Xiaomeng Yin

Association between insomnia and atrial fibrillation in a Chinese population: A cross‐sectional study

Insomnia is the most prevalent sleep disorder; however, little research has explored the link between insomnia and atrial fibrillation (AF).

Association between modifiable lifestyle and the prevalence of atrial fibrillation in a Chinese population: Based on the cardiovascular health score.

The Cardiovascular Health (CVH) Score was comprised of a series of modifiable lifestyle and health factors, which was published by American Heart Association in 2010. Its relationship with atrial fibrillation (AF) remains unclear.

Common Variants in the TBX5 Gene Associated with Atrial Fibrillation in a Chinese Han Population

Background PR interval variations have recently been associated with an increased risk of long-term atrial fibrillation (AF), heart block and all-cause mortality. Genome-wide association studies have linked the PR interval with several common variants in the TBX5 gene. Several variants in the TBX5 gene, including rs7312625 and rs883079, have been associated with AF. The purpose of this study was to determine the association of single-nucleotide polymorphisms (SNPs) in the TBX5 gene, rs7312625 and rs883079, with AF in Chinese Han patients. Methodology/Principal Findings In this case-control association study, large cohorts of AF patients (n = 1132) and controls (n = 1206) were recruited from different hospitals. The genotyping was performed using a Rotor-Gene TM 6000 high-resolution melt system. Rs7312625, rs3825214 and rs883079 were analyzed. We found that SNP 3825214 was significantly associated with AF (P-obs = 0.002, odds ratio [OR] = 0.82), and lone AF (P-obs = 6.77x10-5, odds ratio [OR] = 0.71). SNP rs7312625 was significantly associated with lone AF (P-obs = 0.015, odds ratio [OR] = 1.27), although its association with AF was not significant. No significant association of SNP rs883079 with AF or lone AF was observed. Thus, we analyzed the interaction among these three loci. We demonstrated significant interaction among rs3825214, rs7312625 and rs883079. Four-locus risk alleles showed the highest odds ratio in combined rs3825214 and rs7312625 (P-obs<0.0001, odds ratio [OR] = 2.21). Six-locus risk alleles showed the highest odds ratio in combined rs3825214, rs7312625 and rs 883079(P-obs<0.0001, odds ratio [OR] = 2.35). Significance was established with the trend test (P<0.0001). Conclusions For the first time, we report the strong association of SNP rs3825214 in the TBX5 gene with AF and lone AF in a Chinese Han population. Rs7312625 was significantly associated with lone AF, and snp-snp interaction increased the risk of atrial fibrillation. Our data might provide new insights into understanding AF pathogenesis and designing novel genetic therapies for AF patients.

Epicardial radiofrequency catheter ablation of Brugada syndrome with electrical storm during ventricular fibrillation: A case report

Rationale: Brugada syndrome (BrS) is characterized by ST segment elevation at the J point ≥2 mm in the right precordial electrocardiogram (ECG) leads, in the absence of structural heart disease, electrolyte disturbances, or ischemia. It is a well-described cause of sudden death in young patients, especially in the age of between 30 and 40 years old. Here, we reported an unusual case of electrical storm (ES) of ventricular fibrillation (VF) caused by BrS with complete right bundle-branch block (CRBBB) in a 75-year-old male patient. Patient concerns: A 75-year-old male patient survived sudden cardiac death caused by a ventricular ES. He presented with the cove-shaped ST elevation of 2 mm in lead V1 with typical CRBBB and lacked structural cardiomyopathy and coronary heart disease. The patient suffered ventricular ES again, although the implantable cardioverter defibrillator(ICD) had implanted. Diagnoses: Brugada syndrome with complete right bundle-branch block. Interventions: Implantable cardioverter defibrillator (ICD) implantation was performed. But this therapy could not prevent the recurrence of malignant arrhythmia. Finally, the ES was treated successfully using radiofrequency catheter ablation (RFCA) at the area of the free wall of the right ventricular outflow tract (RVOT) epicardium. Outcomes: During 7 months of follow-up, the patient was asymptomatic and free of arrhythmic events. Lessons: As far as we know, the patient is the oldest patient reported to have BrS. RFCA offers an alternative therapy for patients with BrS, especially when ICD shocks are encountered.

Association between serum uric acid and atrial fibrillation: a cross-sectional community-based study in China

Objectives To investigate the effects of gender on the association of serum uric acid (SUA) levels and atrial fibrillation (AF) prevalence in a community-based Chinese population. Setting Data were obtained from annual Jidong Oilfield employee and family member health checkups. The Jidong community is geographically located in Tangshan City in northern China. Participants A total of 9078 residents were invited to take part in the survey and provided informed consents. Individuals without data of ECG or SUA were excluded, leaving 8937 residents in our study. Primary and secondary outcome measures SUA was measured at baseline using the uricase-peroxidase method. Hyperuricaemia was defined as a SUA level >7.0 mg/dL in men and >5.7 mg/dL in women. AF was diagnosed based on ECG findings and/or any medical history of AF from referring physicians. The crude and independent association between SUA levels and AF prevalence was evaluated with logistic regression analysis. Results AF prevalence was 0.6% (53/8937). Participants with hyperuricaemia had a higher AF prevalence compared with those with normal SUA levels (1.1% vs 0.5%; P=0.02). Hyperuricaemia was correlated with AF after adjustment for various cardiovascular risk factors in all participants (P=0.03, OR 2.051, 95% CI 1.063 to 3.856). This correlation was particularly stronger in women compared with men (P<0.001, OR 6.366, 95% CI 2.553 to 15.871 in women and P=0.96, OR 1.025, 95% CI 0.400 to 2.626 in men). Conclusions We demonstrated a significant association between increased SUA levels and AF prevalence in a Chinese population. Our data indicate that there is a gender-specific mechanism underlying the relationship between SUA and AF.

Elevated Circulating Fibrocytes Is a Marker of Left Atrial Fibrosis and Recurrence of Persistent Atrial Fibrillation

Background In atrial fibrillation (AF), a more extensively fibrotic left atrium (LA) provides a substrate for arrhythmias and increases risk of relapse following ablation. Fibrocytes are bone marrow–derived circulating mesenchymal progenitors that have been identified in the atrium of patients with AF who have valvular diseases. The present study investigates the associations between circulating fibrocytes and LA fibrosis or the prevalence of recurrence after ablation in patients with persistent AF. Methods and Results We measured the proportion, differentiation, and migration of circulating fibrocytes from patients with persistent AF (n=40), those with paroxysmal AF (n=30), and sinus rhythm controls (n=30). LA low‐voltage (fibrosis) area was identified by an electroanatomic mapping system, and patients were followed up for 1 year after ablation. The relationship between circulating fibrocyte percentage and LA low‐voltage area or recurrence was assessed by multivariate regression analysis. Circulating fibrocyte percentage positively associated with LA low‐voltage area in the persistent AF group, and circulating fibrocyte (≥4.05%) was a significant predictor of 1‐year recurrence after ablation. Cultured fibrocytes exhibited enhanced potential of differentiation in the persistent AF group (67.58±1.54%) versus the paroxysmal AF group (56.67±1.52%) and sinus rhythm controls (48.43±1.79%). Furthermore, expression of fibroblast activation markers and cell migratory ability were also elevated in differentiated fibrocytes from patients with persistent AF. Transforming growth factor β1 and stromal cell–derived factor 1 were elevated in the plasma of patients with persistent AF and were shown to promote fibrocyte differentiation and migration, respectively. Conclusions In patients with persistent AF, increased circulating fibrocytes served as a marker of LA fibrosis and recurrence.

Atrial fibrillation is related to lower incidence of deep venous thrombosis in patients with pulmonary embolism

Background Atrial fibrillation (AF) is an established risk factor of left atrial thrombosis and systemic embolism. Traditionally pulmonary embolism (PE) is a recognized complication of deep vein thrombosis (DVT). However, whether AF is responsible for right atrial thrombosis and leads to PE has not been examined. Methods We retrospectively analyzed medical records of patients with confirmed diagnosis of PE with AF (study group) from 2002-2015. Patients with PE without AF, matched by age and sex, served as controls (control group). The CHA2DS2-VASc and CHADS2 scores were classified into two categories, low-intermediate (<2 points) and high-risk (≥2 points). Results A total of 330 patients (110 in study group and 220 in control group). The study group had significantly lower incidence of newly diagnosed DVT (21% vs. 44%, P<0.001), previous history of DVT (6% vs. 17%, P=0.006) and recent surgery or trauma (10% vs. 23%, P=0.004) compared to the control group. When stratified by the CHADS2 score, 49 patients (44.5%) were considered low-intermediate risk. This proportion significantly differed when stratified using CHA2DS2-VASc, in which 13 patients (13.6%) were considered low-intermediate risk, P<0.001. Conclusions The incidence of DVT was much lower in the study group, suggesting the possibility of clots originated from the right heart that may increase the risk of PE. The CHA2DS2-VASc scoring system might be more sensitive for prediction and stratification of the PE in AF patients than the CHADS2 score.

The genetic variation rs12143842 in NOS1AP increases idiopathic ventricular tachycardia risk in Chinese Han populations

Genome-wide association studies identified that the common T of rs12143842 in NOS1AP is associated with a QT/QTc interval in European populations. In this study, we test the association between the variation rs12143842 in NOS1AP and idiopathic ventricular tachycardia (IVT). A case-control association study examining rs12143842 was performed in two independent cohorts. The Northern cohort enrolled 277 IVT patients and 728 controls from a Chinese Gene ID population. The Central cohort enrolled 301 IVT patients and 803 matched controls. Genotyping was performed using high-resolution melt analysis. The minor T allele of the rs12143842 SNP was significantly associated with decreased IVT risk in the Northern cohort (adjusted P = 0.024, OR 0.71(0.52~0.96)), and this association was replicated in an independent Central Gene ID cohort (adjusted P = 0.029, OR 0.78 (0.62~0.97)). The association was more significant in the combined population (adjusted P = 0.001, OR 0.76 (0.64~0.90)). The P values for the genotypic association were significant for the dominant (P < 0.001) and additive (P = 0.001) models. The minor T allele for the SNP rs12143842 in NOS1AP is significantly associated with IVT. NOS1AP might be a novel gene affecting IVT, and further functional studies should be performed.

Frequency Gradient Within Coronary Sinus Predicts the Long‐Term Outcome of Persistent Atrial Fibrillation Catheter Ablation

Background The coronary sinus (CS), as a junction of the atria, contributes to atrial fibrillation (AF) by developing unstable reentry, and isolating the atria by ablation at the CS could terminate AF. The present study evaluated whether AF activities at the CS in a subset of patients contributed to AF maintenance and predicted clinical outcome of ablation. Methods and Results We studied 122 consecutive patients who had a first‐time radiofrequency ablation for persistent AF. Bipolar electrograms were obtained from multiple regions of the left atrium by a Lasso mapping catheter before ablation. Pulmonary vein isolation terminated AF in 12 patients (9.8%). Sequential stepwise ablation was conducted in pulmonary vein isolation nontermination patients and succeeded in 22 patients (18%). In the stepwise termination group, AF frequency in the proximal CS (CSp) was significantly higher (10.2±2.1 Hz versus 8.3±1.8 Hz, P<0.001), and the ratio of distal CS (CSd) to proximal CS (CSd/CSp ratio, 56.6%±10.11% versus 70.7%±9.8%, P<0.001) was significantly lower than that in the nontermination group. The stepwise logistic regression analysis indicated that the CSd/CSp ratio was an independent predictor with an odds ratio of 1.131 (95%CI 1.053‐1.214; P=0.001). With a cutoff of 67%, the patients with lower CSd/CSp ratios had significantly better index and long‐term outcomes than those with higher ratios during a follow‐up of 46±18 months. Conclusions Rapid repetitive activities in the musculature of the proximal CS may contribute to maintenance of AF after pulmonary vein isolation alone in persistent AF. A cutoff at 67%, of the CSd/CSp frequency ratio might be an indicator to stratify the subset of patients who might benefit from CS ablation.

Atrioventricular Node Slow‐Pathway Ablation Reduces Atrial Fibrillation Inducibility: A Neuronal Mechanism

Background Radiofrequency ablation (RFA) for atrioventricular nodal reentrant tachycardia appears to reduce atrial tachycardia, which might relate to parasympathetic denervation at cardiac ganglionated plexuses. Methods and Results Compared to 7 control canines without RFA, in 14 canines, RFA at the bottom of Kochs triangle attenuated vagal stimulation–induced effective refractory periods prolongation in atrioventricular nodal and discontinuous atrioventricular conduction curves but had no effect on the sinoatrial node. RFA attenuated vagal stimulation–induced atrial effective refractory periods shortening and vulnerability window of atrial fibrillation widening in the inferior right atrium and proximal coronary sinus but not in the high right atrium and distal coronary sinus. Moreover, RFA anatomically impaired the epicardial ganglionated plexuses at the inferior vena cava‒inferior left atrial junction. This method was also investigated in 42 patients who had undergone ablation of atrioventricular nodal reentrant tachycardia, or 12 with an accessory pathway (AP) at the posterior septum (AP‐PS), and 34 patients who had an AP at the free wall as control. In patients with atrioventricular nodal reentrant tachycardia and AP‐PS, RFA at the bottom of Kochs triangle prolonged atrial effective refractory periods and reduced vulnerability windows of atrial fibrillation widening at the inferior right atrium, distal coronary sinus and proximal coronary sinus but not the high right atrium. In patients with AP‐free wall, RFA had no significant atrial effects. Conclusions RFA at the bottom of Kochs triangle attenuated local autonomic innervation in the atrioventricular node and atria, decreased vagal stimulation–induced discontinuous atrioventricular nodal conduction, and reduced atrial fibrillation inducibility due to impaired ganglionated plexuses. In patients with atrioventricular nodal reentrant tachycardia or AP‐PS, RFA prolonged atrial effective refractory periods, and narrowed vulnerability windows of atrial fibrillation.