Publications by authors named "Andrew H Locke"

Background: Pulmonary vein isolation (PVI) is superior to antiarrhythmics for the management of atrial fibrillation, but repeat ablation is often required for durable rhythm control. Factors influencing first-pass isolation (FPI) and whether FPI predicts durable isolation are not well known.

Objective: The study sought to determine factors associated with FPI and rates of chronic reconnection among those with and without FPI at index PVI in patients undergoing repeat ablation.

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With the expanding use of cardiac implantable electronic device (CIED) therapy, intravascular device infections are becoming more common. In the case of transvenous implantable cardioverter-defibrillator (ICD) infections requiring extraction for bacterial clearance, there remains no standard method to deliver temporary ICD therapy following device removal. We present a case of persistent bacteremia complicated by monomorphic ventricular tachycardia (VT) electrical storm where biventricular ICD system extraction was performed and a temporary transvenous dual-coil lead with an externalized ICD generator was used to treat VT episodes prior to the re-implantation of a new permanent system.

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The efficacy and safety of hybrid ablation (HA) for patients with non-paroxysmal atrial fibrillation (AF) remain unclear. PubMed, Embase, Cochrane, and ClinicalTrials.gov were searched for randomized controlled trials (RCTs) comparing HA (endo-epicardial ablation) versus endocardial ablation (EA) for patients with persistent/long-standing persistent AF.

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Background: The boundaries of critical isthmuses for re-entrant ventricular tachycardia (VT) are formed by wavefront discontinuities (fixed lines of block, slow propagation, and rotational propagation) seen during baseline rhythm. It is unknown whether wavefront discontinuities can be automatically identified and targeted for ablation using electroanatomic mapping systems.

Objectives: The purpose of this study was to assess the electrophysiologic characteristics of automatically projected wavefront discontinuity lines (WADLs) and outcomes of an ablation strategy targeting WADLs in a mixed cohort of VT patients.

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Background: Myocardial electrical heterogeneity is critical for normal cardiac electromechanical function, but abnormal or excessive electrical heterogeneity is proarrhythmic. The spatial ventricular gradient (SVG), a vectorcardiographic measure of electrical heterogeneity, has been associated with arrhythmic events during long-term follow-up, but its relationship with short-term inducibility of ventricular arrhythmias (VAs) is unclear.

Objective: This study was designed to determine associations between SVG and inducible VAs during electrophysiology study.

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Background: Functional substrate mapping during baseline rhythm can identify arrhythmogenic tissue during ventricular tachycardia (VT) ablation. Wall thinning and wall thickness channels (WTCs) derived from computed tomography angiography have been shown to correlate with low voltage and VT isthmuses. The correlation between functional substrate mapping, wall thinning, and WTCs in patients with infarct- or non-infarct-related cardiomyopathies (ICM and NICM, respectively) has not been previously described.

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Background: The incidence and clinical impact of lead-related venous obstruction (LRVO) among patients with cardiovascular implantable electronic devices (CIEDs) is poorly defined.

Objectives: The objectives of this study were to determine the incidence of symptomatic LRVO after CIED implant; describe patterns in CIED extraction and revascularization; and quantify LRVO-related health care utilization based on each type of intervention.

Methods: LRVO status was defined among Medicare beneficiaries after CIED implant from October 1, 2015, to December 31, 2020.

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Cardiac implantable electronic device implantation rates have increased in recent decades. Venous obstruction of the subclavian, brachiocephalic, or superior vena cava veins represents an important complication of implanted leads. These forms of venous obstruction can result in significant symptoms as well as present a barrier to the implantation of additional device leads.

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Superior vena cava (SVC) syndrome is a rare complication associated with transvenous cardiac implantable electronic devices that may present with a variety of manifestations. Various strategies such as transvenous lead extraction, anticoagulation, venoplasty, and stenting have been used to treat this condition, but the optimal management protocols have yet to be defined. Subcutaneous implantable cardioverter-defibrillator (ICD) (S-ICD) therapy can be an alternative option to a transvenous system for those who require future ICD surveillance.

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Cardiac sarcoidosis (CS) is a complex disease that can manifest as a diverse array of arrhythmias. CS patients may be at higher risk for sudden cardiac death (SCD), and, in some cases, SCD may be the first presenting symptom of the underlying disease. As such, identification, risk stratification, and management of CS-related arrhythmia are crucial in the care of these patients.

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Randomized trials inform the use of implantable cardioverter-defibrillators (ICDs) for prevention of sudden cardiac death, yet management of patients considering ICD generator replacement procedures remains largely dependent on clinical judgment. Thus, we performed a systematic review of all studies evaluating outcomes associated with ICD generator replacement. We queried PubMed, Embase, Web of Science, and the Cochrane Database of Systematic Reviews for relevant studies with a prespecified search and adjudication strategy (PROSPERO registration number CRD42018100818) to evaluate outcomes including (1) survival; (2) clinical complications (eg, infection, hematoma); or (3) incidence of ICD therapy.

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Aortic valve intervention (AVI) in patients with a severe aortic stenosis (AS) and a preserved left ventricular ejection fraction (LVEF) is controversial. Mitral annular plane systolic excursion (MAPSE) is an easily acquired metric of left ventricular longitudinal shortening. We sought to investigate if an asymptomatic decrease in MAPSE preceded the need for AVI in asymptomatic patients with AS and a preserved LVEF.

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Introduction: The use of preprocedural CT or MR imaging to generate patient-specific cardiac anatomy greatly facilitates catheter ablation of the left atrium and pulmonary veins (LA-PVs) to treat atrial fibrillation (AF). This report details the accuracy and utility of an intraprocedural means to generate 3-D volumetric renderings of the LA-PV anatomy: contrast-enhanced rotational X-ray angiography (3DRA).

Methods And Results: Preprocedural CT or MR imaging and intraprocedural rotational angiography was performed in 42 patients undergoing AF ablation procedures.

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