Publications by authors named "William G Stevenson"

Background: The utility of repeat ablation for premature ventricular contractions (PVCs) after prior ablation failure is not clear.

Objective: The purpose of this study was to assess the outcomes of repeat ablation and the use of different techniques in patients who failed prior PVC ablation.

Methods: We reviewed 239 consecutive patients who underwent PVC ablation.

View Article and Find Full Text PDF

Background: Patients with ventricular tachycardia and ischemic cardiomyopathy are at high risk for adverse outcomes. Catheter ablation is commonly used when antiarrhythmic drugs do not suppress ventricular tachycardia. Whether catheter ablation is more effective than antiarrhythmic drugs as a first-line therapy in patients with ventricular tachycardia is uncertain.

View Article and Find Full Text PDF

Catheter ablation to prevent ventricular tachycardia (VT) that emerges late after a myocardial infarction aims to interrupt the re-entry substrate. Interruption of potential channels and regions of slow conduction that can be identified during stable sinus or paced rhythm is often effective and a number of substrate markers for guiding this approach have been described. While there is substantial agreement with different markers in some patients, the different markers select different regions for ablation in others.

View Article and Find Full Text PDF

Background: Patients with ventricular tachycardia (VT) frequently present in unstable VT and are subject to urgent/high-risk ablation procedures. Clinical predictors of prolonged hospitalization and mortality are needed for optimal management of these patients.

Objectives: This study seeks to identify factors associated with prolonged hospitalization and mortality in emergent unplanned VT ablation procedures.

View Article and Find Full Text PDF
Article Synopsis
  • TTN encodes the protein titin and is commonly associated with rare variants in patients diagnosed with atrial fibrillation (AF) during genetic testing.
  • The study compared characteristics and outcomes of patients with AF having pathogenic TTN variants to those without such variants, revealing that TTN(+) patients experience more persistent AF and require more cardioversions.
  • Findings indicate that nearly 50% of TTN(+) AF patients develop serious heart issues, emphasizing the importance of specialized evaluation and management for these individuals.
View Article and Find Full Text PDF
Article Synopsis
  • The study investigates a specific phenomenon called termination without global propagation (TWGP) during ventricular tachycardia (VT), which could indicate important anatomical sites related to re-entry circuits in the heart.
  • It involves analyzing 632 cases of catheter ablation for scar-related VT, finding TWGP occurrences in 12 instances across 11 locations in 10 patients, suggesting certain sites may be critical for VT circuits.
  • The findings indicate that TWGP might help identify previously undetected VT isthmus locations, with specific features such as low voltage zones being linked to these re-entry circuits.
View Article and Find Full Text PDF
Article Synopsis
  • * A study involving 1,366 participants found that while having a pathogenic variant in any CM or arrhythmia gene wasn't significantly linked to AF recurrence, variants in the ALVC gene group (especially LMNA) were associated with a higher risk.
  • * Overall, AF ablation appears beneficial for most patients with these variants, but those with ALVC variants may face a greater chance of experiencing recurrence of arrhythmias.
View Article and Find Full Text PDF

Stereotactic arrythmia radioablation (STAR) is a novel, non-invasive and promising treatment option for ventricular arrythmias (VA). It has been applied in highly selected patients mainly as bail-out procedure, when (multiple) catheter-ablations, together with anti-arrhythmic drugs, were unable to control the VAs. Despite the increasing clinical use there is still limited knowledge of the acute and long-term response of normal and diseased myocardium to STAR.

View Article and Find Full Text PDF
Article Synopsis
  • * Most patients had drug-refractory VT, with a significant portion having low-voltage zones in the heart, particularly in the interventricular septum, indicating a specific substrate for VT.
  • * After an average follow-up of 32 months, 41% of patients experienced sustained VT/VF recurrence, but those achieving complete procedural success had a reduced risk of recurrence compared to those who did not.
View Article and Find Full Text PDF

Introduction: Catheter-based radiofrequency (RF) ablation is generally regarded as the standard approach for patients with ventricular tachycardia (VT) refractory to antiarrhythmic drug therapy and may be considered as a first-line approach when there is a preference to avoid these agents. Patients with a history of cardiac surgery may have VT substrate inaccessible to catheter ablation due to intervening prosthetic materials or scar.

Methods And Results: This article describes a 55-year-old patient with a history of surgically repaired subvalvular aortic stenosis and subsequent valve-sparing root replacement who presented with sustained VT.

View Article and Find Full Text PDF

Background: Irrigated radiofrequency ablation with half-normal saline can potentially increase lesion size but may increase the risk of steam pops with the risk of emboli or perforation. We hypothesized that pops would be preceded by intracardiac echocardiography (ICE) findings as well as a large impedance fall.

Methods: In 100 consecutive patients undergoing endocardial ventricular arrhythmia radiofrequency ablation with half-normal saline, we attempted to observe the ablation site with ICE.

View Article and Find Full Text PDF

Background: Recurrent ventricular tachycardia (VT) in patients with prior myocardial infarction is associated with adverse quality of life and clinical outcomes, despite the presence of implanted defibrillators (ICDs). Suppression of recurrent VT can be accomplished with antiarrhythmic drug therapy or catheter ablation. The Ventricular Tachycardia Antiarrhythmics or Ablation In Structural Heart Disease 2 (VANISH2) trial is designed to determine whether ablation is superior to antiarrhythmic drug therapy as first line therapy for patients with ischemic cardiomyopathy and VT.

View Article and Find Full Text PDF

Introduction: When ventricular tachycardia (VT) recurs after standard RF ablation (sRFA) some patients benefit from repeat sRFA, whereas others warrant advanced methods such as intramural needle ablation (INA). Our objectives are to assess the utility of repeat sRFA and to clarify the benefit of INA when repeat sRFA fails in patients with VT due to structural heart disease.

Methods: In consecutive patients who were prospectively enrolled in a study for INA for recurrent sustained monomorphic VT despite sRFA, repeat sRFA was considered first.

View Article and Find Full Text PDF

Aims: Failure of radiofrequency (RF) ablation of ventricular arrhythmias is often due to inadequate lesion size. Irrigated RF ablation with half-normal saline (HNS) has the potential to increase lesion size and reduce sodium delivery to the patient if the same volume of RF irrigant were used for normal saline (NS) and HNS but could increase risks related to steam pops and lesion size. This study aims to assess periprocedural complications and acute ablation outcome of ventricular arrhythmias ablation with HNS.

View Article and Find Full Text PDF

Background: Voltage mapping to detect ventricular scar is important for guiding catheter ablation, but the field-of-view of unipolar, bipolar, conventional, and microelectrodes as it relates to the extent of viable myocardium (VM) is not well defined.

Objectives: The purpose of this study was to evaluate electroanatomic voltage-mapping (EAVM) with different-size electrodes for identifying VM, validated against high-resolution ex-vivo cardiac magnetic resonance (HR-LGE-CMR).

Methods: A total of 9 swine with early-reperfusion myocardial infarction were mapped with the QDOT microcatheter.

View Article and Find Full Text PDF
Article Synopsis
  • * 663 procedures were assessed, revealing low rates of stroke (0.3%) and bleeding complications (5.9%), with associations found between pre-procedure antithrombotic medications and increased bleeding risk.
  • * The findings suggest that while strokes are rare, using aspirin (ASA) as a minimum post-procedure regimen is effective, indicating that stronger medications may be needed for certain patients based on their individual risk factors.
View Article and Find Full Text PDF

Introduction: Intracardiac echocardiography (ICE) reveals mobile thrombus on implantable electronic device leads in some patients undergoing electrophysiologic procedures.

Methods: ICE was performed in a patient undergoing ventricular tachycardia (VT) ablation.

Results: ICE showed extensive mobile thrombi on the implantable cardioverter defibrillator lead.

View Article and Find Full Text PDF
Article Synopsis
  • Rare genetic variants are a leading cause of early-onset issues like atrial fibrillation and dilated cardiomyopathy.
  • Cardiac sarcoidosis is often misdiagnosed, but it frequently shows up as ventricular arrhythmias.
  • The report highlights a patient who has both a likely harmful genetic variant and cardiac sarcoidosis.
View Article and Find Full Text PDF

A PHP Error was encountered

Severity: Notice

Message: fwrite(): Write of 34 bytes failed with errno=28 No space left on device

Filename: drivers/Session_files_driver.php

Line Number: 272

Backtrace:

A PHP Error was encountered

Severity: Warning

Message: session_write_close(): Failed to write session data using user defined save handler. (session.save_path: /var/lib/php/sessions)

Filename: Unknown

Line Number: 0

Backtrace: