Catheter ablation of atrial fibrillation in Korea: results from the Korean Heart Rhythm Society Ablation Registry for Atrial Fibrillation (KARA)

Background@#This study aims to investigate the current status of AF (atrial fibrillation) catheter ablation in Korea. @*Methods@#The patients who underwent AF catheter ablation from September 2017 to December 2019 were pro‑ spectively enrolled from 37 arrhythmia centers. Demographic data, procedural characteristics, the extent of catheter ablation, acute success of the ablation lesion set, rate and independent risk factor for recurrence of AF were analyzed. @*Results@#A total of 2402 AF patients [paroxysmal AF (PAF) 45.7%, persistent AF (PeAF) 43.1% and redo AF 11.2%] were included. Pulmonary vein isolation (PVI) was performed in 2378 patients (99%) and acute success rate was 97.9%.Additional non-PV ablation (NPVA) were performed in 1648 patients (68.6%). Post-procedural complication rate was 2.2%. One-year AF-free survival rate was 78.6% and the PeAF patients showed poorer survival rate than the ones with other types (PeAF 72.4%, PAF 84.2%, redo AF 80.0%). Additional NPVA did not influence the recurrence of AF in the PAF patients (PVI 17.0% vs. NPVA 14.6%, P value 0.302). However, it showed lower AF recurrence rate in the PeAF patients (PVI 34.9% vs. NPVA 24.4%, P value 0.001). Valvular heart disease, left atrial diameter, PeAF, PVI alone, need of NPVA for terminating AF, and failed ablation were independent predictors of AF recurrence. @*Conclusions@#Additional NPVA was associated better rhythm outcome in the patients with PeAF, not in the ones with PAF. The independent risk factors for AF recurrence in Korean population were similar to previous studies. Further research is needed to discover optimal AF ablation strategy.

The Korean Heart Rhythm Society's 2014 Statement on Antithrombotic Therapy for Patients with Nonvalvular Atrial Fibrillation: Korean Heart Rhythm Society

In patients with nonvalvular atrial fibrillation (AF), the risk of stroke varies considerably according to individual clinical status. The CHA2DS2-VASc score is better than the CHADS2 score for identifying truly lower risk patients with AF. With the advent of novel oral anticoagulants (NOACs), the strategy for antithrombotic therapy has undergone significant changes due to its superior efficacy, safety and convenience compared with warfarin. Furthermore, new aspects of antithrombotic therapy and risk assessment of stroke have been revealed: the efficacy of stroke prevention with aspirin is weak, while the risk of major bleeding is not significantly different from that of oral anticoagulant (OAC) therapy, especially in the elderly. Reflecting these pivotal aspects, previous guidelines have been updated in recent years by overseas societies and associations. The Korean Heart Rhythm Society has summarized the new evidence and updated recommendations for stroke prevention of patients with nonvalvular AF. First of all, antithrombotic therapy must be considered carefully and incorporate the clinical characteristics and circumstances of each individual patient, especially with regards to balancing the benefits of stroke prevention with the risk of bleeding, recommending the CHA2DS2-VASc score rather than the CHADS2 score for assessing the risk of stroke, and employing the HAS-BLED score to validate bleeding risk. In patients with truly low risk (lone AF, CHA2DS2-VASc score of 0), no antithrombotic therapy is recommended, whereas OAC therapy, including warfarin (international normalized ratio 2-3) or NOACs, is recommended for patients with a CHA2DS2-VASc score > or =2 unless contraindicated. In patients with a CHA2DS2-VASc score of 1, OAC therapy should be preferentially considered, but depending on bleeding risk or patient preferences, antiplatelet therapy or no therapy could be permitted.

Changes of QT dispersion in relation to etiology of left ventricular hypertrophy

BACKGROUND: Left ventricular hypertrophy(LVH) is known to increase the risk of sudden cardiac death, potentially in association with exercise. Increased QT disepersion(QTd) has been reported to pridict the risk of ventricular tachyarrhythmias. However, it is unknown whether various etiologies of LVH alter QTd in the same manner during and after exercise. Method: 2-D echocardiography and symptom-limited treadmill exercise test were performed in 34 hypertrophic cardiomyopathy(HCMP), 27 hypertensive hypertrophy(HTN), 20 athlete's heart(Athlete) and normal controls. QTd was measured at baseline(QTd0), at peak exercise(QTdp), after 1min (QTd1), and after 5 min(QTd5). And corrected QTd(QTcd)s were calculated. Result: Baseline QTd in HCMP group was greater than that of other groups. QTd at peak exercise of HCMP group was greater than that of other groups. There was insignificant serial change of QTd in each group. In all groups, QTcd increased at peak exercise and decreased after exercise. QTcds at baseline and at peak exercise in HCMP group were greater than those of other groups. Only in HCMP group, QTcd5 remained higher than QTcd0. CONCLUSION: Serial changes of QTcd at peak exercise and after exercise were different according to the etiology of LVH. The risk of sudden death related to exercise in patients with LVH would be different among patients with various LVH etiologies.

The Relationship between Ventricular Arrhythmia in Patients with Myocardial Infarction and Ventricular Late Potential

Ventricular arrhythmia is known as a major cause of sudden death in patients with heart disease, especially in patients with myocardial infarct. Programmed electrical stimulation (PES) is used in order to identify patients with high risk of ventricular arrhythmia, but it is invasive. So ventricular late potential is studied, which can be performed safely. Ventricular late potential was measured in the 65 normal subjects, 17 patients with in-hospital period acute myocardial infarction and 29 patients with old myocardial infarction using signal-averaged high resolution EKG, Mac-15. The positive criteria of ventricular late potential was one of the following : The duration of TQRS is more than 120 msec, or the amplitude of RMS is less than 25microV, or the duration of LP 40 is more than 40 msec. The results are as follows : 1) Among 65 normal subjects(male ; 33, female ; 32), total QRS duration(TQRS)was 103.9+/-8.3msec(mean S.D), terminal 40msec root mean square amplitude(RMS) 47.8+/-24.3uV and terminal 40msec mean amplitude was 32.5+/-15.4uV. Variables of ventricular late potential showed no significant difference by age. 10 subjects showed positive ventricular late potential. 2) Among 17 patients with in-hospital period myocardial infarction, there was no significant difference in variables of ventricular late potential between patients with ventricular arrhythmia(3 subject) and patients without ventricular arrhythmia(14 subjects). 3) Among 29 subjects with old myocardial infarction, TQRS showed significant differrence between patients with ventricular arrhythmia(3 subjects) and patients without ventricular arrhythmias(26 subjects). All of the patients with ventricular arrhythmia(100%) and 6 subjects(24%) of the patients without ventricular arrhythmia showed positive ventricular late potential, and the difference was significant statistically between groups(p value<0.05). This showed that ventricular late potential is helpful in predicting the risk of ventricular arrhythmia among patients with old myocardial infarction.

Usefulness of a Transesophageal Echocardiography in Patients with Isolated Coronary Ostial Stenosis during a Surgical Angioplasty

No abstract available.