14 research outputs found
Clinical and electrophysiologic characteristics of left septal atrial tachycardia
AbstractObjectivesIt was the purpose of this study to define the electrophysiologic (EP) identity of left septal atrial tachycardia (AT).BackgroundThe clinical and EP characteristics of this particular type of arrhythmia have not been fully described.MethodsA total of 120 patients with AT underwent invasive EP evaluation. Five patients (two men and three women; mean age 49 ± 15 years) with left septal AT were identified. Mapping of the right and left atrium was performed using conventional electrode catheters (five patients) and a three-dimensional electroanatomic mapping system (three patients) followed by radiofrequency (RF) ablation at the earliest site of local endocardial activation.ResultsFive tachycardias with a mean cycle length of 320 ± 94 ms were mapped, and the earliest endocardial electrogram occurred 22 ± 10 ms before the onset of the surface P-wave. Three left septal ATs were found to be originating from the left inferoposterior atrial septum and two from the left midseptum. During tachycardia, positive (three patients), biphasic negative-positive deflection (one patient), or isoelectric (one patient) P waves were recorded in lead V1. The inferior leads demonstrated a positive or biphasic P-wave morphology in four of five patients (80%). Four patients were given both adenosine and verapamil during AT. In three of four patients, verapamil successfully terminated AT after adenosine had failed. Adenosine successfully terminated AT in one of four patients. Successful RF ablation was performed in all patients (mean 2.2 ± 1.7 RF applications) without affecting atrioventricular conduction properties. No recurrence of AT was observed after a mean follow-up of 14 ± 8 months.ConclusionsLeft septal AT ablation is safe and effective. There was no consistent P-wave morphology associated with this particular type of AT. This arrhythmia appears to be resistant to adenosine and moderately responsive to calcium antagonists
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In Vitro Performance Characteristics of Reused Ablation Catheters
Prior studies have found that there is a widespread practice of catheter reprocessing in cardiac electrophysiology laboratories. Effects of reprocessing of ablation catheters on temperature sensing and mechanical deflection are not fully known.
Twenty-four new and used ablation catheters were studied. Deviation of temperature sensing by catheters from the temperature of a heated saline bath was measured. The angle of deflection of digitally scanned catheters at 75% and 100% handle deflection was also measured. New and used catheters were compared with respect to their temperature sensing accuracy and deflection characteristics.
Overall, there was 0.7 +/- 0.1 degrees C (mean +/- standard error) deviation of the sensed temperature from the bath temperature, with no significant difference between new and used catheters. Similarly, there was no significant difference in the angle of deflection between new (66.7 degrees +/- 6.2 degrees and 24.3 degrees +/- 6.8 degrees at 75% and 100% deflections, respectively) and used (59.6 degrees +/- 5.6 degrees and 28.7 degrees +/- 9.9 degrees at 75% and 100% deflections, respectively) catheters. The difference in the angle of deflection between matched new and used catheters was 18.9 degrees +/- 4.2 degrees and 10.9 degrees +/- 2.4 degrees at 75% and 100% deflections, respectively, with a relatively broad range (5.0 degrees -35.6 degrees and 0.4 degrees -19.0 degrees at 75% and 100% deflections, respectively).
This study found no significant overall difference in temperature sensing accuracy and deflection angle of new and used ablation catheters. Nevertheless, individual differences in deflection characteristics between new and used catheters are occasionally seen and warrant screening of reprocessed catheters prior to their reuse
1130-225 New simplified technique for 3-D mapping and ablation of right ventricular outflow tachycardia
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Radiofrequency Ablation of Atrial Flutter:. A Randomized Controlled Trial of Two Anatomic Approaches
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Spatiotemporal characterization of atrial activation in persistent human atrial fibrillation: Multisite electrogram analysis and surface electrocardiographic correlations—A pilot study
The mechanisms of persistent human atrial fibrillation (AF) are not well understood.
The purpose of this study was to examine whether left atrial (LA) drivers are present in persistent AF by performing a comprehensive evaluation of atrial activation frequency and organization using multisite atrial recordings and correlating the findings with atrial waveform frequency and organization on surface ECG.
Nine patients undergoing catheter ablation for persistent AF were studied. Electrograms were recorded from at least 10 sites in each atrium, tagged to an electroanatomic map, and subjected to spectral analysis. Dominant frequency (DF) and regularity index were calculated at each site. Surface ECG recordings were analyzed to obtain precordial lead DFs and AF vector stability index.
Mean, maximum, and minimum DF and mean regularity index were higher in LA than right atrium (RA). DF was correlated with regularity index (R = 0.59,
P <.0001) and negatively correlated with distance from maximal DF site (R = −0.80,
P <.0001). Precordial lead DFs were highly correlated with atrial DFs. Vector stability index was 0.39 ± 0.12 (
P <.01 vs predicted if AF vector direction was random). LA–RA DF gradient and vector stability index were negatively correlated (R = −0.83,
P <.05).
The existence of LA–RA frequency gradients in most patients in this study along with the regularity of LA activation and centrifugal dissipation of activation frequency suggest that LA drivers are often present in persistent AF. Analysis of AF vectors from surface ECG demonstrates spatial stability and correlates with intracardiac recordings. These findings may have implications for catheter ablation of persistent AF
Spontaneous Ventricular Arrhythmias in Patients with ICDs for Primary Versus Secondary Prophylaxis
1130-225 New simplified technique for 3-D mapping and ablation of right ventricular outflow tachycardia
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Endocardial Ablation of Atrial Tachycardias Occurring after Epicedial Maze Procedures
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New simplified technique for 3D mapping and ablation of right ventricular outflow tract tachycardia
To evaluate the safety and efficacy of using a circular multielectrode catheter for mapping and ablation of ventricular tachycardia (VT) or premature ventricular complexes (PVCs) from the right ventricular outflow tract (RVOT).
Three-dimensional (3D) mapping systems are commonly used for mapping and ablation of RVOT VT and PVCs. Newer catheters that are circular with multiple electrodes, such as the Lasso catheter, are capable of simultaneously recording from multiple points within a circumferential plane. Given the tubular structure of the RVOT, these catheters could be used for mapping tachycardias from the RVOT.
A retrospective cohort study of patients undergoing radiofrequency (RF) ablation of RVOT VT or PVCs was performed. In group 1 (n = 7), mapping was performed with a single ablation catheter and fluoroscopy. In group 2 (n = 10), 3D mapping using ESI (n = 9) or CARTO (n = 1) was performed. In group 3 (n = 12), mapping was performed with a circular multielectrode catheter (n = 12). All ablations were performed with 4-mm tip catheters using RF energy.
Catheter ablation for RVOT VT (n = 15) or PVCs (n = 14) was performed on 29 cases in 26 patients, 9 males. Mean age was 35.9 years. In groups 1, 2, and 3, the mean number of lesions was 17.7 +/- 7.7, 13.6 +/- 7.7, and 18.2 +/- 22.7 and the median number of lesions was 20, 13, and 5, respectively. There were no significant differences in the number of lesions, RF time, fluoroscopy time, procedure time, and acute success rate among the three techniques. There were three complications in group 2 and one in group 3.
The use of a circular multielectrode catheter is as effective as the other standard available 3D mapping techniques, both in terms of procedural success and procedural characteristics. Additionally, because of the lower cost associated with using the circular multielectrode catheter approach, further evaluation should be performed to determine whether this is the most cost-effective approach to 3D mapping and ablation of RVOT tachycardias