Advancements in Imaging for Atrial Fibrillation Ablation: Is There a Potential to Improve Procedural Outcomes?

Since the introduction of atrial fibrillation (AF) ablation in the 1990s, the procedure has continuously evolved, with gradual improvements in outcomes and safety. Recent technological advancements include the introduction of contact force catheters and high-resolution electroanatomical mapping systems, while imaging modalities including transesophageal echocardiography and fluoroscopy have become integral parts of AF ablation procedures. Further, intraprocedural intracardiac echocardiography and the integration of cardiac magnetic resonance and computed tomography images with electroanatomical mapping have shown promise to improve procedural outcomes by reducing radiation exposure and procedural times.

Interleukin-1β gene variants are associated with QTc interval prolongation following cardiac surgery: a prospective observational study.

Background: We characterized cardiac surgery-induced dynamic changes of the corrected QT (QTc) interval and tested the hypothesis that genetic factors are associated with perioperative QTc prolongation independent of clinical and procedural factors.

Methods: All study subjects were ascertained from a prospective study of patients who underwent elective cardiac surgery during August 1999 to April 2002. We defined a prolonged QTc interval as > 440 msec, measured from 24-hr pre- and postoperative 12-lead electrocardiograms.

Rapid achievement of therapeutic anticoagulation positively affects outcome in patients undergoing cardioversion for persistent atrial fibrillation.

Background: Current guidelines recommend anticoagulation with warfarin with documentation of an International Normalized Ratio (INR) of 2-3 for 3 weeks prior to cardioversion of persistent atrial fibrillation (AF). Achievement of adequate anticoagulation often takes longer than 3 weeks, increasing the time to cardioversion.

Hypothesis: The goal of the study was to quantify the total time elapsed for adequate anticoagulation and to identify differences in time to cardioversion between patients managed by primary care physicians (PCP) compared with those enrolled in a structured anticoagulation clinic (AC).

Inter-atrial conduction time shortens after blood pressure control in hypertensive patients with left ventricular hypertrophy.

Unlabelled: Assuming that blood pressure control could induce a shortening of the inter-atrial conduction time and prevent atrial fibrillation occurrence, we studied the inter-atrial conduction time in hypertensive patients with left ventricular hypertrophy.

Methods: Sixty-eight (26 male) 58.34+/-8.

Bedside programmed ventricular stimulation for sudden death risk stratification.

Background: Patients with myocardial infarction and left ventricular dysfunction are at risk for sudden death. This research was conducted to determine the applicability and safety of a bedside programmed stimulation protocol to determine the risk for sudden death in these patients.

Methods: Four hundred and twelve patients with acute myocardial infarction were studied.

The effects of hormones on arrhythmias in women.

The reproductive hormones play a significant role in modulating the presentation and behavior of numerous types of arrhythmias. Differences exist between men and women in normal electrophysiology; along with heart rate, the QT interval is a basic parameter that is affected by the presence or absence of certain reproductive hormones. Women have a lower prevalence of atrial fibrillation, yet they have a higher mortality once atrial fibrillation is established.

QT interval and final portion of T wave: measurements and dispersion in infants born at high altitude.

Background: This research was conducted to determine whether the depolarization and repolarization cardiac process of children born at high altitude differs from that of children born at lower altitudes.

Methods: We studied three groups of 30 healthy newborns in the Venezuelan Andes. Group 3500 m consisted of infants born at 3500 m above sea level; Group 3000 m of infants born at 3000 m above sea level and Group 1600 m of infants born at 1600 m above sea level.

Serial defibrillation lead impedance in patients with epicardial and nonthoracotomy lead systems.

Introduction: The stability of implantable cardiac defibrillation lead impedance subsequent to implantation has not been reported and may have important clinical implications. The objective was to characterize the incidence and degree of impedance changes occurring after implantation of defibrillation lead systems.

Methods And Results: The study cohort consisted of patients who received epicardial or nonthoracotomy lead systems.

Heart rate and heart rate variability changes induced by right atrial pacing.

This research was conducted to determine (1) whether heart rate and R-R interval variability are modified by atrial pacing, and (2) whether these changes (if they do occur) are related to the inducibility of tachyarrhythmias during electrophysiological studies. We studied 42 patients who were referred for electrophysiological evaluation of supraventricular (n = 16) or ventricular arrhythmias (n = 26). The patients studied for the evaluation of ventricular arrhythmias had structural and functional cardiac damage.