed atrioventricular (A-V) junctional extrasystoles. This case meets the criteria for concealed junctional extrasystoles producing "pseudo A-V block." Pertinent literature is reviewed, and the manifestations of variable antegrade and retrograde conduction of A-V junctional extrasystoles are discussed. Increased awareness of this unusual rhythm disturbance can prevent unnecessary pacemaker therapy for apparent A-V block.

Adult↗
PubMed1993

Significance of R wave changes in exercise-induced supraventricular extrasystoles. Angiographic correlates.

To evaluate the clinical significance of observed R wave amplitude changes in exercise-induced supraventricular extrasystoles in comparison to the preceding sinus beat, 94 patients catheterized for possible coronary artery disease (CAD) were studied. Significant CAD was documented in 63 patients--34 with myocardial infarction (group A1) and 29 without (group A2)--whereas 31 patients had normal coronary arteries or coronary lesions less than 30% (group B). All patients underwent treadmill stress testing using the Bruce protocol within a month after cardiac catheterization. R wave amplitude increased or remain unchanged in extrasystole (R(x-s) > or = 0) in patients with CAD, while it decreased (negative R(x-s) in patients without significant CAD (P < .0001). In patients with CAD R(x-s) values were positively related to the number of obstructed coronary arteries (P < .01), while no significant difference was found between groups A1 and A2. The correlations of R wave amplitude changes in extrasystoles were significant with coronary obstruction score values (r = .82 and .85 in groups A1 and A2, respectively) and with left ventricular ejection fraction values (r = -.88, -.86 and -.90 in groups A1, A2, and B, respectively). R(x-s) > or = 0 value had a sensitivity of 79% and a specificity of 90% for CAD detection, while sensitivity was higher (89%) and specificity was lower (57%) for the prediction of left ventricular dysfunction. It is concluded that R(x-s) > or = 0 value is indicative of CAD, multivessel disease, and poor left ventricular performance, while its negative value is combined with minimal or no CAD and normal ejection fraction values.

Adult↗
PubMed1990

Epinephrine-induced decrease in repetitive extrasystole threshold is reversed by tyrosine in conscious dogs.

Previous studies indicate that availability of L-tyrosine, the precursor for catecholaminergic neurotransmitters, reduced psychological and physiological effects of stressful situations including hypotension, cold and behavioral stress. The current study examined the effect of L-tyrosine administration on cardiac vulnerability to arrhythmia induced by an infusion of epinephrine in conscious dogs. Heart rate, mean arterial pressure and cardiac electrophysiologic parameters, i.e., effective refractory period and repetitive extrasystole threshold, were measured during infusion of epinephrine (0.3 micrograms/kg/min x 30 min), before and after L-tyrosine (B mg/kg iv bolus). Epinephrine administration significantly increased heart rate by 39% (p less than 0.05), and decreased repetitive extrasystole threshold by 33% (p less than 0.05). Mean arterial pressure and effective refractory period were unchanged. Following L-tyrosine, repetitive extrasystole threshold was restored to baseline levels. Tyrosine may thus ameliorate stress-induced increases in ventricular vulnerability to arrhythmias in conscious animals.

Animals↗
PubMed1991

Decrease in repetitive extrasystole threshold during epinephrine infusion is enhanced in conscious dogs with perinephritic hypertension.

Hypertension is associated with myocardial hypertrophy as well as increased adrenergic responsiveness, both of which can predispose to malignant ventricular arrhythmias. This study was designed to test the effects of subpressor doses of epinephrine (0.15 and 0.3 micrograms/kg/min x 30 min) on vulnerability to ventricular arrhythmia in normotensive and perinephritic hypertensive dogs. Two groups of 6 dogs each were chronically instrumented with aortic catheters to measure mean arterial pressure and bipolar pacing catheters in the apex of the right ventricle to measure repetitive extrasystole threshold, an index of vulnerability to ventricular fibrillation. In the normotensive dogs, the low dose of epinephrine (0.15 micrograms/kg/min IV) had no significant effects on mean arterial pressure, heart rate of repetitive extrasystole threshold. However, in the hypertensive dogs, the same dose caused a significant 39% increase in heart rate (p less than 0.05) and 41% decrease in repetitive extrasystole threshold (p less than 0.05). These findings suggest that electrophysiological vulnerability of the myocardium caused by epinephrine infusion is enhanced in the hypertensive animal.

Animals↗
PubMed1989

The effect of potassium and potassium plus magnesium supplementation on ventricular extrasystoles in mild hypertensives treated with hydrochlorothiazide.

Eleven mild hypertensives with base-line ventricular extrasystoles underwent a 24-week period of treatment with hydrochlorothiazide 50 mg daily. After 8 weeks of treatment either potassium as hydrochloride 1 g twice daily, or a combination of potassium hydrochloride 1 g and magnesium hydroxide 500 mg twice daily was added to the diuretic therapy in a randomised, double-blind, cross-over design. Each treatment period lasted 8 weeks. Supplementation with potassium or potassium plus magnesium resulted in a clear trend for suppression of ventricular ectopic activity. There was no difference in ventricular extrasystoles between the two supplementation groups. Supplementation with potassium plus magnesium but not with potassium only, resulted in a significant rise in serum potassium values (P less than 0.01). Our study suggests that potassium should be supplemented in thiazide-treated hypertensives who are prone to develop ventricular extrasystoles. Addition of magnesium to potassium supplementation does not result in further improvement in ventricular ectopic suppression.

Adult↗
PubMed1985

Electrocardiographic criteria for differentiating aberrancy and ventricular extrasystole in chronic atrial fibrillation: validation by intracardiac recordings.

Many electrocardiographic criteria have been proposed for the differentiation of ventricular extrasystole and supraventricular conduction with aberrancy in atrial fibrillation but the validity of these have not been confirmed by intracardiac studies. We recorded His bundle electrograms in nineteen patients (eleven men, eight women) referred for diagnosis of abnormal QRS complexes in the context of chronic atrial fibrillation. Of 1,068 wide QRS complexes analyzed, 91% proved to be of ventricular origin. Electrocardiographic criteria which were specific for ventricular extrasystole included: left bundle branch block morphology, right bundle branch block morphology with a monophasic R in lead V1 or an RS or QS pattern in lead V6, presence of a "compensatory pause", i.e., compensatory cycle (V2-V3) longer than the average cycle length of ten normally conducted beats preceding the abnormal complex (927 +/- 317 vs 780 +/- 199, mean +/- SD in msec. p less than 0.005), frontal QRS axis of the abnormal complex directed superiorly or to the right and the presence of a "short-long" cycle sequence. Right bundle branch morphology with a triphasic R in lead V1 or QRS pattern in V6 and concordant initial vector in lead V1 or in more than one ECG leads were very specific for supraventricular conduction with aberrancy. Analysis of coupling interval and Ashman's phenomenon, i.e., the long-short cycle sequence, were not specific for supraventricular conduction with aberrancy. We conclude that in digitalis-treated patients with chronic atrial fibrillation the majority of abnormal QRS complexes are of ventricular origin. The diagnosis of ventricular extrasystole or aberrancy can be made using a single ECG lead (V1) and applying a combination of easily applied criteria.

Adult↗
PubMed2001

Long-term follow-up of right ventricular monomorphic extrasystoles.

OBJECTIVES: The purpose of this study was to verify in a long-term follow-up whether frequent monomorphic right ventricle extrasystoles may progress to arrhythmogenic right ventricular dysplasia (ARVD). BACKGROUND: Frequent monomorphic right ventricle extrasystoles are generally considered benign. However, in patients with this pattern, cardiac magnetic resonance (MR) has recently shown anatomical and functional abnormalities of the right ventricle. METHODS: Sixty-one patients who had been classified by noninvasive examinations as having frequent idiopathic right ventricle ectopy were contacted after 15 +/- 2 years (12 to 20) and submitted to clinical examination, electrocardiogram (ECG), Holter monitoring, stress test, signal averaged ECG, echocardiography and, in 11 patients, cardiac MR. The primary end point was to ascertain the presence of cases of sudden death or progression to ARVD. RESULTS: At the end of the follow-up, 55 patients were alive; six died, none of sudden death; eight stated to be well but refused further examinations. The 47 patients examined had normal ECG; in 24 patients (51%), extrasystoles were no longer present at Holter monitoring; late potentials were present in up to 15% of the patients; the right ventricle was normal at echocardiography. In 8 of 11 patients (73%), cardiac MR showed focal fatty replacement and other abnormalities of the right ventricle. CONCLUSIONS: In this long-term follow-up study, no patient died of sudden death nor developed ARVD; two-thirds of the patients were asymptomatic, and, in half of the patients, ectopy had disappeared. Focal fatty replacement in the right ventricle was present in most.

Adolescent↗
PubMed1997

Influence of ryanodine on the mechanical restitution and on the post-extrasystolic potentiation of the guinea-pig ventricular myocardium.

This paper records the results of an investigation into potentiation and staircase phenomena in rightventricular guinea-pig papillary muscles with particular reference to the sarcoplasmic Ca(2+)-channel. As a tool to isolate the second ('late', 'tonic') component of isoproterenol-induced biphasic contractions ryanodine was used. On the evidence at present available the monophasic ryanodine-resistant component of the twitch represents that portion of the activator calcium which reaches the troponin C directly, that is, not taking the roundabout way through the intracellular storage structures. In order to avoid functional instabilities of the isolated muscle preparation a short-time double rest stimulation programme was used which combines a number of different tests and gives information on (1) the post-rest potentiation, (2) the post-extrasystolic potentiation, (3) the mechanical post-rest recovery, (4) the interval-strength relationship, and (5) the mechanical restitution. The results of the present work show that under the influence of ryanodine (1) the Bowditch staircase, a typical feature of normodynamic mammalian ventricular preparations as well as of hypodynamic frog heart preparations, does not exist, (2) the post-extrasystolic potentiation disappears, (3) the curve reflecting the mechanical restitution, under normal in vitro conditions a monotonically increasing function, becomes biphasic within the relative refractory period, (4) the conspicuous depression of the isometric post-rest contraction for long lasting pauses interrupting the regular pacing rhythm, a typical feature of isolated guinea-pig ventricular tissue, is clearly diminished, and (5) the characteristic curve, reflecting the potentiation of the post-extrasystolic post-rest contraction as a function of the delay time preceding the extrastimulus, becomes displaced to the premature interstimulus interval. The concept of an 'extended 2-calcium-store model' is supported by this work.

Action Potentials↗
PubMed2003

Post-extrasystolic potentiation recruits incremental contractile reserve of dyssynergic myocardium during dobutamine stress testing: evidence by pulsed wave tissue Doppler imaging.

Dobutamine stress echocardiography is an established diagnostic method for the detection of myocardial viability in patients with severe left ventricular dysfunction([1]). The presence of viable myocardium identifies patients who will benefit from coronary revascularization, by improving both functional capacity and long-term survival. Occasionally, dobutamine infusion has been combined with other stressors, such as post-extrasystolic potentiation, in order to improve accuracy. The contractile reserve after combined dobutamine infusion and post-extrasystolic potentiation can be quantified by pulsed wave tissue Doppler imaging. We describe a patient with severe left ventricular dysfunction, in which pulsed wave tissue Doppler imaging allowed to demonstrate that post-extrasystolic potentiation superimposed on dobutamine infusion is able to further recruit contractile reserve, as compared to dobutamine infusion alone. A nuclear scan assessing glucose utilization was used as a reference.

Aged↗