ajmaline and Tachycardia--Supraventricular

Tachyarrhythmias which originate above the bifurcation of the bundle of His or incorporate tissue proximal to it are classified as supraventricular tachyarrhythmias (SVT). Primary treatment of SVT attempts to influence the underlying disease. Therapy is subdivided into drug therapy, electrotherapeutic tools (e.g. antitachycardia pacemakers, catheter ablation) and antiarrhythmic surgery. Antiarrhythmic agents which slow conduction and suppress premature beats are efficient for emergency and long-term treatment of supraventricular tachycardias. We evaluated some of the most relevant antiarrhythmic drugs for SVT including propafenone, diprafenone, cibenzoline, lorcainide and sotalol; in addition, usage and efficacy of quinidine/verapamil, disopyramide, amiodarone, ajmaline, adenosine and flecainide are summarized. The principles for acute management of tachycardia episodes with narrow and broad complexes are outlined. The reason for the selection as well as the efficacy in the termination of the tachycardias is described for different antiarrhythmic agents including verapamil, adenosine, ajmaline, propafenone and flecainide.

Topics: Ajmaline; Amiodarone; Anti-Arrhythmia Agents; Atrial Fibrillation; Atrial Flutter; Disopyramide; Flecainide; Humans; Imidazoles; Pre-Excitation Syndromes; Propafenone; Quinidine; Sotalol; Tachycardia, Paroxysmal; Tachycardia, Supraventricular; Verapamil

The aim of this study was to determine whether an antiarrhythmic, Ajmaline, could have proarrhythmic effects on the atrium and to compare the results with those of other antiarrhythmic drugs. A total of 1950 patients without cardiac failure or recent (less than 6 weeks) myocardial infarction were given 1 mg/kg of Ajmaline intravenously during electrophysiological investigation. A proarrhythmic effect was defined as the occurrence of supraventricular tachycardia (SVT) in a patient without this arrhythmia before the test or the facilitation of its induction. Fifty five patients developed SVT (mainly atrial tachyarrhythmias: 48 cases, and some junctional tachycardia: 7 cases) which occurred spontaneously in 22 patients and during fixed atrial pacing in 33 patients. Fifteen patients developed ventricular tachycardia (VT). The predisposing factors for the development of SVT were: a previous history suggesting spontaneous SVT (28 patients; 51 p. 100); sinoatrial block (14 patients--the only abnormality in 10 cases). Seventeen patients had none of these factors but 8 had known cardiac pathology and the other 9 were relatively elderly patients (79 years). Twelve of the patients developing VT had known cardiac disease, bundle branch block in 12 cases and previous VT in 6 cases. In conclusion, proarrhythmic effects of Ajmaline are infrequent if its contraindications are respected, but they do exist at both atrial (2.8 p. 100) and ventricular levels (0.8 p. 100): the risk factors are comparable: previous spontaneous arrhythmias or ECG changes (SA block at the atrial and bundle branch block at the ventricular level).

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Ajmaline; Anti-Arrhythmia Agents; Coronary Disease; Electric Stimulation; Electrocardiography; Female; Heart Atria; Humans; Male; Middle Aged; Myocardial Infarction; Retrospective Studies; Risk Factors; Tachycardia, Supraventricular

ATP is an effective treatment of supraventricular tachycardia when the atrioventricular (AV) node is part of the reentrant circuit. However, the lower a pace-maker in the pacemaker hierarchy, the more sensitive it is to adenosine. Therefore, we investigated the effects of ATP on ventricular automaticity in in vivo and in vitro conditions. Wide and narrow QRS complex tachycardia in 46 patients was treated with 6, 12, and 18 mg ATP as sequential intravenous (i.v.) bolus. ATP terminated tachycardias in 67%. Bolus infusion ATP caused < or = 6.4-s asystole that was self-limited. Perfusion of isolated spontaneously beating guinea pig heart with 100 microM ATP completely suppressed ventricular automaticity. After ATP-infusion was discontinued, the first ventricular beat was evident after 3.1 +/- 0.9 s and sinus node activity recovered with a time constant of 3.0 +/- 1.1 s. Because sinus node and ventricular automaticity recovered within seconds after ATP infusion was discontinued in vitro, recovery in vivo is also likely to be determined by the short half-life (+1/2) of ATP.

Topics: Adenosine Triphosphate; Adrenergic beta-Antagonists; Ajmaline; Animals; Anti-Arrhythmia Agents; Austria; Cardiac Pacing, Artificial; Drug Interactions; Emergency Medical Services; Female; Guinea Pigs; Heart Ventricles; Humans; Injections, Intravenous; Male; Propafenone; Prospective Studies; Quinidine; Tachycardia, Supraventricular; Ventricular Function; Verapamil

Topics: Adolescent; Adult; Aged; Ajmaline; Child; Child, Preschool; Clinical Trials as Topic; Female; Humans; Male; Middle Aged; Tachycardia, Paroxysmal; Tachycardia, Supraventricular; Verapamil

The aim of this study was to assess the response of refractoriness in normal and diseased human bundle branches to changes in cycle length, as well as during a long period of continuous overdrive pacing.. The anterograde refractory period of the bundle branches in patients with functional bundle branch block shortens as the rate is increased. The rate-dependent response of refractoriness in diseased bundle branches is quite different. However, this difference has not been precisely delineated, and its physiologic meaning is uncertain.. Refractoriness of the bundle branches was measured by the extrastimulus technique in 16 patients with tachycardia-dependent bundle branch block and 10 patients with functional bundle branch block, both after basic trains of 8 atrial-paced impulses at different cycle lengths and during a 10-min period of continuous overdrive pacing.. The baseline refractory period in the bundle branches of patients with functional bundle branch block measured 430 +/- 32 ms (mean +/- SD) and shortened to 368 +/- 30 ms at the shortest cycle length. The maximal effect was reached within the 1st min of overdrive pacing. The baseline refractory period of the bundle branches was significantly longer in patients with tachycardia-dependent bundle branch block (611 +/- 184 ms) and demonstrated a cumulative overdrive prolongation in 15 (83%) of 18 studies with typical manifestations of fatigue. In two other studies, this occurred only after ajmaline administration.. A rate- and time-dependent prolongation of refractoriness frequently occurs in diseased human bundle branches. When absent, this response may be induced under the effects of sodium channel blockers. This would suggest that an abnormality in the recovery from inactivation of the sodium channel might underlie the early stages of bundle branch disease.

Topics: Adult; Aged; Ajmaline; Bundle of His; Bundle-Branch Block; Cardiac Pacing, Artificial; Electrocardiography; Female; Heart Conduction System; Humans; Male; Middle Aged; Tachycardia, Paroxysmal; Tachycardia, Supraventricular

Antiarrhythmic drugs may aggravate or induce ventricular arrhythmia. The induction of a supraventricular tachycardia or its facilitation has rarely been reported. The purpose of the study was to know whether the potential for supraventricular proarrhythmic effect of a class Ia intravenous antiarrhythmic drug can be exposed during electrophysiologic study. Ajmaline was chosen because of its short duration of action. The protocol of the study consisted of an electrophysiological study and programmed atrial stimulation using 1 and 2 extrastimuli on driven rhythm and atrial pacing up to second-degree atrioventricular block. Then 1 mg/kg of ajmaline was injected and atrial pacing was performed 3 minutes after its injection. Supraventricular proarrhythmic effect of ajmaline was defined as the spontaneous occurrence of a supraventricular tachycardia or the facilitation of its induction. Seventy patients among 1955 presented a proarrhythmic effect: 63 developed a supraventricular tachyarrhythmia (atrial flutter, fibrillation, tachycardia) and 7 an atrioventricular reentrant tachycardia, either spontaneously (n = 23) or during atrial pacing (n = 47). Risk factors were identified in most patients: old age, underlying heart disease, history of spontaneous supraventricular tachycardia and/or induction of a supraventricular tachycardia by 2 extrastimuli on driven rhythm in the control state (34 patients), sinus node dysfunction (22 patients). Compared with patients without proarrhythmic supraventricular effect only the history of spontaneous supraventricular tachycardia and the existence of a sinus node dysfunction were significantly more frequent (P less than 0.05) in patients with proarrhythmic effect of ajmaline. In conclusion, the supraventricular proarrhythmic effect of intravenous ajmaline exists and is related both to the electrophysiologic characteristics of the drug and to the arrhythmia substrate. The results indicate that a supraventricular tachyarrhythmia may be induced by a class I antiarrhythmic drug.

Topics: Adolescent; Adult; Aged; Ajmaline; Atrial Function; Electrophysiology; Female; Heart Atria; Heart Conduction System; Heart Rate; Humans; Male; Middle Aged; Stimulation, Chemical; Tachycardia, Supraventricular

Electrophysiological examination of hearts were performed in 35 women and 25 men aged 18-63 years (mean age 38 years) without any concurrent heart diseases, divided into two groups: with PMVP (group I--40 subjects) and patients without this valvular anomaly (group II--20 subjects). In the patients with PMVP the examination revealed a significantly more frequent occurrence of the so-called "electrophysiological anomalies" (in 67.5%). The following appeared most frequently: sinus automatism disorders (32.5%), accessory a-v pathways (32.5%), longitudinal a-v node dissection (20%), and disorders of intracardiac conduction in segments: proximal (15%), distal (7.5%) and in both (5%). The implementation of pharmacological tests (with ajmalin, propranolol and atropine) made it possible to detect, in group with PMVP, the existence of occult conduction disturbances, particularly in distal segments of the conduction system (10%), and also to estimate exactly the character of the sinus node dysfunction (the background being in 7 patients functional, in 6 organic). During the programmed heart stimulation supraventricular dysrhythmias were evoked in 17 patients with PMVP. This is a proof that there is increased predisposition for paroxysmal supraventricular arrhythmias to occur in patients with mitral valve anomaly.

Topics: Action Potentials; Adolescent; Adult; Ajmaline; Arrhythmia, Sinus; Atrial Function, Right; Atropine; Female; Heart Conduction System; Humans; Male; Middle Aged; Mitral Valve Prolapse; Propranolol; Sinoatrial Node; Tachycardia, Supraventricular; Ventricular Function, Right

We present electrophysiological studies in two patients with atrioventricular reciprocating tachycardias. The first patient had anterograde dual atrioventricular nodal pathways with a right-sided concealed accessory pathway. The retrograde atrioventricular nodal pathway showed evidence suggestive of slow pathway properties. After block was induced with ajmaline in the accessory pathway, a typical pattern of discontinuous retrograde atrioventricular nodal conduction curves was recognized. We then observed three types of induced atrioventricular reentry. The other patient had continuous anterograde atrioventricular nodal conduction, a fast-conducting retrograde atrioventricular nodal pathway and a left-sided concealed accessory pathway. After refractoriness had been induced in the accessory pathway with ajmaline, a typical pattern of retrograde dual atrioventricular nodal pathways was recognized, and it proved impossible to induce atrioventricular nodal echoes. Induction of block or impairment of conduction with ajmaline in the concealed accessory pathway proved helpful in the disclosure of retrograde dual atrioventricular nodal pathways by means of the ventricular extrastimulus method.

Topics: Adolescent; Ajmaline; Atrioventricular Node; Electrophysiology; Heart Conduction System; Humans; Male; Tachycardia, Atrioventricular Nodal Reentry; Tachycardia, Supraventricular

The 12 lead electrocardiographic (ECG) findings were reviewed in 17 patients having two or more accessory pathways as documented during electrophysiologic study in all 17 patients and by intraoperative mapping in 8. Twelve patients had findings suggesting the presence of more than one atrioventricular (AV) pathway. These were 1) more than one P wave configuration during orthodromic circus movement tachycardia (four patients); 2) a "mismatch" between the location of the ventricular and atrial ends of the accessory pathway as assessed when comparing exclusive AV and ventriculoatrial conduction over the accessory pathway during antidromic and orthodromic circus movement tachycardia, respectively (seven patients); 3) atrial fibrillation showing more than one pre-excitation pattern (six patients); 4) a spontaneous change from orthodromic to antidromic circus movement tachycardia and vice versa (two patients); 5) a spontaneous change from one type of antidromic tachycardia to another (two patients); and 6) a change in pre-excitation pattern after administration of a drug that prolongs the anterograde refractory period of the accessory pathway (three patients). The retrospective nature of this study does not allow conclusions as to the true value of the ECG in predicting the presence of more than one accessory pathway. This issue needs to be evaluated in a prospective study.

Topics: Adolescent; Adult; Ajmaline; Atrial Fibrillation; Atrioventricular Node; Cardiac Pacing, Artificial; Child; Electrocardiography; Electrophysiology; Female; Heart Conduction System; Humans; Male; Pre-Excitation Syndromes; Procainamide; Tachycardia, Supraventricular

Topics: Adult; Ajmaline; Exercise Test; Humans; Male; Tachycardia, Paroxysmal; Tachycardia, Supraventricular; Wolff-Parkinson-White Syndrome

Topics: Ajmaline; Electrocardiography; Heart Arrest; Heart Block; Humans; Iatrogenic Disease; Injections, Intravenous; Rauwolfia; Tachycardia; Tachycardia, Supraventricular; Toxicology

Topics: Administration, Intravenous; Ajmaline; Humans; Infusions, Intravenous; Netherlands; Publications; Tachycardia, Supraventricular