Search PubMed⌕ Search

Biomedical subjects

A Waleffe

Publications and source records attributed to A Waleffe.

48 records · Page 3Linked to original sources

Combined mexiletine and amiodarone treatment of refractory recurrent ventricular tachycardia.

A combined mexiletine and amiodarone treatment was applied in nine cases with recurrent refractory ventricular tachycardia. During the first two days of treatment, mexiletine and amiodarone were perfused intravenously at a dose of 1,000 mg. and 1,500 mg. per 24 hours, respectively. Simultaneously amiodarone was also given orally at a dose of 600 mg. per 24 hours. From the third day onwards, the intravenous administration was interrupted and both drugs were continued orally at a dose of 600 mg. daily. The first three patients were very critically ill and had had at least five episodes of ventricular tachycardia per 24 hours during the last 10 days in the intensive care unit. The treatment resulted in total suppression of the tachycardic episodes within three days after initiation of therapy. In the remaining six cases, ventricular tachycardia was easily initiated by programmed electrical stimulation of the heart. No arrhythmia could be elicited by repeated testing on the seventh day of treatment. The mean follow-up period was 6 months. Two patients with poor left ventricular function died in intractable heart failure. Another one died suddenly 4-1/2 months after his release from the hospital. He had a large aneurysm and whether he continued his treatment is unknown. A fourth patient had an aneurysmectomy; he suffered a recurrence, and died at his second operation. All the others presently remain asymptomatic. The association of a class I (mexiletine) with a class III (amiodarone) agent is theoretically attractive for the treatment of refractory ventricular arrhythmias. The present findings corroborate this hypothesis, but show that this association is not able to protect individuals with severe underlying myocardial damage.

Adult↗

Severe conduction disturbances and ventricular arrhythmias complicating mediastinal irradiation for Hodgkin's disease: a case report.

A 27-year-old male had undergone mediastinal and retroperitoneal irradiation for stage IIIA Hodgkin's disease at age 19. When he was admitted to the hospital, because of lightheadedness and syncope, trifascicular bundle branch block was noted and the patient underwent a clinical electrophysiological investigation. AH and HV intervals were prolonged and ventricular fibrillation was induced during programmed right ventricular stimulation. Serial electrophysiological studies allowed us to prescribe effective antiarrhythmic drug therapy with no recurrence of symptoms during a follow-up period of 12 months.

Adult↗

The efficacy of intravenous moxaprindine on ventricular ectopic activity.

Moxaprindine, a new derivative of aprindine, has been showed to possess strong antiarrhythmic properties in the dog. It is significantly less toxic than aprindine on hematopoietic cells in culture. This drug was given intravenously (2 mg/kg given over a 30 min period), to 10 patients with severe, refractory and symptomatic ventricular arrhythmias. In 8 of them, all ventricular ectopic activity was suppressed for at least 90 min following the end of perfusion. In 7, no ventricular ectopic beats recurred before the end of the experimentation (150 min). There were two non-responders: one of them developed a torsade de pointes phenomenon under the influence of the drug. The mean drug concentration which was reached at the end of perfusion was 4.83 +/- 2.46 gamma/ml. It progressively fell to a value of 1.11 +/- 0.35 gamma/ml, 150 min later. The drug prolongs the PR interval, QRS duration and QT interval. Moxaprindine is a powerful antiarrhythmic agent which deserves further assessment in long term studies.

Adult↗

Electrophysiological effects of L 9394 (benzoyl-indolizine) in man.

The electrophysiological effects of L 9394 (benzoyl-indolizine), a substance chemically related to amiodarone, but devoid of iodine atoms, were investigated by programmed electrical stimulation of the heart in 12 patients with various forms of tachycardia. Four subjects had electrocardiographic evidence of the WPW syndrome and episodes of circus movement tachycardia. Paroxysmal supraventricular tachycardia, confined to the atrioventricular (AV) node, was found in 3 patients. In 2 cases, where a short PR interval was present, the main complaint was the occurrence of paroxysmal atrial fibrillation. In the remaining 3 instances, the arrhythmia consisted of slow ventricular tachycardia (1 case), supraventricular tachycardia of the focal type (1 case), and episodes of primary ventricular fibrillation, not related to acute myocardial ischaemia (1 case). L 9394 injected intravenously was seen to lengthen the transnodal conduction time as well as the effective and functional refractory periods of the node. Similar effects were found on the retrograde VA pathway. The drug had no action on the infra-Hisian conduction system, on the refractory periods of ventricular muscle, or on the refractory periods of accessory bypasses. The drug was injected during an episode of tachycardia in 6 cases with reproducible supraventricular re-entrant tachycardia. Three had a tachycardia circuit confined to the node. In those instances, the drug had beneficial effects (slowing and interruption of tachycardia, decrease or abolition of echo zone; loss of ability to induce tachycardia). In the other 3 cases, an accessory pathway was incorporated in the circuit. L 9394 interrupted the tachycardia in 2 instances (by anterograde AV block), but failed to protect all 3 patients against reinitiation of tachycardia by premature stimuli. It is concluded that L9394 does not share all the pharmacological properties of amiodarone and will not replace it in all its indications.

Adult↗

Two unusual cases of intra-atrial gap.

Two cases are described in which, during investigation of rhythm disturbances, it was shown that, by delivering atrial stimuli of increasing prematurity, a point was reached where the artificial stimulus failed to induce an atrial response. However, with even more premature stimulations, atrial responses were again observed. These observations are best explained by a gap phenomenon in which very early stimuli delivered during the effective refractory period of the atria were delayed long enough in the exit area around the pacing electrode to allow atrial recovery.

Arrhythmias, Cardiac↗

The efficacy of intravenous mexiletine on ventricular ectopic activity.

Twelve patients with severe ventricular dysrhythmias were treated by one single dose of 250 mg of mexiletine injected intravenously over a 15 min. period. All patients showed some antiarrhythmic response. In 9 cases, the ventricular premature beats were totally or almost totally abolished up to 20 to 100 min. after the end of the infection. In most patients (5/7), there existed a correlation between the plasma concentration of the drug and the antiarrhymic action. However, the drug levels were not different in the good responders as compared to the poor responders or in those who manifested a prolonged antiarrhythmic activity as compared to the others. Side-effect appeared in three cases and consisted of vomiting, tremor, and episodes of sinus arrest.

Aged↗