BACKGROUND AND OBJECTIVES: The aim of this study was to investigate the effectiveness and selected adverse events of radiofrequency catheter ablation in patients treated for drug-refractory atrial fibrillation (AF) using claims data provided by the Health Insurance Review and Assessment Service, which covers all ablation procedures conducted in South Korea. SUBJECTS AND METHODS: The study population included patients who underwent catheter ablation for AF between January 2011 and December 2013. A total of 3,850 patients without a previous history of catheter ablation procedure were enrolled. We analyzed 2-year effectiveness of the index ablation. Any redo ablation, electrical cardioversion, or use of antiarrhythmic drug beyond the blanking period of 3 months was considered a failure of index ablation. RESULTS: Overall recurrence rate following AF ablation was 61.1%. The recurrence rate was lower in patients under 65 years old than in those over 65 years old (hazard ratio [HR] 0.89; 95% confidence interval [CI], 0.81 to 0.97, P=0.009). Repeat ablation was more frequent in men (HR 1.56; 95% CI, 1.20 to 2.04; P=0.001) and patients under 65 years old (HR 1.79; 95% CI, 1.34 to 2.38; P < 0.001). Electric cardioversion was more frequent in men (HR 1.35; 95% CI, 1.06 to 1.72; P=0.014) than in women. The overall rate of stroke, blood transfusion, significant pericardial complication, and cardiopulmonary resuscitation was 0.5%, 4.8%, 2.7%, and 0.2%, respectively. CONCLUSIONS: In the present study, old age was associated with treatment failure of catheter ablation for drug-refractory AF in the Korean population. Overall recurrence did not vary with respect to sex.
Atrial Fibrillation ; Blood Transfusion ; Cardiopulmonary Resuscitation ; Catheter Ablation ; Catheters ; Electric Countershock ; Female ; Hemorrhage ; Humans ; Insurance, Health ; Korea ; Male ; Pericardiocentesis ; Recurrence ; Stroke ; Treatment Failure

BACKGROUND AND OBJECTIVES: Electroanatomical mapping using a three-dimensional (3D) system has high accuracy and improves the results of the ablation of outflow tract (OT) premature ventricular contraction (PVC) or ventricular tachycardia (VT) but imposes a considerable economic burden. Here, we compared detailed diagnostic catheterization and 3D mapping system for the ablation of OT PVC/VT. MATERIALS AND METHODS: Between June 2012 and February 2017, patients with symptomatic OT PVC/VT underwent radiofrequency ablation. Group 1 underwent detailed diagnostic catheterization (using circular and linear multielectrodes) without a 3D mapping system, while group 2 underwent diagnostic catheterization using a conventional 3D mapping system. Procedural success of PVC reduction, remaining symptoms, need for post-operative medications, and procedural time were evaluated. RESULTS: Ninety-eight OT PVC/VT cases were consecutively enrolled. The mean follow-up period was 17.7±14.5 months. Neither acute success rate (95% vs. 82%, p=0.06) nor a PVC reduction > 80% (84% vs. 87%, p=0.74) differed significantly between the two groups. The recurrence rates of PVC-related symptoms were similar (12% vs. 7%, p=0.06) between the groups, but the medication requirement for symptomatic PVC differed (12% vs. 29%, p < 0.01). The total procedure time of group 1 was shorter than that of group 2 (132±42 min vs. 157±47 min, p=0.01) and fluoroscopy time (24±15 min vs. 38±22 min, p < 0.01) and ablation time (528±538 sec vs. 899±598 sec, p < 0.01) were also significantly shortened. CONCLUSION: Detailed electrode catheter positioning is a safe and cost-effective method for the ablation of OT PVC/VT.
Arrhythmias, Cardiac* ; Catheter Ablation ; Catheterization ; Catheters* ; Electrodes* ; Fluoroscopy ; Follow-Up Studies ; Humans ; Methods ; Recurrence ; Tachycardia, Ventricular ; Ventricular Premature Complexes

In 1901, in a historic first, Willem Einthoven invented electrocardiography using a string galvanometer. He assigned the letters P, Q, R, S, and T to the major deflections and described electrocardiographic features of a number of cardiovascular disorders. Water pots that he initially used to record electrical signals from the skin were replaced with patchy electrodes later. These electrodes detect tiny electrical currents arising from the heart muscle during cardiac cycles. The tiny currents are amplified, filtered, and displayed to produce electrocardiographic recordings. The P wave is generated by depolarization of atria. The PR interval represents the duration of atrioventricular conduction, the QRS complex is produced by depolarization of both ventricles, and the ST-T wave reflects ventricular repolarization. Electrocardiography is essential to diagnose myocardial ischemia and various rhythm disorders. It has expanded its scope to include long-term monitoring, exercise tests, signal averaged electrocardiography, electrophysiologic studies, and three-dimensional electrocardiographic mapping system. Owing to these advances, electrocardiography now plays a critical role not only in diagnosis but also in the therapeutic fields of cardiac disease.
Diagnosis ; Electrocardiography* ; Electrodes ; Exercise Test ; Heart Diseases ; Myocardial Ischemia ; Myocardium ; Skin ; Water

A patient was admitted for catheter ablation of atrial fibrillation. Cardiac computed tomography and transesophageal echocardiography revealed the absence of the left atrial appendage. However, the right atrial appendage looked normal and the level of pro B-natriuretic peptide was within normal limits. Successful catheter ablation was performed without any procedural complications and the sinus rhythm was appropriately maintained for 10 months with an antiarrhythmic drug.
Atrial Appendage* ; Atrial Fibrillation ; Catheter Ablation ; Echocardiography, Transesophageal ; Humans

BACKGROUND AND OBJECTIVES: Identifying the critical isthmus of slow conduction is crucial for successful treatment of scar-related ventricular tachycardia. Current 3D mapping is not designed for tracking the critical isthmus and may lead to a risk of extensive ablation. We edited the algorithm to track the delayed potential in order to visualize the isthmus and compared the edited map with a conventional map. SUBJECTS AND METHODS: We marked every point that showed delayed potential with blue color. After substrate mapping, we edited to reset the annotation from true ventricular potential to delayed potential and then changed the window of interest from the conventional zone (early, 50-60%; late, 40-50% from peak of QRS) to the edited zone (early, 80-90%; late, 10-20%) for every blue point. Finally, we compared the propagation maps before and after editing. RESULTS: We analyzed five scar-related ventricular tachycardia cases. In the propagation maps, the resetting map showed the critical isthmus and entrance and exit sites of tachycardia that showed figure 8 reentry. However, conventional maps only showed the earliest ventricular activation sites and searched for focal tachycardia. All of the tachycardia cases were terminated by ablating the area around the isthmus. CONCLUSION: Identifying the channel and direction of the critical isthmus by a new editing method to track delayed potential is essential in scar-related tachycardia.
Tachycardia ; Tachycardia, Ventricular*

BACKGROUND AND OBJECTIVES: The number of permanent pacemakers (PPMs) implanted in patients in Japan and Korea differs significantly. We aimed to investigate the differences in decision making processes of implanting a PPM. MATERIALS AND METHODS: Our survey included 15 clinical case scenarios based on the 2008 AHA/ACC/HRS guidelines for device-based therapy of cardiac rhythm abnormalities (class unspecified). Members of the Korean and Japanese Societies of Cardiology were asked to rate each scenario according to a 5-point scale and to indicate their decisions for or against implantation. RESULTS: Eighty-nine Korean physicians and 192 Japanese physicians replied to the questionnaire. For the case scenarios in which there was a class I indication for PPM implantation, the decision to implant a PPM did not differ significantly between the two physician groups. However, the Japanese physicians were significantly more likely than the Korean physicians to choose implantation in class IIa scenarios (48% vs. 37%, p<0.001), class IIb scenarios (40% vs. 19%, p<0.001), and class III scenarios (36% vs. 18%, p<0.001). These results did not change when the cases were categorized based on disease entity, such as sinus node dysfunction and conduction abnormality. CONCLUSION: Korean physicians are less likely than Japanese physicians to favor a PPM implantation when considering a variety of clinical case scenarios, which probably contributes to the relatively small number of PPMs implanted in patients in Korea as compared with those in Japan.
Asian Continental Ancestry Group ; Atrioventricular Block ; Cardiology ; Decision Making* ; Humans ; Japan* ; Korea* ; Pacemaker, Artificial ; Sick Sinus Syndrome

BACKGROUND AND OBJECTIVES: In cases of radiofrequency catheter ablation (RFCA) for patients with atrioventricular nodal re-entrant tachycardia (AVNRT), complete elimination of slow pathway is not always achievable. Furthermore, in situations of the so-called modified slow pathway, the underlying mechanism of tachycardia elimination remains unclear. SUBJECTS AND METHODS: Patients who underwent RFCA for AVNRT, and showed persistence of dual atrioventricular nodal physiology but no induction of AVNRT after ablation were enrolled. We measured electrophysiologic parameters before and after the ablation procedure. RESULTS: The study subjects included 31 patients (39% men; mean age 43±19 years). The RR interval, Wenckebach cycle length of AV node, slow pathway effective refractory period, maximal AH interval of fast pathway and slow pathway showed no significant changes before and after ablation. However, fast pathway effective refractory period (360±67 vs. 304±55, p<0.001) and differences between slow pathway effective refractory period and fast pathway effective refractory period (90±49 vs. 66±35, p=0.009) were decreased after slow pathway ablation. CONCLUSION: We suggest a possible relationship between the mechanism of tachycardia elimination in AVNRT and an alteration of the re-entrant circuit by removal of the atrial tissue in Koch's triangle. This may be a critical component of providing the excitable gap for the maintenance of tachycardia rather than the electrical damage of slow pathway itself.
Atrioventricular Node* ; Catheter Ablation ; Humans ; Male ; Physiology* ; Tachycardia*

No abstract available.
Advanced Cardiac Life Support* ; Cardiopulmonary Resuscitation*

Sudden cardiac death (SCD) is a significant issue affecting national health policies. The National Emergency Department Information System for Cardiac Arrest (NEDIS-CA) consortium managed a prospective registry of out-of-hospital cardiac arrest (OHCA) at the emergency department (ED) level. We analyzed the NEDIS-CA data from 29 participating hospitals from January 2008 to July 2009. The primary outcomes were incidence of OHCA and final survival outcomes at discharge. Factors influencing survival outcomes were assessed as secondary outcomes. The implementation of advanced emergency management (drugs, endotracheal intubation) and post-cardiac arrest care (therapeutic hypothermia, coronary intervention) was also investigated. A total of 4,156 resuscitation-attempted OHCAs were included, of which 401 (9.6%) patients survived to discharge and 79 (1.9%) were discharged with good neurologic outcomes. During the study period, there were 1,662,470 ED visits in participant hospitals; therefore, the estimated number of resuscitation-attempted CAs was 1 per 400 ED visits (0.25%). Factors improving survival outcomes included younger age, witnessed collapse, onset in a public place, a shockable rhythm in the pre-hospital setting, and applied advanced resuscitation care. We found that active advanced multidisciplinary resuscitation efforts influenced improvement in the survival rate. Resuscitation by public witnesses improved the short-term outcomes (return of spontaneous circulation, survival admission) but did not increase the survival to discharge rate. Strategies are required to reinforce the chain of survival and high-quality cardiopulmonary resuscitation in Korea.
Cardiopulmonary Resuscitation/*mortality ; Critical Care/*statistics & numerical data ; Death, Sudden, Cardiac/*epidemiology ; Electric Countershock/mortality ; Emergency Medical Services ; Humans ; Out-of-Hospital Cardiac Arrest/*epidemiology/*mortality/therapy ; Registries ; Republic of Korea/epidemiology ; Survival Rate ; Treatment Outcome

Left ventricular hypertrabeculation/noncompaction (LVHT) is an uncommon type of genetic cardiomyopathy characterized by trabeculations and recesses within the ventricular myocardium. LVHT is associated with diastolic or systolic dysfunction, thromboembolic complications, and arrhythmias, including atrial fibrillation, ventricular arrhythmias, atrioventricular block and Wolff-Parkinson-White syndrome. Herein, we describe a patient who presented with heart failure and wide-complex tachycardia. Echocardiography showed LVHT accompanied with severe mitral regurgitation. The electrophysiologic study revealed a fasciculo-ventricular accessory pathway and atrial flutter (AFL). The AFL was successfully treated with catheter ablation.
Arrhythmias, Cardiac ; Atrial Fibrillation ; Atrial Flutter ; Atrioventricular Block ; Cardiomyopathies ; Catheter Ablation ; Echocardiography ; Heart Failure ; Humans ; Isolated Noncompaction of the Ventricular Myocardium ; Mitral Valve Insufficiency ; Myocardium ; Pre-Excitation, Mahaim-Type ; Tachycardia ; Wolff-Parkinson-White Syndrome