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Shih-ann Chen - One of the best experts on this subject based on the ideXlab platform.

  • frequency analysis in different types of Paroxysmal Atrial Fibrillation
    Journal of the American College of Cardiology, 2006
    Co-Authors: Satoshi Higa, Hsuan Ming Tsao, Shihlin Chang, Ming Hsiung Hsieh, Shih-ann Chen
    Abstract:

    Objectives This study sought to investigate the regional frequency distribution from multiple bi-Atrial sites in different types of Paroxysmal Atrial Fibrillation (AF). Background A previous study showed a left atrium (LA) to right atrium (RA) frequency gradient in patients with Paroxysmal AF. Methods Forty-four patients (age = 60 ± 16, male patients = 27) with Paroxysmal AF originating from the pulmonary veins (PVs) (n = 31) or superior vena cava (SVC) (n = 13) were included. Frequency analysis was performed on the intracardiac electrograms (7 s, 1 kHz/channel) recorded from PV, posterior LA, coronary sinus (CS), posterolateral RA, and SVC. The largest peak frequency was identified as the dominant frequency (DF). Results In the PV-AF patients, there was a frequency gradient from the PV ostium to the LA, RA, and SVC (8.5 ± 3.3 Hz vs. 5.9 ± 1.1 Hz vs. 5.2 ± 0.85 Hz vs. 5.5 ± 0.48 Hz, respectively, p Conclusions The location of the highest DF depended on the arrhythmogenic PV or SVC. A frequency gradient was present between the arrhythmogenic thoracic vein and atrium in all patients.

  • Catheter ablation of Paroxysmal Atrial Fibrillation.
    Cardiology in Review, 2005
    Co-Authors: Shih-ann Chen
    Abstract:

    Abstract In the recent years, many investigators have proved the efficacy and safety of catheter ablation in patients with Paroxysmal Atrial Fibrillation. Further studies would be necessary to decrease the recurrence rate and complication rate, and make the procedure more simple.

  • catheter ablation of Paroxysmal Atrial Fibrillation initiated by non pulmonary vein ectopy
    Circulation, 2003
    Co-Authors: Ming Hsiung Hsieh, Wen-chung Yu, Yu-an Ding, Mau-song Chang, Hsuan Ming Tsao, Chin Feng Tsai, Jin Long Huang, Shih Ping Yang, Shih-ann Chen
    Abstract:

    Background— Most of the ectopic beats initiating Paroxysmal Atrial Fibrillation (PAF) originate from the pulmonary vein (PV). However, only limited data are available on PAF originating from the non-PV areas. Methods and Results— Two hundred forty patients with a total of 358 ectopic foci initiating PAF were included. Sixty-eight (28%) patients had AF initiated by ectopic beats (73 foci, 20%) from the non-PV areas, including the left Atrial posterior free wall (28, 38.3%), superior vena cava (27, 37.0%), crista terminalis (10, 3.7%), ligament of Marshall (6, 8.2%), coronary sinus ostium (1, 1.4%), and interAtrial septum (1, 1.4%). Catheter ablation eliminated AF with acute success rates of 63%, 96%, 100%, 50%, 100%, and 0% in left Atrial posterior free wall, superior vena cava, crista terminalis, ligament of Marshall, coronary sinus ostium, and interAtrial septum, respectively. During a follow-up period of 22±11 months, 43 patients (63.2%) were free of antiarrhythmic drugs without AF recurrence. Conclusio...

  • Electrophysiologic Characteristics of a Dilated Atrium in Patients with Paroxysmal Atrial Fibrillation and Atrial Flutter
    Journal of Interventional Cardiac Electrophysiology, 1998
    Co-Authors: Yi-jen Chen, Shih-ann Chen, Wen-chung Yu, An-ning Feng, Yu-an Ding, Mau-song Chang
    Abstract:

    This study investigated the difference of Atrial electrophysiologic characteristics between a normal and dilated atrium and compared them among patients with Paroxysmal Atrial Fibrillation and flutter. Twenty-seven patients with Paroxysmal Atrial Fibrillation and 28 patients with Paroxysmal Atrial flutter were divided into four subgroups, according to the presence of a normal atrium or bilateral Atrial enlargement. Thirty patients without Atrial arrhythmia (20 patients with normal atrium and 10 patients with bilateral Atrial enlargement) were included in control group. The Atrial refractoriness in patients with a dilated atrium was longer than those with normal Atrial size. In patients with Paroxysmal Atrial Fibrillation and patients of control group, the P-wave duration and interAtrial conduction velocity with or without Atrial enlargement were similar. However, in patients with Paroxysmal Atrial flutter, P-APCS (86 ± 10 ms vs. 73 ± 9 ms, p < 0.05) and P-ADCS (109 ± 9 ms vs. 95 ± 9 ms, p < 0.05) in patients with a dilated atrium were longer than in patients with a normal atrium. The patients with Paroxysmal Atrial Fibrillation or Atrial flutter all demonstrated longer P-wave duration and interAtrial conduction time than control group. Among the groups with a normal atrium or a dilated atrium, Atrial refractoriness in patients with Paroxysmal Atrial flutter was shorter than that in control group. Moreover, in the patients with a normal atrium, the potential minimal wavelength in control group (6.6 ± 1.7) was longer than that of Paroxysmal Atrial Fibrillation (5.3 ± 1.1), or Atrial flutter (5.0 ± 1.2). These findings suggest that Atrial electrophysiologic characteristics of a dilated atrium were different from those of normal atrium, and these changes were different between Paroxysmal Atrial Fibrillation and flutter. Multiple factors are considered to be related to the genesis of Atrial tachyarrhythmias.

Masahiro Ogawa - One of the best experts on this subject based on the ideXlab platform.

  • neural mechanisms of Paroxysmal Atrial Fibrillation and Paroxysmal Atrial tachycardia in ambulatory canines
    Circulation, 2008
    Co-Authors: Shengmei Zhou, Masahiro Ogawa, Juan Song, Hongmei Li, Michael C Fishbein, Lan S Chen, Pengsheng Chen
    Abstract:

    Background— The relationship between autonomic activation and the mechanisms of Paroxysmal Atrial Fibrillation remains unclear. Methods and Results— We implanted a pacemaker and a radio transmitter in 7 dogs (group 1). After baseline recording, we paced the left atrium at 20 Hz for 1 week and then monitored left stellate ganglion nerve activity, left vagal nerve activity, and left Atrial electrogram without pacing for 24 hours. This protocol repeated itself until sustained Atrial Fibrillation (>48 hours) was induced in 3±1 weeks. In another 6 dogs (group 2), we cryoablated left and right stellate ganglia and the cardiac branch of the left vagal nerve during the first surgery and then repeated the same pacing protocol until sustained Atrial Fibrillation was induced in 7±4 weeks (P=0.01). There were 4±2 episodes of Paroxysmal Atrial Fibrillation per day and 10±3 episodes of Paroxysmal Atrial tachycardia per day in group 1. Simultaneous sympathovagal discharges were observed to immediately precede the onset ...

  • Cholesterol paradox in patients with Paroxysmal Atrial Fibrillation.
    The Cardiology, 1999
    Co-Authors: Miyuki Annoura, Masahiro Ogawa, Koichiro Kumagai, Bo Zhang, Keijiro Saku, Kikuo Arakawa
    Abstract:

    Hypercholesterolemia is a major risk factor for coronary heart disease (CHD), but the associations among lipids, lipoproteins and Paroxysmal Atrial Fibrillation (PAF) have not yet been reported. The a

Adnan Safdar - One of the best experts on this subject based on the ideXlab platform.

Pengsheng Chen - One of the best experts on this subject based on the ideXlab platform.

  • neural mechanisms of Paroxysmal Atrial Fibrillation and Paroxysmal Atrial tachycardia in ambulatory canines
    Circulation, 2008
    Co-Authors: Shengmei Zhou, Masahiro Ogawa, Juan Song, Hongmei Li, Michael C Fishbein, Lan S Chen, Pengsheng Chen
    Abstract:

    Background— The relationship between autonomic activation and the mechanisms of Paroxysmal Atrial Fibrillation remains unclear. Methods and Results— We implanted a pacemaker and a radio transmitter in 7 dogs (group 1). After baseline recording, we paced the left atrium at 20 Hz for 1 week and then monitored left stellate ganglion nerve activity, left vagal nerve activity, and left Atrial electrogram without pacing for 24 hours. This protocol repeated itself until sustained Atrial Fibrillation (>48 hours) was induced in 3±1 weeks. In another 6 dogs (group 2), we cryoablated left and right stellate ganglia and the cardiac branch of the left vagal nerve during the first surgery and then repeated the same pacing protocol until sustained Atrial Fibrillation was induced in 7±4 weeks (P=0.01). There were 4±2 episodes of Paroxysmal Atrial Fibrillation per day and 10±3 episodes of Paroxysmal Atrial tachycardia per day in group 1. Simultaneous sympathovagal discharges were observed to immediately precede the onset ...

Juan Song - One of the best experts on this subject based on the ideXlab platform.

  • neural mechanisms of Paroxysmal Atrial Fibrillation and Paroxysmal Atrial tachycardia in ambulatory canines
    Circulation, 2008
    Co-Authors: Shengmei Zhou, Masahiro Ogawa, Juan Song, Hongmei Li, Michael C Fishbein, Lan S Chen, Pengsheng Chen
    Abstract:

    Background— The relationship between autonomic activation and the mechanisms of Paroxysmal Atrial Fibrillation remains unclear. Methods and Results— We implanted a pacemaker and a radio transmitter in 7 dogs (group 1). After baseline recording, we paced the left atrium at 20 Hz for 1 week and then monitored left stellate ganglion nerve activity, left vagal nerve activity, and left Atrial electrogram without pacing for 24 hours. This protocol repeated itself until sustained Atrial Fibrillation (>48 hours) was induced in 3±1 weeks. In another 6 dogs (group 2), we cryoablated left and right stellate ganglia and the cardiac branch of the left vagal nerve during the first surgery and then repeated the same pacing protocol until sustained Atrial Fibrillation was induced in 7±4 weeks (P=0.01). There were 4±2 episodes of Paroxysmal Atrial Fibrillation per day and 10±3 episodes of Paroxysmal Atrial tachycardia per day in group 1. Simultaneous sympathovagal discharges were observed to immediately precede the onset ...