Adrenergic and metabolic effects of electrical weapons: review and meta-analysis of human data.

INTRODUCTION: Electronic control with the CEW (conducted electrical weapon) has gained widespread acceptance as the preferred force option due to its significant injury reduction. However, a CEW application does stress the human body. In the case of the CEW, the human body response is similar to the challenge of physical exercise combined with emotional stress over a very short time interval. There has been concern whether the tension of the skeletal-muscle system together with the emotional stress of being exposed to the effects of a CEW, can lead to severe metabolic dysfunction. METHODS: A systematic and careful search of the MedLine database was performed to find publications describing pathophysiological effects of CEWs. Additional publications were collected through a manual search of reference lists in retrieved articles. After preliminary exclusions, we carefully reviewed the remaining publications and found 24 papers reporting prospective human clinical research data on adrenergic, ventilation, or metabolic effects. Where there were multiple studies on the same endpoints, we performed meta-analyses. RESULTS: A CEW exposure provides a clinically insignificant increase in heart rate (7.5 BPM) and a drop in both systolic and diastolic blood pressure. Alpha-amylase goes down but cortisol levels increase-both epinephrine and norepinephrine levels are increased by levels similar to mild exercise. A CEW exposure increases ventilation but does not appear to interfere with gas exchange. Lactate is increased slightly while the pH is decreased slightly with changes equivalent to mild exercise. The lactate and pH changes appear quickly and do not appear to be affected by increasing the exposure duration from 5 to 30 s. CONCLUSIONS: Thorough review and meta-analyses show that electrical weapon exposures have mixed and mild adrenergic effects. Ventilation is increased and there are metabolic changes similar to mild exercise.

Complications associated with radiofrequency catheter ablation of cardiac arrhythmias.

Catheter ablation using radiofrequency energy has evolved as a safe and effective means for the treatment of various supraventricular and ventricular arrhythmias. Despite the overall efficacy of radiofrequency catheter ablation, cardiovascular complications can occur in a small number of patients. The purpose of this article is to review the current understanding of the risks and complications that can occur during catheter ablation procedures.

Sudden cardiac death in heart failure. The role of abnormal repolarization.

Congestive heart failure is a common, highly lethal cardiovascular disorder claiming over 200,000 lives a year in the United States alone. Some 50% of the deaths in heart failure patients are sudden, and most of these are probably the result of ventricular tachyarrhythmias. Methods designed to identify patients at risk have been remarkably unrewarding, as have attempts to intervene and prevent sudden death in these patients. The failure to impact favorably on the incidence of sudden death in heart failure patients stems largely from a lack of understanding of the underlying mechanisms of arrhythmogenesis. This article explores the role of abnormalities of ventricular repolarization in heart failure patients. We will examine evidence for the hypothesis that alteration of repolarizing K+ channel expression in failing myocardium predisposes to abnormalities in repolarization that are arrhythmogenic. The possible utility of novel electrophysiological and ECG measures of altered ventricular repolarization will be explored. Understanding the mechanism of sudden death in heart failure may lead to effective therapy and more accurate identification of patients at greatest risk.

Aortic leaflet perforation during radiofrequency ablation.

A 15-year-old girl underwent successful radiofrequency ablation of an accessory pathway. Following ablation, a new III/VI diastolic murmur was noted. Echocardiography revealed a perforated aortic leaflet, with a small amount of adherent valvular tissue and trivial aortic insufficiency by color Doppler. The patient remains asymptomatic. We are not aware of any similar complication from electrophysiological study, catheter ablation, coronary angiography, or percutaneous transluminal coronary angioplasty. We speculate that the current state of catheter technology contributed significantly to this complication. This case illustrates the need for using care in crossing the valve, continued advances in catheter technology to reduce the incidence of complications, and careful physical examination prior to and following attempts at ablation.