The clinical use of external noninvasive pacing in the termination of sustained ventricular tachycardia

In order to evaluate the potential use of external cardiac pacing (EXP) in the clinical termination of sustained ventricular tachycardia (VT), we attempted VT terminations in seven patients. All had recurrent sustained monomorphic ventricular tachycardia (mean rate 145 beats/min), which had previously required cardioversion. During subsequent VT episodes, all seven underwent overdrive pacing with EXP at a pulse amplitude of 120 mA, and rates of 200 pulses/min. A total of 18 of 18 episodes of VT were successfully terminated by EXP alone. In one patient, the first attempt at EXP termination of one episode of VT resulted in an acceleration of the tachycardia, which was then terminated by EXP. All patients tolerated EXP well with minimal sedation. We conclude that EXP may be an effective clinical modality for the termination of sustained monomorphic ventricular tachycardia.

External pacing for the termination of sustained supraventricular tachycardia in children

Cardiac pacing from either endocardial or transesophageal sites has proven useful in termination of sustained supraventricular tachycardia in children. In two patients we demonstrated the efficacy of external pacing in the termination of sustained supraventricular tachycardia. The ease and apparent safety of the technique make it an attractive addition to our current therapies for supraventricular tachycardia in children. The usefulness of external pacing in treating pediatric arrhythmias needs further evaluation.

A technique for intraoperative arrhythmia induction during automatic implantable defibrillator placement

In 14 patients (12 men, 2 women, mean age 51 +/- 4 years) we evaluated a new technique for intraoperative arrhythmia induction during Ventak 1550 automatic implantable cardioverter defibrillator (AICD), pulse generator placement. At the time of surgery (nine new implants, five pulse generator replacements), when the AICD pulse generator is in its final configuration with the rate sensing and patch electrodes leads inserted into the header, a #2 hex wrench was inserted into each of the rate sensing lead set screw sites. The alligator clips of a temporary pacing cable were placed on each of the hex wrenches and the remainder of the cable passed off field for attachment to a programmed stimulator or AC fibrillator. In all 14 patients, the clinical arrhythmia was induced at least twice (ventricular tachycardia in eight patients, ventricular fibrillation in six patients). No difficulties with arrhythmia induction or AICD sensing as discharge were encountered. We conclude that this technique is both a safe and effective means of intraoperative arrhythmia induction during placement or replacement in the Ventak AICD 1550 and 1600 series pulse generators.

A technique for the prevention of automatic implantable cardioverter defibrillator generator migration

In order to prevent AICD generator migration in nine patients and correct chronic painful generator migration in three patients, we placed the AICD generator in an absorbable microfibrillar collagen pouch at the time of implant to facilitate fibrous capsule formation. Over a mean follow-up period of 14 +/- 2 months for the new implants, there have been no episodes of generator erosion, migration or infection. The three patients who suffered from generator migration have been symptom free for 12 +/- 2 months. We conclude that use of a microfibrillar collagen pouch at the time of AICD implant is a safe, inexpensive, and effective method for preventing generator migration.

Hypervitaminosis A following long-term use of high-dose fish oil supplements

The use of various dietary supplements containing fish oils has become popular as a method of reducing the risk of developing cardiovascular disease. However, consumption of large amounts of these substances may pose some potential hazards. Described herein is a patient who developed hypervitaminosis A after prolonged fish oil supplement ingestion.

Propafenone--a new agent for the treatment of ventricular arrhythmias

Over the last several years a number of new and potent antiarrhythmic agents have been developed. One of these promising new drugs, propafenone hydrochloride (Rhythmol), will soon be available for use in this country. Although similar in some aspects to flecainide and encainide, the drug possesses some unique characteristics. The purpose of this review is to summarize the pharmacologic and physiologic effects of propafenone and to outline its clinical use.

Termination of ventricular tachycardia by carotid sinus stimulation

A 56-year-old white male developed sustained ventricular tachycardia which was terminated by carotid sinus stimulation. Intracardiac electrophysiologic study reproduced the tachycardia which was repeatedly terminated by carotid massage. This report, together with others reviewed here, suggests that tachycardia termination by simple carotid stimulation does not always prove a supraventricular origin.

Clinical suppression of refractory ventricular tachycardia with oral bretylium not predicted by electrophysiologic drug testing

We report the findings in a patient in whom intravenous bretylium was the only effective agent to suppress refractory ventricular tachycardia and ventricular fibrillation. After attempts to switch the patient to amiodarone and bethanidine (an oral analogue of bretylium) caused proarrhythmic effects, he was successfully converted to oral therapy with bretylium. Electrophysiologic testing was not predictive of the clinical response from oral bretylium. To our knowledge, this is the first report of a proarrhythmic effect from bethanadine and it suggests a divergence in the actions of various class 3 antiarrhythmic agents.

Termination of sustained ventricular tachycardia by external noninvasive pacing

Cardiac pacing has proven useful in the termination of sustained ventricular tachycardia (VT). In this study, the effectiveness of external noninvasive temporary pacing was compared with traditional endocardial burst ventricular pacing for the termination of sustained and hemodynamically stable VT. In 14 patients, 16 VT morphologies induced by programmed right ventricular extrastimulation were reproducibly terminated by endocardial burst pacing (3 to 9 complexes). VT cycle lengths averaged 392 +/- 97 ms (standard deviation) and ranged from 300 to 690 ms. The endocardial burst pacing cycle length used to terminate VT averaged 298 +/- 93 ms (range 220 to 600 ms). External burst pacing terminated 14 of 16 VT morphologies (88%). The pacing cycle length used to terminate these 14 VTs averaged 282 +/- 44 ms. The number of ventricular captures ranged from 5 to 20 beats. Failure to terminate 2 VT morphologies probably represented a failure of the device to capture the ventricle. Acceleration of VT occurred in 1 patient with burst external noninvasive pacing. These observations suggest that external burst pacing may be an effective means of terminating sustained VT in some patients.

Digitalis delirium in an elderly woman

A case of anorexia, paranoid delusions, and lethargy associated with digoxin toxicity is presented here. The digitalis glycosides are among the most commonly used drugs in modern medicine, and as such, they frequently cause toxicity. Although cardiac side effects of digoxin are well recognized, less attention has been paid to potential CNS effects. Psychiatric manifestations, from calm disorientation to violent psychosis, tend to occur more often in elderly patients and may be the earliest or only sign of digitalis toxicity.

Acute myelocytic leukemia in a patient treated with hexamethylmelamine

This case report describes a 76-year-old white woman who was found to have ovarian cancer and underwent chemotherapy with hexamethylmelamine. After 34 months of therapy, she developed an acute myelocytic leukemia. Although commonly reported as a side effect of alkylating agents, this is believed to be the first reported case of an acute nonlymphocytic leukemia associated with hexamethylmelamine use.

Flecainide: a new agent for the treatment of ventricular arrhythmias

Flecainide has been shown to be a relatively safe and effective antiarrhythmic agent. Its twice daily dosage schedule and demonstrated efficacy in suppression of ventricular ectopy suggest that it will be a valuable agent in the therapy of ventricular arrhythmias.

Candidal costochondritis responsive to ketoconazole in an iv drug abuser

Infections caused by Candida albicans have been reported in many organ systems in intravenous drug users. Amphotericin B (Fungizone) has been shown to be effective in treatment. However, because of its numerous side effects and difficulty in maintaining intravenous access in this population, the agent is difficult to use. Ketoconazole (Nizoral), administered orally, is a more convenient and better tolerated agent and was efficacious in the case of candidal costochondritis described here. Further evaluation of ketoconazole is needed to better define its role in the treatment of disseminated candidiasis, particularly in cases associated with intravenous drug abuse.

Neuroblastoma in an adult

Neuroblastoma in adults is probably a more frequent disease than is generally recognized, owing to difficulties in the microscopic diagnosis. It has no sex predominance and has occurred in patients aged 18 to 72 years. Based on the results in the patient we have described, cyclophosphamide and prednisone would seem an effective and well tolerated chemotherapeutic combination.