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Biomedical subjects

R Ruffy

Publications and source records attributed to R Ruffy.

At least 37 records · Page 2Linked to original sources
PubMed1986

Flecainide in the treatment of nonsustained ventricular tachycardia.

Thirty-two patients received flecainide acetate for nonsustained ventricular tachycardia after having had unsuccessful treatment with a mean of four antiarrhythmic drugs. The mean left ventricular ejection fraction was 41% in 27. Thirty-one patients had organic heart disease, and 22 patients had arrhythmia-related symptoms. Total suppression of ventricular tachycardia occurred in 22 patients. Thirty patients were discharged from the hospital receiving flecainide at a mean (+/- SD) dosage of 315 +/- 76 mg/d and 26 of these patients attained a mean trough plasma drug level of 567 +/- 254 ng/mL. One patient had proarrhythmia and 3 had worsening of heart failure. Twenty-two patients remained in the trial for a mean follow-up of 13 +/- 7 months. Five patients died (1 suddenly) during the follow-up period. Our data indicate that flecainide suppresses refractory nonsustained ventricular tachycardia in 69% of patients who have organic heart disease. Serious adverse effects were minimized by initiation of treatment in the hospital and careful surveillance of electrocardiograms and plasma drug levels.

Adult↗
PubMed1985

Out-of-hospital automatic cardioversion of ventricular tachycardia.

A 42 year old man who survived sudden cardiac death was treated with an automatic implantable cardioverter/defibrillator. After a 5 month symptom-free interval, the patient received two internal discharges in the conscious state while wearing an ambulatory electrocardiographic recorder. Analysis of the tape revealed that both discharges were activated by two bursts of polymorphous ventricular tachycardia, the first one occurring at the end and the second at the onset of episodes of slow, hemodynamically stable monomorphous ventricular tachycardia. This case illustrates the reliability of the automatic implantable cardioverter/defibrillator as an antiventricular tachycardia device and the problem posed by its exposure to nonsustained ventricular tachycardia.

Adult↗
PubMed1985

Paroxysmal fascicular tachycardia: electrophysiologic characteristics and treatment by catheter ablation.

A 69 year old man with ischemic heart disease underwent electrophysiologic evaluation for paroxysmal wide QRS tachycardia, the configuration of which was identical to that recorded during sinus rhythm, that is, right bundle branch block, left anterior fascicular block and anterior myocardial infarction. Electrocardiographic recordings during tachycardia showed atrioventricular dissociation and His bundle activation occurring 5 ms after the onset of the QRS complex recorded on the surface electrocardiogram, consistent with a left posterior fascicular tachycardia. All traditional therapeutic attempts failed to prevent frequent recurrences of tachycardia, which was finally ablated by three 300 J shocks delivered through an electrode catheter positioned in the posterobasal region of the left ventricular septum.

Aged↗
PubMed1985

Short- and long-term experience with flecainide acetate in the management of refractory life-threatening ventricular arrhythmias.

Thirty-eight patients with organic heart disease and history of sudden cardiac arrest or recurrent sustained ventricular tachycardia were treated with flecainide. Coronary artery disease was present in 33 patients. Previous antiarrhythmic therapy consisted of two to eight drugs (mean four). Fourteen patients were resuscitated from sudden cardiac death and 24 patients had chronic recurrent sustained ventricular tachycardia. Twenty-eight patients had electrophysiologic testing before and during flecainide treatment. Sustained ventricular tachycardia became noninducible in 5 patients, nonsustained in 5 patients and slowed in 13 patients (cycle length increased from 278 +/- 64 to 395 +/- 91 ms; p = 0.002). Three of the 14 patients with sudden cardiac death and 15 of the 24 patients with recurrent sustained ventricular tachycardia remained on long-term flecainide treatment. The mean left ventricular ejection fraction in 16 of these 18 patients was 37%. Nonlimiting side effects occurred in seven patients (18%). Proarrhythmic effects were seen in four patients (10%). At a mean follow-up time of 11 +/- 3 months, 15 patients (39%) had had no recurrence, including 5 who had inducible sustained ventricular tachycardia and 5 who did not on retesting during treatment. In the 18 patients who received long-term therapy, 3 late deaths occurred, 1 of which was of arrhythmic origin. These data suggest that flecainide is effective in about 40% of patients with severe refractory ventricular arrhythmias. Its value as a single drug in the treatment of sudden cardiac death remains to be defined.

Adolescent↗
PubMed1985

Beta-adrenergic modulation of direct defibrillation energy in anesthetized dog heart.

Catecholamines facilitate ventricular defibrillation in animals. We examined the effects of beta-adrenergic stimulation and blockade on ventricular defibrillation threshold in anesthetized dogs. Calibrated shocks were delivered between epicardial and superior vena caval electrodes, and defibrillation threshold was measured before and after administration of isoproterenol and propranolol. Eight dogs (group 1) received isoproterenol before propranolol. Nine dogs (group 2) received propranolol before isoproterenol. In group 1, the minimum energy required to defibrillate before isoproterenol was 10.6 +/- 1.7 (SE) J and decreased to 5.9 +/- 1.3 with isoproterenol (P less than 0.001). In group 2, the minimum energy required to defibrillate was 8.3 +/- 2.4 J before propranolol and increased to 10.7 +/- 2.2 after propranolol (P less than 0.001). In group 1, propranolol after isoproterenol increased defibrillation threshold (P less than 0.07), whereas in group 2 isoproterenol after propranolol produced no significant change in defibrillation threshold. Thus beta-stimulation decreased defibrillation threshold significantly in the anesthetized dog heart, an effect that was blocked by propranolol. Conversely, propranolol increased defibrillation threshold, an effect that occurred despite prior beta-stimulation, probably because of the short half-life of isoproterenol.

Animals↗
PubMed1983

An electrophysiology report-generating system with data base capabilities.

This article describes the Electrophysiology Report-Generating system (EPREG) which produces reports of clinical cardiac electrophysiologic studies. Reports generated by EPREG are permanently stored on floppy disk media. Selected information from the reports is used to generate an on-line data base upon which selective searches may be made. Use of the system saves an estimated 2 to 3 hours per week compared to an equivalent manual approach. The system has been implemented on a programmable word processor (Wang OIS-140) which is also used for other activities within our medical division.

Computers↗
PubMed1983

Termination of ventricular tachycardia by single extrastimulation during the ventricular effective refractory period.

Termination of ventricular tachycardia by low-energy shocks delivered during the ventricular refractory period has been reported. We describe a case of reproducible termination of multiple episodes of sustained ventricular tachycardia by a low-current extrastimulus delivered during the effective refractory period of the right ventricle, from the distal bipole of a quadripolar electrode catheter.

Cardiac Pacing, Artificial↗
PubMed1983

Evaluation and treatment of survivors of sudden cardiac death or nonbradycardic syncope unrelated to coronary artery disease.

The authors describe their clinical strategy and experience with electrophysiologic testing in a group of patients who have had at least one episode of sudden cardiac death or nonbradycardic syncope in the absence of coronary artery disease. Their study shows that for this population programmed stimulation commonly induces ventricular tachycardia, which can then be suppressed by drug therapy.

Adolescent↗
PubMed1981

Effect of ethanol on electrogram changes and regional myocardial blood flow during acute myocardial ischaemia.

Acute occlusion of the left anterior descending coronary artery in dogs produced delayed conduction and diminished amplitude of bipolar electrograms recorded from ischaemic zones. Intravenous infusion of ethanol (1.2 g . kg-1), before coronary artery occlusion, delayed conduction and reduced the amplitude of electrograms recorded in normal myocardium, but attenuated ischaemia-induced electrogram changes produced by the subsequent occlusion. Ethanol (0.6 g . kg-1 iv) did not significantly alter activation of electrograms recorded from normal myocardium, but reduced ischaemia-induced electrogram changes and decreased the incidence of ventricular fibrillation elicited by rapid ventricular pacing from five of eight to one of eight dogs. Infusion of 10 or 30% (V/V) ethanol directly into a non-occluded coronary artery significantly increased conduction time and reduced electrogram amplitude recorded in the epicardium perfused by that coronary artery. These effects were more pronounced when ethanol was infused into an occluded coronary artery distal to the site of occlusion. Ethanol did not alter regional myocardial blood flow determined by labelled microspheres during ischaemia. Thus, despite a direct depressant effect on extracellular electrical activity recorded from normal and ischaemic myocardium, ethanol reduced the severity of ischaemia-induced electrogram alterations and decreased the incidence of ventricular fibrillation when given intravenously prior to coronary artery occlusion.

Acute Disease↗
PubMed1981

Influence of secobarbital and alpha-chloralose, and of vagal and sympathetic interruption, on left ventricular activation after acute coronary artery occlusion in the dog.

The purpose of this study was to examine the effect of secobarbital vs. alpha-chloralose anesthesia, and of tonic autonomic influence, upon ischemia-induced subepicardial and subendocardial bipolar electrogram changes during acute coronary artery occlusion in the open-chest dog. We found that the degree of bipolar electrogram alterations for similar reductions of regional myocardial blood flow was less in dogs anesthetized with alpha-chloralose than in those anesthetized with secobarbital. We also noted greater electrogram change when the sympathetic system was unopposed by the vagus nerves. Finally, this study demonstrates the reproducibility of ischemia-induced changes in bipolar electrograms during serial, short term, acute coronary artery occlusions.

Animals↗