Safety and efficacy of advanced atrial pacing therapies for atrial tachyarrhythmias in patients with a new implantable dual chamber cardioverter-defibrillator
Anne M. Gillis, MD*,*,
Christina Unterberg-Buchwald, MD ,
Herwig Schmidinger, MD ,
Santini Massimo, MD ,
Kevin Wolfe, MD||,
Deborah J. Kavaney, MS¶,
Mary F. Otterness, MS¶,
Stefan H. Hohnloser, MD** GEM III AT Worldwide Investigators
* Foothills Hospital and the University of Calgary, Calgary, Alberta, Canada
Georg-August Universitätskliniken, Göttingen, Germany
Allgemeines Krankenhaus, Vienna, Austria
San Filippo Neri Hospital, Rome, Italy
|| Winnipeg Health Sciences Centre, Winnipeg, Manitoba, Canada
¶ Medtronic Inc., Minneapolis, Minnesota, USA
** J. W. Goethe University, Department of Medicine, Division of Cardiology, Frankfurt, Germany
View larger version (13K):
[in a new window]
|
Figure 1 Atrial tachycardia (AT) and atrial fibrillation (AF) detection zones programmed in the study population. The minimum and maximum AF detection intervals were 100 and 230 ms, respectively. The minimum and maximum AT detection intervals were 180 and 330 ms, respectively. The overlap zone was 180 to 230 ms.
|
|
View larger version (60K):
[in a new window]
|
Figure 2 Examples of atrial tachycardia pacing. (A) A ramp pacing therapy terminates atrial tachycardia with immediate restoration of atrial-paced rhythm. This episode is classified as a primary termination. The upper tracing shows atrial and ventricular electrograms. The lower tracing illustrates the marker channel annotations and intervals between sensed or paced events. (B) Device-based atrial fibrillation terminates within 2.6 s of delivery of a 50-Hz Burst train. The format is similar to A. AP = atrial-paced event; AR = atrial-sensed event in the refractory period; AS = atrial-sensed event; FD = fibrillation detected; TD = tachycardia detection; TS = tachycardia-sensed; VP = ventricular-paced event; VS = ventricular-sensed event.
|
|
View larger version (17K):
[in a new window]
|
Figure 3 Efficacy of atrial tachycardia (AT) pacing (ATP). Data show efficacy rates with 95% confidence intervals for spontaneous episodes of device-classified AT, atrial fibrillation (AF), or all episodes of AT/AF. The arrhythmia classification was based on the arrhythmia type at the time of delivery of first ATP therapy. The efficacy rates were adjusted for multiple events in patients using the Generalized Estimating Equations method. Solid square = episode termination based on device classification of efficacy; solid circle = episode termination defined as termination within 20 s of delivery of the last ATP therapy.
|
|
View larger version (14K):
[in a new window]
|
Figure 4 Efficacy of Ramp or Burst+ atrial tachycardia (AT) pacing (ATP) therapies based on cycle length of the AT at the time of detection (odds ratio, 1.009; 95% confidence interval, 1.003 to 1.016; p = 0.004). Episodes were grouped in quartiles. For every 50 ms increase in cycle length of AT, the odds of effective termination increased by 59%. Solid square = episode termination based on device classification of efficacy; solid circle = episode termination defined as termination within 20 s of delivery of the last pacing therapy. AF = atrial fibrillation.
|
|
View larger version (14K):
[in a new window]
|
Figure 5 Upper: Efficacy of Ramp and Burst+ atrial tachycardia (AT) pacing (ATP). Data show efficacy rates with 95% confidence intervals for spontaneous episodes of device-classified AT, atrial fibrillation (AF), or all episodes of AT/AF. The arrhythmia classification was based on the arrhythmia type at the time of delivery of first ATP therapy. The efficacy rates were adjusted for multiple events in patients using the Generalized Estimating Equation. Lower: Efficacy of 50-Hz Burst ATP. Data show efficacy rates with 95% confidence intervals for spontaneous episodes of device-classified AT, AF, or all episodes of AT/AF. The arrhythmia classification was based on the arrhythmia type at the time of delivery of first ATP therapy. The efficacy rates were adjusted for multiple events in patients using the Generalized Estimating Equation. The 50-Hz Burst pacing was less efficacious compared with Ramp and Burst+ ATP. Solid square = episode termination based on device classification of efficacy; solid circle = episode termination defined as termination within 20 s of delivery of the last pacing therapy.
|
|
|
