Publications by authors named "Callans David"
Preclinical Experience Using 4D Intracardiac Echocardiography to Guide Cardiac Electrophysiology Procedures.
J Cardiovasc Electrophysiol
December 2024
Introduction: Intracardiac echocardiography (ICE) is an essential imaging modality for electrophysiology procedures, allowing intraprocedural monitoring, real-time catheter manipulation guidance, and visualization of complex anatomic structures. Four-dimentional (4D) ICE is the next stage in the evolution of the technology, permitting 360° rotation of the imaging plane, simultaneous multiplanar imaging, and volumetric acquisition, similar to transesophageal echocardiography (TEE). In this study, we report our experience with a novel 4D ICE catheter (NuVision, Biosense Webster) in structural electrophysiology procedures and difficult ventricular ablations in a swine preclinical model.
View Article and Find Full Text PDFImportance: Infrequent intraprocedural premature ventricular complexes (PVCs) limit the efficacy of catheter ablation. Intravascular stimulation of sympathetic nerves via vertebral veins (VVs) has been used to activate cardiac sympathetic tone and may promote PVCs.
Objective: To characterize the ability of direct electrical sympathetic stimulation via VVs to induce PVCs at the time of catheter ablation.
Background: Patients undergoing first-time atrial fibrillation (AF) ablation can benefit from targeting non-pulmonary vein (PV) triggers. Preprocedural identification of high-risk individuals can guide planning of ablation strategy. This study aimed to create a preprocedural screening tool to identify patients at risk of non-PV triggers during first-time AF ablation.
View Article and Find Full Text PDFThe international Working Group of the Signal Summit is a consortium of experts in the field of cardiac electrophysiology dedicated to advancing knowledge on understanding and clinical application of signal recording and processing techniques. In 2023, the working group met in Reykjavik, Iceland, and laid the foundation for this manuscript. Atrial fibrillation (AF) is the most common arrhythmia in adults, with a rapidly increasing prevalence worldwide.
View Article and Find Full Text PDFObjectives: To investigate tailored approaches, techniques, and outcomes of catheter ablation in patients with persistent left superior vena cava (PLSVC) undergoing atrial fibrillation (AF) ablation.
Background: PLSVC presents unique challenges for AF ablation due to its potential as an arrhythmogenic source and the complex anatomical variations it introduces.
Methods: The retrospective cohort included 16 patients with PLSVC that underwent 21 AF ablation procedures between August 1, 2008, and February 14, 2024, at the Hospital of the University of Pennsylvania.
Article Synopsis
- The study investigates the role of lipomatous metaplasia (LM) as a critical anatomical feature in the pathways that lead to ventricular tachycardia (VT) in patients with nonischemic cardiomyopathy (NICM).
- Researchers analyzed cardiac MRI and electroanatomical maps from 49 patients, revealing that VT corridors had significantly higher volumes of LM.
- The findings suggest that these VT corridors not only contain more LM but also show lower variability in current amplitude, indicating that LM may help stabilize electrical signaling during VT episodes.
Article Synopsis
- Lead-related venous stenosis (LRVS), often diagnosed incidentally, can cause symptoms like swelling and discomfort in patients with transvenous leads, although actual symptomatic cases are rarer.
- A study at the Hospital of the University of Pennsylvania analyzed 18 patients with symptomatic LRVS who did not respond to anticoagulation and underwent balloon venoplasty, finding that a significant majority (72%) experienced complete symptom relief post-procedure.
- The study concluded that while balloon venoplasty is generally safe and effective, timely intervention is crucial, especially as treatment becomes less effective when secondary lymphedema is present.
Article Synopsis
- Atrial conduction velocity (CV) is important in understanding heart conditions like atrial fibrillation, and it can be influenced by the body's autonomic nervous system.
- This study investigated how CV in the right atrium changes with sympathetic stimulation, either through medication (isoproterenol) or direct electrical stimulation of the vertebral vein.
- Results showed that both methods significantly increased CV and reduced CV variability compared to baseline sinus rhythm, indicating that sympathetic stimulation improves heart conduction efficiency.
Article Synopsis
- The study investigates the long-term risk of damage to the right coronary artery (RCA) after patients undergo radiofrequency ablation (RFA) for atrial flutter related to the cavotricuspid isthmus (CTI).
- A comparison was made between patients who had CTI RFA and those who only received ablation for atrial fibrillation (AF), with coronary angiography performed afterward to evaluate any differences in RCA stenosis.
- Results indicate that there were no significant differences in the incidence or severity of RCA stenoses between the two groups, suggesting that CTI RFA does not increase the risk of RCA damage in the long term.
Background: Cardiac implantable electronic device (CIED) procedures can cause significant postoperative pain. Opioid use for postoperative pain is associated with risk of persistent use. The benefits of pectoral nerve (PECs) blocks have been established for other chest wall surgeries, but adoption in electrophysiology has been limited.
View Article and Find Full Text PDFBackground: The importance of nonpulmonary vein (PV) triggers for the initiation/recurrence of atrial fibrillation (AF) is well established.
Objectives: This study sought to assess the incremental benefit of provocative maneuvers for identifying non-PV triggers.
Methods: We included consecutive patients undergoing first-time AF ablation between 2020 and 2022.
Article Synopsis
- The study examines the effectiveness of endocardial (ENDO) ablation in treating arrhythmogenic right ventricular cardiomyopathy (ARVC), specifically focusing on its long-term outcomes and factors influencing survival without ventricular tachycardia (VT).
- A total of 74 patients with ARVC underwent ENDO-only VT ablation between 1998 and 2020, with about 66% achieving noninducibility of VT and a median follow-up of 6.6 years revealing that over 54% remained free of VT recurrence.
- Important predictors for long-term VT-free survival included being over 45 years at diagnosis and achieving VT noninducibility, suggesting that ENDO-only ablation could be a viable initial
Article Synopsis
- Epicardial access is important during ventricular tachycardia ablation, and the study compares two methods: traditional ConvEpi access and a newer method called EpiCO, which involves puncturing coronary venous branches.
- The study included 153 patients and found that both methods had similar success rates, but ConvEpi was quicker and associated with more complications, especially significant bleeding.
- Overall, EpiCO access showed a decrease in major complications and bleeding compared to ConvEpi, suggesting it might be a safer option for patients.
Article Synopsis
- - The study focuses on patients with nonischemic cardiomyopathy (NICM) and ventricular tachycardia (VT), aiming to explore the prevalence of lipomatous metaplasia (LM) and its effect on VT recurrence after ablation treatment.
- - Researchers analyzed 113 NICM patients who had undergone VT ablation, finding that 100% of those with VT recurrence had LM, while only 57% of control patients without VT showed LM.
- - The extent of LM was identified as a significant predictor for VT recurrence; patients with more than 2.5 grams of LM were nearly five times more likely to experience recurrence compared to those with less.
Electrophysiologic testing with programmed ventricular stimulation (PVS) has been utilized to induce ventricular tachycardia (VT), thereby improving risk stratification for patients with ischemic and nonischemic cardiomyopathies and determining the effectiveness of antiarrhythmic therapies, especially catheter ablation. A variety of procedural aspects can be modified during PVS in order to alter the sensitivity and specificity of the test including the addition of multiple baseline pacing cycle lengths, extrastimuli, and pacing locations. The definition of a positive result is also critically important, which has varied from exclusively sustained monomorphic VT (>30 seconds) to any ventricular arrhythmia regardless of morphology.
View Article and Find Full Text PDFClass 1C Antiarrhythmics for Premature Ventricular Complex Suppression in Nonischemic Cardiomyopathy With Implantable Cardioverter-Defibrillators.
JACC Clin Electrophysiol
May 2024
Background: Premature ventricular complexes (PVCs) are common and associated with worse outcomes in patients with heart failure. Class 1C antiarrhythmic drugs (AADs) effectively suppress PVCs, but guidelines currently restrict their use in structural heart disease.
Objectives: This study aimed to assess the safety and efficacy of class 1C AADs in patients with nonischemic cardiomyopathy (NICM) and implantable cardioverter-defibrillators (ICDs).