A novel automated peak frequency annotation algorithm for identifying deceleration zones and ventricular tachycardia ablation sites.

BACKGROUND: Current annotation of local fractionated signals during ventricular electroanatomic mapping (EAM) requires manual input subject to variability and error. OBJECTIVES: The purpose of this study was to evaluate a novel peak frequency (PF) annotation software for its ability to automatically detect late potentials (LPs) and local abnormal ventricular activity (LAVA), determine an optimal range for display, and assess its impact on isochronal late activation mapping (ILAM). METHODS: EAM data from 25 patients who underwent ventricular tachycardia (VT) ablation were retrospectively analyzed. Samplings of electrogram PFs from areas of normal bipolar voltage, areas of low voltage, and areas of low voltage with fractioned signals were performed. An optimal range of frequency display was identified from these patients and applied to a validation cohort of 10 prospective patients to assess high PF within scar as a predictor of VT ablation target sites, in particular deceleration zones (DZs) identified by ILAM, LP, and LAVA. RESULTS: Voltage and PF ranges of normal endocardial tissue varied widely. Using 220 Hz as a frequency cutoff value in areas of low bipolar voltage, areas of high fractionation were identified with sensitivity of 91% and specificity of 85% There was no significant reduction in targeted DZ surface areas, and colocalization with DZs was observed in all cases. Applied to the prospective cohort, PF predicted fractionated areas and DZ in 9 of 10 patients. CONCLUSION: A PF annotation algorithm with a cutoff of 220 Hz accurately identifies areas of fractioned signals and accurately predicts DZs during ILAM.

Use of antibiotic envelopes to prevent cardiac implantable electronic device infections: A meta-analysis.

INTRODUCTION: The rates of cardiac implantable electronic device (CIED) infections have risen over the past decade and are associated with increased hospitalizations and mortality. A number of preventative strategies have been developed including an antibiotic coated envelope, but it has yet to gain widespread use. METHODS: A meta-analysis was performed on controlled studies of the antibiotic envelope. PubMed and Google Scholar were searched for studies comparing infection rates with and without the use of an antibiotic envelope. Studies including both new implants and pulse generator replacements were included in the analysis. RESULTS: Five studies were included in the meta-analysis. A total of 4,490 patients underwent CIED implantation, 1,798 with an antibiotic envelope and 2,692 without an envelope. In the pooled cohort, the envelope was associated with a 69% relative risk reduction in CIED infection (0.31 [0.17, 0.58] 95% CI, P = 0.0002). Propensity matched data from three studies were analyzed to ensure accurate comparison. In the risk-matched cohort, infections were significantly lower in the envelope group (3 vs. 26, P < 0.0003). CONCLUSION: The use of antibiotic envelopes in CIED implant is associated with a significantly lower rate of infection.

Intractable cardiac arrest due to lidocaine toxicity successfully resuscitated with lipid emulsion.

OBJECTIVE: Demonstrate a case report involving successful use of lipid emulsion therapy for intractable cardiac arrest due to lidocaine toxicity. DATA SOURCE: Lipid emulsion therapy has been shown to be effective in treating the cardiotoxic effects of such drugs as bupivacaine, verapamil, propranolol, and clomipramine as mentioned in a 2009 editorial in Critical Care Medicine by Jeffrey Bent. The mechanism of action of lipid emulsion therapy is not well defined and has been postulated to work by both a "lipid sink," decreasing circulating amounts of drugs to the periphery, or through a direct "energy source" to the myocardium. We present a case report of a patient successfully resuscitated with lipid emulsion therapy after prolonged and intractable lidocaine toxicity. Lidocaine is generally considered much less cardiotoxic than other local anesthetics and is used commonly as infusions for intractable ventricular arrhythmias. CONCLUSION: This case demonstrates the need to consider lipid emulsion therapy in the advanced cardiac life support algorithm for lidocaine toxicity as well as other lipid soluble drug intoxications.