The general concept and initial approach to syncope patients has been mentioned in the general sections. This special sections have been described the characteristics, diagnosis, and treatment with patient education for the each syncope. It has been described in order of reflex syncope, orthostatic hypotension, postural orthostatic tachycardia syndrome (POTS), cardiac syncope, and unexplained syncope. Several clinical issues will have been dealt with in special issues. Neurological assessment is added when the patients were diagnosed with psychogenic pseudosyncope (PPS). Although many childhood syncope caused by reflex syncope, they are also presented as syncope caused by arrhythmic events in patients with congenital heart disease. In the elderly patients, syncope is because of not only a single cause of syncope but a combination of various conditions. In case of a syncope patient visiting the emergency department, a standardized systematic approach will be required to determine whether hospitalize the patient according to the risk of recurrence and the needs for the syncope management unit. We also mention recommendations on the limits of driving, exercising and social life style that are relevant to syncope in all patients. In this guideline, we reviewed the Korean published literatures and European/American guidelines on syncope.

We report a case of successfully treated acute fulminant myocarditis induced by ulcerative colitis with extracorporeal life support and infliximab. Myocarditis is a rare but crucial complication during an exacerbation of inflammatory bowel disease. In our case, we applied extracorporeal membrane oxygenation (ECMO) for cardiac rest under impression of acute myocarditis associated with ulcerative colitis, and added infliximab for uncontrolled inflammation by corticosteroid. As a result, our patient was completely recovered with successful weaning of ECMO.

Purpose Electric cardioversion has been successfully used in terminating symptomatic atrial fibrillation (AF). Nevertheless, largescale study about the acute cardiovascular events following electrical cardioversion of AF is lacking. This study was performed to evaluate the incidence, risk factors, and clinical consequences of acute cardiovascular events following electrical cardioversion of AF. Materials and Methods The study enrolled 1100 AF patients (mean age 60±11 years) who received cardioversion at four tertiary hospitals. Hospitalizations for stroke/transient ischemic attack, major bleedings, and arrhythmic events during 30 days post electric cardioversion were assessed. Results The mean duration of anticoagulation before cardioversion was 95.8±51.6 days. The mean International Normalized Ratio at the time of cardioversion was 2.4±0.9. The antiarrhythmic drugs at the time of cardioversion were class I (45%), amiodarone (40%), beta-blocker (53%), calcium-channel blocker (21%), and other medication (11%). The success rate of terminating AF via cardioversion was 87% (n=947). Following cardioversion, 5 strokes and 5 major bleedings occurred. The history of stroke/transient ischemic attack (OR 6.23, 95% CI 1.69-22.90) and heart failure (OR 6.40, 95% CI 1.77-23.14) were among predictors of thromboembolic or bleeding events. Eight patients were hospitalized for bradyarrhythmia. These patients were more likely to have had a lower heart rate prior to the procedure (p=0.045). Consequently, 3 of these patients were implanted with a permanent pacemaker. Conclusion Cardioversion appears as a safe procedure with a reasonably acceptable cardiovascular event rate. However, to prevent the cardiovascular events, several risk factors should be considered before cardioversion.

AIMS Successful rhythm control after atrial fibrillation catheter ablation is known to induce left atrial reverse remodelling and improve left ventricular (LV) function. We explored the clinical factors affecting LV systolic and diastolic function 1-year after catheter ablation for atrial fibrillation. METHODS AND RESULTS We compared pre-procedural and 1-year follow-up echocardiograms in 521 patients with atrial fibrillation who underwent catheter ablation. Left ventricular systolic function was estimated by the ejection fraction (EF); diastolic function was estimated by the ratio of early transmitral flow velocity (E) to early mitral annular velocity (Em). (i) Catheter ablation of atrial fibrillation significantly reduced left atrium volume index (P < 0.001) and improved LV EF both in patients with recurrent atrial fibrillation (n = 133, P = 0.008) and those without recurrence (n = 388, P < 0.001). (ii) Follow-up EF was significantly improved in patients with baseline E/Em < 15 (n = 454, P < 0.001), whereas E/Em was significantly reduced in patients with pre-procedural E/Em ≥ 15 (n = 67, P = 0.008). (iii) Baseline E/Em < 15 (β = -3.854, 95% CI -5.99 to -1.72, P < 0.001), baseline EF <50% (β = 10.586, 95% CI 7.55 to 13.63, P < 0.001), and female (β = -1.726, 95% CI -3.36 to -0.10, P = 0.038) were independently associated with improved EF. Baseline E/Em ≥ 15 (β = 4.896, 95% CI 3.45 to 6.34, P < 0.001) and younger age (β = -0.066, 95% CI -0.11 to -0.02, P = 0.003) were independent factors associated with improved E/Em. CONCLUSION Pre-procedural E/Em predicted improvement in LV systolic and diastolic functions 1 year after catheter ablation for atrial fibrillation. Low baseline E/Em was independently associated with improved EF, while high E/Em predicted improvement in LV diastolic function.

Background/Aims In the bare-metal stent era, routine follow-up coronary angiography (RFU CAG) was used to ensure stent patency. With the advent of drug-eluting stents (DESs) with better safety and efficacy profiles, RFU CAG has been performed less often. There are few data on the clinical impact of RFU CAG after second- or third-generation DES implantation in clinically stable patients with coronary artery disease; the aim of this study was to examine this issue. Methods We analyzed clinical outcomes retrospectively of 259 patients who were event-free at 12-month after stent implantation and did not undergo RFU CAG (clinical follow-up group) and 364 patients who were event-free prior to RFU CAG (angiographic follow-up group). Baseline characteristics were compared between the groups. Results The Kaplan-Meier estimated total survival and major adverse cardiac event (MACE)-free survival did not differ between the groups (p = 0.100 and p = 0.461, respectively). The cumulative MACE rate was also not different between the groups (hazard ratio, 0.85; 95% confidence interval, 0.35 to 2.02). In the angiographic follow-up group, 8.8% revascularization was seen at RFU CAG. Conclusions RFU CAG did not affect long-term clinical outcome after second- or third-generation DES implantation in clinically stable patients.

BACKGROUND:The pathophysiology of diastolic dysfunction is complex, but can be simply described as impaired LV myocardial relaxation and/or increased LV stiffness. The objective of this study is to clarify true normal left ventricular (LV) diastolic function and early stage of diastolic dysfunction before relaxation abnormality develops in patients with normal LV diastolic function using simple diastolic wall strain (DWS) in South Korea.METHODS:DWS which is a non-invasive, load-independent, and reproducible estimator of LV stiffness using two-dimensional echocardiography using the difference between posterior wall thickness in systole and diastole to approximate LV stiffness. A total of 349 consecutive patients with normal LV diastolic function by echocardiography were enrolled. According to DWS, patients were divided into two groups: high DWS (≥median 175) vs. low DWS (<median 174).RESULTS:Patients with low DWS were more obese and showed higher blood pressure, and had more prevalent hypertension and hyperlipidemia. In addition, those with low DWS had higher LV end-systolic volume, LV mass index, E/E' and lower ejection fraction and E' velocity. Among them, higher LVESV and LVMI were independently associated with low DWS.CONCLUSIONS:These data suggests that simple DWS might be helpful in identifying a subgroup of subtle diastolic dysfunction. Our data suggest that early change of diastolic dysfunction might start with abnormal LV geographic changes preceding functional changes.

Background: Left ventricular (LV) diastolic dysfunction occurs before LV systolic dysfunction and electrocardiographic changes in ischemic cascade. Diastolic wall strain (DWS) has been proposed as a marker of LV diastolic stiffness. Therefore, the objectives of this study were to defined the relationship between DWS and percutaneous coronary intervention (PCI) and see other echocardiographic parameters in patients who undergoing coronary angiography (CAG). Methods: 254 patients (mean age: 61 ± 10, 136 (54%) men) undergoing CAG and normal left ventricular systolic function without regional wall motion abnormalities were enrolled, and among them, 68 (27%) patients performed PCI. All patients performed echocardiography before CAG and DWS defined using posterior wall thickness (PWT) measurements from standard echocardiographic images (DWS =[PWT(systole)-PWTdiastole)]/PWT(systole)). Results: Patients who performed PCI showed significantly lower DWS (0.27 ± 0.09 vs. 0.39 ± 0.08, p < 0.001). Age did not differ between the two groups (61.6 ± 10.6 vs. 60.9 ± 10.4, p = 0.623), and LV ejection fraction was also similar (62.8 ± 4.6 vs. 63.5 ± 5.2%, p = 0.380). Other echocardiographic parameters did not show significance differences but E/E’ ratio was slightly but significantly elevated in patients performed PCI (10.9 ± 4.8 vs 9.2 ± 3.3, p = 0.011). In multiple regression analysis, lower DWS was an independent predictor for PCI (Cut-off value: 0.34, sensitivity: 89%, AUC: 0.870, SE: 0.025, p < 0.001). Conclusion: DWS, a simple parameter that can be calculated from routine 2D echocardiography, is inversely associated with presence of coronary artery disease and PCI.

Current guidelines advocate for patients with AF ≥ 48 h to achieve a therapeutic International Normalized Ratio (INR) 3 weeks prior to cardioversion and maintain anticoagulation for at least 4 weeks following cardioversion. If a patient did not receive anticoagulation for preceding 3 weeks, it is reasonable to perform a transesophageal echocardiography (TEE) prior to cardioversion [ 1 European Heart Rhythm A. European Association for Cardio-Thoracic S Camm A.J. Kirchhof P. Lip G.Y. Schotten U. et al. Guidelines for the management of atrial fibrillation: the Task Force for the Management of Atrial Fibrillation of the European Society of Cardiology (ESC). Europace. 2010; 12: 1360-1420 Crossref PubMed Scopus (1335) Google Scholar , 2 January C.T. Wann L.S. Alpert J.S. Calkins H. Cigarroa J.E. Cleveland Jr., J.C. et al. 2014 AHA/ACC/HRS guideline for the management of patients with atrial fibrillation: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines and the Heart Rhythm Society. J. Am. Coll. Cardiol. 2014; 64: e1-e76 Abstract Full Text Full Text PDF PubMed Scopus (2784) Google Scholar ]. However, whether TEE reduces thromboembolism during cardioversion in AF patients receiving guideline-oriented anticoagulation is still controversial. Recently, it was revealed that in AF patients with a low stroke risk, a routine TEE even before ablation might be unnecessary to decrease periprocedural stroke [ 3 Han J.H. Shin D.H. Lee H.J. Kim Y.J. Lee S.H. Shim J. et al. Routine preprocedural transesophageal echocardiography might not be necessary for stroke prevention evaluation in AF patients on anticoagulation therapy. Int. J. Cardiol. 2013; 168: 1992-1996 Abstract Full Text Full Text PDF PubMed Scopus (7) Google Scholar , 4 Hong S.J. Kim J.Y. Kim J.B. Sung J.H. Wook Kim D. Uhm J.S. et al. Multidetector computed tomography may be an adequate screening test to reduce periprocedural stroke in atrial fibrillation ablation: a multicenter propensity-matched analysis. Heart Rhythm. 2014; 11: 763-770 Abstract Full Text Full Text PDF PubMed Scopus (15) Google Scholar ]. The aim of this study was to determine clinical impact of an additional pre-cardioversion TEE on the incidence of thromboembolism in patients with AF ≥ 48 h under adequate anticoagulation in real-world clinical practice.

Introduction: Sick sinus syndrome (SSS) is mainly diagnosed based on clinical criteria and there is still no non-invasive study to assess the degree of sinoatrial node (SAN) dysfunction. Hypothesis: This study sought to evaluate whether a combined algorithm using a poor increase in inferior P-wave amplitude during sympathetic stimulation and conventional CSNRT might be a helpful diagnostic tool for SSS. Methods: Three dimensional endocardial mapping of right atrium (RA), P-wave amplitude of inferior axis and corrected sinus node recovery time (CSNRT) were compared in consecutive 105 atrial fibrillation patients with (n=18) and without SSS (n=87). Results: The distances from the superior vena cava (SVC) to the RA early activation site (EAS) were negatively correlated with P-wave amplitude of lead II (r=-0.41, p<0.001), III (r=-0.41, p<0.001) and aVF (r=-0.43, p<0.001). The significant cranial shift of EAS (the distance from SVC to EAS: 11.0 vs. 6.1 mm, p<0.001), and the increase of P-wave amplitude of lead...

Background The current standard of care is to delay noncardiac procedure (NCP) 5 to 7 days after discontinuation of antiplatelet agents (APAs) in patients with coronary stents. However, it is often difficult to follow because of concerns over stent thrombosis. The point-of-care aspirin/P2Y12 assay (VerifyNow; Accumetrics Inc, San Diego, CA) is useful to evaluate platelet reactivity in conjunction with APAs. In this study, we evaluated the feasible timing after discontinuation of APAs. Methods and Results Sixty-two patients taking APAs, who were scheduled to undergo elective NCP, were enrolled. All patients took either aspirin 100 mg or aspirin 100 mg plus clopidogrel 75 mg daily. The aspirin-reactivity unit (ARU) and P2Y12-reactivity unit (PRU) were measured from 0 days (day 0, no discontinuation) to as long as 5 days (day 5, 5 days after discontinuation) depending on each procedure schedule. For 15 patients, baseline ARU and PRU (592 and 288) before aspirin/clopidogrel loading at index percutaneous coronary intervention were collected as control. For ARU after discontinuation of APA, days 0 to 5 values progressively increased over time (489.4 ± 85.3, 512.6 ± 77.0, 589.9 ± 58.8, 613.6 ± 47.3, 632.6 ± 49.2, 662.0 ± 4.2). Likewise, for PRUs, days 0 to 5 values also increased over time (245.0 ± 96.9, 253.9 ± 80.9, 270.9 ± 45.8, 289.0 ± 68.6, 306.5 ± 29.2, 351.0 ± 8.5). The ARU and PRU well correlated with days after APA discontinuation by linear regression analysis ( y = 490.897 + 39.238 * x, R2 = 0.43, P < 0.001; y = 241.739 + 16.701 * x, R2 = 0.092, P = 0.018, respectively). Assuming baseline ARU and PRU as 592 and 288, the mean days after complete reversal of platelet reactivity by APAs are 2.6 and 2.8, respectively. Conclusions The feasible timing of NCP after discontinuation of APAs showed less than 5 days. VerifyNow is useful in the evaluation of antiplatelet reversal after discontinuation of APAs.

PURPOSE:Recent studies show positive association of early repolarization (ER) with the risk of life-threatening arrhythmias in patients with coronary artery disease (CAD). This study was to investigate the relationships of ER with myocardial scarring and prognosis in patients with CAD.MATERIALS AND METHODS:Of 570 consecutive CAD patients, patients with and without ER were assigned to ER group (n=139) and no ER group (n=431), respectively. Myocardial scar was evaluated using cardiac single-photon emission computed tomography.RESULTS:ER group had previous history of myocardial infarction (33% vs. 15%, p<0.001) and lower left ventricular ejection fraction (57±13% vs. 62±13%, p<0.001) more frequently than no-ER group. While 74 (53%) patients in ER group had myocardial scar, only 121 (28%) patients had in no-ER group (p<0.001). During follow up, 9 (7%) and 4 (0.9%) patients had cardiac events in ER and no-ER group, respectively (p=0.001). All patients with cardiac events had ER in inferior leads and horizontal/descending ST-segment. Patients with both ER in inferior leads and horizontal/descending ST variant and scar had an increased adjusted hazard ratio of cardiac events (hazard ratio 16.0; 95% confidence interval: 4.1 to 55.8; p<0.001).CONCLUSION:ER in inferior leads with a horizontal/descending ST variant was associated with increased risk of cardiac events. These findings suggest that ER in patients with CAD may be related to myocardial scar rather than pure ion channel problem.

The clinical presentation of Kawasaki disease (KD) is variable and clinical implication among adults is rarely important but coronary involvement. Here we report a young patient showing recurrent acute coronary syndrome (ACS) who had a history of high-grade fever and conjunctivitis when he was little. Coronary angiography revealed aneurysmal coronary artery change in this patient. There is no particular consensus on guidelines for treatment for KD in case of coronary aneurysm causing ACS. In this case, we treated him medically without stent implantation successfully.

Introduction: Loss of atrioventricular synchrony has been known to impair left ventricular (LV) systolic and diastolic function in patients with atrial fibrillation (AF), and radiofrequency catheter ablation (RFCA) may recover them. Hypothesis: We explored the clinical factors affecting the reverse LV systolic and diastolic functions after RFCA for AF. Methods: We compared pre- and post-1-year RFCA follow-up echocardiography in 521 patients with AF (male 76.2%, 57.1±11.2 years old, paroxysmal AF 68.5%) who underwent RFCA. Left ventricular (LV) systolic and diastolic functions were estimated by ejection fraction (EF) and the ratio of the early transmitral flow velocity (E) and early mitral annular velocity (Em), respectively. Results: 1. AF ablation significantly reduced left atrium volume index (p<0.001) and improved LVEF (p=0.008 and p<0.001) in both recurred (n=133) and non-recurred patients (n=388). 2. In patients with baseline E/Em<15 (n=454), significant EF improvement was observed (63.2±8.0 to 65.1±...

It is a matter of debate whether metabolic syndrome (MS) improves cardiovascular risk prediction beyond the risk associated with its individual components. The present study examined the association of MS score with high sensitivity C-reactive protein (hs-CRP), interleukin-6 (IL-6), resistin, adiponectin, and angiographic coronary artery disease (CAD) severity according to the presence of DM. In addition, the predictive value of various clinical and biochemical parameters were analyzed, including the MS score for angiographic CAD.

BACKGROUND:The mechanisms underlying amiodarone-induced sinoatrial node (SAN) dysfunction remain unclear, so we used 3-dimensional endocardial mapping of the right atrium (RA) to investigate.METHODS AND RESULTS:In a matched-cohort design, 18 patients taking amiodarone before atrial fibrillation (AF) ablation (amiodarone group) were matched for age, sex and type of AF with 18 patients who had undergone AF ablation without taking amiodarone (no-amiodarone group). The amiodarone group had a slower heart rate than the no-amiodarone group at baseline and during isoproterenol infusion. Only the amiodarone group had sick sinus syndrome (n=4, 22%, P=0.03) and abnormal (>550ms) corrected SAN recovery time (n=5, 29%; P=0.02). The median distance from the junction of the superior vena cava (SVC) and RA to the most cranial earliest activation site (EAS) was longer in the amiodarone group than in the no-amiodarone group at baseline (20.5 vs. 10.6mm, P=0.04) and during isoproterenol infusion (12.8 vs. 6.3mm, P=0.03). The distance from the SVC-RA junction to the EAS negatively correlated with the P-wave amplitudes of leads II (r=-0.47), III (r=-0.60) and aVF (r=-0.56) (P<0.001 for all).CONCLUSIONS:In a quarter of the AF patients, amiodarone causes superior SAN dysfunction, which results in a downward shift of the EAS and reduced P-wave amplitude in leads II, III and aVF at baseline and during isoproterenol infusion.

AIMS:It is difficult to differentiate the origins of focal atrial tachycardias (ATs) in adjacent structures by electrocardiography (ECG) alone. The aim of this study was to evaluate whether the clinical features of these ATs may help differentiate their origins.METHODS AND RESULTS:One hundred and ninety-four patients (mean age, 43.5 ± 17.9 years; male, 53.6%) who underwent electrophysiological study for focal AT were included. We evaluated accuracy in differentiating the origin of AT by using ECG alone as well as with the addition of the clinical features. Electrocardiographs of ATs originating from the left superior pulmonary vein (LSPV, n = 24) vs. the left atrial appendage (LAA, n = 6), and from the right superior pulmonary vein (RSPV, n = 14) vs. the superior vena cava (SVC, n = 8) showed similar patterns. However, while no ATs from the LAA were found to be related to paroxysmal atrial fibrillation, 22 out of 24 ATs from the LSPV were associated with this condition. After localizing AT by using ECG, this clinical feature helped differentiate the ATs from the LSPV vs. the LAA with 93% accuracy. Moreover, while an on-and-off tachycardia (initiated and terminated more than 10 times per day) was observed in 4 of 8 ATs from the SVC, this pattern was observed in 13 of 14 ATs from the RSPV. After localizing the ATs by using ECG, on-and-off tachycardia helped differentiate the ATs from the RSPV vs. the SVC with 82% accuracy.CONCLUSION:The clinical features and Holter monitoring can give additional information for differentiating the focal ATs originating from the adjacent structures.

Background: Previous reports have demonstrated the association between single nucleotide polymorphism (SNP) of the eNOS gene and atrial fibrillation (AF). This study evaluated whether eNOS gene variants are associated with high-sensitivity C-reactive protein (hsCRP) and AF recurrence after radiofrequency catheter ablation (RFCA). Methods: A total of 500 consecutive patients (56±11 years, 77% male) with paroxysmal (68%) or persistent (32%) AF who underwent RFCA were included. Plasma hsCRP concentration was measured and SNP of the eNOS gene, rs1799983, was genotyped. A 24- to 48-hour Holter ECG recording was performed at 3, 6, and 12 months after the ablation. Results: When we compared the patients with rs1799983 variant allele (T, n=84) and those without T allele (n=416), rs1799983 variant allele carriers are more likely to have coronary artery disease or stroke (31.0% vs. 17.8%, p=0.004). The early recurrence (ER) of AF (within 3 months) was observed in 31.8%, whereas the clinical recurrence (CR) of AF (after 3 months) occurred in 24.8% of the patients during the median 17 months of follow-up. The patients with ER were more likely to have persistent AF (44.4% vs. 27.1%, p<0.001) and larger left atrium (42.8±6.4 vs. 41.2±6.2 mm, p=0.011) than those without the ER. Although rs1799983 variant was not associated with the CR, carriers of the variant allele had an increased risk of the ER (OR 1.717 for TT+GT vs. GG, 95% CI 1.059-2.785, p=0.028) and experienced recurrence earlier than those without variant allele (11±16 vs. 20±25 days, p=0.016). However, there were no significant differences in hsCRP between variant and non-variant patients (2.32±4.94 vs. 2.06±4.36 mg/L, p=0.618). A multiple logistic regression analysis showed that the rs1799983 variant (OR 1.714, 95% CI 1.045-2.812, p=0.033) and persistent AF (OR 1.905, 95% CI 1.234-2.939, p=0.004) were independent predictors of the ER. Conclusions: The rs1799983 variant of the eNOS gene was associated with early recurrence after RFCA, but not with hsCRP level. A study that further investigates the relationship between genetic variations of eNOS and post-ablation inflammatory process will be warranted.

Background: Although it has been known that left ventricular (LV) function may affect to left atrial pressure (LAP) or LA remodeling, their relationships and clinical significance are not clearly elucidated. The purpose of this study was to compare the clinical, image, and electrophysiological parameters in terms of LAP in patients with atrial fibrillation (AF) who underwent radiofrequency catheter ablation (RFCA). Methods: We measured LAP during sinus rhythm (SR) and AF in 454 patients with non-valvularAF (76.7% male, 58±11years, 65.7% paroximal AF) who underwent RFCA. Pressures of LA v-wave (LApeak), LA x-wave (LAnadir), mean LAP (LAmean), and LA pulse pressure (LAP-P) were compared with cardiac CT, Echocardiogram, NavX voltage maps, and clinical outcome. Results: 1 . The group with LApeak(SR)≥22mmHg(n=184) had larger LA dimension (42.61±6.66 vs 40.07±5.77mm, p<0.001), LA volume index (37.11±14.00 vs 33.00±10.56ml/m2, p=0.003),higher E/E’ (11.31±6.59 vs 9.91±5.55, p<0.001), reduced S’ (6.14±1.75 vs 6.78...

Background: Radiofrequency catheter ablation (RFCA) for intraatrial reentrant tachycardia (IART) in congenital heart disease (CHD) remains difficult.Methods: Thirty-four consecutive adult patients (age, 37.6 +/- 12.8 years; male, 21) with previously repaired CHD and IART underwent an electrophysiological study and RFCA. CHD included atrial septal defect (ASD, n = 14), tetralogy of Fallot (n = 11), ventricular septal defect (n = 4), pulmonary atresia (n = 2), atrioventricular septal defect (n = 1), transposition of the great arteries (n = 1), and double-outlet right ventricle (n = 1).Results: Duration of CHD repair to IART onset was 19.1 +/- 8.5 years. Thirty and four patients had single- and double-loop reentrant tachycardia, respectively. Among the total of 38 IARTs, which were mapped, 22 (57.9%) and 13 (34.2%) IARTs were cavotricuspid isthmus (CTI)-dependent atrial flutter (AFL) and scar-related AFL, respectively. Typical AFL electrocardiography findings including definite sawtooth appearance in inferior leads and positive F wave in lead V1 were observed in only 12 of 21 patients (57.1%) with CTI-dependent AFL. CTI-dependent AFL had a significantly longer tachycardia cycle length (TCL) than scar-related AFL (267.6 +/- 34.4 ms and 235.9 +/- 37.0 ms, respectively; P = 0.031). TCL > 250 ms had 79% sensitivity as the cutoff value for differentiating CTI-dependent from scar-related AFL. The acute success rates of RFCA in CTI-dependent and scar-related AFLs were 85.7% and 90.0%, respectively. The recurrence rates in CTI-dependent and scar-related AFLs were 11.1% and 11.1%, respectively, during a follow-up of 21.2 +/- 28.3 months.Conclusions: CTI-dependent AFL was the most common IART in adult patients with repaired CHD and was easily manageable by RFCA. TCL might help to differentiate CTI-dependent AFL from other IARTs. (PACE 2012;35:13381347)