Mechanisms of persistent atrial fibrillation and recurrences within 12 months post-ablation: Non-invasive mapping with electrocardiographic imaging.

Introduction: Catheter ablation of persistent AF has not been consistently successful in terminating AF or preventing arrhythmia recurrences. Non-invasive Electrocardiographic Imaging (ECGI) can help to understand recurrences by mapping the mechanisms of pre-ablation AF and comparing them with the patterns of recurrent arrhythmias in the same patient.

Methods: Seventeen persistent AF patients underwent ECGI before their first catheter ablation.

Phase I/II Trial of Electrophysiology-Guided Noninvasive Cardiac Radioablation for Ventricular Tachycardia.

Background: Case studies have suggested the efficacy of catheter-free, electrophysiology-guided noninvasive cardiac radioablation for ventricular tachycardia (VT) using stereotactic body radiation therapy, although prospective data are lacking.

Methods: We conducted a prospective phase I/II trial of noninvasive cardiac radioablation in adults with treatment-refractory episodes of VT or cardiomyopathy related to premature ventricular contractions (PVCs). Arrhythmogenic scar regions were targeted by combining noninvasive anatomic and electric cardiac imaging with a standard stereotactic body radiation therapy workflow followed by delivery of a single fraction of 25 Gy to the target.

Noninvasive Cardiac Radiation for Ablation of Ventricular Tachycardia.

Background: Recent advances have enabled noninvasive mapping of cardiac arrhythmias with electrocardiographic imaging and noninvasive delivery of precise ablative radiation with stereotactic body radiation therapy (SBRT). We combined these techniques to perform catheter-free, electrophysiology-guided, noninvasive cardiac radioablation for ventricular tachycardia.

Methods: We targeted arrhythmogenic scar regions by combining anatomical imaging with noninvasive electrocardiographic imaging during ventricular tachycardia that was induced by means of an implantable cardioverter-defibrillator (ICD).

Methodology Considerations in Phase Mapping of Human Cardiac Arrhythmias.

Background: Phase analysis of cardiac arrhythmias, particularly atrial fibrillation, has gained interest because of the ability to detect organized stable drivers (rotors) and target them for therapy. However, the lack of methodology details in publications on the topic has resulted in ongoing debate over the phase mapping technique. By comparing phase maps and activation maps, we examined advantages and limitations of phase mapping.

Implementation of a Screening Program for Patients at Risk for Posttraumatic Stress Disorder.

Introduction: Implantable cardioverter defibrillator (ICD) recipients who suffer from posttraumatic stress disorder (PTSD) are known to be associated with significant cardiac-specific mortality. Clinical observations suggest that PTSD is frequently undetected in ICD recipients followed up at electrophysiology (EP) outpatient clinics. Early recognition of PTSD is important to reduce the risk of serious manifestations on patient outcomes.

Cardiac electrophysiological substrate underlying the ECG phenotype and electrogram abnormalities in Brugada syndrome patients.

Background: Brugada syndrome (BrS) is a highly arrhythmogenic cardiac disorder, associated with an increased incidence of sudden death. Its arrhythmogenic substrate in the intact human heart remains ill-defined.

Methods And Results: Using noninvasive ECG imaging, we studied 25 BrS patients to characterize the electrophysiological substrate and 6 patients with right bundle-branch block for comparison.

Repolarization changes underlying long-term cardiac memory due to right ventricular pacing: noninvasive mapping with electrocardiographic imaging.

Background: Cardiac memory refers to the observation that altered cardiac electrical activation results in repolarization changes that persist after the restoration of a normal activation pattern. Animal studies, however, have yielded disparate conclusions, both regarding the spatial pattern of repolarization changes in cardiac memory and the underlying mechanisms. The present study was undertaken to produce 3-dimensional images of the repolarization changes underlying long-term cardiac memory in humans.

Noninvasive electroanatomic mapping of human ventricular arrhythmias with electrocardiographic imaging.

The rapid heartbeat of ventricular tachycardia (VT) can lead to sudden cardiac death and is a major health issue worldwide. Efforts to identify patients at risk, determine mechanisms of VT, and effectively prevent and treat VT through a mechanism-based approach would all be facilitated by continuous, noninvasive imaging of the arrhythmia over the entire heart. Here, we present noninvasive real-time images of human ventricular arrhythmias using electrocardiographic imaging (ECGI).

Catheter ablation of atrial fibrillation: long-term outcomes.

Atrial fibrillation is the most common arrhythmia faced in clinical practice with a substantial impact on morbidity, mortality, and heathcare expenditures. Patients with atrial fibrillation in which a rhythm control strategy is desired to improve quality of life have had limited options. The discovery of the role of pulmonary vein triggers has led to the development of catheter ablation techniques that have shown promising short-term success rates.

Noninvasive characterization of epicardial activation in humans with diverse atrial fibrillation patterns.

Background: Various mechanisms of atrial fibrillation (AF) have been demonstrated experimentally. Invasive methods to study these mechanisms in humans have limitations, precluding continuous mapping of both atria with sufficient resolution. In this article, we present continuous biatrial epicardial activation sequences of AF in humans using noninvasive electrocardiographic imaging (ECGI).

Accurate ECG diagnosis of atrial tachyarrhythmias using quantitative analysis: a prospective diagnostic and cost-effectiveness study.

Unlabelled: Quantitative ECG Analysis.

Introduction: Optimal atrial tachyarrhythmia management is facilitated by accurate electrocardiogram interpretation, yet typical atrial flutter (AFl) may present without sawtooth F-waves or RR regularity, and atrial fibrillation (AF) may be difficult to separate from atypical AFl or rapid focal atrial tachycardia (AT). We analyzed whether improved diagnostic accuracy using a validated analysis tool significantly impacts costs and patient care.

Transient local injury current in right ventricular electrogram after implantable cardioverter-defibrillator shock predicts heart failure progression.

Objectives: This study aimed to identify an early marker of functional impairment after an implantable cardioverter-defibrillator (ICD) shock as a predictor of heart failure progression.

Background: The ICD population has substantial risk of death due to progressive pump failure.

Methods: Near-field (NF) bipolar right ventricular (RV) electrograms (EGMs) during induced ventricular fibrillation (VF) and 10 s after rescue ICD shock were analyzed in 310 patients (mean age 59 +/- 14.

The azygos defibrillator lead for elevated defibrillation thresholds: implant technique, lead stability, and patient series.

Background: Conventional insertion of implantable cardioverter-defibrillator (ICD) includes an evaluation of the defibrillation threshold (DFT). Implanting an ancillary defibrillation lead in the azygos vein has been introduced as a therapeutic option in patients with "high" DFT. This study reports the efficacy and stability of azygos defibrillation coils implanted for elevated DFTs.

Left ventricular diastolic filling prior to cardiac resynchronization therapy: implications for atrioventricular delay programming.

Background: The programmed atrioventricular delay (AVD) is an important determinant of the response in left ventricular (LV) systolic performance during cardiac resynchronization therapy (CRT). It is not well established if the optimal AVD for CRT may be influenced by the LV diastolic filling pattern.

Methods: Thirty patients were studied pre- and post-CRT at programmed AVD of 60-160 ms.

Sustained polymorphic arrhythmias induced by programmed ventricular stimulation have prognostic value in patients receiving defibrillators.

Background: Patients with ischemic cardiomyopathy (ICM) who have monomorphic ventricular tachycardia (VT) induced by programmed ventricular stimulation (PVS) are at increased risk of sudden cardiac death (SCD). Among a primary prevention population, the prognostic significance of induced polymorphic ventricular arrhythmias is unknown.

Methods: A total of 105 consecutive patients who received an implantable cardioverter-defibrillator (ICD) for primary prevention of SCD in the setting of ICM and non-sustained VT were retrospectively evaluated.