Fang-Zhou Liu

Background: Atrial fibrillation (AF) significantly increases the ischemic stroke risk. However, the relationship between age at diagnosis of AF and subsequent stroke risk remains poorly understood. Methods and Results: We analyzed data from 5 prospective cohorts: ARIC (Atherosclerosis Risk in Communities) study, CHS (Cardiovascular Health Study), CARDIA (Coronary Artery Risk Development in Young Adults), MESA (Multi‐Ethnic Study of Atherosclerosis), and Framingham Heart Study (including Offspring cohort and the Third‐Generation cohorts). Cox regression models and competing risk survival analyses were used to assess incidence rates and hazard ratios (HRs) for ischemic stroke stratified by age groups. Among 47 239 participants (median follow‐up: 21.1 years), 6689 (14.2%) developed AF, and 536 (8.0%) subsequently experienced ischemic stroke. Younger age at AF diagnosis was significantly associated with a higher ischemic stroke risk. Fully adjusted HRs for ischemic stroke were 5.35 (95% CI, 3.56–8.03), 2.99 (95% CI, 2.32–3.86), 2.13 (95% CI, 1.75–2.58), and 1.93 (95% CI, 1.59–2.34) for AF diagnosed at ages 55, 65, 75, and 85, respectively. Compared with participants without AF at age 55, HRs for ischemic stroke were 7.30 (95% CI, 3.27–16.31) for AF diagnosed >10 years earlier, 4.98 (95% CI, 2.99–8.29) for 6 to 10 years earlier, and 4.60 (95% CI, 1.48–14.34) for ≤5 years earlier ( P ‐trend <0.001). The presence of AF yielded a 13.9 years earlier occurrence of ischemic stroke among those with AF diagnosis at 55 years compared with 1.5 years earlier at age 85. Conclusions: Younger age at AF diagnosis was associated with a higher risk of subsequent ischemic stroke.

Pulsed field ablation (PFA) is emerging as a non-thermal, tissue-specific technique for pulmonary vein isolation (PVI) in atrial fibrillation therapy. This pre-clinical study aims to investigate the feasibility and safety of PVI using a novel PFA system including a nanosecond-scale PFA generator, a novel lotos PFA catheter, and a customized 12 Fr steerable sheath. A total of 11 Yorkshire swine were included in this study, with 4 in the acute cohort and 7 in the chronic cohort. Under general anaesthesia, transseptal puncture and pulmonary vein (PV) angiography was initially performed. The PFA catheter was navigated to position at the right and left PV antrum after the electroanatomic reconstruction of the left atrium. Biphasic PFA applications were performed on PVs in both the spindle-shaped and the lotos-shaped poses. Pulmonary vein isolation and PFA-associated safety were assessed 30 min after ablation in both cohorts and 30 days later in the chronic cohort. Detailed necropsy and histopathology were performed. Additional intracardiac echocardiography and coronary angiogram were evaluated for safety. All target PVs (n = 20) were successfully isolated on the first attempt. No spasm of coronary artery or microbubble was seen during the procedure. Eleven of 12 PVs (91.6%) remained in isolation at the 30-day invasive study. No evidence of PV stenosis was observed in any targets. However, transient diaphragm capture occurred in 17.6%. Histopathological examinations showed no evidence of collateral injury. This study provides scientific evidence demonstrating the safety and efficacy of the novel PFA catheter and system for single-shot PVI, which shows great potential.

Background. Diabetes mellitus (DM) is a prognostic marker in elderly patients with cardiovascular diseases, but its predictive value in elderly valvular heart disease (VHD) patients is unclear. This study aimed to investigate the effect of DM on the long-term outcome of elderly VHD patients. Methods. This single-center, observational study enrolled patients aged 65 and older consecutively with confirmed VHD using echocardiography. Patients, divided into the DM group and non-DM group, were followed up for major adverse cardiac and cerebrovascular events (MACCEs), including all-cause death, ischemic stroke, and heart failure rehospitalization. Results. Our study consisted of 532 patients over a median follow-up of 52.9 months. Compared with the non-DM group (n = 377), the DM group (n = 155) had higher incidences of ischemic stroke (25.2% vs. 13.5%, ), heart failure rehospitalization (37.4% vs. 20.7%, ), and MACCEs (60.0% vs. 35.8%, ). After adjustment of confounders by the multivariable cox regression, DM appeared as an independent predictor for MACCEs (adjusted hazard ratio, aHR: 1.88; 95% confidence interval 1.42–2.48; ). In the subgroup analysis of VHD etiology and functional style, conversely, DM was a protective factor for MACCEs in the patients with rheumatic VHD compared with those without rheumatic VHD (aHR: 0.43 vs. 2.27, ). Conclusions. DM was an independent predictor for ischemic stroke and heart failure rehospitalization in elderly VHD patients undergoing conservative treatment.

We present a case of wide‐complex tachycardia in which the clinical electrophysiological diagnosis was considered to be bundle branch re‐entry ventricular tachycardia. A series of ventricular entrainment attempts were performed from the left and right ventricular septum to confirm the diagnosis. Entrainment pacing with a general current output (10 mA) was performed from the right ventricular septum with manifest fusion and a post‐pacing interval similar to tachycardia cycle length. Thereafter, another entrainment attempt with a greater current output (20 mA) was performed from the same site. Paradoxically, concealed fusion was demonstrated by selective RB capture only, though there was no clear “RB” potential seen. In this case, we attempt to explain and illustrate the mechanism of paradoxical near‐field inability to capture with increasing current strength.

Objectives: This meta-analysis and systematic review seeks to compare both characteristic parameters and procedural outcomes of atrial fibrillation (AF) catheter ablation in patients under general anaesthesia (GA)/deep sedation and mild/moderate sedation. Background: Catheter ablation has become a widely applied intervention for treating symptomatic AF and arrhythmias that are refractory to medical therapy. It can be conducted through from mild sedation to GA. Methods: PubMed and Embase were searched up to July 2018 for randomised controlled trials, cohort and observational studies that assessed the outcomes of catheter ablation under GA/deep sedation or mild/moderate sedation. Nine studies were included in this meta-analysis after screening with the inclusion and exclusion criteria. Heterogeneity between studies and publication bias was evaluated by I² index and Egger’s regression, respectively. Results: Our meta-analysis found catheter AF ablation with GA/deep sedation to be associated with reduced risk of recurrence (RR: 0.79, 95% CI 0.56 to 1.13, p=0.20) and complications (RR: 0.95, 95% CI 0.64 to 1.42, p=0.82), though statistically insignificant. In terms of procedural parameters, there was no significant difference between the two groups for both procedural time (SMD: −0.13, 95% CI −0.90 to 0.63, p=0.74) and fluoroscopy time (SMD: −0.41, 95% CI −1.40 to 0.58, p=0.41). Univariate meta-regression did not reveal any covariates as a moderating factor for complication and recurrence risk. Conclusion: Apart from an increased likelihood of procedural success, ablation by GA/deep sedation was found to be non-significantly different from the mild/moderate sedation approach in both procedural parameters and outcome measures.

The QT interval along with its heart rate corrected form (QTc) are well-established ECG markers that have been found to be associated with malignant ventricular arrhythmogenesis. However, extensive preclinical and clinical investigations over the years have allowed for novel clinical ECG markers to be generated as predictors of arrhythmogenesis and sudden cardiac death. Repolarization markers include the older QTc, QT dispersion and newer Tpeak - Tend intervals, (Tpeak - Tend) / QT ratios, T-wave alternans (TWA), microvolt TWA and T-wave area dispersion. Meanwhile, conduction markers dissecting the QRS complex, such as QRS dispersion (QRSD) and fragmented QRS, were also found to correlate conduction velocity and unidirectional block with re-entrant substrates in various cardiac conditions. Both repolarization and conduction parameters can be combined into the excitation wavelength (λ). A surrogate marker for λ is the index of Cardiac Electrophysiological Balance (iCEB: QT / QRSd). Other markers based on conduction-repolarization are [QRSD x (Tpeak-Tend) / QRSd] and [QRSD x (Tpeak-Tend) / (QRSd x QT)]. Advancement in technology permitted sophisticated electrophysiological analyses such as principal component analysis and periodic repolarization dynamics to further improve risk stratification. This was closely followed by other novel indices including ventricular ectopic QRS interval, the f99 index and EntropyXQT, which integrates mathematical and physical calculations for determining the risk markers. Though proven to be effective in limited patient cohorts, more clinical studies across different cardiac pathologies are required to confirm their validity. As such, this review seeks to encapsulate the development of old and new ECG markers along with their associated utility and shortcomings in clinical practice.

The incidence of atrial tachycardia (AT) after rheumatic mitral valvular (RMV) surgery has been well described. However, there have been few reports on the characteristics, mechanism, and long-term ablation outcome of ATs after RMV surgery and concomitant Cox-MAZE IV procedure.The present study reviewed consecutive patients who underwent AT ablation between May 2008 and July 2013. All patients were refractory to antiarrhythmic drugs (AADs) and had a history of RMV surgery and Cox-MAZE IV procedure. A total of 34 patients underwent AT ablation after RMV surgery and concomitant Cox-MAZE IV procedure, and presented 57 mappable and 2 unmappable ATs. The 57 mappable ATs included 14 focal-ATs and 43 reentry-ATs. Ten of the 14 focal-like ATs were located at the pulmonary vein (PV) antrum and border of a box lesion. Of the 43 reentry-ATs, 16 were marco-reentrant around the mitral annulus (MA) and 16 around the tricuspid annulus. There were 41 atypical ATs (non-cavotricuspid isthmus related) including 16 ATs related to the box lesion and 21 ATs related to other Cox-MAZE IV lesions. The AT were successfully terminated in 33 (97.1%) patients. After mean follow-up of 46.9 ± 15.7 months, 25 (73.5%) patients maintained sinus rhythm without AADs after a single procedure and 28 (82.4%) patients after repeated procedures.The recurrent ATs after RMV surgery and concomitant Cox-MAZE IV were mainly reentry mechanism, and largely related to LA. An incomplete lesion or re-conductive gaps in a prior lesion might be the predominant mechanisms for these ATs. Catheter-based mapping and ablation of these ATs seems to be effective and safe during a long-term follow-up.