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.

Leadless Pacemakers: Recent and Future Developments.

PURPOSE OF REVIEW: Leadless pacemakers were developed to reduce complications associated with transvenous pacemaker implant and long-term follow-up. Since initial market release, however, there have been registry and single-center reports documenting improvements in implant technique, reduced complication rates, and new patient populations studied. RECENT FINDINGS: Most studies have demonstrated a further reduction in complication rates and safe implant in those on continuous anticoagulation. Perforation rates are decreasing but still occur and risk factors include BMI < 20 kg/m2, age ≥ 85 years, females, history of heart failure, indication not including atrial fibrillation, and chronic lung disease. Device infections are exceedingly rare, even in those undergoing infected transvenous devices at the same time. For appropriate patients, leadless pacing is a safe and reasonable option, especially if atrial-based sensing or pacing is not needed. Future iterations may include VDD pacing, atrial pacing, dual-chamber pacing, biventricular pacing, and device-device communication.

Special Operations Soldier With Cardiac Family History: Use of CCTA and Protein Biomarker Testing to Detect Risk of Heart Attack From Noncalcified Plaque.

OBJECTIVE: We sought to characterize the risk of a heart attack in a 48-year-old asymptomatic US Special Operations Command (SOCOM) Soldier without known coronary artery disease (CAD). BACKGROUND: CAD continues to be a leading cause of morbidity and mortality among most age groups in the United States. Much research is dedicated to establishing new techniques to predict myocardial infarction (MI). METHODS: Coronary computed tomography (CT) angiography, also known as CCTA, along with 7-protein serum biomarker risk assessment was performed for risk evaluation. RESULTS: A 48-year-old SOCOM Soldier with a family history of heart disease had skeletal chest pain from war injuries and a 5-fold higher risk of heart attack over the next 5 years on the basis of protein markers. A nonobstructive left anterior descending coronary artery (LAD) plaque with a lipid-rich core and a thin fibrous cap (i.e., vulnerable plaque) was detected by CCTA. The patient was warned about his risk and prescribed four cardiac medications and scheduled for angioplasty even though he fell outside the guidelines by not having a severe obstructive blockage. Four days later, unfortunately, he had a heart attack before starting his medications and before angioplasty. CONCLUSION: CCTA with biomarker testing may have an important role in predicating acute coronary syndrome (ACS) in Special Operations Forces (SOF) Soldiers with at least one risk factor. Conventional stress testing and nuclear scanning would not detect non-flow-limiting vulnerable plaques in vulnerable patients. In order to collect more data, the PROTECT Registry has been started to evaluate asymptomatic Soldiers with at least one risk factor referred to the clinic by military physicians.