المؤلفون: Jay W. Mason, Roger A. Winkle, Charles D. Swerdlow

المصدر: Circulation. 68:400-405

مصطلحات موضوعية: Adult, Male, Tachycardia, medicine.medical_specialty, Ventricular Tachyarrhythmias, Heart Ventricles, Pharmacology, Sudden death, Death, Sudden, Electrocardiography, Physiology (medical), Internal medicine, Therapy assessment, Humans, Medicine, Cumulative incidence, cardiovascular diseases, Aged, medicine.diagnostic_test, business.industry, Incidence (epidemiology), Middle Aged, Prognosis, medicine.disease, Electric Stimulation, Ventricular fibrillation, cardiovascular system, Cardiology, Female, medicine.symptom, Cardiology and Cardiovascular Medicine, business, Follow-Up Studies

الوصف: We analyzed 255 long-term trials of antiarrhythmic therapy, each of which had been evaluated at electrophysiologic study, to identify the maximum number of induced ventricular complexes consistent with the long-term efficacy of antiarrhythmic therapy. All patients had spontaneous and inducible sustained ventricular tachycardia or ventricular fibrillation. The incidence of therapeutic efficacy at 1 month and throughout follow-up was similar for trials in which zero, one, two, three, four, five, six to 10, and 11 to 15 complexes were induced, but significantly lower (p less than .001) for trials in which 16 or more complexes were induced. The cumulative incidence of efficacy at 1 year was 75 +/- 5% for 0 to 5 induced complexes, 72 +/- 11% for six to 10 complexes, 83 +/- 15% for 11 to 15 complexes, 42 +/- 10% for 16 complexes to 15 sec, and 48 +/- 6% for sustained ventricular tachycardia. At 1 year, the incidence of "sudden death-free" survival was higher for patients in trials that prevented initiation of sustained ventricular tachycardia than for those in trials that permitted initiation of sustained ventricular tachycardia (91 +/- 3% vs 75 +/- 6%; p = .01). The duration of the arrhythmia induced at therapy assessment was in the range of 11 to 20 complexes for only 4% of trials. Antiarrhythmic therapy is likely to be effective if as many as 15 complexes are induced at therapy assessment. The best cutoff, between 11 and 20 complexes, is difficult to identify because of the small fraction of trials in this range. Patients in whom initiation of sustained ventricular tachycardia is not prevented are at high risk for arrhythmia recurrence and sudden death.

URL الوصول: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::6b748a24de90761ebda97d4a71b4e4df
https://doi.org/10.1161/01.cir.68.2.400

المؤلفون: J W Mason, R A Winkle

المصدر: Circulation. 58:971-985

مصطلحات موضوعية: Adult, Male, Tachycardia, Drug, medicine.medical_specialty, Adolescent, media_common.quotation_subject, Electric Countershock, Administration, Oral, Procainamide, Ventricular tachycardia, Intracardiac injection, Efficacy, Electrocardiography, Pharmacotherapy, Recurrence, Physiology (medical), Internal medicine, medicine, Humans, cardiovascular diseases, Aged, Monitoring, Physiologic, media_common, business.industry, Cardiac Pacing, Artificial, Lidocaine, Middle Aged, medicine.disease, Propranolol, Quinidine, Catheter, Phenytoin, Anesthesia, Injections, Intravenous, cardiovascular system, Cardiology, Drug Evaluation, Female, medicine.symptom, Cardiology and Cardiovascular Medicine, business, Cardioversions, Anti-Arrhythmia Agents, Disopyramide, Follow-Up Studies

الوصف: We performed intracardiac electrophysiologic studies in 33 patients with recurrent ventricular tachycardia. Nineteen patients underwent one, 10 patients two, and four patients three serial electrophysiologic studies. Ventricular tachycardia was successfully induced in 83% of the patients, and pacing methods were successful in terminating tachycardia in 71% of the studies, although pacing-induced acceleration of ventricular tachycardia occurred at least once in 36% of the studies. Seventeen of the 33 patients (52%) required a total of 24 external direct current cardioversions during study. In 21 patients a variety of antiarrhythmic drugs were given I.V. and attempts at ventricular tachycardia induction were repeated to assess prophylactic effects of the drugs. An acutely effective drug or combination of drugs was found in 15 of the patients (71%). Fourteen of the 15 were placed on chronic oral therapy with the effective agent and were followed for an average period of 8.1 months (range one to 33 months). In all 14 patients we could document complete (13 patients) or partial (one patient) long-term prophylaxis against ventricular tachycardia. We conclude that drug efficacy trials in patients with recurrent ventricular tachycardia using intracardiac pacing techniques is a rapid and accurate method of selecting effective long-term antiarrhythmic therapy.

URL الوصول: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::9f2d813f4dbc2d6bd713aca641ae4167
https://doi.org/10.1161/01.cir.58.6.971

المؤلفون: J W Mason, F A Peters

المصدر: Circulation. 63:670-675

مصطلحات موضوعية: Adult, Male, medicine.medical_specialty, Encainide, Resuscitation, medicine.medical_treatment, Electric Countershock, Antiarrhythmic agent, Ventricular tachycardia, Electrocardiography, QRS complex, Refractory, Actuarial Analysis, Tachycardia, Physiology (medical), Internal medicine, Humans, Medicine, Anilides, In patient, cardiovascular diseases, PR interval, Aged, Dose-Response Relationship, Drug, business.industry, Recurrent ventricular tachycardia, Middle Aged, medicine.disease, cardiovascular system, Cardiology, Female, Cardiology and Cardiovascular Medicine, business, Anti-Arrhythmia Agents, medicine.drug

الوصف: Encainide is a new agent for treating ventricular arrhythmias. We attempted long-term oral therapy with encainide in 38 patients with recurrent, strikingly drug-refractory ventricular tachycardia. The usual daily dose of encainide ws 150-250 mg divided into four or six doses. The mean period until withdrawal of encainide or the date of follow-up was 4.2 months. Encainide completely eliminated recurrence of ventricular tachycardia in 54% of the patients for 6 months of therapy and in 29% of the patients for 18-30 months of therapy. Twelve patients (32%) had side effects possibly due to encainide; in four, the arrhythmia may have been worsened by encainide. During chronic therapy, encainide increased the PR interval by 18% and the QRS duration by 32%. There was no significant change in the corrected QT interval. The presence of QRS prolongation appeared to correlate with antiarrhythmic effect. We conclude that encainide is a safe, well-tolerated antiarrhythmic agent that is often effective against previously drug-refractory ventricular tachycardia.

URL الوصول: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::f9026f264a7fce70069e090d98d8dc58
https://doi.org/10.1161/01.cir.63.3.670

المؤلفون: E B Stinson, D R Ricci, Bruce A. Reitz, A E Orlick, J W Mason, Donald C. Harrison

المصدر: Circulation. 57(5)

مصطلحات موضوعية: Tachycardia, medicine.medical_specialty, Digoxin, medicine.drug_class, Propranolol, QRS complex, Heart Conduction System, Heart Rate, Physiology (medical), Internal medicine, polycyclic compounds, Medicine, Humans, Transplantation, Homologous, cardiovascular diseases, Atrial pacing, business.industry, Atrioventricular conduction, Atropine, Anesthesia, Depression, Chemical, Cardiology, Atrioventricular Node, Heart Transplantation, Depressant, medicine.symptom, Cardiology and Cardiovascular Medicine, business, medicine.drug

الوصف: We examined the effect of chronically administered digoxin on atrioventricular (A-V) conduction in nine cardiac transplant recipients. We assessed A-V conduction by measuring the duration from the pacing stimulus to the onset of the QRS complex (S'R interval) and by determining the occurrence of Wenckebach periodicity during rapid atrial pacing. We made measurements during a control period and during a period of digoxin administration of up to 37 days. During the digoxin period, the cycle length at which Wenckebach block occurred was prolonged by 14% of the control value and the S'R interval was significantly prolonged at paced rates of 110 beats per minute and faster. After digoxin was discontinued, the Wenckebach periodicity and S'R interval returned to control values. Atropine and propranolol did not alter digoxin's effect on A-V conduction. We conclude that digoxin exerts a direct (or non-neurally mediated) depressant effect upon A-V conduction in man, although the stress of tachycardia is necessary to demonstrate the effect.

URL الوصول: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::8a0c42c17ef7558bf70b20efb5d3b645
https://pubmed.ncbi.nlm.nih.gov/346256

المؤلفون: J. C. Griffin, Jay W. Mason, C. R. Kerr, R. C. Wyndham, Roger A. Freedman, Kelley P. Anderson, Craig M Pratt, A. Pacifico, D. A. Rawling, D. Mann, J. M. Herre, M. Scheimnan, F. I. Marcus, J. A. Yeung, Jeffrey L. Anderson, T. Moon, L. Faileson, J. T. Bigger, M. J. Reiter

المصدر: Circulation. 79(6)

مصطلحات موضوعية: medicine.medical_specialty, Randomization, Propafenone, Sudden death, Electrocardiography, Random Allocation, Physiology (medical), Internal medicine, Mexiletine, Multicenter trial, Tachycardia, medicine, Humans, Multicenter Studies as Topic, cardiovascular diseases, Monitoring, Physiologic, business.industry, Sotalol, Cardiac Pacing, Artificial, Procainamide, United States, Electrophysiology, Anesthesia, Inclusion and exclusion criteria, Cardiology, Exercise Test, Cardiology and Cardiovascular Medicine, business, Anti-Arrhythmia Agents, medicine.drug

الوصف: ESVEM (Electrophysiologic Study Versus Electrocardiographic Monitoring) is an ongoing multicenter trial supported by the National Heart, Lung, and Blood Institute that began enrollment of patients on October 1, 1985. We describe here the methodology of the trial and data regarding enrollment of patients in the trial. The purpose of the trial is to determine whether electrophysiologic study or electrocardiographic Holter monitoring more accurately predicts antiarrhythmic drug efficacy in patients with aborted sudden death or sustained ventricular tachyarrhythmias. Consenting patients with inducible, sustained ventricular tachyarrhythmias and at least 480 premature ventricular contractions during 48 hours are randomized to undergo antiarrhythmic drug selection either by electrophysiologic study or by Holter monitoring. Up to six drugs (mexiletine, pirmenol, procainamide, propafenone, quinidine, and sotalol) are assessed in random order until one is predicted effective. An efficacy prediction is achieved in the electrophysiology limb if ventricular tachyarrhythmias are no longer inducible and in the Holter limb if ventricular ectopy is largely suppressed. Patients in whom a drug is predicted effective are followed while they are taking that drug to detect one of the three primary endpoints: arrhythmia recurrence, sudden death, or unmonitored syncope. In the first 37 months, 967 patients satisfied inclusion and exclusion criteria to undergo baseline studies. Two hundred eighty-six were eligible for and consented to randomization. In total, approximately 500 patients will be randomized and 285 subjects will be followed while receiving drugs that are predicted effective in this trial. Approximately 70 patients are expected to attain a primary end-point during a mean follow-up ot 3 years.(ABSTRACT TRUNCATED AT 250 WORDS)

URL الوصول: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::8f83667af9bb46150b741625b4989bdb
https://pubmed.ncbi.nlm.nih.gov/2655967

المؤلفون: Melvin M. Scheinman, Edward N. Shen, Anil K. Bhandari, Fred Morady, William Shapiro, J Mason

المصدر: Circulation. 71(1)

مصطلحات موضوعية: Adult, Male, medicine.medical_specialty, Adolescent, medicine.medical_treatment, Long QT syndrome, Heart Ventricles, Adrenergic beta-Antagonists, Propranolol, Ventricular tachycardia, QT interval, Syncope, Electrocardiography, Physiology (medical), Internal medicine, Tachycardia, medicine, Humans, cardiovascular diseases, Heart Atria, Sympathectomy, Child, Atrium (architecture), medicine.diagnostic_test, business.industry, Cardiac Pacing, Artificial, Arrhythmias, Cardiac, Syndrome, Middle Aged, medicine.disease, Heart Arrest, Anesthesia, Ventricular fibrillation, cardiovascular system, Cardiology, Female, Cardiology and Cardiovascular Medicine, business, medicine.drug

الوصف: Electrophysiologic studies were performed in 15 patients with syncope and/or cardiac arrest who had the long QT syndrome and 11 control subjects who had normal QT intervals. The syndrome was familial in five patients and idiopathic in 10. All patients had a prolonged QT (546 +/- 68 msec, mean +/- SD) and corrected QT (550 +/- 51 msec). Incremental atrial pacing at cycle lengths of 600 to 400 msec resulted in shortening of the QT interval, but there was no significant difference in the magnitude or percent of shortening of the QT interval between patients with the long QT syndrome and control subjects. Intravenous propranolol did not influence the QT interval measured at fixed atrial-paced cycle lengths in patients with either the familial or idiopathic form of the syndrome. Programmed right and left ventricular stimulation with up to three extrastimuli before and during isoproterenol infusion did not induce sustained ventricular tachycardia or ventricular fibrillation in any of the patients. However, rapid polymorphic nonsustained ventricular tachycardia was induced in six of the 15 patients (40%). Neither the inducibility of nonsustained ventricular tachycardia nor the results of electropharmacologic testing with beta-blockers proved to be of any prognostic value during the mean follow-up period of 28 +/- 17 months. Electrophysiologic studies are of limited value in the diagnosis and treatment of patients with the long QT syndrome.

URL الوصول: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::6a9aea0350d59a686d717eb2e9714d02
https://pubmed.ncbi.nlm.nih.gov/2856866