Atrial tachycardia initiating atrial fibrillation successfully ablated in the non-coronary cusp of the aorta

Prevalence and Characteristics of Atrial Tachycardia From Noncoronary Aortic Cusp During Atrial Fibrillation Catheter Ablation

The prevalence of the uncommon atrial tachycardia (AT) originating from the non-coronary cusp (NCC) in patients undergoing atrial fibrillation (AF) ablation were overall 0.08% (0.07% in initial AF ablation cases, and 0.15% in redo cases). The characteristics of NCC ATs uncovered during AF ablation presented shorter tachycardia cycle length and increased P-wave duration compared to that of de novo NCC AT without AF. The AF recurrence rate after pulmonary vein isolation and NCC AT ablation was low without significant procedure related complication such as atrioventricular conduction block.

Background and Objectives

Atrial tachycardias (ATs) from noncoronary aortic cusp (NCC) uncovered after radiofrequency ablation for atrial fibrillation (AF) are rarely reported. This study was conducted to investigate the prevalence and clinical characteristics of NCC ATs detected during AF ablation and compare their characteristics with de novo NCC ATs without AF.

Methods

Consecutive patients who underwent radiofrequency catheter ablation for AF were reviewed from the multicenter AF ablation registry of 11 tertiary hospitals. The clinical and electrophysiological characteristics of NCC AT newly detected during AF ablation were compared with its comparators (de novo NCC AT ablation cases without AF).

Results

Among 10,178 AF cases, including 1,301 redo ablation cases, 8 (0.08%) NCC AT cases were discovered after pulmonary vein isolation (PVI; 0.07% in first ablation and 0.15% in redo ablation cases). All ATs were reproducibly inducible spontaneously or with programmed atrial stimulation without isoproterenol infusion. The P-wave morphological features of tachycardia were variable depending on the case, and most cases exhibited 1:1 atrioventricular conduction. AF recurrence rate after PVI and NCC AT successful ablation was 12.5% (1 of 8). Tachycardia cycle length was shorter than that of 17 de novo ATs from NCC (303 versus 378, p=0.012). No AV block occurred during and after successful AT ablation.

Conclusions

Uncommon NCC ATs (0.08% in AF ablation cases) uncovered after PVI, showing different characteristics compared to de-novo NCC ATs, should be suspected irrespective of P-wave morphologies when AT shows broad propagation from the anterior interatrial septum.

Atrial fibrillation

Atrial fibrillation is the most common arrhythmia affecting patients today. Disease prevalence is increasing at an alarming rate worldwide, and is associated with often catastrophic and costly consequences, including heart failure, syncope, dementia, and stroke. Therapies including anticoagulants, anti-arrhythmic medications, devices, and non-pharmacologic procedures in the last 30 years have improved patients' functionality with the disease. Nonetheless, it remains imperative that further research into AF epidemiology, genetics, detection, and treatments continues to push forward rapidly as the worldwide population ages dramatically over the next 20 years.

Prevalence, risk, and benefits of radiofrequency catheter ablation at the aortic cusp for the treatment of mid- to anteroseptal supra-ventricular tachyarrhythmias

BACKGROUND

Some outflow tract ventricular tachycardias (VTs) are known to be successfully ablated from the aortic cusp (AC). However, radiofrequency catheter ablation (RFCA) at the AC for the treatment of supraventricular tachyarrhythmia (SVT) has limited experience.

METHODS

We performed RFCA at the AC in 19 patients (male 64.7%, 46.9 ± 21.9 years old) with mid- to anteroseptal SVTs (12 atrial tachycardias [AT], 7 atrioventricular reciprocating tachycardia [AVRT]), and analyzed the prevalence, electrophysiologic findings, clinical outcome, and compilation risk.

RESULTS

1. Among 113 patients with AT, 13 patients had mid- to anteroseptal AT and 12 patients (8.8%, 53.4 ± 19.8 years old, 58.3% female) underwent successful ablation from the non-coronary cusp (NCC; n=10), right CC (RCC; n=1) or left CC (LCC; n=1) without complication (3.1 ± 2.3 times RF delivery, 6.15 ± 3.08 s for termination). During 19.7 ± 9.8 months of follow-up, AT recurred in a patient with multiple foci. 2. Among 580 patients with AVRT, 27 patients had a mid- to anteroseptal bypass tract (4.7%), and 7 of them (1.1%, 2 pre-excitation syndrome, 5 concealed bypass tract) were successfully ablated at the NCC (n=2) or RCC (n=5) (7.0 ± 7.1 times RF delivery, 9.1 ± 4.4s for termination). Among 5 patients with AVRT successfully ablated at the RCC, one patient developed complete heart block 48 h after procedure, and 2 patients recurred AVRT or delta-wave in ECG during 13.9 ± 11.7 month follow-up.

CONCLUSION

Catheter ablation within the AC is an effective procedure to eliminate mid- to anteroseptal SVTs. However, RFCA on RCC requires a caution for heart block in our limited experience.