Comparison of High- and Low-Dose Rivaroxaban Regimens in Elderly East Asian Patients With Atrial Fibrillation.

BACKGROUND: In the Rivaroxaban Once-daily oral direct factor Xa inhibition Compared with vitamin K antagonism for prevention of stroke and Embolism Trial in Atrial Fibrillation (ROCKET AF) trial, rivaroxaban 20 mg was the on-label dose, and the dose-reduction criterion for rivaroxaban was a creatinine clearance of < 50 mL/min. Some Asian countries are using reduced doses label according to the J-ROCKET AF trial. The aim of this study was to assess the safety and efficacy of a high-dose rivaroxaban regimen (HDRR, 20/15 mg) and low-dose rivaroxaban regimen (LDRR, 15/10 mg) among elderly East Asian patients with atrial fibrillation (AF) in real-world practice. METHODS: This study was a multicenter, prospective, non-interventional observational study designed to evaluate the efficacy and safety of rivaroxaban in AF patients > 65 years of age with or without renal impairment. RESULTS: A total of 1,093 patients (mean age, 72.8 ± 5.8 years; 686 [62.9%] men) were included in the analysis, with 493 patients allocated to the HDRR group and 598 patients allocated to the LDRR group. A total of 765 patients received 15 mg of rivaroxaban (203 in the HDRR group and 562 in the LDRR group). There were no significant differences in the incidence rates of major bleeding (adjusted hazard ratio [HR], 0.64; 95% confidential interval [CI], 0.21-1.93), stroke (adjusted HR, 3.21; 95% CI, 0.54-19.03), and composite outcomes (adjusted HR, 1.13; 95% CI, 0.47-2.69) between the HDRR and LDRR groups. CONCLUSION: This study revealed the safety and effectiveness of either dose regimen of rivaroxaban in an Asian population for stroke prevention of AF. Considerable numbers of patients are receiving LDRR therapy in real-world practice in Asia. Both regimens were safe and effective for these patients. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT04096547.

Excessive blood pressure rise and cardiovascular remodeling in marathon runners.

Exercise-induced hypertension (EIH) is thought to be associated with increased cardiovascular (CV) risks. However, no previous studies have investigated the effects of EIH on CV systems in marathon runners without CV risk factors using both 24-hr ambulatory blood pressure (BP) monitoring and exercise stress echocardiography (ESE). This study firstly described differences in CV adaptations according to EIH assessed by both exams. Marathon runners between 35 and 64 years of age without CV risk factors were eligible. All the participants underwent both 24-hr ambulatory BP monitoring and ESE. EIH was defined as a maximal exercise systolic BP ≥210 mmHg. The EIH group (n = 19) had shorter training history and higher exercise intensity compared to the non-EIH group (n = 23). The average systolic BP was higher in the EIH group than in the non-EIH group. Left cardiac chamber size and left ventricular mass (LVM) were also higher in the EIH group compared to the non-EIH group. Maximal BP during ESE was positively correlated with both parameters. Exaggerated BP response during exercise needs to be monitored for pre-emptive measurements before it results in progressive cardiovascular maladaptation.

Long-term outcome of thoracoscopic ablation and radiofrequency catheter ablation for persistent atrial fibrillation as a de novo procedure.

AIMS: Limited data are available regarding the efficacy of thoracoscopic ablation as the first procedure for persistent atrial fibrillation (AF). We sought to compare the long-term efficacy of thoracoscopic ablation vs. radiofrequency (RF) catheter ablation as the first procedure for persistent AF. METHODS AND RESULTS: Between February 2011 and December 2020, 575 patients who underwent ablation for persistent AF were studied. Among them, thoracoscopic ablation was performed in 281 patients, RF catheter ablation in 228, and hybrid ablation in 66. Rhythm, clinical, and safety outcomes during 7-year follow-up were compared. The patients who underwent thoracoscopic ablation were older, had a higher prevalence of stroke, and had a larger left atrial volume than those who underwent RF catheter ablation. In the propensity score-matched population (n = 306), incidences of atrial tachyarrhythmia recurrence were 51.4% in the thoracoscopic ablation group and 62.5% in the RF catheter ablation group [adjusted hazard ratio (HR) 0.869, 95% confidence interval (CI) 0.618-1.223, P = 0.420]. Stroke and total procedural adverse events were not significantly different between thoracoscopic and RF catheter ablation (2.7 vs. 2.5%, P = 0.603, and 7.1 vs. 4.8%, P = 0.374, respectively). The hybrid ablation group showed similar rhythm outcomes compared with both the thoracoscopic and the RF catheter ablation groups. At the redo procedure, pulmonary vein gaps were more frequently observed in the RF catheter ablation group (32.6%) than in the thoracoscopic ablation group (7.9%) and in the hybrid ablation group (8.8%) (P < 0.001). CONCLUSION: As a first procedure in persistent AF, thoracoscopic ablation and RF catheter ablation showed comparable efficacy, clinical, and safety outcomes during long-term follow-up.

Association of right bundle branch block or intraventricular conduction delay with recurrence of atrial fibrillation after catheter ablation.

BACKGROUND: The association between bundle branch block (BBB) and recurrence of atrial fibrillation (AF) after catheter ablation is unclear. The aim of this study was to determine whether AF combined with BBB is associated with AF recurrence after catheter ablation. METHODS: A total of 477 consecutive AF patients who underwent catheter ablation were included. The AF patients were divided into three groups according to BBB: AF without BBB (n = 427), AF with right bundle branch block (AF with RBBB) (n = 16), and AF with intraventricular conduction delay (AF with IVCD) (n = 34). RESULTS: Of the 477 AF patients (mean age 57 years, 81% men, median CHA2 DS2 -VASc score of 1), 16 (3.4%) patients had RBBB, and 34 (7.1%) patients had IVCD. During a mean follow-up of 15.2 ± 6.7 months, 119 patients (24.9%) had recurrence of AF. Of these, 111 (26%) patients were in the AF without BBB group, with 2 (12.5%) and 6 (17.6%) patients in the RBBB and IVCD groups, respectively. The Kaplan-Meier estimate of the rate of recurrent AF was not significantly different among the three groups (p = .39). Multivariable analysis showed that persistent AF (HR 1.7, 95% CI 1.15-2.50, p = .007), chronic kidney disease (HR 2.94, 95% CI 1.20-7.17, p = .01), and left atrial diameter (HR 1.04, 95% CI 1.009-1.082, p = .01) were significantly associated with AF recurrence. CONCLUSION: AF with BBB was not significantly associated with the recurrence of AF after catheter ablation in middle-aged patients with low-risk cardiovascular profile.

Totally Thoracoscopic Ablation in Patients With Recurrent Atrial Fibrillation After Catheter Ablation.

BACKGROUND: The objective of this study was to evaluate the efficacy and safety of totally thoracoscopic ablation (TTA) in patients with recurrent atrial fibrillation (AF) after radiofrequency catheter ablation (RFCA). METHODS: From February 2012 to May 2020, 460 patients who underwent TTA were classified into two groups: CA (presence of RFCA history, n = 74) and nCA groups (absence of RFCA history, n = 386). Inverse probability of treatment weighting (IPTW) analyses were used to adjust for confounders. The primary endpoint was freedom from the composite of AF, typical atrial flutter, atypical atrial flutter and any atrial tachyarrhythmia, lasting more than 30 seconds during the follow-up. All patients were followed up at 3, 6, and 12 months via electrocardiogram and 24-hour Holter monitoring. RESULTS: Bilateral pulmonary vein isolation (PVI) was conducted in all patients and the conduction block tests were confirmed. In the CA group, difficult PVI occasionally occurred due to structural changes, such as pericardial adhesion and fibrosis of the pulmonary venous structure, caused by a previous catheter ablation. Early complications such as stroke and pacemaker insertion were not different between the two groups. The normal sinus rhythm was maintained in 70.1% (317/460) patients after a median follow-up period of 38.1 months. The IPTW-weighted Kaplan-Meier curves revealed that freedom from AF events at 5 years was 68.4% (95% confidence interval, 62.8-74.5) in the nCA group and 31.2% (95% confidence interval, 16.9-57.5) in the CA group (P < 0.001). In IPTW-weighted Cox regression, preoperative left atrial diameter, persistent or long-standing AF, the presence of congestive heart failure and catheter ablation history were associated with AF events. CONCLUSION: Patients in the CA group showed a higher recurrence rate of AF than those in the nCA group, while TTA was safely performed in both the groups.

The efficacy of single-lead implantable cardioverter-defibrillator with atrial sensing dipole to detect atrial fibrillation and to reduce inappropriate therapy according to atrial sensing ON or OFF: Rationale and design of the SMART-CONTROL study, a prospective multicenter randomized trial.

BACKGROUND: Few studies have compared the efficacy of single-lead implantable cardioverter-defibrillator (ICD) with atrial sensing dipole (VDD-ICD) and conventional single-chamber ICD from the aspect of atrial fibrillation (AF) detection or inappropriate ICD therapy reduction. In the SMART-CONTROL trial (NCT03932604), we primarily aim to investigate whether the atrial sensing capability of VDD-ICD is useful in AF detection and inappropriate therapy reduction by randomly activating or deactivating the atrial sensing function. METHODS AND DESIGN: This study was designed as a prospective, multicenter, open-label, randomized trial to enroll 640 patients with no history of clinical AF or rhythm control for AF within 1 year who were undergoing the implantation of VDD-ICD system. Patients are assigned randomly to atrial sensing "ON" or "OFF" group, with crossover allowed during follow-up. The coprimary outcomes are the incidence of AF detection and inappropriate ICD therapy over a 2-year follow-up period. The secondary outcomes include non-AF atrial tachyarrhythmia, ventricular tachyarrhythmia with or without ICD therapy, thromboembolic events, bleeding, heart failure hospitalization, mortality, a composite of adverse cardiovascular events, and long-term atrial sensing stability or variability. CONCLUSION: We expect that this trial can evaluate the efficacy of a single-lead ICD system on various clinical outcomes including AF detection and inappropriate therapy reduction, and ultimately provide guidance to selection of ICD system.

Edoxaban-based long-term antithrombotic therapy in patients with atrial fibrillation and stable coronary disease: Rationale and design of the randomized EPIC-CAD trial.

BACKGROUND: Anticoagulants are the standard therapy for patients with atrial fibrillation (AF) and antiplatelet therapy for those with coronary artery disease (CAD). However, compelling clinical evidence is still lacking regarding the long-term maintenance strategy with the combination of anticoagulant and antiplatelet drugs in patients with AF and stable CAD. DESIGN: The EPIC-CAD trial is an investigator-initiated, multicenter, open-label randomized trial comparing the safety and efficacy of 2 antithrombotic strategies in patients with high-risk AF (CHA2DS2-VASc score ≥ 2 points) and stable CAD (≥6 months after revascularization for stable angina or ≥12 months for acute coronary syndrome; or medical therapy alone). Patients (approximately N = 1,038) will be randomly assigned at a 1:1 ratio to (1) monotherapy with edoxaban (a non-vitamin K antagonist oral anticoagulant) or (2) combination therapy with edoxaban plus a single antiplatelet agent. The primary endpoint is the net composite outcome of death from any cause, stroke, systemic embolism, myocardial infarction, unplanned revascularization, and major or clinically relevant nonmajor bleeding at 1 year after randomization. RESULTS: As of December 2021, approximately 901 patients had been randomly enrolled over 2 years at 18 major cardiac centers across South Korea. The completed enrollment is expected at the mid-term of 2022, and the primary results will be available by 2023. CONCLUSIONS: EPIC-CAD is a large-scale, multicenter, pragmatic design trial, which will provide valuable clinical insight into edoxaban-based long-term antithrombotic therapy in patients with high-risk AF and stable CAD.

Clinical Significance of Ventricular Premature Contraction Provoked by the Treadmill Test.

Background and Objectives: The treadmill test (TMT) is a predictive tool for myocardial ischemia. Recently, exercise-provoked ventricular premature contracture (VPC) during TMT was shown to have a relation with coronary artery disease and cardiovascular mortality. Therefore, we evaluate clinical correlates of exercise-provoked VPC and compare the predictive power for myocardial ischemia and cardiovascular events. Method: Data of 408 patients (≥18 years of age) who underwent TMT for work up of angina, palpitation, dyspnea, syncope, or arrhythmia between February 2015, and January 2016, were collected with consent at Samsung Medical Center, Seoul, Republic of Korea. Among total of 408 patients, 208 were excluded according to the previous history of PCI or CABG, previous MI, decreased left ventricular ejection fraction lower than 50%, arrhythmia that could affect ST-segment change on ECG. Results: Among 200 patients, 32 (16.0%) developed exercise-provoked VPC (21 patients in the exercise phase, 20 patients in the recovery phase). Of them, 20 patients (10.0%) showed positive TMT, and 4 patients (2.0%) underwent revascularization after TMT. Among 21 patients showing exercise phase VPC, 5 (23.8%) showed positive TMT results. In patients younger than 65 years, exercise phase VPC was associated with positive TMT (odds ratio 6.879, 1.458-32.453) considering demographics and previous medical history in multivariable analysis. Among the 20 patients showing recovery phase VPC, 2 (10.0%) underwent revascularization after TMT. In multivariable analysis, recovery phase VPC was associated with revascularization (odds ratio 9.381, 1.144-76.948) considering age, sex, BMI, and TMT result. Conclusion: VPC during the treadmill test was a useful predictor of myocardial ischemia in this study.

Subclinical Atrial Fibrillation Burden and Adverse Clinical Outcomes in Patients With Permanent Pacemakers.

BACKGROUND AND PURPOSE: Unlike clinical atrial fibrillation (AF), the significance of subclinical AF (SCAF) burden in patients with permanent pacemakers has not been fully evaluated. METHODS: We investigated whether the SCAF burden was associated with increased risks of composite adverse outcomes, including progression to clinical AF, ischemic stroke, myocardial infarction, heart failure-related hospitalization, or cardiac death, in patients without previous AF. To quantify the 6-month SCAF burden, the total cumulative time spent in SCAF during every 6-month follow-up was summed. RESULTS: During the median 5.2-year follow-up, 496 consecutive permanent pacemaker patients were classified into the no SCAF (no SCAF episode in any device analysis; n=152), low-burden SCAF (6-month SCAF <24 hours in at least one device analysis; n=287), or high-burden SCAF (6-month SCAF ≥24 hours in at least 1 device analysis; n=57) groups. The risk of composite adverse outcomes was greatest in the high-burden SCAF group (P<0.001) and was primarily driven by progression to clinical AF (P<0.001) and ischemic stroke (P<0.001). The presence of high-burden SCAF, which always preceded ischemic stroke events, was independently associated with composite adverse outcomes (odds ratio=20.1 [95% CI, 7.60-52.7], P<0.001) and progression to clinical AF (odds ratio, 36.2 [95% CI, 15.9-87.8], P<0.001). CONCLUSIONS: In permanent pacemaker patients without preexisting AF, the presence of high-burden SCAF was closely associated with increased risks of composite adverse outcomes, particularly progression to clinical AF and ischemic stroke. Therefore, prospective studies deserve to be performed on the optimal anticoagulation therapy for permanent pacemaker patients with both high-burden SCAF and high stroke risk.

Predictors of long-term success after catheter ablation of premature ventricular complexes.

INTRODUCTION: Some patients have late recurrence after acutely successful radiofrequency catheter ablation (RFCA) of premature ventricular complexes (PVCs). The aim of this study was to evaluate predictors of long-term success following acutely successful PVC RFCA. METHODS: We identified consecutive patients at our institution with frequent PVCs undergoing RFCA and reviewed procedural data and medical records. Acute success was defined as elimination of targeted PVCs for at least 30-min after RFCA. Long-term success was defined as absence of targeted PVCs during all follow-up visits and PVC-burden <5% on follow-up monitoring. RESULTS: Among 241 patients (mean age 57 ± 15 years, 58% male), 161 (66.8%) had long-term success with median follow-up of 17.7 (IQR, 12.2-29.8) months. Unadjusted predictors of late PVC recurrence were increasing age, diabetes mellitus and alcohol use, while female-sex, shorter ablation-time, right ventricular PVC-origin, single PVC morphology, and earliest bipolar activation ≥24 ms pre-QRS were predictors of long-term success. In multivariate-analysis, female-sex, single-PVC morphology and earliest-onset of PVC ≥ 24 ms pre-QRS were independent predictors for long-term success. The positive-predictive value of earliest-bipolar onset of PVC ≥ 24 ms pre-QRS for long-term success was 0.77 (p < .001). Negative-predictive value of PVC < 15 ms pre-QRS for long-term success was 0.86 (p = .003), suggesting that RFCA when the bipolar electrogram preceded QRS by <15 ms was unlikely to result in long-term success. CONCLUSIONS: Female-sex, single-PVC morphology, and earliest-onset of bipolar electrogram ≥24 ms pre-QRS were multivariable predictors of long-term success in patients with PVCs undergoing RFCA. RFCA at sites with local onset <15 ms pre-QRS are unlikely to be successful.

Electrocardiographic predictors of early recurrence of atrial fibrillation.

BACKGROUND: Electrical cardioversion (ECV) is an effective method for restoring sinus rhythm after atrial fibrillation (AF). However, early recurrence of AF occurs in a significant number of patients after ECV. This study aimed to identify electrocardiographic (ECG) predictors of early AF recurrence after ECV. METHODS: A total of 272 patients with persistent AF undergoing successful ECV were consecutively enrolled in this study. We investigated clinical, echocardiographic, and ECG data. The 12-lead ECG parameters were measured during sinus rhythm right after ECV using a digital caliper. The early AF recurrence was defined as recurrence within 2 months. RESULTS: Of the 272 patients, 165 patients (60.7%) experienced an early AF recurrence. Maximum P-wave duration (PWD) in limb leads (OR: 1.086; 95% CI: 1.019-1.157; p = .012) and P-terminal force (PTF) in V1 (OR: 1.019; 95% CI: 1.004-1.033; p = .011) were independent predictors of early AF recurrence after ECV. The optimal cutoff value of the maximum PWD in limb leads for predicting early AF recurrence was 134 ms, characterized by 90.3% sensitivity and 72.0% specificity. Likewise, the optimal cutoff value of PTF in V1 was 50 ms × mm, characterized by 80.0% sensitivity and 64.5% specificity. CONCLUSION: A longer PWD (>134 ms) and a larger PTF (>50 ms × mm) were useful predictors of early recurrence of AF after successful ECV in clinical practice. A more effective rhythm control therapy such as catheter ablation or rate control strategy rather than a repeat ECV should be considered.

Effectiveness of the Early Staged Hybrid Approach for Treatment of Symptomatic Atrial Fibrillation: the Electrophysiology Study Could Be Deferred?

BACKGROUND: The efficacy of catheter ablation for persistent atrial fibrillation (AF) remains suboptimal. A hybrid approach of catheter ablation combined with totally thoracoscopic surgical ablation can improve outcomes. In this study, we evaluated the efficacy of the early staged hybrid procedure in hospital stay after totally thoracoscopic ablation compared to the stand-alone totally thoracoscopic ablation. METHODS: Patients who underwent totally thoracoscopic ablation from February 2012 to December 2018 were included in this study. We compared the outcomes of the totally thoracoscopic ablation only group versus the early staged hybrid procedure group. The primary outcome was recurrence of atrial tachyarrhythmia after three months of blanking period. The secondary outcome was repeated unplanned additional electrophysiology study and catheter ablation due to atrial tachyarrhythmia recurrence. RESULTS: A total of 306 patients (mean age, 56.8 ± 8.5 years; 278 [90.8%] males) was included in the study, with 81 patients in the early staged hybrid group and 225 patients in the stand-alone totally thoracoscopic ablation only group. The mean follow-up duration was 30.0 months. Overall arrhythmia-free survival showed no significant difference between the two groups (log-rank P = 0.402). There was no significant difference in the rate of repeat procedure between the two groups (log-rank = 0.11). CONCLUSION: The early staged hybrid procedure after thoracoscopic ablation could not improve the outcome of recurrence of atrial tachyarrhythmia. The second stage of electrophysiology study could be deferred to patients with recurrence of atrial tachyarrhythmia during follow up after totally thoracoscopic ablation.

Hybrid Approach for Indoor Localization Using Received Signal Strength of Dual-Band Wi-Fi.

In this paper, we propose a hybrid localization algorithm to boost the accuracy of range-based localization by improving the ranging accuracy under indoor non-line-of-sight (NLOS) conditions. We replaced the ranging part of the rule-based localization method with a deep regression model that uses data-driven learning with dual-band received signal strength (RSS). The ranging error caused by the NLOS conditions was effectively reduced by using the deep regression method. As a consequence, the positioning error could be reduced under NLOS conditions. The performance of the proposed method was verified through a ray-tracing-based simulation for indoor spaces. The proposed scheme showed a reduction in the positioning error of at least 22.3% in terms of the median root mean square error compared to the existing methods. In addition, we verified that the proposed method was robust to changes in the indoor structure.

Radiofrequency vs. Cryoballoon vs. Thoracoscopic Surgical Ablation for Atrial Fibrillation: A Single-Center Experience.

Background and Objectives: Cryoballoon ablation (CBA) and totally thoracoscopic surgical ablation (TTA) have emerged as alternatives to radiofrequency catheter ablation (RFCA) for atrial fibrillation. In this study, we describe our experience comparing patient characteristics and outcomes of RFCA, CBA, and TTA. Materials and Methods: We retrospectively analyzed data from patients who underwent RFCA, CBA, or TTA. Both atrial fibrillation (AF)- and atrial tachyarrhythmia (ATa)-free survival rates were compared using time to recurrence after a 3-month blanking period (defined by a duration of more than 30 s). All patients were regularly followed using 12-lead ECGs or Holter ECG monitoring. Results: Of 354 patients in this study, 125 underwent RFCA, 97 underwent CBA and 131 underwent TTA. The TTA group had more patients with persistent AF, a larger LA diameter, and a history of stroke. The CBA group showed the shortest procedure time (p < 0.001). The CBA group showed significantly lower AF-free survival at 12 months than the RFCA and TTA groups (RFCA 84%, CBA 74% and TTA 85%, p = 0.071; p = 0.859 for TTA vs. RFCA, p = 0.038 for RFCA vs. CBA and p = 0.046 for TTA vs. CBA). There were no significant differences in ATa-free survival among the three groups (p = 0.270). There were no procedure-related adverse events in the RFCA group, but some complications occurred in the CBA group and the TTA group (6% and 5%, respectively). Conclusions: RFCA and CBA are effective and safe as first-line treatments for paroxysmal and persistent AF. In some high-risk stroke patients, TTA may be a viable option. It is important to consider patient characteristics when selecting an ablation method for AF.

Effectiveness and safety of high-power and short-duration ablation for cavotricuspid isthmus ablation in atrial flutter.

BACKGROUND: Despite many studies on new tools and strategies for cavotricuspid isthmus (CTI) ablation, there is an unmet need to improve the CTI ablation procedure. Recently, high-power short-duration (HPSD) ablation has been widely used for pulmonary vein (PV) isolation in atrial fibrillation. We evaluated the effectiveness and safety of HPSD for CTI ablation in atrial flutter (AFL). METHODS: Eighty-four patients who underwent CTI ablation with or without simultaneous PV isolation between January 2018 and February 2019 were enrolled in this prospective cohort study. We compared procedural characteristics, periprocedural complications, and recurrence of atrial tachyarrhythmia (ATa) between the HPSD group (50 W for 15 s) and conventional group (30 W for 60 s). RESULTS: A total of 84 patients were divided into the HPSD (n = 42) and conventional (n = 42) groups. Bidirectional CTI block was achieved in all patients and 95% achieved bidirectional block after the first-line ablation in both groups. Although there was no difference in the total number of ablation lines between the two groups (1.17 ± 0.7 vs 1.38 ± 0.8, P = .067), HPSD ablation significantly reduced total ablation time compared to the conventional group (236.0 ± 85.6 vs 534.2 ± 235.2 s, P < .001). One pericardial tamponade was reported in the HPSD group. During the mean follow-up of 9.3 ± 4.8 months, CTI-dependent AFL recurrence occurred in one patient in the HPSD group. Recurrence of ATa developed in 14 patients with no significant difference between the groups. CONCLUSION: Our study demonstrates that HPSD CTI ablation is safe and can shorten procedure time.

Characteristics of symptomatic recurrent tachyarrhythmia after thoracoscopic ablation for persistent atrial fibrillation.

BACKGROUND: Recurrent atrial tachyarrhythmia (ATa) is a challenge in all ablation procedures for atrial fibrillation (AF). However, data on ATa after totally thoracoscopic ablation (TTA) is lacking. This study aimed to investigate the mechanisms and outcomes of recurrent ATa after TTA. METHODS: Eligible patients for the present study were those who underwent electrophysiologic study and catheter-based radiofrequency ablation (RFA) at least 3 months after TTA for symptomatic recurrent ATa that was refractory to antiarrhythmic drugs and/or cardioversion. Follow-up outcomes included recurrent ATa after first or repeated RFA. RESULTS: A consecutive 154 TTA patients were evaluated. A total of 24 patients showed symptomatic recurrent ATa after TTA, and 22 underwent RFA. Half of the patients (11/22, 50%) had AF as a form of recurrent ATa. Nonpulmonary vein (PV)-related mechanisms of ATa were noted in half of patients. PV gaps showed a characteristic distribution: most gaps in right PVs were located at the posterior ridge (71.4%) with the posterior ridge of left PVs saved in all patients. Post-RFA recurrence rate was 27.3% during a median follow-up of 9.1 months, with all recurrences except for one occurring within 3 months after first RFA. CONCLUSIONS: During a median of 17.8 months after TTA, 24 patients (24/154, 15.6%) developed symptomatic recurrent ATa, and 22 patients underwent RFA. Post-RFA recurrence rate was 27.3%, which mostly occurred within 3 months after RFA. Catheter-based ablation of recurrent arrhythmias may be effective, but challenging.

Right ventricle apex pacing identifies the presence of ventricular premature depolarizations-induced cardiomyopathy.

BACKGROUND: A high burden of ventricular premature depolarizations (VPDs) has been associated with potentially reversible left ventricular (LV) dysfunction, termed as VPD-induced cardiomyopathy (CMP). However, many patients maintain normal LV function despite a high VPD burden. The purpose of this study was to identify CMP by right ventricle apex (RVa) pacing method in patients with high VPD burden. METHODS: A total of 62 patients (28 male; mean age = 50 ± 15 years) with idiopathic VPDs undergoing ablation were enrolled. RVa pacing was recorded in all patients during the procedure. The paced QRS duration (QRSd) during RV pacing was measured from the pacing spike to the latest QRS deflection on any surface electrocardiogram lead. Patients were divided into two groups: reversible VPD-induced CMP (Group R; n  = 15, 14 males, mean age = 54 ± 14 years) and normal LV function (Group N; n = 47, 23 males, mean age = 54 ± 15 years). RESULTS: The LV ejection fraction (%) was significantly lower in Group R as compared with Group N (Group R, Group N = 36 ± 6, 58 ± 4; P < 0.001); however, LV end-diastolic dimension mm was not significantly different between the two study groups (Group R, Group N = 54 ± 5, 50 ± 6; P = 0.06). Similarly, sinus QRS width (P = 0.10), VPD-burden (P = 0.36), and body surface area (P = 0.75) were not significantly different between Group R and Group N. The QRSd was significantly longer in Group R compared with Group N (177 ± 8 vs 150 ± 14; P < 0.001). Using a QRSd cut-off value of 170.1 ms, VPD-induced CMP was identified with a sensitivity of 73% and a specificity of 97%. CONCLUSION: RVa pacing with transmyocardial conduction time assessment was a useful method for identifying idiopathic VPD-induced CMP. Using a QRSd cut-off value of 170.1 ms, VPD-induced CMP was identified with a sensitivity of 73% and a specificity of 97%.

Efficacy of Cardiac Resynchronization Therapy Using Automated Dynamic Optimization and Left Ventricular-only Pacing.

BACKGROUND: Although device-based optimization has been developed to overcome the limitations of conventional optimization methods in cardiac resynchronization therapy (CRT), few real-world data supports the results of clinical trials that showed the efficacy of automatic optimization algorithms. We investigated whether CRT using the adaptive CRT algorithm is comparable to non-adaptive biventricular (BiV) pacing optimized with electrocardiogram or echocardiography-based methods. METHODS: Consecutive 155 CRT patients were categorized into 3 groups according to the optimization methods: non-adaptive BiV (n = 129), adaptive BiV (n = 11), and adaptive left ventricular (LV) pacing (n = 15) groups. Additionally, a subgroup of patients (n = 59) with normal PR interval and left bundle branch block (LBBB) was selected from the non-adaptive BiV group. The primary outcomes included cardiac death, heart transplantation, LV assist device implantation, and heart failure admission. Secondary outcomes were electromechanical reverse remodeling and responder rates at 6 months after CRT. RESULTS: During a median 27.5-month follow-up, there was no significant difference in primary outcomes among the 3 groups. However, there was a trend toward better outcomes in the adaptive LV group compared to the other groups. In a more rigorous comparisons among the patients with normal PR interval and LBBB, similar patterns were still observed. CONCLUSION: In our first Asian-Pacific real-world data, automated dynamic CRT optimization showed comparable efficacy to conventional methods regarding clinical outcomes and electromechanical remodeling.

Is the stroke volume during post-ectopic beat associated with ventricular premature complex-related symptoms?

Aims: This study aimed to investigate if increased stroke volume (SV) after a ventricular premature complex (VPC) was related to VPC-related symptoms. Methods and results: We selected patients having an isolated VPC during echocardiography from a prospective registry that included patients with a structurally normal heart and 24-h VPC >1%. Patients were divided into two groups according to the presence or absence of VPC-related symptoms (skipped beat or palpitation) when VPC occurred. Left ventricular (LV) volumes and time-velocity integral (TVI) at the LV outflow tract were measured during the preceding sinus beat, VPC, and post-ectopic sinus beat. Percent LV SV of the VPC and post-ectopic sinus beat were calculated by dividing each SV by the SV of the preceding sinus beat. A total of 47 patients were eligible. Most patients had VPC with left bundle branch block morphology and inferior axis. Patients in the symptom (+) group had a significantly lower SV, %LV SV, and TVI during post-ectopic sinus beat than those in the symptom (-) group. The sum of SVs during VPC and post-ectopic beat was significantly lower in symptomatic patients than non-symptomatic patients (103.4 mL vs. 125.1 mL, P = 0.02), while the sum of %LV SVs during VPC and post-ectopic beat tended to be lower in patients with symptoms than those without symptoms (P = 0.08). The sum of %LV SVs during VPC and post-VPC was positively correlated with coupling interval (CI) and CI ratio. Conclusion: Ventricular premature complex-related symptoms may not be associated with the amount of post-VPC SV.

Identification of pathogenic variants in genes related to channelopathy and cardiomyopathy in Korean sudden cardiac arrest survivors.

Pathogenic variants in genes related to channelopathy and cardiomyopathy are the most common cause of sudden unexplained cardiac death. However, few reports have investigated the frequency and/or spectrum of pathogenic variants in these genes in Korean sudden cardiac arrest survivors. This study aimed to investigate the causative genetic variants of cardiac-associated genes in Korean sudden cardiac arrest survivors. We performed exome sequencing followed by filtering and validation of variants in 100 genes related to channelopathy and cardiomyopathy in 19 Korean patients who survived sudden cardiac arrest. Five of the 19 patients (26.3%) had either a pathogenic variant or a likely pathogenic variant in MYBPC3 (n=1), MYH7 (n=1), RYR2 (n=2), or TNNT2 (n=1). All five variants were missense variants that have been reported previously in patients with channelopathies or cardiomyopathies. Furthermore, an additional 12 patients (63.2%) had more than one variant of uncertain significance. In conclusion, pathogenic or likely pathogenic variants in genes related to channelopathy and cardiomyopathy are not uncommon in Korean sudden cardiac arrest survivors and cardiomyopathy-related genes should be included in the molecular diagnosis of sudden cardiac arrest in Korea.