Efficacy and toxicity of amiodarone for the treatment of supraventricular tachyarrhythmias.

Amiodarone is an effective agent for all types of supraventricular tachyarrhythmias regardless of mechanism and may, in fact, control a high percentage of supraventricular tachyarrhythmias refractory to conventional antiarrhythmic agents. However, its toxicity should temper enthusiasm for the use of the medication in non-life-threatening arrhythmias. As always, when recommending specific therapies the potential benefit should be weighed in light of the related risk.

Drug therapy for survivors of sudden cardiac death.

The proliferation of standard as well as novel community based systems for resuscitation of victims of out-of-hospital cardiac arrest has provided a large group of sudden cardiac death survivors who present a therapeutic challenge. The nature and severity of the underlying heart disease must be delineated. Particularly, myocardial ischemia and congestive heart failure must be controlled.

Proarrhythmic effects of antiarrhythmic drugs in patients with malignant ventricular arrhythmias evaluated by electrophysiologic testing.

The provocation or worsening of arrhythmias by antiarrhythmic regimens was evaluated in patients with malignant ventricular arrhythmias undergoing electrophysiologic studies. In 314 patients with sustained or nonsustained ventricular tachycardia or ventricular fibrillation, 801 drug studies were performed using a standard protocol of programmed electrical stimulation. The criteria for proarrhythmia were: 1) initiation of sustained ventricular tachyarrhythmia in a patient in whom only nonsustained tachycardia was induced at baseline; 2) conversion of a sustained tachycardia that could be terminated by programmed electrical stimulation at baseline to one that required cardioversion for termination during drug therapy; 3) initiation of a sustained tachyarrhythmia by a less aggressive mode of stimulation than was required at baseline; and 4) development of spontaneous or incessant ventricular tachycardia.

Relation of acute antiarrhythmic drug efficacy to left ventricular function in coronary artery disease.

This study assessed the relation between acute antiarrhythmic drug efficacy and left ventricular (LV) function in patients with sustained ventricular tachyarrhythmias, that is, sustained ventricular tachycardia (VT) or ventricular fibrillation (VF). Electrophysiologic studies (n = 560) were performed in 201 patients, separated for analysis into less than 30 and greater than or equal to 30% ejection fraction groups. Coronary artery disease was present in all patients.

The electrophysiologic properties of esmolol, a short acting beta-blocker.

Although beta-blockers have established efficacy in treating ventricular ectopy and PSVT, their applicability for acute antiarrhythmic interventions in patients with organic heart disease or COPD, is frequently limited by negative inotropic or bronchospastic side effects. The development of an ultrashort acting beta-blocker with rapid reversibility of its side effects would widen their applicability. Therefore, we tested the electrophysiologic properties of such a new short acting beta-blocker, esmolol, in 14 patients (10 with organic heart disease) with a mean EF of 47.

New antiarrhythmic drugs.

While controversy still exists as to the precise indications for the treatment of all forms of ventricular arrhythmia, advances in the number and, more importantly, type of antiarrhythmic drugs can provide the clinician with a rational basis for selecting antiarrhythmic drug therapy. A host of new agents with different pharmacokinetic and electrophysiological actions are now available, and can be compared or contrasted to conventional antiarrhythmic agents such as quinidine, procainamide, disopyramide, lignocaine (lidocaine) and bretylium. This review summarises the electrophysiological, haemodynamic, pharmacokinetic, and efficacy and safety data of mexiletine, tocainide, flecainide, encainide, propafenone, amiodarone, sotalol, pirmenol, cibenzoline (cifenline) and ethmozine (moracizine, moricizine), and aims to provide a basis on which clinicians can compare and contrast these agents and form an algorithm for selection of antiarrhythmic drug therapy in the treatment of patients with ventricular arrhythmias.

Inducible atrial flutter after the Mustard repair of complete transposition of the great arteries.

Atrial flutter is a common postoperative arrhythmia in patients with complete transposition of the great arteries (d-TGA) after the Mustard repair. Sixty patients with d-TGA who had the Mustard repair were evaluated by electrophysiologic studies. Thirty-three (55%) had inducible sustained atrial flutter; 17 of them developed spontaneous clinical episodes of atrial flutter (clinical atrial flutter group) and 16 did not (nonclinical atrial flutter group).

Development of prone extension postures in healthy infants.

The purposes of this study were to 1) investigate the sequence of development of head, upper extremity, and lower extremity extension in the prone extension posture in healthy infants; 2) identify the variations in the sequence; and 3) compare these postures within the sequence with the development of prone-on-elbows and prone-on-hands postures. Twenty healthy, full-term infants were observed longitudinally from 8 to 28 weeks of age. Two of the infants could not complete the study, and two infants never used the prone extension posture.

Electrophysiologic consequences of the Mustard repair of d-transposition of the great arteries.

This study describes the electrophysiologic effects of the Mustard repair of d-transposition of the great arteries on the sinus node and on conduction and refractoriness in the atrium, atrioventricular (AV) node and ventricle. Seventy-two electrophysiologic studies were performed on 64 patients after the Mustard operation. Standard rest and 24 hour ambulatory electrocardiograms were evaluated.

Development of congestive heart failure and alterations in left ventricular function in patients with sustained ventricular tachyarrhythmias treated with amiodarone.

The interaction between the efficacy and tolerance of amiodarone and the degree of left ventricular (LV) dysfunction was assessed in 126 patients with sustained ventricular tachyarrhythmias. In all patients radionuclide angiographic LV ejection fraction (EF) was measured before and after 8 to 12 months of amiodarone therapy. At baseline mean EF was 25 +/- 13% and 86 patients had an EF of 30% or less.

Determinants of hospital cost and length of stay for patients undergoing electrophysiologic testing.

To assess the effects of various clinical factors in determining the cost and length of stay in patients undergoing electrophysiologic testing for cardiac arrhythmias, the hospital cost and length of stay data were reviewed in 222 consecutive inpatients who underwent electrophysiologic testing from January 1 to December 31, 1984. Admissions were classified as: primarily for treatment of arrhythmias (171 patients); primarily for treatment of arrhythmias but with serious concurrent illnesses that prolonged hospitalization (43 patients); or primarily for nonarrhythmic problems with electrophysiologic study an incidental part of hospitalization (8 patients). Based on allowable length of stay for the applicable DRGs, actual hospitalizations exceeded Medicare allowable length of stay by 50 to 500%.

Reduction in sudden death and total mortality by antiarrhythmic therapy evaluated by electrophysiologic drug testing: criteria of efficacy in patients with sustained ventricular tachyarrhythmia.

Reports of the results of electrophysiologic testing of antiarrhythmic regimens have concentrated on inducibility of ventricular tachycardias during drug treatment. Many drug regimens, however, affect the tachycardia but fail to prevent its initiation. In this study, 258 patients who underwent serial electrophysiologic studies were followed up.

Poor social performance of lonely people: lacking a skill or adopting a role?

A substantial literature has shown that lonely people differ from nonlonely people on a variety of measures of social performance. These differences have usually been conceptualized as a social skills deficit, which implies that lonely people lack the ability to perform appropriate and effective social behavior. Rather than a lack of this ability, the authors hypothesize that the adoption of passive interpersonal roles predisposes lonely people to exhibit inadequate performance.

Risks and complications of clinical cardiac electrophysiologic studies: a prospective analysis of 1,000 consecutive patients.

The complications of clinical cardiac electrophysiologic studies were prospectively evaluated in 1,000 consecutive patients studied in one laboratory with an unaltered protocol to better assess the risks of this procedure. There were 728 men and the mean age of the entire group was 58 years (range 16 to 84). Coronary artery disease was the most common type of heart disease (56%) and 200 patients had no identifiable organic heart disease.

Efficacy of oral and intravenous indecainide in ventricular arrhythmias.

To evaluate the efficacy of oral and intravenous indecainide, a new class IC antiarrhythmic agent, 3 separate protocols were performed in patients with benign or potentially lethal ventricular arrhythmias. An open-label intravenous trail in 10 patients was conducted using a dose of 1.7 mg/kg/min under constant monitoring.

Proarrhythmic responses during electrophysiologic testing.

Antiarrhythmic drugs may worsen ventricular arrhythmias in certain patients. This effect, termed proarrhythmia, aggravation or provocation of arrhythmia, can be investigated with either noninvasive or invasive techniques. Using electrophysiologic study, 160 patients with ventricular tachycardia or ventricular fibrillation were evaluated during treatment with 432 different antiarrhythmic regimens.