P977Selective liner ablation according to the type of tachycardia induced after pulmonary vein isolation in single-procedure for long-standing persistent atrial fibrillation

Background

The most effective approach for long-standing persistent atrial fibrillation (LSPAF) ablation remained undetermined. Here, we hypothesized that selective linear ablation (SLA) according to the type of tachycardia induced by burst atrial pacing (BAP) after pulmonary venous isolation (PVI) in single-procedure reduces the recurrence.

Methods

A cohort of 66 LSPAF patients (Mean age 71.0±8.2 years, AF duration 40.5±58.8 months) who underwent PVI in single-procedure between April 2016 and November 2018 was evaluated.

Results

Any sustained atrial tachycardia (AT) or AF were not inducible by BAP after PVI in 21 patients (Non-inducible group, 31.8%, 71.3±7.9 years, 34.4±54.2 months). These patients underwent cavo-tricuspid isthmus (CTI) ablation after PVI. Forty-one patients underwent selective liner ablation according to the type of tachycardia induced by BAP after PVI (SLA group, 62.1%, 71.2±8.3 years, 39.3±55.6 months). Maccroreentry ATs (6 common atrial flutter, 5 AT originating from left atrial anterior wall, 2 peri-mitral atrial flutter, 1 roof-dependent atrial flutter) were induced by BAP in 14 patients of SLA group (73.2±19.7 years, 51.7±83.5 months). RF applications created the complete linear lesions to terminate maccroreentry ATs. Sustained AF was induced by BAP after PVI in 27 patients of SLA group (70.2±9.2 years, 32.9±31.2 months). These patients underwent posterior wall isolation (PWI) and CTI ablation. Unmappable AT was induced by BAP after PVI in 4 patients (Non-SLA group, 6.1%, 67.0±9.7 years, 84.5±105.6 months). These patients underwent PWI, CTI and mitral isthmus ablation on an empirical basis instead of SLA. Using a 90-day blanking period, the single-procedure Kaplan-Meier estimates of AT or AF event-free survival were 79% at 12 months. During follow-up (14.5±8.0 months), although 19 /21 (90.5%) of Non-inducible group patients and 33/41 (80.5%) of SLA group patients did not experience AT or AF recurrence, all of Non-SLA group patients experienced AF recurrence. There was no difference between Non-inducible group and SLA group in predicting recurrence of AT or AF (p=0.3). However, there was a difference when compared with Non-SLA group (each p<0.001). Non-SLA group was an independent powerful predictor resulting in recurrence of AF after adjusting for potential confounding factors (adjusted hazard ratio = 7.17; 95% confidence interval; 2.2–23.1, p=0.001, Wald χ2=10.9). Furthermore, in Kaplan-Meier survival curves for predicting AT or AF recurrence, Non-SLA group was the significant predictive marker of AT or AF recurrence (Log-Lank χ2=18.0, p<0.001).

Kaplan-Meier survival curves

Conclusions

In LSPAF patients without inducibility of any tachycardia after PVI, sinus rhythm was highly maintained without stepwise ablation other than CTI ablation. SLA reduced recurrence of AF in LSPAF patients with AT and AF induced after PVI. In addition, nonselective liner ablations for unmappable AT after PVI were less effective in LSPAF patients.

[The effect of hypotensive anesthesia with nitroglycerin and verapamil on platelets]

Recently, there have been many cases in which nitroglycerin (TNG) is used for anesthesia for patients with low blood pressure. Since, it has been reported that TNG suppresses the platelet aggregation function in vitro. Verapamil (Vp), known as another platelet aggregation suppressant, and nicardipine (Nc) were used together with TNG and the platelet aggregation function was studied in vitro and in vivo. The results of the in vitro experiment showed that TNG 250 ng.ml-1 + Vp 250 ng.ml-1 suppressed the platelet aggregation function, and when TNG + Vp (was used for low hypotensive anesthesia, a large amount of Vp i.e. over 15 mg of Vp is injected as a bolus into the artery, there is a possibility the platelet aggregation function will be suppressed. No platelet aggregation function suppression was found when TNG+Nc was used in hypotensive anesthesia.