[show abstract][hide abstract] ABSTRACT: Purpose: Our study aims to analyze prognosis after implantable cardioverter-defibrillator (ICD) implantation in Korean patients with Brugada syndrome (BrS). Materials and Methods: This was a retrospective study of BrS patients implanted with an ICD at one of four centers in Korea between January 1998 and April 2012. Sixty-nine patients (68 males, 1 female) were implanted with an ICD based on aborted cardiac arrest (n=38, 55%), history of syncope (n=17, 25%), or induced ventricular tachyarrhythmia on electrophysiologic study in asymptomatic patients (n=14, 20%). A family history of sudden cardiac death and a spontaneous type 1 electrocardiography (ECG) were noted in 13 patients (19%) and 44 patients (64%), respectively. Results: During a mean follow-up of 59±46 months, 4.6±5.5 appropriate shocks were delivered in 19 patients (28%). Fourteen patients (20%) experienced 5.2±8.0 inappropriate shocks caused by supraventricular arrhythmia, lead failure, or abnormal sensing. Six patients were admitted for cardiac causes during follow-up, but no cardiac deaths occurred. An episode of aborted cardiac arrest was a significant predictor of appropriate shock, and the composite of cardiac events in the Cox proportional hazard model [hazard ratio (95% confidence interval) was 11.34 (1.31-97.94) and 4.78 (1.41-16.22), respectively]. However, a spontaneous type 1 ECG was not a predictor of cardiac events. Conclusion: Appropriate shock (28%) and inappropriate shock (20%) were noted during a mean follow-up of 59±46 months in Korean BrS patients implanted with an ICD. An episode of aborted cardiac arrest was the most powerful predictor of cardiac events.
Yonsei medical journal 01/2014; 55(1):37-45. · 0.77 Impact Factor
[show abstract][hide abstract] ABSTRACT: Ventricular fibrillation (VF) can inadvertently occur during electrophysiologic study (EPS) or catheter ablation. We investigated the incidence, cause, and progress of inadvertently developed VF during EPS and catheter ablation.
We reviewed patients who had developed inadvertent VF during EPS or catheter ablation. Patients who developed VF during programmed ventricular stimulation to induce ventricular tachycardia or VF were excluded.
Inadvertent VF developed in 11 patients (46.7±9.3 years old) among 2624 patients (0.42%); during catheter ablation for atrial fibrillation (AF) in nine patients, frequent ventricular premature beats (VPBs) in one, and Wolff-Parkinson-White (WPW) syndrome were observed in one. VF was induced after internal cardioversion in six AF patients due to incorrect R-wave synchronization of a direct current shock. Two AF patients showed spontaneous VF induction during isoproterenol infusion while looking for AF triggering foci. The remaining AF patient developed VF after rapid atrial pacing to induce AF, but the catheter was accidentally moved to the right ventricular (RV) apex. A patient with VPB ablation spontaneously developed VF during isoproterenol infusion. The focus of VPB was in the RV outflow tract and successfully ablated. A patient with WPW syndrome developed VF after rapid RV pacing with a cycle length of 240 ms. Single high energy (biphasic 150-200 J) external defibrillation was successful in all patients, except in two, who spontaneously terminated VF. The procedure was uneventfully completed in all patients. At a mean follow-up period of 17.4±15.5 months, no patient presented with ventricular arrhythmia.
Although rare, inadvertent VF can develop during EPS or catheter ablation. Special caution is required to avoid incidental VF during internal cardioversion, especially under isoproterenol infusion.
[show abstract][hide abstract] ABSTRACT: This study evaluated the feasibility and accuracy of three-dimensional rotational angiography (3DRA) to determine the anatomy of the left atrium (LA) and pulmonary veins (PVs) compared with cardiac computed tomography (CCT) and trans-thoracic echocardiography (TTE). One hundred two patients (56.1 ± 9.9 years, 86 males) with an indication for atrial fibrillation ablation were prospectively enrolled. Intra-procedural 3DRA was performed with power injected contrast medium (20 cc/s for 4 s, 240°) in the LA. 3DRA images of the LA and PVs were assessed qualitatively and then compared quantitatively. LA volume measured by 3DRA, CCT and TTE were compared. The majority of 3DRA acquisitions were optimal in delineating the right-side LA-PV (95 % for right superior PV and 96 % for right inferior PV) and left inferior PV anatomy (91 %), whereas it was optimal in only 63 % of left superior PV and 73 % of the LA appendage. The circumferences of PV ostia identified by 3DRA and CCT were correlated in four PVs (r = 0.57 for right superior PV, r = 0.67 for right inferior PV, r = 0.60 for left superior PV, and r = 0.52 for left inferior PV, p < 0.001). The mean LA volume measured by 3DRA (120 ± 32 mL) was greater than that found by CCT (109 ± 35 mL) or TTE (64 ± 23 mL), but the 3DRA LA volume measurements correlated well with those of CCT (r = 0.83, p < 0.001) and TTE (r = 0.69, p < 0.001). Intra-procedural 3DRA provided anatomical accuracy of LA and PVs comparable to those of CCT. However, optimal delineation of the left superior PV and LA appendage was limited. The LA volume determined by 3DRA was well correlated with those of CCT and TTE, despite different absolute values of each.
The international journal of cardiovascular imaging 04/2013; · 2.15 Impact Factor
[show abstract][hide abstract] ABSTRACT: BACKGROUND: -Iatrogenic myocardial injury by radiofrequency catheter ablation (RFCA) releases pro-inflammatory substances from damaged myocardium, and these may contribute to endothelial dysfunction in systemic vascular structure. The aim of this study is to evaluate effect of non-ischemic myocardial damage on coronary microvascular function in patients undergoing atrial fibrillation (AF) ablation. METHODS AND RESULTS: -We included 49 patients who underwent AF ablation (paroxysmal AF[PAF] = 25, persistent AF[PeAF] = 24) and 34 controls. Immediately before and after RFCA, index of microvascular resistance (IMR) was assessed at left anterior descending coronary artery and blood samples were obtained for analyses of nitric oxide (NO), activated leukocyte cell adhesion molecule (ALCAM), and lipoprotein-associated phospholipase (LpPLA2). Transthoracic echocardiography was performed at baseline, one day, one month, and 3 months after RFCA. Compared with baseline, IMR, ALCAM, and LpPLA2 increased and NO decreased after RFCA. In 36 subjects with increasing IMR, E/E' ratio increased at one day and returned to baseline level at 3 months after RFCA. Changes in ALCAM and LpPLA2 between baseline and after RFCA were independently related to the increase in IMR. In 14 subjects (28.6%), arrhythmia recurred. Using a cutoff value of 9.3 mmHg/s, sensitivity was 56.7% and specificity was 91.2% for IMR change in predicting AF recurrence (P = 0.028). CONCLUSIONS: -Myocardial damage by RFCA provoked coronary microvascular dysfunction through systemic pro-inflammatory reaction that may contribute to transient diastolic dysfunction. This phenomenon may represent a mechanism for early recurrence of arrhythmia following RFCA. Clinical Trial Registration Information-http://cris.cdc.go.kr; Identifier: KCT0000030.
Circulation Arrhythmia and Electrophysiology 03/2013; · 5.95 Impact Factor
[show abstract][hide abstract] ABSTRACT: We report a case about a 27-year-old healthy young male who developed syncope during exercise, which was subsequently identified to be attributable to non-sustained polymorphic ventricular tachycardia (VT). Occurrence of polymorphic VT was neither related to a prolonged QT interval nor a fixed short coupling interval. Standard examinations including echocardiography, coronary angiography, isoproterenol infusion study, and cardiac MRI showed no structural heart disease. On the electrophysiology study, activation mapping revealed that a discrete potential preceded the premature ventricular complex (PVC) triggered polymorphic VT, which was recorded just above the pulmonary valve. After radiofrequency ablation at this area, PVC and polymorphic VT disappeared and did not recur after a 2 month follow up.
Korean Circulation Journal 02/2013; 43(2):119-122.
[show abstract][hide abstract] ABSTRACT: The sinus venosus (SV) is not a well known source of atrial tachycardia (AT), but it can harbor AT during catheter ablation of atrial fibrillation (AF).
A total of 1223 patients who underwent catheter ablation for AF were reviewed. Electrophysiological and electrocardiographic characteristics and outcomes after catheter ablation of AT originating from the SV were investigated.
Ten patients (0.82%) demonstrated AT from the SV (7 males, 53.9±16.0 years, 6 persistent) during ablation of AF. The mean cycle length was 281±73 ms. After pulmonary vein isolation and left atrial ablation, AF converted to AT from the SV during right atrial ablation in 2 patients, by rapid atrial pacing after AF termination in 7 patients, and during isoproterenol infusion in 1 patient. Positive P-waves in inferior leads were shown in most patients (90%). The activation sequence of AT was from proximal to distal in the superior vena cava and high to low in the right atrium, which was similar to that of AT from crista terminalis. Fragmented double potentials were recorded during sinus, and a second discrete potential preceded the onset of P wave by 80±37 ms during AT. Using 4.4±2.7 radiofrequency focal applications, ATs were terminated and became no longer inducible in all. After ablation procedure, two patients showed transient right phrenic nerve palsy. After 19.9±14.8 months, all but 1 patient were free of atrial tachyarrhythmia without complications.
The AT which develops during AF ablation is rarely originated from SV, and its electrophysiologic characteristics may be helpful in guiding effective focal ablation.
[show abstract][hide abstract] ABSTRACT: Prediction of Long-Term Outcomes of Catheter Ablation of Persistent Atrial Fibrillation. Aim: 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. Method: From 2006 to 2009, 94 patients with PeAF and LPAF who had undergone elective DC CV before RFCA were studied. The parameters associated with DC CV, including number of shocks, cumulative energy adjusted, highest energy adjusted, with or without intravenous amiodarone use, and other clinical parameters were assessed. Result: Thirty-two out of the 94 patients (34%) experienced AF recurrence during the follow-up of 19.8 ± 12.3 months after RFCA. The average time to recurrence of AF after RFCA was 9.2 ± 3.2 months. Of the 62 patients, 29 patients (31%) remained sinus rhythm (SR) without antiarrhythmic drug (AAD). The patients who maintained SR had smaller body mass index (BMI) (P = 0.048), shorter duration of AF (P = 0.012), and lower prevalence of diabetes mellitus (P = 0.023) compared with patients in whom AF recurred. Total number of shocks, total energy, and highest shock energy during CV were lower (P < 0.001, P = 0.002, P = 0.048, respectively) in patients with SR during the follow-up. The outcome in patients who used amiodarone IV prior to CV, however, was not different from that in those who did not use amiodarone IV. Conclusion: DC energy parameters for successful CV before RFCA were useful to predict the long-term outcome after RFCA in patients with PeAF and LPAF. The presence of the atrial substrate making DC CV difficult might reflect atrial substrate that subsequently related to the recurrence of AF after RFCA in chronic AF. These DC energy parameters may be related to the chronicity or electroanatomical remodeling of AF. (J Cardiovasc Electrophysiol, Vol. pp. 1-6).
Journal of Cardiovascular Electrophysiology 08/2012; · 3.48 Impact Factor
[show abstract][hide abstract] ABSTRACT: The circadian and seasonal patterns of ventricular tachyarrhythmia (VTA) in patients with early repolarization syndrome (ERS) have not been determined. We compared the timing of VTAs in patients with ERS and Brugada syndrome (BS).
We enrolled patients with ERS (n = 14) and BS (n = 53) who underwent implantable cardioverter defibrillator (ICD) implantation. The timing of VTAs, including cardiac arrest and appropriate shocks, was determined. During follow up of 6.4 ± 3.6 years in the ERS group and 5.0 ± 3.3 years in the BS group, 5 of 14 (36%) ERS and 10 of 53 (19%) BS patients experienced appropriate shocks (P = 0.37). Cardiac arrest showed a trend of nocturnal distribution peaking from midnight to early morning (P = 0.14 in ERS, P = 0.16 in BS). Circadian distribution of appropriate shocks showed a significant nocturnal peak in patients with ERS (P < 0.0001) but a trend toward a nocturnal peak in patients with BS (P = 0.08). There were no seasonal differences in cardiac arrest in patients with ERS and BS. However, patients with ERS showed a seasonal peak in appropriate shocks from spring to summer (P < 0.0001). There was no significant seasonal peak in patients with BS. The timing of VTAs (cardiac arrest plus appropriate shock) showed significant nocturnal distributions in patients with ERS and BS (P < 0.01, respectively). A significant clustering of VTAs was noted from spring to summer (P < 0.01) in patients with ERS, but not in patients with BS (P = 0.42).
Incidence of VTAs showed marked circadian variations with night-time peaks in patients with ERS and BS.
Journal of Cardiovascular Electrophysiology 02/2012; 23(7):757-63. · 3.48 Impact Factor
[show abstract][hide abstract] ABSTRACT: atrial tachycardia (AT) commonly recurs within 3 months after radiofrequency catheter ablation for atrial fibrillation (AF). However, it remains unclear whether early recurrence of atrial tachycardia (ERAT) predicts late recurrence of AF or AT.
of 352 consecutive patients who underwent circumferential pulmonary vein isolation with or without linear ablation(s) for AF, 56 patients (15.9%) with ERAT were identified by retrospective analysis. ERAT was defined as early relapse of AT within a 3-month blanking period after ablation.
during 21.7 ± 12.5 months, the rate of late recurrence was higher in patients with ERAT (41.1%) compared with those without ERAT (11.8%, P < 0.001). In a multivariable model, positive inducibility of AF or AT immediately after ablation (65.2% vs 36.4%, P = 0.046; odd ratio, 3.9; 95% confidence interval, 1.0-14.6) and the number of patients who underwent cavotricuspid isthmus (CTI) ablation (73.9% vs 42.4%, P = 0.042; odd ratio, 4.5; 95% confidence interval, 1.1-19.5) were significantly related to late recurrence in the ERAT group. The duration of ablation (174.3 ± 62.3 vs 114.7 ± 39.5 minutes, P = 0.046) and the procedure time (329.3 ± 83.4 vs 279.2 ± 79.7 minutes, P = 0.027) were significantly longer in patients with late recurrence than in those without late recurrence following ERAT.
the late recurrence rate is higher in the patients with ERAT compared with those without ERAT following AF ablation, and is more often noted in the patients who underwent CTI ablation and had a prolonged procedure time. Furthermore, inducibility of AF or AT immediately after ablation independently predicts late recurrence in patients with ERAT.
Journal of Cardiovascular Electrophysiology 12/2010; 21(12):1331-7. · 3.48 Impact Factor
[show abstract][hide abstract] ABSTRACT: Although atrial fibrillation (AF) is a risk factor for endothelial dysfunction (ED), the effect of catheter ablation (CA) on AF-associated ED has not been evaluated. The aims of this study are to determine if the degree of ED predicts the outcome of AF ablation and to evaluate whether ED can be improved through restoring sinus rhythm (SR) by successful CA.
This study prospectively enrolled 80 subjects who underwent CA for AF (paroxysmal AF = 61, persistent AF = 19). Eighty subjects with no history of AF were enrolled as controls, all of whom were matched by age, gender, body mass index, and atherosclerotic risk factor distribution. Brachial artery flow-mediated dilatation (FMD) was measured at baseline, and at 1 month and 6 months post CA in AF subjects who remained in SR. Among controls, FMD was measured at baseline and at 6 months. We used high sensitivity C-reactive protein (hs-CRP), interleukin-6, soluble E- or P-selectin, and endothelin-1 as biomarker indices for inflammation and/or ED.
Compared with controls, AF subjects had lower FMD at baseline (FMD(baseline), P < 0.001). After successful CA, FMD was significantly improved at 1 month and 6 months, nearly approaching control levels. A multivariate analysis revealed that FMD(baseline), hs-CRP, and left atrial volume (LAV) were independent predictors for arrhythmia recurrence after CA. Other biomarkers were not related to rhythm outcome.
AF subjects have significantly impaired FMD, which can be reversed through maintenance of SR by successful CA. FMD(baseline), hs-CRP, and LAV are important predictors for AF recurrence after CA.
Journal of Cardiovascular Electrophysiology 10/2010; 22(4):376-82. · 3.48 Impact Factor
[show abstract][hide abstract] ABSTRACT: Complex fractionated atrial electrogram (CFAE) guided ablation is effective in some patients with persistent atrial fibrillation (PeAF), but the pattern of CFAE may be different in the remodeled left atrium (LA).
In 100 AF patients (83 males, 55.0+/-10.6 years old) with AF (51 paroxysmal AF (PAF), 49 PeAF) who underwent catheter ablation, CFAE cycle length (CL) and distribution (NavX 3D map) were compared according to the LA volume (3D-CT) and endocardial voltage (during high right atrial pacing 500-ms (Vol(PACE)) and AF (Vol(AF); NavX). The mean CFAE-CL was longer (P=0.003) and the % area CFAE was smaller (P=0.006) in patients with LA >or=125 ml than those with <125 ml. The mean CFAE-CL was longer in patients with Vol(PACE) <1.7 mV than those with >or=1.7 mV (P=0.002) and in Vol(AF) <0.7 mV than >or=0.7 mV (P<0.001). The % area CFAE was smaller in patients with Vol(PACE) <1.7 mV than those with >or=1.7 mV (P=0.006). The incidence of septal CFAE was consistently high, regardless of the degree of LA remodeling.
In the AF patients with an electroanatomically remodeled LA, the % area of CFAE was smaller and mean CFAE-CL was longer than in those with a less remodeled LA. However, the majority of CFAE are consistently positioned on the septum in the remodeled LA.
[show abstract][hide abstract] ABSTRACT: Although open irrigation tip catheters (OITC) are effective in producing transmural radiofrequency (RF) lesions, they have the potential for fluid overload or excessive tissue damage.
The 203 patients with non-paroxysmal atrial fibrillation (NPAF; 85.2% males, 55.2+/-10.6 years old) who underwent RF catheter ablation (RFCA) were analyzed retrospectively. Clinical outcomes and complications were compared between RFCA using OITC (n=92) and that using conventional catheters (CONC; n=111). Both the total procedure time (P<0.01) and fluoroscopic time (P<0.001) were shorter in the OITC group than in the CONC group. Total fluid loading during RFCA with OITC was 3.2+/-0.9L, and the average body weight increase was 1.8+/-1.2 kg. Symptomatic pulmonary edema and/or pleural effusion occurred in 3.3% of patients who had a bigger left atrium (P=0.005), longer duration of ablation procedure (P=0.002), higher post-RFCA serum pro-ANP level (P<0.001), and longer hospitalization (P<0.01).
RFCA for NPAF using OITC results in a shorter procedure time compared with CONC. However, patients with a large left atrium and a large amount of fluid (>4L) infused via the OITC need to be carefully monitored to prevent pulmonary edema or pleural effusion because of fluid overload.