Distributions and number of drivers on real-time phase mapping associated with successful atrial fibrillation termination during catheter ablation for non-paroxysmal atrial fibrillation.

BACKGROUND: Real-time phase mapping (ExTRa™) is useful in determining the strategy of catheter ablation for non-paroxysmal atrial fibrillation (AF). This study aimed to investigate the features of drivers of AF associated with its termination during ablation. METHODS: Thirty-six patients who underwent catheter ablation for non-paroxysmal AF using online real-time phase mapping (ExTRa™) were enrolled. A significant AF driver was defined as an area with a non-passively activated ratio of ≥ 50% on mapping analysis in the left atrium (LA). All drivers were simultaneously evaluated using a low-voltage area, complex fractionated atrial electrogram (CFAE), and rotational activity by unipolar electrogram analysis. The electrical characteristics of drivers were compared between patients with and without AF termination during the procedure. RESULTS: Twelve patients achieved AF termination during the procedure. The total number of drivers detected on the mapping was significantly lower (4.4 ± 1.6 vs. 7.4 ± 3.8, p = 0.007), and the drivers were more concentrated in limited LA regions (2.8 ± 0.9 vs. 3.9 ± 1.4, p = 0.009) in the termination group than in the non-termination group. The presence of drivers 2-6 with limited (≤ 3) LA regions showed a tenfold increase in the likelihood of AF termination, with 83% specificity and 67% sensitivity. Among 231 AF drivers, the drivers related to termination exhibited a greater overlap of CFAE (56.8 ± 34.1% vs. 39.5 ± 30.4%, p = 0.004) than the non-related drivers. The termination group showed a trend toward a lower recurrence rate after ablation (p = 0.163). CONCLUSIONS: Rotors responsible for AF maintenance may be characterized in cases with concentrated regions and fewer drivers on mapping.

Spontaneous Dissection of Left Internal Mammary Artery Graft: A Case Report and Literature Review.

Spontaneous left internal mammary artery (LIMA) graft dissection is a rare condition, and clinical findings remain to be elucidated. We report a case of LIMA graft dissection diagnosed by a coronary computed tomography and intravascular ultrasound. The patient was successfully treated with percutaneous intervention. We also conducted a literature review of published cases and summarized the clinical presentation, pathophysiology, diagnosis, and treatment.

＜Editors' Choice＞ Very long-term clinical outcomes after percutaneous coronary intervention for complex vs non-complex lesions: 10-year outcomes following sirolimus-eluting stent implantation.

Few studies have reported the long-term outcomes (>10 years) following first-generation drug-eluting stent implantation. In this single-center retrospective study, we investigated the very long-term clinical outcomes after first-generation sirolimus-eluting stent (SES) implantation in patients with complex lesions. The study included 383 consecutive patients who underwent initial SES implantation between July 2004 and January 2006; 84 and 299 of these patients reported a history of percutaneous coronary intervention (PCI) for complex and noncomplex lesions, respectively. Complex PCI was defined as having at least one of the following features: left main trunk PCI, implantation of ≥3 stents, bifurcation lesions with implantation of 2 stents, total stent length >60 mm, or chronic total occlusion. The target lesion revascularization (TLR) rate was significantly higher in the complex PCI than in the noncomplex PCI group (29.4% vs 13.0%, P=0.001), and we observed a significant intergroup difference in the late TLR (>1 year) rates (21.6% vs 9.5%, P=0.008). Late TLR continued over 10 years at a rate of 2.4%/year in the complex PCI and 1.1%/year in the noncomplex PCI group. Cox regression analysis revealed that complex PCI was related to TLR both over 10 years (hazard ratio 2.29, P=0.003) and beyond 1 year (hazard ratio 2.32, P=0.01). Cardiac death was more common in the complex PCI than in the noncomplex PCI group, particularly 4 years after PCI (15.8% vs 7.5%, P=0.031). Sudden death was the major cause of cardiac death beyond 4 years in the complex PCI group. These data indicate that long-term careful follow-up is essential for patients implanted with SES, especially those treated for complex lesions.

Depolarization and repolarization dynamics after His-bundle pacing: Comparison with right ventricular pacing and native ventricular conduction.

BACKGROUND: The current study aimed to evaluate changes in electrical depolarization and repolarization parameters after His-bundle pacing (HBP) compared with right ventricular pacing (RVP) and its association with ventricular arrhythmia (VA). METHODS: Forty-one patients (13 with HBP, 14 with RVP, and 14 controls [AAI mode]) were evaluated. After continuous pacing algorithm, QRS duration, QT interval, QTc, JT interval, T-peak to T-end (Tpe), and Tpe/QT ratio were measured on electrocardiography at baseline and 1 week, 1 month, and 6 months postoperatively. We investigated VA occurrence and adverse events after implantation. RESULTS: At 6 months, QRS duration was significantly shorter in the HBP (121.6 ± 15.6 ms) than in the RVP (150.1 ± 14.9 ms) group. The QT intervals were lower in the HBP (424.0 ± 40.9 ms) and control (405.9 ± 23.0 ms) groups than in the RVP (453.0 ± 40.2 ms) group. The Tpe and Tpe/QT ratios at 6 months differed significantly between the HBP and RVP groups (Tpe, 69.8 ± 19.7 ms vs 87.4 ± 11.9 ms and Tpe/QT, 0.16 ± 0.03 vs 0.19 ± 0.02, respectively). The Tpe and Tpe/QT ratios were similarly shortened in the HBP and control groups. VA occurred less frequently in the HBP (15%) and control (7.1%) groups than in the RVP (50%) group (p = 0.020). The non-RVP group showed significantly lower rates of VA and major adverse events than the RVP group. Patients with VA demonstrated significantly longer QRS duration, QT interval, Tpe, and Tpe/QT at 6 months than those without VA. CONCLUSION: HBP showed better depolarization and repolarization stability than RVP.

Coagulation Response and Prothrombotic Effect of Uninterrupted Oral Anticoagulant Administration After Catheter Ablation for VT.

BACKGROUND: Catheter ablation for ventricular tachycardia (VT) is associated with perioperative thromboembolic risk. However, the strategy for postprocedural management remains unknown. OBJECTIVES: The aim of this study was to evaluate the prothrombotic response after VT ablation in various coagulation biomarkers in patients with and without the administration of oral anticoagulation (OAC). METHODS: Data from 112 patients (58 with uninterrupted OAC and 54 without) with structural heart disease who underwent endocardial VT ablation were retrospectively analyzed. We also included 41 patients who underwent ablation for premature ventricular contraction from the right ventricle and 13 patients who underwent electrophysiology study (the control group). Blood samples of coagulation markers were collected before and 3 days after the procedure in all patients. RESULTS: The percentage of D-dimer levels ≤1.0 µg/mL at baseline was lower in the VT ablation groups (76% and 50% in the OAC and non-OAC groups, respectively) than in the other groups (100%). After 3 days, the percentage remained at 67% in the OAC group; however, the non-OAC VT group demonstrated a remarkable decrease of 20%. Similarly, fibrin monomer complex, thrombin antithrombin, and prothrombin fragment 1+2 levels were well suppressed in the control, premature ventricular contraction, and OAC groups. However, the non-OAC group demonstrated increased coagulation markers both before and after 3 days. Multivariate analysis demonstrated that OAC administration and normal coagulation markers at baseline were independent predictors of stable coagulation status after ablation. CONCLUSIONS: The coagulation cascade was significantly activated in patients undergoing VT ablation. Uninterrupted OAC administration suppressed the coagulation response, which might be associated with a reduction in perioperative prothrombotic risk.

Percutaneous Treatment for Venous Stenosis Caused by a Vascular Closure Device.

Vascular closure devices (VCDs) are widely used as an alternative to manual compression of femoral puncture sites. In this report, we present a 73-year-old man who developed symptomatic venous stenosis related to VCD after pulmonary vein isolation. We performed percutaneous treatment with balloon angioplasty. This case suggests that balloon angioplasty with proper safety measures can be an option for treating venous stenosis related to VCDs.

Identification of high priority focal activations in persistent atrial fibrillation using a novel mapping strategy.

Focal activation is believed to be an atrial fibrillation (AF) driver; however, little is known about whether all focal activations are necessary for AF persistence. The purpose of this study was to assess the electrical nature of focal activation and identify high-priority focal activations using a novel mapping system (CARTOFINDER). Thirty-five patients with persistent AF who underwent catheter ablation were assessed. Cycle length (CL) and CL standard deviation (CLSD) on unipolar recordings and voltage amplitude and electrogram morphologies on bipolar recordings were evaluated at all points of interest. The most frequent CL at each mapping site was defined as the dominant CL. We identified dominant focal activations (DFAs) that had a shorter dominant CL on the integrated CARTOFINDER map. The effect of elimination of DFAs on AF maintenance was assessed by the composite endpoint (termination to sinus rhythm, organization of the rhythm to atrial tachycardia, and AF CL slowing). In all, 450 focal activations were identified among 10,868 points, and 50.4% of focal activations were DFAs. Focal activations showed relatively long CL and regularity with short CLSD. Most focal activations showed an isoelectric baseline and were located outside of the fractionated electrogram area. Both DFAs and non-DFAs were typically observed in the normal voltage range. Elimination of DFAs was achieved in 19 (54.3%) patients, with a remarkable impact on AF maintenance (68.4% vs. 25.0%, p = 0.018). In conclusion, DFAs may play an important role in AF maintenance and could be an attractive therapeutic target for AF.

Incidence of Left Atrial Thrombus Development and Imaging Approach in Patients Scheduled for Repeat Catheter Ablation for Atrial Fibrillation.

The risk for developing left atrial (LA) thrombi after initial catheter ablation for atrial fibrillation (AF) and requirements for imaging evaluation for thrombi screening at repeat ablation is unclear. This study aimed to assess the occurrence of thrombus development and frequency of any imaging study evaluating thrombus formation during repeat ablation for AF. Of 2,066 patients undergoing initial catheter ablation for AF with uninterrupted oral anticoagulation, 615 patients underwent repeat ablation after 258.0 (105.0-882.0) days. We investigated the factors associated with safety outcomes and requirements for thrombus screening. All patients underwent at least one imaging examination to screen for thrombi in the initial session; however, the examination rate decreased to 476 patients (77%) before the repeat session. The frequency of imaging evaluations was 5.0%, 11%, 21%, 84%, and 91% for transesophageal echocardiography and 18%, 33%, 49%, 98%, and 99% for any imaging modality at repeat ablation performed ≤60 days, ≤90 days, ≤180 days, >180 days, and >1 year after the initial session, respectively. Three patients (0.5%) developed LA thrombi at repeat ablation due to identifiable causes, and no patients experienced thromboembolic events when no imaging evaluation was performed. Multivariate analysis revealed that repeat ablation performed after >180 days, non-paroxysmal atrial arrhythmias, and lower left ventricular ejection fraction were predictors of thrombus development and severe spontaneous echocardiography contrast. In conclusion, the risk for thrombus development at repeat ablation for AF was low. There needs to be a risk stratification of the imaging screening for thrombi at repeat ablation.

Dynamic Changes in Electrocardiogram Parameters After Epicardial Substrate Catheter Ablation of Brugada Syndrome.

BACKGROUND: Catheter ablation (CA) is effective for recurrent episodes of ventricular fibrillation (VF) in Brugada syndrome (BrS). VF development in BrS is associated with several electrocardiogram (ECG) abnormalities. This study investigated changes in ECG parameters in high-risk BrS patients who underwent epicardial CA.Methods and Results:In all, 27 BrS patients were implanted with an implantable cardioverter-defibrillator (ICD). Patients were divided into 2 groups: (1) an ablation group (n=11) that underwent epicardial CA because of VF recurrence; and (2) a primary prevention (PP) group (n=16) with ICD implantation only. ECG parameters were evaluated before and 12 months after CA and compared with ECG parameters in the PP group. The T wave peak-to-end interval was significantly longer and the number of abnormal spikes in leads V1-V3 at the second, third, and fourth intercostal spaces was greater in the ablation than PP group. After ablation, ST levels and the sum of abnormal spikes in leads V1-V3 were significantly decreased. The mean (±SD) number of ICD shocks decreased markedly during a mean follow-up period of 42.0 months (from 3.8±3.7 to 0.2±0.4/year). Four patients had an ICD shock following the ablation procedure. Greater reductions in ST-segment elevation and abnormal spikes were observed in the group without than with VF recurrence. CONCLUSIONS: Improvements in surface ECG parameters appear to be associated with successful ablation in high-risk BrS patients.

The mechanism and prognosis of acute and late improvement in mitral regurgitation after cardiac resynchronization therapy.

Cardiac resynchronization therapy (CRT) improves functional mitral regurgitation (MR); however, the mechanism and differences in acute and late improvement in MR are unclear. We aimed to evaluate the factors associated with the acute and late MR improvements and the prognosis of MR improvement after CRT. This retrospective study included 121 patients who underwent CRT implantation with full echocardiography assessment at baseline, 1 week, and 6 months after implantation. MR severity was classified into five grades (0: none to 4: severe). Two-dimensional speckle-tracking echocardiography with radial strain was used to assess dyssynchrony, and the time difference between the lateral and inferior segments at papillary muscle levels (TDlate-inf) was calculated. The MR improved 1 week and 6 months after CRT in 40 (33%) and 45 (37%) patients, respectively. On multivariate analyses, TDlate-inf (baseline-1 week) and SPWMD were independently associated with acute MR improvement. The %reduction in left ventricular end-systolic volume (LVESV) (baseline-6 months) and TDlate-inf (baseline-1 week) were independently correlated with late MR improvement. The patients with pre-MR grades 2-4 and improved MR after CRT showed significantly better prognosis in heart failure hospitalization. Cutoff values of ≥ 19.5 ms of the reduction of TDlate-inf and ≥ 30.8% of the %reduction of LVESV were significantly associated with the decrease in heart failure hospitalization. The improved interpapillary muscle activation time delay and volume reduction after CRT were associated with acute and late MR improvements. There may be different time course of recovery and distinct causes for late MR improvement.

Coronary Drug-Eluting Stent Infection Complicated by Coronary Artery Aneurysm and Purulent Pericarditis: Complete Resolution Without Surgery.

Coronary stent infection is considered to be a rare but catastrophic complication of percutaneous coronary intervention. In this report, we present a 72-year-old man who developed a coronary stent infection complicated by coronary aneurysm and purulent pericarditis. Coronary artery aneurysm resolved over a period of 8 months following the successful management of infection with intensive antibiotic therapy alone. This case suggests that conservative therapy can be a therapeutic option in patients with high operative risks.

Refractory ventricular fibrillation caused by caffeine intoxication.

A 30-year-old female with no history of cardiac or systemic disease presented with incessant ventricular fibrillation (VF) after an intake of 12 g of over-the-counter caffeine tablets for a suicidal purpose. Her VF was refractory, and repeated defibrillations were needed to attain a recovery of sinus rhythms. We then performed percutaneous cardiopulmonary support and therapeutic hypothermia to stabilize her circulation and prevent anoxic brain damage, respectively. A blood examination revealed an extremely high concentration of caffeine (172 mg/L). She fully recovered 16 days after her admission. Our findings reveal the potentially lethal arrhythmogenic nature of caffeine. .