Atrial Antitachycardia Pacing Research Articles

Characteristics of successful termination of atrial fibrillation by atrial antitachycardia pacing in patients with cardiac implantable electronic devices.

Asymptomatic paroxysmal atrial fibrillation (AF) is often found in patients implanted with cardiac implantable electronic devices (CIEDs). Second-generation atrial antitachycardia pacing (A-ATP) is effective in managing AF in patients implanted with CIEDs. The purpose of this study was to evaluate the efficacy and safety of A-ATP in patients implanted with CIEDs. This was a single-center retrospective study involving 91 patients (male 46 patients, mean age 74 ± 9years) implanted with Reactive A-ATP equipped devices (84 patients with pacemakers, 6 with ICDs, and 1 with a CRT-D). The AF burden, rate of AF termination, and details of the activation of the A-ATP were analyzed in each patient. During a mean follow-up period of 21 ± 13months, A-ATP was activated in 45 of 91 patients (49.5%). No patients had adverse events. Although the efficacy of the A-ATP varied among the patients, the median rate of AF termination was 44%. In comparison to the A-ATP start time, "0min" had a higher AF termination rate by the A-ATP (39.4% vs. 24.4%, P = 0.011). The rate of termination by the A-ATP was high for AF with a long cycle length and a relatively regular rhythm. A-ATP successfully terminated AF episodes in some patients implanted with CIEDs. The optimal settings of the A-ATP will be determined in future studies.

Combined effects of high atrial septal pacing and reactive atrial antitachycardia pacing for reducing atrial fibrillation in sick sinus syndrome.

It is unknown whether atrial fibrillation (AF) burden varies by pacing site in patients with reactive atrial antitachycardia pacing (rATP). We aimed to compare AF burden in patients with high atrial septal pacing (HASp) via delivery catheter and right atrial appendage pacing (RAAp) in patients with sick sinus syndrome (SSS). We retrospectively identified 109 patients with a history of paroxysmal AF and SSS who had received dual-chamber pacemaker implantation between January 2017 and December 2019, of whom 39 and 70 patients had HASp and RAAp, respectively. rATP was initiated after a 1-month post-implantation run-in period. Patients with HASp had a significantly shorter P-wave duration during atrial pacing than those with RAAp (99.3 ± 10.4 vs. 116.0 ± 14.3 ms, p < .001). During the 3-year follow-up period, the incidence of an AF lasting longer than 1 or 7 days was significantly lower (hazard ratio [HR], 0.45; p = .016; HR, 0.24; p = .004) than in those with RAAp. The median time of AF/AT per day in the follow-up periods was significantly shorter in the HASp group than in the RAAp group (10 vs. 18 min/day, p = .018). Atrial lead division did not occur in the HASp group during the follow-up period. HASp via delivery catheter is as safe as RAAp, and HASp combined with rATP is effective for reducing AF burden in patients with SSS and paroxysmal AF.

Patient-activated anti-tachycardia pacing in adult congenital heart disease.

IntroductionIn adults with congenital heart disease, intra‐atrial reentrant tachycardia (IART) is a common arrhythmia that causes significant morbidity and mortality. One treatment option for IART is antitachycardia pacing. Atrial antitachycardia pacing algorithms deliver therapy for IART with ≥2:1 conduction, but most algorithms will not recognize IART with 1:1 conduction. Temporary Patient Activated Rx (TPARx) is Medtronic software that can be installed in antitachycardia pacemakers allowing patients to deliver therapies on demand for IART with 1:1 conduction.MethodsRetrospective chart review at a single institution of all patients who had TPARx installed into their pacemaker.ResultsFour adults with single ventricle congenital heart disease and IART underwent Fontan conversion, arrhythmia surgery, and placement of an epicardial dual‐chamber antitachycardia pacemaker. They had recurrent IART with a long cycle length and 1:1 conduction that failed to trigger antitachycardia pacing therapies. TPARx software was programmed into their pacemakers to allow recognition and treatment of IART with 1:1 conduction. Mean follow‐up duration after TPARx programming was 4.9 years. Each patient received at least one successful antitachycardia pacing therapy via TPARx – range 0.4–26 treated IART episodes per year. There were no atrial or ventricular arrhythmias induced with antitachycardia pacing. Two patients were able to discontinue anticoagulation after TPARx installation.ConclusionThis series demonstrates the use of TPARx software as part of a long‐term IART management strategy in select patients with IART who have failed more conventional therapies.

Utility of Simultaneous Biatrial Atrial Anti-Tachycardia Pacing for the Termination of Atrial Fibrillation during Catheter Ablation of Atrial Fibrillation.

Background: Atrial anti-tachycardia pacing (A-ATP) of the right atrium (RA) has been shown to decrease the burden of atrial fibrillation (AF) in patients with dual-chamber pacemakers. The aim of this study is to identify the novel predictors of effective A-ATP for terminating AF in patients with AF undergoing catheter ablation. Methods: This study included 41 consecutive patients undergoing a first ablation procedure for paroxysmal (PAF: n = 21) or persistent (PEF: n = 20) AF. We prospectively evaluated predictors of AF termination after A-ATP. The coefficient of variation (CoV = SD/mean × 100) of the dominant frequencies (DFs) was calculated to evaluate the variability in atrial activation. Results: AF was terminated by A-ATP in 29% of PAF and 5% of PEF patients. In these patients, simultaneous high-rate pacing from the RA and the coronary sinus (CS) terminated AF in 71% of patients, in whom the mean AF cycle length (CL) before A-ATP was longer (214 ± 23 vs. 177 ± 35 ms, p = 0.02) and became slower after A-ATP (234 ± 37 vs. 176 ± 32 ms, p < 0.01), compared to unsuccessful patients. The CoV of the DFs before A-ATP were lower in both RA (6.2 ± 2.0 vs. 15.3 ± 7.9, p = 0.02) and CS (11.0 ± 7.9 vs. 24.3 ± 9.3, p < 0.01) in successful patients. Conclusions: Simultaneous biatrial A-ATP from the RA and CS could terminate AF in patients with PAF. The predictors for successful termination include longer AF CL and higher AF stability.

Identification of Predictors of Atrial Antitachycardia Pacing Effectiveness

心房性頻脈性不整脈（AT/AF）のburdenを減少させる機能として，第2世代心房抗頻拍ペーシング（A-ATP）の有用性が報告されているが，導入後に治療が有効となる症例の特徴は明らかでない．そこでわれわれは，A-ATP（Reactive ATP, メドトロニック社製）作動症例22名の患者背景，心内心電図，12誘導心電図，エコー所見，BNPから治療が有効となる因子を検討した．AT/AF burdenの50％以上減少をA-ATP有効と定義し, AT/AF burden＜5％の症例とAT/AFのエピソードが1件のみの症例は治療有効性の判断が困難なため，10名を除外した．有効群（5名）は無効群（7名）と比較して，心内AT/AF average tachycardia cycle length（AvCL）＞300ms（28.6％ vs 5.2％，p＜0.05）および規則的なAT/AF（71.9％ vs 48.5％，p＜0.05）が多く，AT/AFに対するカテーテルアブレーション（CA）またはMaze手術既往が多かった（80％ vs 14％，p＜0.02）．また，12誘導心電図において有効群はf波のCLが無効群より延長していた（220.5ms vs 141.4ms，p＜0.05）．A-ATPは延長したAT/AF AvCL，または規則的なAT/AF症例で有効であり，CAやMaze手術の既往，12誘導心電図のf波CL延長が植込み前に観察可能な有効性の予測因子として有用な可能性がある．

Prevention of long-lasting atrial fibrillation through antitachycardia pacing in DDDR pacemakers.

The MINERVA trial showed that in pacemaker patients with atrial fibrillation (AF) history, DDDRP pacing combining three algorithms - (a) atrial antitachycardia pacing with Reactive ATP enabled, (b) atrial preventive pacing and (c) managed ventricular pacing (MVP)-may effectively delay progression to persistent/permanent AF compared with standard DDDR pacing. We performed a comparative non-randomised evaluation to evaluate if Reactive ATP can be the main driver of persistent/permanent AF reduction independently on preventive pacing. Thirty-one centres included consecutive dual-chamber pacemaker patients with AF history. Reactive ATP was programmed in all patients while preventive atrial pacing was not enabled. These patients were compared with the three groups of MINERVA randomised trial (Control DDDR, MVP, and DDDRP). The main endpoint was the incidence of AF longer than 7 consecutive days. A total of 146 patients (73years old, 54% male) were included and followed for a median observation period of 31months. The 2-year incidence of AF>7days was 12% in the Reactive ATP group, very similar to that found in the DDDRP arm of the MINERVA trial (13.8%, P=.732) and significantly lower than AF incidence found in the MINERVA Control DDDR arm (25.8%, P=.012) and in the MINERVA MVP arm (25.9%, P=.025). In a real-world population of dual-chamber pacemaker patients with AF history, the use of Reactive ATP is associated with a low incidence of persistent AF, highlighting that the positive results of the MINERVA trial were related to the effectiveness of Reactive ATP rather than to preventive pacing.

Prevention of long-lasting atrial fibrillation through antitachycardia pacing in 584 dual-chamber pacemaker patients

Abstract Background Atrial fibrillation (AF) is a frequent arrhythmia in pacemaker patients and is associated with poor quality of life and increased risks of heart failure, dementia, stroke, and death. The MINERVA trial has shown that the combination of 3 pacing algorithms – 1) atrial antitachycardia pacing (aATP), 2) atrial preventive pacing and 3) managed ventricular pacing (MVP) - delays progression to persistent and permanent AF, compared with standard DDDR pacing mode and with MVP mode, in pacemaker patients with AF history. Purpose We performed a comparative non randomized evaluation to confirm the hypothesis that aATP is the main driver of persistent/permanent AF reduction independently on the effect of preventive atrial pacing. Methods Thirty-one Italian and Japanese Cardiology centers included consecutive dual-chamber pacemaker patients with AF history. aATP was programmed in all patients while preventive atrial pacing was not enabled. Comparison was made with all the 3 groups in MINERVA randomized trial. The main endpoint was incidence of AF longer than 7 consecutive days, as detected by device diagnostics. Results A total of 146 patients (73 years old, 54% male) were included and followed for a median observation period of 31 months. The 2-year incidence of AF&amp;gt;7 days was 12% in the aATP group, very similar to that found in the arm of the MINERVA trial with aATP enabled (13.8%, p=0.732) and significantly lower than AF incidence found in the MINERVA Control DDDR arm (25.8%, p=0.012) and in the MINERVA MVP arm (25.9%, p=0.025). Conclusions In a real-world population of dual-chamber pacemaker patients with AF history, use of aATP was associated with low incidence of persistent AF during follow up, highlighting that the positive results of the MINERVA trial are related to the effectiveness of aATP rather than to the effects of preventive atrial pacing. Funding Acknowledgement Type of funding source: None

Dizziness during atrial antitachycardia pacing: What is the cause.

A 74-year-old with a history of sinus node dysfunction and intermittent AV block s/p permanent pacemaker implant 6 years prior, complains of one episode of dizziness.

Efficacy and safety of new-generation atrial antitachycardia pacing for atrial tachyarrhythmias in patients implanted with cardiac resynchronization therapy devices

BackgroundAtrial tachyarrhythmias (ATAs) have a significant negative impact on the prognosis of patients implanted with cardiac resynchronization therapy (CRT) devices. New-generation atrial antitachycardia pacing (Reactive ATP, Medtronic Inc., Minneapolis, MN, USA) is effective in managing ATAs in patients implanted with pacemakers. The purpose of this study was to evaluate the efficacy and safety of Reactive ATP in patients implanted with CRT devices. MethodsThis was a single-center retrospective study involving 72 CRT patients with a history of ATAs [44 patients with a device capable of Reactive ATP (ATP group) and 28 patients with a device without ATP function (Control group)]. The atrial fibrillation (AF) burden, the biventricular pacing rate, and clinical outcomes were compared between the two groups. ResultsAt baseline, there was no significant difference in the AF burden and biventricular pacing rate between the ATP and Control groups. During the 832±489 days of the follow-up period, 23 of the 44 patients (52%) received a total of 2862 ATP deliveries and the median ATP success rate was 23.6% (interquartile range: 12.5–50.0%) in the ATP group. The AF burden was significantly decreased only in the ATP group 6 months after ATP was programmed (from 6.1±18.2% to 2.0±5.4%, p=0.0083) and maintained low throughout the follow-up period. Moreover, there were no Reactive ATP-related complications observed. Patients in the ATP group showed a significantly lower incidence of heart failure (HF) hospitalization (log-rank, p=0.041) and ventricular arrhythmias (log-rank, p=0.039) than those reported in the Control group. ConclusionsReactive ATP successfully and safely reduced AF burden, and was associated with a lower incidence of HF hospitalization in patients implanted with CRT devices.

P5655Efficacy of new-generation atrial antitachycardia pacing for atrial tachyarrhythmias in patients with left ventricular dysfunction

Abstract Background The progression to persistent atrial fibrillation (AF) is associated with a worse clinical outcome in patients with previous atrial tachyarrhythmias. New-generation atrial antitachycardia pacing (ATP) (Reactive ATP) reduced the progression to persistent AF in patients with pacemaker and preserved left ventricular (LV) function. However, little is known about the efficacy of Reactive ATP in patients with cardiac implantable electronic devices (CIED) and LV dysfunction. Purpose We aimed to investigate the efficacy of Reactive ATP for atrial tachyarrhythmias in patients with LV dysfunction (LV ejection fraction [LVEF] &lt;40%). Methods This study included 423 patients with CIED and previous atrial tachyarrthythmias. Reactive ATP was programmed in 284 patients (ATP group) and 139 were implanted with a dual-chamber device without ATP function (control group). The differences in the success rate of ATP and incidence of progression to persistent AF (≥7 days) between the ATP and control groups were evaluated in 108 patients with LVEF &lt;40% (reduced LVEF) and 315 with LVEF ≥40% (preserved LVEF). Patients with persistent AF were excluded from this study. Results During 710±337 days of follow-up period, 16 patients (15%) with reduced LVEF and 51 (16%) with preserved LVEF progressed to persistent AF (p=0.88). The mean ATP success rate was lower in patients with reduced LVEF than in those with preserved LVEF, although not statistically significant (reduced LVEF: 27.2±19.4% and preserved LVEF: 35.1±29.2%, p=0.12). The incidence of progression to persistent AF was significantly lower in the ATP group than in the control group both in patients with reduced and preserved LVEF (log-rank, reduced LVEF: p=0.0070 and preserved LVEF: p&lt;0.0001) (Figure). Multivariate analysis showed that use of Reactive ATP and smaller left atrium were associated with lower incidences of persistent AF, while LVEF was not predictive of progression to persistent AF (Reactive ATP: hazard ratio [HR] 0.28, 95% confidence interval [CI] 0.17–0.46, p&lt;0.0001, left atrium diameter: HR 1.03, 95% CI 1.00–1.07, p=0.030). Figure 1 Conclusions Reactive ATP was effective in preventing AF progression in patients with LV dysfunction.

P6544A real world study of high frequency atrial anti-tachycardia pacing in new algorithm for atrial arrhythmia

Abstract Background Advanced pacemakers feature atrial antitachycardia pacing (aATP) therapies for terminating atrial arrhythmia. Previous studies showed the efficacy of combined atrial preventive pacing and aATP in patients with pacemakers. The independent effect of aATP and the impact for patients outside the clinical trials has not been well elucidated. Methods In a single center, prospective, all-comers trial, we enrolled 567 patients implanted cardiac devices with Reactive ATP function. History of permanent atrial fibrillation (AF) was not included. After device interrogation of the AF burden and the longest AF duration in the last 6 months, aATP was programmed as a bit more aggressive setting than MINERVA trial (time interval was set as every 2 hours). As for newly implanted devices, aATP was activated after at least 3 months run-in period. Primary and secondary outcomes were the longest AF duration and cumulative percentage of progression into permanent AF, respectively. Results Of 541 eligible patients, aged 75.3±10.7 years, 356 pacemaker, 82 ICD and 103 CRT patients, the longest single episode of AF lasted ≤6 min in 439 patients (81.1%), &gt;6 min to 6 h in 43 (8.0%), &gt;6–24 h in 33 (6.1%), and &gt;24 h in 26 (4.8%) at the enrollment. During mean follow-up of 1.9 years, the longest AF episode lasted &gt;24 h in 49 patients (9.1%) and 14 patients (2.6%) progressed into permanent AF. According with baseline longest single episode of AF, patients with AF ≤6 min developed an episode &gt;24 h in 0.8% at 1 year and 3.2% at 2 years follow up; patients with AF &gt;6 min to 6 h developed an episode &gt;24 h in none at 1 year and 7% at 2 years follow up; and patients with AF &gt;6–24 h developed an episode &gt;24 h in 19% at 1 year and 42% at 2 years follow up, respectively. In a subgroup analysis of in 192 patients with at least 1 aATP, 46 patients with high efficacy (&gt;44%) did not developed an episode &gt;24 h. Only one patient developed into permanent AF without aATP therapy. On multivariate analysis, neither ICD nor CRT was independent risk factor for developing the longest AF episode &gt;24 h. Conclusions The independent use of aATP without atrial preventive pacing was effective for preventing AF progression in a real world cohort. Even without the previous AF episodes, aATP could prevent AF development, especially in patients showing high aATP efficacy. Future research is required to enhance the aATP success rate.

Programming Pacemakers to Reduce and Terminate Atrial Fibrillation.

The goal of this paper is to review present knowledge regarding preventive and antitachycardia pacing algorithms, aimed to reduce atrial fibrillation (AF) burden in patients when pacing is indicated. Reactive antitachycardia pacing (ATP), the new generation of ATP, is significantly associated with a reduced risk of AF. In patients with indication for pacing and history of AF, pacemakers endowed with atrial preventive pacing and atrial ATP combined with managed ventricular pacing proved superior to standard dual-chamber pacing. Managed ventricular pacing is an algorithm that minimizes unnecessary right ventricular pacing. Progression to persistent AF is prevented by ventricular pacing minimization in patients with normal PR interval. The synergistic effect of pacemakers that combine atrial preventive pacing with reactive ATP and with algorithms that minimize ventricular pacing can reduce AF incidence and decrease the combined endpoint of permanent AF, hospital admissions, and mortality.

Implication of ventricular pacing burden and atrial pacing therapies on the progression of atrial fibrillation: A systematic review and meta-analysis of randomized controlled trials

Atrial fibrillation (AF) is common after pacemaker implantation. However, the impact of pacemaker algorithms in AF prevention is not well understood. The purpose of this study was to evaluate the role of pacing algorithms in preventing AF progression. A systematic search of articles using the PubMed and Embase databases resulted in a total of 754 references. After exclusions, 21 randomized controlled trials (8336 patients) were analyzed, comprising studies reporting ventricular pacing percentage (VP%) (AAI vs DDD, n = 1; reducing ventricular pacing [RedVP] algorithms, n = 2); and atrial pacing therapies (atrial preference pacing [APP], n = 14; atrial antitachycardia pacing [aATP]+APP, n = 3; RedVP+APP+aATP, n = 1). Low VP% (<10%) lead to a nonsignificant reduction in the progression of AF (hazard ratio [HR] 0.80; 95% confidence interval [CI] 0.57-1.13; P = .21; I2 = 67%) compared to high VP% (>10%). APP algorithm reduced premature atrial complexes (PAC) burden (mean difference [MD] -1117.74; 95% CI -1852.36 to -383.11; P = .003; I2 = 67%) but did not decrease AF burden (MD 8.20; 95% CI -5.39 to 21.80; P = .24; I2 = 17%) or AF episodes (MD 0.00; 95% CI -0.24 to 0.25; P = .98; I2 = 0%). Similarly, aATP+APP programming showed no significant difference in AF progression (odds ratio 0.65; 95% CI 0.36-1.14; P = .13; I2 = 61%). No serious adverse events related to algorithm were reported. This meta-analysis of randomized controlled trials demonstrated that algorithms to reduce VP% can be considered safe. Low burden VP% did not significantly suppress AF progression. The atrial pacing therapy algorithms could suppress PAC burden but did not prevent AF progression.

Effect of PR interval and pacing mode on persistent atrial fibrillation incidence in dual chamber pacemaker patients: a sub-study of the international randomized MINERVA trial.

Per standard of care, dual-chamber pacemakers are programmed in DDDR mode with fixed atrioventricular (AV) delay or with long AV delay to minimize ventricular pacing. We aimed to evaluate whether the PR interval may be a specific criterion of choice between standard DDDR, to preserve AV synchrony in long PR patients, and managed ventricular pacing (MVP), to avoid ventricular desynchronization imposed by right ventricle apical pacing, in short PR patients. In the MINERVA trial, 1166 patients were randomized to Control DDDR, MVP, or atrial anti-tachycardia pacing plus MVP (DDDRP + MVP). We evaluated the interaction of PR interval with pacing mode by comparing the risk of atrial fibrillation (AF) longer than 7 consecutive days as a function of PR interval. Out of 906 patients with available data, the median PR interval was 180 ms. The PR interval was found to significantly (P = 0.012) interact with pacing mode for AF incidence: the risk of AF > 7 days was lower [hazard ratio (HR) 0.58, 95% confidence interval (95% CI) 0.34-0.99; P = 0.047] in patients with short PR (shorter than median PR) if programmed in MVP mode compared with DDDR mode and it was lower (HR 0.65, 95% CI 0.43-0.99; P = 0.049) in patients with long PR (equal to or longer than median PR) if programmed in DDDR mode compared with MVP. Our data show that PR interval may be used as a selection criterion to identify the optimal physiological pacing mode. Persistent AF incidence was lower in short PR patients treated by right ventricular pacing minimization and in long PR patients treated by standard dual-chamber pacing.

Health care cost analysis of enhanced pacing modalities in bradycardia patients: Portuguese case study on the results of the MINERVA trial

IntroductionThe MINERVA trial established that atrial preventive pacing and atrial antitachycardia pacing (DDDRP) in combination with managed ventricular pacing (MVP) reduces progression to permanent atrial fibrillation (AF) in patients with paroxysmal or persistent AF and bradycardia who need cardiac pacing, compared to standard dual-chamber pacing (DDDR). It was shown that AF-related health care utilization was significantly lower in the DDDRP + MVP group than in the control group. Cost analysis demonstrated significant savings related to this new algorithm, based on health care costs from the USA, Italy, Spain and the UK. ObjectiveTo calculate the savings associated with reduced health care utilization due to enhanced pacing modalities in the Portuguese setting. MethodsThe impact on costs was estimated based on tariffs for AF-related hospitalizations and costs for emergency department and outpatient visits in Portugal. ResultsThe MINERVA trial showed a 42% reduction in AF-related health care utilization thanks to the new algorithm. In Portugal, this represents a potential cost saving of 2323 euros per 100 patients in the first year and 17118 euros over a 10-year period. Considering the number of patients who could benefit from this new algorithm, Portugal could save a total of 75369 euros per year and 555410 euros over 10 years. Additional savings could accrue if heart failure and stroke hospitalizations were considered. ConclusionThe combination of atrial preventive pacing, atrial antitachycardia pacing and an algorithm to minimize the detrimental effect of right ventricular pacing reduces recurrent and permanent AF. The new DDDRP + MVP pacing mode could contribute to significant costs savings in the Portuguese health care setting.

P5740Efficacy and safety of new-generation atrial antitachycardia pacing for atrial tachyarrhythmias in patients implanted with a cardiac resynchronization therapy

P5740Efficacy and safety of new-generation atrial antitachycardia pacing for atrial tachyarrhythmias in patients implanted with a cardiac resynchronization therapy

P1904Comparison of the efficacy of new-generation atrial antitachycardia pacing between patients with sick sinus syndrome and atrioventricular block

P1904Comparison of the efficacy of new-generation atrial antitachycardia pacing between patients with sick sinus syndrome and atrioventricular block

1355Real-world observational data confirm the efficacy of atrial antitachycardia pacing in terminating slow and regular atrial tachyarrhythmias in patients wearing implantable cardiac electronic devices

1355Real-world observational data confirm the efficacy of atrial antitachycardia pacing in terminating slow and regular atrial tachyarrhythmias in patients wearing implantable cardiac electronic devices

P894Real-world observational data confirm the efficacy of atrial antitachycardia pacing in terminating slow and regular atrial tachyarrhythmias in patients wearing implantable cardiac electronic devices

P894Real-world observational data confirm the efficacy of atrial antitachycardia pacing in terminating slow and regular atrial tachyarrhythmias in patients wearing implantable cardiac electronic devices

Safety and efficacy of atrial antitachycardia pacing in congenital heart disease

Intra-atrial reentrant tachycardia (IART) is a common sequela in the congenital heart disease (CHD) population, and it significantly increases morbidity and mortality. Atrial antitachycardia devices (ATDs) capable of atrial antitachycardia pacing (ATP) therapy have been used to manage IART in the CHD population, but there are limited data on their safety and efficacy. To determine whether ATD implantation was associated with reduced direct current (DC) cardioversions and to compare ATP success between different CHD diagnoses and ATP programs. A single-center retrospective chart review was performed on CHD patients with ATDs. Demographic data were collected in addition to the number of DC cardioversions required before and after ATD implantation; data on ATP efficacy and the specific ATP program utilized; and adverse events related to ATD implantation or subsequent ATP treatments. ATD implantation in 91 CHD patients was associated with a significant reduction in DC cardioversions (P < .01). Overall, 72% of IART episodes were successfully terminated by ATP. Patients with levo-transposition of the great arteries experienced lower rates of ATP success than the remainder of the cohort (P < .01). There was no evidence of degeneration to ventricular arrhythmia or death directly attributed to ATP. ATD implantation was associated with reduced DC cardioversion burden. Patients with levo-transposition of the great arteries may experience lower ATP efficacy than patients with other CHDs; however, a larger patient population is required to better determine subgroup efficacy. These results support the safety and efficacy of ATP in the CHD population.