From the Guidelines
Anti-tachycardia pacing (ATP) is a therapy delivered by implantable cardioverter-defibrillators (ICDs) to terminate certain types of rapid heart rhythms without delivering a shock, and it is successful in terminating approximately 85-90% of slow to fast ventricular tachycardias with a low risk of acceleration.
Key Points About Anti-Tachycardia Pacing
- ATP works by interrupting the abnormal electrical circuit causing the tachycardia, allowing the heart's normal pacemaker to regain control 1.
- The therapy is painless, unlike defibrillation shocks, which can be uncomfortable and distressing for patients, and it can improve quality of life for patients with ICDs 1.
- ATP is typically used to attempt termination of tachycardias in the range of 150-200 beats per minute before delivering a shock, and it can be programmed with multiple attempts before resorting to shock therapy 1.
- Different pacing sequences (burst, ramp, or scan) can be used depending on the specific characteristics of the patient's arrhythmia, and the device can be programmed to optimize ATP therapy for individual patients 1.
Benefits of Anti-Tachycardia Pacing
- Reduces the need for painful shocks, which can improve patient quality of life and reduce psychological distress 1.
- Can extend ICD pulse-generator longevity by reducing the number of shocks delivered 1.
- Is a valuable therapy for patients with ventricular tachycardia, particularly those with monomorphic VT associated with chronic ischemic heart disease, which is most commonly due to classic reentry and is therefore susceptible to termination by ATP 1.
From the Research
Definition of Anti-Tachycardia Pacing
- Anti-tachycardia pacing (ATP) is a therapy delivered by implantable cardioverter-defibrillators (ICDs) to terminate ventricular tachycardias (VTs) without painful ICD shocks 2, 3, 4, 5, 6.
- ATP is an established treatment that safely avoids painful shocks with minimum risk of tachycardia acceleration 4.
Efficacy of Anti-Tachycardia Pacing
- The success rate of ATP in terminating VTs varies between studies, with reported rates ranging from 62.1% to 85% 2, 3, 4, 5.
- ATP efficacy is similar between ICD patients with and without coronary artery disease (CAD) etiology 4.
- The success rate of ATP is higher for arrhythmias with a median cycle length of ≥320 ms, with a reported success rate of 88.0% 5.
- Delivering more ATP sequences is associated with higher overall success of terminating VTs and lower shock burden, without increasing syncope or acceleration 5.
Factors Influencing Anti-Tachycardia Pacing Success
- Left ventricular ejection fraction (LVEF) is a significant predictor of ATP success, with higher LVEF associated with higher success rates 3, 6.
- The etiology of structural heart diseases, indication of device implantation, and electrocardiogram (ECG) parameters are not useful predictors for successful ATP therapy 3.
- Amiodarone use is associated with lower ATP success rates 3.