Dae In Lee

Prediction of Long‐Term Outcomes of Catheter Ablation of Persistent Atrial Fibrillation by Parameters of Preablation DC Cardioversion

Prediction of Long‐Term Outcomes of Catheter Ablation of Persistent Atrial Fibrillation.u2003Aim: It has been demonstrated that atrial fibrillation (AF) frequently recurred after cardioversion (CV) using direct current (DC) or radiofrequency catheter ablation (RFCA) in patients with persistent (PeAF) or longstanding persistent AF (LPAF). We hypothesized that the atrial substrate impeding successful CV would also produce difficulty in catheter ablation, and therefore, the outcomes of RFCA for PeAF and LPAF could be predicted by the parameters determined at the time of DC CV.

The clinical efficacy of left atrial appendage isolation caused by extensive left atrial anterior wall ablation in patients with atrial fibrillation

BackgroundThe left atrial appendage (LAA) can be a source of atrial fibrillation (AF) triggering or a part of reentry. We sought to determine the characteristics and clinical outcomes of patients with LAA potential delay including electrical isolation (LAAEI) following LA anterior wall (LAAW) ablation for AF.MethodsLAAW ablation cases were collected from among 846 patients who underwent catheter ablation (CA). A total of 89 patients were enrolled; they were divided into three groups according to the extent of LAA potential injury. The ejection fractions (EFs) of the LAA and LA were measured by means of LA angiograms.ResultsThe mean age of all patients was 56.2u2009±u200910.7xa0years (74 males, 83xa0%). In 47 of the 89 patients, an LAA potential delay was identified after LAAW ablation (group 2). LAAEI was seen in 18 patients (group 3). In the remaining 24 patients, there was no LAA potential delay or LAAEI (group 1). The mean EF decreased significantly after CA in group 3 (Pu2009<u20090.001). At 21-month follow-up, three patients (17xa0%) in group 3 had recurrence compared with 11 (42xa0%) in group 2 and 12 (46xa0%) in group 3 (Pu2009=u20090.028). In multivariate analysis, diabetes mellitus and LAA potential delay were independent predictors of AF recurrence (Pu2009=u20090.021, Pu2009=u20090.008, respectively).ConclusionAblation of the LA anterior wall near the insertion of Bachmann’s bundle and the neck of the LAA resulting in LAA potential delay or electrical isolation is effective in preventing recurrence of atrial fibrillation.

Evaluation of quantification methods for left arial late gadolinium enhancement based on different references in patients with atrial fibrillation

By using late gadolinium enhancement cardiac magnetic resonance (LGE-CMR) imaging, we compared left atrial late gadolinium enhancement (LA-LGE) quantification methods based on different references to characterize the left atrial wall in patients with atrial fibrillation (AF). Thirty-eight patients who underwent three-dimensional LGE-CMR imaging before catheter ablation for AF were classified into three groups depending on their clinical AF type: (1) paroxysmal AF (PAF; nxa0=xa012); (2) persistent AF (PeAF; nxa0=xa016); and (3) recurrent AF after catheter ablation (RAF; nxa0=xa010). To quantify LA-LGE on LGE-CMR imaging, we used the thresholds of 2 standard deviations (2-SD), 3-SD, 4-SD, 5-SD, or 6-SD above the mean signal from the unenhanced left ventricular myocardium, and we used the full width at half maximum (FWHM) technique, which was based on the maximum signal from the mitral valve with high signal intensity. The 6-SD threshold and FWHM techniques were statistically reproducible with an intraclass correlation coefficient >0.7. On applying the FWHM technique, the normalized LA-LGE volume by LA wall area showed a significant difference between the RAF, PeAF, and PAF groups (0.22xa0±xa00.04, 0.16xa0±xa00.06, and 0.09xa0±xa00.03xa0mL/cm2, respectively) (Pxa0<xa00.05). Furthermore, most of the fibrotic scarring and low-voltage tissue on the electroanatomic map corresponded well with the extent of LA-LGE. The FWHM technique based on the mitral valve can provide a reproducible quantification of LA-LGE related to AF in the thin LA wall.

Relation between left atrial wall composition by late gadolinium enhancement and complex fractionated atrial electrograms in patients with persistent atrial fibrillation: influence of non-fibrotic substrate in the left atrium

AbstractnThe complex fractioned atrial electrogram (CFAE) has been considered as the catheter ablation target of left atrium (LA) under persistent atrial fibrillation (PeAF). We evaluated the relation between the LA wall composition by late gadolinium enhancement cardiac magnetic resonance (LGE-CMR) and the CFAE in patients with PeAF. Forty-three patients underwent LGE-CMR and CFAE mapping before catheter ablation for PeAF. The LA wall substrates were classified into three: the fibrotic, intermediate, and normal substrates by using two thresholds of 2 standard deviation (2-SD) and 6-SD above the mean signal from the normal myocardium. For each of 12 preselected LA wall regions, the composition ratios (CRs) of fibrotic, indeterminate, and normal substrates were calculated as a percentage to the volume of LA wall region, and compared depending on the CFAE, respectively. The CR of normal substrate was significantly greater at the LA wall region with CFAE (52xa0±xa038xa0% vs. 20xa0±xa028xa0%, Pxa0<xa00.01) than without CFAE. In contrast, the LA wall region with CFAE showed significantly lower CRs of intermediate substrate (39xa0±xa034xa0% vs. 57xa0±xa031xa0%, Pxa0<xa00.01) and fibrotic substrate (7xa0±xa017xa0% vs. 21xa0±xa024xa0%, Pxa0<xa00.01) than did the LA wall region without CFAE, respectively. Thus, the high CR (>18xa0%) of normal substrate predicted the CFAE at the corresponding LA wall region with 71xa0% sensitivity and 62xa0% specificity. In conclusion, the evaluation of LA wall normal substrate by LGE-CMR might be useful to predict the CFAE occurrence before catheter ablation of PeAF.

Idiopathic ventricular arrhythmia originating from the para-Hisian area: Prevalence, electrocardiographic and electrophysiological characteristics

We investigated the prevalence and the electrocardiographic and electrophysiological characteristics of ventricular arrhythmias (VAs) originating from the para‐Hisian area.

Long‐term Outcome of Catheter Ablation for Atrial Fibrillation in Patients with Apical Hypertrophic Cardiomyopathy

Atrial fibrillation (AF) is a common manifestation in cases of hypertrophic cardiomyopathy (HCM). Catheter ablation (CA) for AF in patients with asymmetric septal HCM (SeHCM) is selectively effective and often needs a repeat procedure. Apical HCM (ApHCM) has a better prognosis than SeHCM. However, the outcome of CA for AF in patients with ApHCM is unclear.

Relationship Between Complex Fractionated Atrial Electrograms During Atrial Fibrillation and the Critical Site of Atrial Tachycardia That Develops After Catheter Ablation for Atrial Fibrillation

Complex fractionated atrial electrograms (CFAEs) are a substrate modification target in patients with atrial fibrillation (AF). However, whether CFAEs can be also arrhythmogenic grounds of atrial tachycardia (AT) presenting after AF ablation remains to be determined. We investigated the relationship between CFAEs and the critical site of AT after CFAE‐guided AF ablation.

Gender-related Difference in Clinical Outcome of the Patient with Atrial Fibrillation after Radiofrequency Catheter Ablation

Background and Objectives Previous studies provided controversial result about gender differences in the clinical outcome after radiofrequency catheter ablation (RFCA) for atrial fibrillation (AF). We assessed pure difference after adjustment of referral bias. Methods The clinical outcomes including freedom from AF/atrial tachycardia (AT) recurrence after RFCA were compared between women and men in 1:1 confounding factor matching with age, AF type, periods since diagnosis (±12 months), and procedure era (±12 months). Subgroup analysis was performed in categories defined by AF type and age of 55 (mean menopausal age of Asian women). Results Total 1,875 patients with AF underwent 2,307 RFCA between January 1998 and May 2014 in a single center. Total 367 women (19.6%, 59±10 years) who had undergone first ablation were included. Women had larger left atrial diameter index (26±4 vs. 23±4 mm/m2; p<0.001) and higher peri-procedural complications (9.2% vs. 4.9%; p=0.030) compared to men. The freedom from AF/AT recurrence after RFCA was not different between both groups (71% vs. 76%; log-rank p=0.131, mean follow-up of 55 months). Women with non-paroxysmal AF (PAF) had significantly worse outcome (54% vs. 69%; p=0.014), especially in subgroup with age ≤55 (48% vs. 71%; p=0.010). In multivariate analysis, female gender was an independent predictor of recurrence in subgroup with non-PAF and age ≤55 (hazard ratio [HR], 2.539; 95% confidence interval [CI], 1.112–5.801; p=0.027). Conclusions The clinical outcome after RFCA was not different between both genders regardless of referral bias. However, the gender difference became evident in patients under 55 years with non-PAF.

Long-Term Clinical Comparison of Procedural End Points After Pulmonary Vein Isolation in Paroxysmal Atrial Fibrillation: Elimination of Nonpulmonary Vein Triggers Versus Noninducibility

Background: Pulmonary vein isolation (PVI) is effective for maintenance of sinus rhythm in 50% to 75% of patients with paroxysmal atrial fibrillation, and it is not uncommon for patients to require additional ablation after PVI. We prospectively evaluated the relative effectiveness of 2 post-PVI ablation strategies in paroxysmal atrial fibrillation. Methods and Results: A total of 500 patients (mean age, 55.7±11.0 years; 74.6% male) were randomly assigned to undergo ablation by 2 different strategies after PVI: (1) elimination of non-PV triggers (group A, n=250) or (2) stepwise substrate modification including complex fractionated atrial electrogram or linear ablation until noninducibility of atrial tachyarrhythmia was achieved (group B, n=250). During a median follow-up of 26.0 months, 75 (32.2%) patients experienced at least 1 episode of recurrent atrial tachyarrhythmia after the single procedure in group A compared with 105 (43.8%) patients in group B (P value in log-rank test of Kaplan–Meier analysis: 0.012). Competing risk analysis showed that the cumulative incidence of atrial tachycardia was significantly higher in group B compared with group A (P=0.007). With the exception of total ablation time, there were no significant differences in fluoroscopic time or procedure-related complications between the 2 groups. Conclusions: Elimination of triggers as an end point of ablation in patients with paroxysmal atrial fibrillation decreased long-term recurrence of atrial tachyarrhythmia compared with a noninducibility approach achieved by additional empirical ablation. The post-PVI trigger test is thus a better end point of ablation for paroxysmal atrial fibrillation.

Long-term clinical outcomes of catheter ablation in patients with atrial fibrillation predisposing to tachycardia-bradycardia syndrome: a long pause predicts implantation of a permanent pacemaker

BackgroundThere is a controversy as to whether catheter ablation should be the first-line therapy for tachycardia-bradycardia syndrome (TBS) in patients with atrial fibrillation (AF).MethodsWe aimed to investigate long-term clinical outcomes of catheter ablation in patients with TBS and AF. Among 145 consecutive patients who underwent catheter ablation of AF with TBS, 121 patients were studied.ResultsAmong 121 patients, 11 (9.1%) received implantation of a permanent pacemaker during a mean 21xa0months after ablation. Length of pause on termination of AF was significantly greater in patients who received pacemaker implantation after ablation than those who underwent ablation only (7.9u2009±u20093.5 vs. 5.1u2009±u20092.1xa0s, pu2009<u20090.001). Using a multivariate model, a long pause of 6.3xa0s or longer after termination of AF was associated with the requirement to implant a permanent pacemaker after ablation (HR 1.332, 95% CI 1.115-1.591, pu2009=u20090.002).ConclusionThis study suggests that, in patients with AF predisposing to TBS, long pause on termination of AF predicts the need to implant a permanent pacemaker after catheter ablation.