Is the left bundle branch pacing a choice to conquer the right bundle branch block?-A case report.

In patients with preserved ejection fraction or right bundle branch block (RBBB) pattern requiring a high percentage of ventricular pacing, His-bundle pacing (HBP) might be an alternative to biventricular pacing, although the high threshold occasionally occurs. We provided a case of the intrinsic RBBB correction by capturing intra-Hisian left bundle branch (LBB) or distal His-bundle with different output settings. LBB pacing had the advantage of a much lower threshold while remained most synchrony as HBP. LBB pacing might be a promisingly safe and effective procedure for patients with high-grade atrioventricular (AV) block and RBBB pattern.

Remodeling of myocardial energy and metabolic homeostasis in a sheep model of persistent atrial fibrillation.

BACKGROUND: Atrial fibrillation (AF) is the most common progressive cardiac arrhythmia and is often associated with rapid contraction in both atria and ventricles. The role of atrial energy and metabolic homeostasis in AF progression is under-investigated. OBJECTIVES: To determine the remodeling of energy metabolism during persistent AF and the effect of eplerenone (EPL), an aldosterone inhibitor, on metabolic homeostasis. METHODS: A nonsustained atrial pacing sheep model was developed to simulate the progression of AF from paroxysmal to persistent. Metabolomic and proteomic analyses at termination of the experiment were used to analyze atrial tissues obtained from sheep in sham, sugar pill (SP) and EPL-treated groups. RESULTS: Proteomic analysis indicated that compared to the sham group, in SP group, fatty acid (FA) synthesis, FA oxidation, tricarboxylic acid (TCA) cycle processes and amino acids (AAs) transport and metabolism were reduced, while glycolytic processes were increased. In metabolomic analysis, the levels of intermediate metabolites of the glycolytic pathways, including 2-phosphoglyceric acid (2 PG), 1,3-bisphosphoglyceric acid (1,3 PG), and pyruvate, HBP (uridine diphosphate-N-acetylglucosamine, UDP-GlcNAc), TCA (citrate) and AAs were greater while the levels of the majority of lipid classes, including phosphatidic acid (PA), phosphatidylcholine (PC), phosphatidylglycerol (PG), glycerophosphoglycerophosphates (PGP), glycerophosphoinositols (PI) and glycerophosphoserines (PS), were decreased in the atria of SP group than in those of sham group. EPL-pretreatment decreased the expression of glut4 and increased the content of acylcarnitines and lipids, such as lyso phospholipids, phospholipids and neutral lipids. CONCLUSION: In the metabolic remodeling during AF, glucose and lipid metabolism were up- and down-regulated, respectively, to sustain TCA cycle anaplerosis. EPL partialy reversed the metabolic shifting.

The serum galectin-3 levels are associated with the severity and prognosis of ischemic stroke.

Galectin-3, a microglia/macrophage-derived inflammatory mediator, plays a role in the stroke progression. In this single-center prospective study, we included 288 consecutive patients with a first-ever acute ischemic stroke to assess the association between galectin-3 serum level and clinical severity at admission and outcome at discharge by univariate and multivariate logistic regression. The results were presented as odds ratios (OR) and 95% confidence intervals (CI). Patients with high severity and poor outcomes had higher serum levels of galectin-3 (P<0.001 and P<0.001). Multivariate analysis suggested that a galectin-3 serum level in the highest quartile (The lowest three quartiles[Q1-3] as the reference) was associated with poor functional outcome (OR, 3.15; 95% CI, 2.44-3.87). The AUC (standard error) for the NIHSS and the combined model were 0.764 (0.031) and 0.823 (0.027), corresponding to a difference of 0.059 (0.004). This study shows that higher serum levels of galectin-3 are associated with stroke severity at admission and stroke prognosis at discharge in ischemic stroke.

Atrial Fibrillation Burden Detected by Dual-Chamber Pacemakers as a Predictor for Cardiac Outcomes: A Retrospective Single-Center Cohort Study.

Background: Atrial fibrillation (AF) might lead to adverse cardiac consequences. The association between AF burden and cardiac prognosis is unknown. Methods and Results: This retrospective cohort study enrolled 204 patients (117 males; age 74.5 ± 11.5 years) who underwent dual-chamber pacemaker implantation in our center from October 2003 to May 2017. During a median follow-up of 66.5 months, AF could be detected in 153 (75%) of the 204 pacemaker patients. Primary endpoint events (composite cardiac readmission, stroke or systemic embolism, and all-cause death) occurred in 83 cases (40.7%). In logistic regression analysis, AF detection was associated with increased risks of composite endpoints [odds ratio (OR) = 2.9, 95% confidence interval (CI): 1.3-6.2, p = 0.007], and the hazard was mainly driven by increased cardiac readmission (OR = 2.2, 95% CI: 1.1-4.7, p = 0.034). No significantly elevated risk for new-onset stroke, systemic embolism, or deaths were found in patients with AF detected than those without AF recorded. AF duration grade of more than 6 min suggested progressively increased composite endpoints (OR = 1.8, 95% CI: 1.2-2.7, p for trend = 0.005), cardiac readmission (OR = 1.8, 95% CI: 1.2-2.7, p for trend = 0.005), especially heart failure or acute coronary syndrome-associated readmission (OR = 1.8, 95% CI: 1.2-2.9, p for trend = 0.010), than those with shorter (<6 min) or no AF episodes. Kaplan-Meier analyses and Cox regression also suggested that episodes of AF more than 6 min predicted future cardiac events. Conclusions: AF detected by pacemakers were common. Higher AF burden predicted more adverse cardiac outcomes and might suggest the intervention of rhythm control in these population.

[Multi-center clinical trial on efficacy of national-made radiofrequency ablation catheter for the treatment of atrioventricular nodal reentrant tachycardia and atrioventricular reentrant tachycardia].

OBJECTIVE: The aim of this trial is to compare the efficacy and safety between national-made and imported ablation catheters for the treatment of atrioventricular nodal reentrant tachycardia (AVNRT) and atrioventricular reentrant tachycardia (AVRT). METHOD: A total of 1342 patients with AVNRT or AVRT were randomly treated with national-made ablation catheter (Group 1, n = 672) or imported ablation catheter (Group 2, n = 670). RESULTS: The immediate ablation success rate was similar in Group 1 and Group 2 (97.9% vs. 99.1%, P > 0.05). There were also no significant differences in the procedure time [(68 +/- 36) min vs. (67 +/- 34) min], the fluoroscopic time [(14 +/- 14) min vs. (10 +/- 11) min], the number of energy delivery [(4.5 +/- 4.5) beats vs. (4.6 +/- 3.9) beats], the ablation time [(260 +/- 218) s vs. (257 +/- 207) s] and the score of ablation catheter performance evaluation [(4.4 +/- 0.5) vs. (4.5 +/- 0.4) ] between the two groups (all P > 0.05). Three patients developed pericardial effusion (1 in Group 1 and 2 in Group 2, P > 0.05). Incidence of recurrence of tachycardia during the 3 months follow up was similar between the 2 groups (14 in Group1 vs. 16 in Group 2, P > 0.05). CONCLUSION: National-made and imported radiofrequency ablation catheters have similar efficacy and safety for treatment of AVNRT and AVRT.

Pacemaker-detected atrial fibrillation burden and risk of ischemic stroke or thromboembolic events-A cohort study.

BACKGROUND: Atrial fibrillation (AF) burden might link to increased risk of systemic embolism. Current scoring systems for evaluating stroke risks such as CHA2DS2-VASc do not incorporate AF burden partly because of the difficulty to assess these data. Patients with dual-chamber pacemakers implanted have opportunities to acquire incidence and duration of AF. OBJECTIVES: We aimed to evaluate the AF burden and its association with thromboembolism in patients with dual-chamber pacemakers. METHODS: This retrospective cohort study enrolled patients who underwent dual-chamber pacemaker implantation at our center between October 2003 and May 2017. We excluded patients with prior thromboembolism or receiving anticoagulants. The incidence and duration of pacemaker-detected AF were compared between patients with and without thromboembolic outcomes. Propensity score matching (1:1) was conducted based on clinical characteristics. Multivariate regressions were performed to determine the predictors of thromboembolic outcomes. Survival free from stroke and thromboembolism was assessed using Kaplan-Meier analysis in groups with different AF burden. RESULTS: Among the 152 patients enrolled (43.4% women; age 73.2 ±â€¯13.3 years), ten experienced thromboembolic events within a median follow-up of 67 months. Patients with thromboembolisms had higher CHA2DS2-VASc scores but not higher AF burden. Higher CHA2DS2-VASc score was associated with increased risk for systemic thromboembolism [hazard ratio (HR), 1.87; 95% confidence interval (CI), 1.07-3.24; P = 0.027). In the propensity score-matched cohort with comparable CHA2DS2-VASc score, patients with thromboembolism had higher AF burden. Pacemaker-detected AF was associated with increased risk for thromboembolism (propensity-adjusted HR, 9.33; 95% CI, 1.19-72.99; P = 0.033). Experiencing AF episodes lasting >6 min was a predictor of significantly higher risk of future stroke or thromboembolism (propensity-adjusted HR, 6.75; 95% CI, 1.30-35.11; P = 0.023). CONCLUSION: In patients with dual-chamber pacemakers and comparable CHA2DS2-VASc score, pacemaker-detected AF burden is associated with elevated risk for thromboembolism. Further research is needed to clarify how pacemaker-detected AF burden could incorporate with CHA2DS2-VASc score variables and help to guide anticoagulation.

A Pilot Study on Parameter Setting of VisiTag™ Module during Pulmonary Vein Isolation.

OBJECTIVES: To identify optimal predefined criteria (OPC) for filters of the VisiTag™ module in the CARTO 3 system during pulmonary vein isolation (PVI). METHODS: Thirty patients with atrial fibrillation (AF) who experienced PVI first were enrolled. PVI was accomplished by using a Thermocool SmartTouch catheter. Ablation lesions were tagged automatically as soon as predefined criteria of the VisiTag™ module were met. OPC should be that ablation with the setting resulting in the conduction gap (CG) as few as possible, while contiguous encircling ablation line (CEAL) without the tag gap (TG) on the 3D anatomic model as much as possible. RESULTS: When ablation with parameter setting is being catheter movement with a 3 mm distance limit for at least 20 s and force over time (FOT) being off, there were 60 CEAL without TG on the 3D anatomic model. However, 26 CGs were found. After changing FOT setting to be a minimal force of 5 g with 50% stability time, 22 TGs were displayed. Of them, 20 TGs were accompanied by CGs. On reablation at sites of TG with changed parameter setting, 18 CGs were eliminated when 20 TGs disappeared. When reablation with FOT is being a minimal force of 10 g with 50% stability time, 6 remaining CGs were eliminated. However, there was no CEAL. With a mean of follow-up 10.93 months, 2 patients with persistent AF suffered AF recurrence. CONCLUSION: A 3 mm distance limit for at least 20 s and FOT being a minimal force of 5 g with 50% stability time might be OPC for the VisiTag™ module.

Inhibition of late sodium current suppresses calcium-related ventricular arrhythmias by reducing the phosphorylation of CaMK-II and sodium channel expressions.

Cardiac arrhythmias associated with intracellular calcium inhomeostasis are refractory to antiarrhythmic therapy. We hypothesized that late sodium current (I Na) contributed to the calcium-related arrhythmias. Monophasic action potential duration at 90% completion of repolarization (MAPD90) was significantly increased and ventricular arrhythmias were observed in hearts with increased intracellular calcium concentration ([Ca2+]i) by using Bay K 8644, and the increase became greater in hearts treated with a combination of ATX-II and Bay K 8644 compared to Bay K 8644 alone. The prolongations caused by Bay K 8644 and frequent episodes of ventricular tachycardias, both in absence and presence of ATX-II, were significantly attenuated or abolished by late I Na inhibitors TTX and eleclazine. In rabbit ventricular myocytes, Bay K 8644 increased I CaL density, calcium transient and myocyte contraction. TTX and eleclazine decreased the amplitude of late I Na, the reverse use dependence of MAPD90 at slower heart rate, and attenuated the increase of intracellular calcium transient and myocyte contraction. TTX diminished the phosphorylation of CaMKII-δ and Nav 1.5 in hearts treated with Bay K 8644 and ATX-II. In conclusion, late I Na contributes to ventricular arrhythmias and its inhibition is plausible to treat arrhythmias in hearts with increased [Ca2+]i.

Reduction of atrial fibrillation in remotely monitored pacemaker patients: results from a Chinese multicentre registry.

BACKGROUND: Many recipients of implantable cardiac electronic devices have atrial fibrillation (AF) occurrences after device implantation, even if there is no previous history of AF, and some of the episodes are asymptomatic. The purpose of this study was to evaluate trends in AF burden following early AF detection in patients treated with pacemakers equipped with automatic, daily Home Monitoring function. METHODS: Between February 2009 and December 2010, the registry recruited 701 pacemaker patients (628 dual-chamber, 73 biventricular devices) at 97 clinical centers in China. Daily Home Monitoring data transmissions were analyzed to screen for the AF burden. In-office follow-ups were scheduled for 3 and 6 months after implantation. Upon first AF (i.e., mode-switch) detection in a patient, screening of AF burden by Home Monitoring was extended for the next 180 days. RESULTS: At least one episode of AF was observed in 22.9% of patients with dual-chamber pacemakers and in 28.8% of patients with biventricular pacemakers. The first AF detection in a patient occurred, on average, about 2 months before scheduled follow-up visits. In both pacemaker groups, mean AF burden decreased significantly (P < 0.05) over 180 days following first AF detection: from 12.0% to 2.5% in dual-chamber and from 12.2% to 0.5% in biventricular pacemaker recipients. The number of patients with an AF burden >10% per month was significantly reduced over 6 months of implantation in both dual chamber (38 patients in the first month vs. 21 patients in month 6, P < 0.05) and biventricular (7 patients in the first month vs. 0 patient in months 4-6, P < 0.05) pacemaker recipients. CONCLUSIONS: Automatic, daily Home Monitoring of patients treated with cardiac pacemakers allows early detection of AF, and there is a gradual and significant decrease in AF burden.

Clinical profile and outcomes of atrial fibrillation in elderly patients with acute myocardial infarction.

BACKGROUND: Atrial fibrillation (AF) occurs commonly in patients with acute myocardial infarction (MI) and is associated with an increased long-term mortality. This study aimed to investigate the clinical characteristics and outcomes of AF in in-hospital elderly Chinese patients with acute MI. METHODS: A total of 967 patients with acute MI, aged >/= 65 years, were categorized on the basis of the absence or presence of AF. Patients with documented AF were classified into two subgroups: the ongoing AF group and the new-onset AF group. We retrospectively evaluated the clinical profile, in-hospital outcomes, and effects of revascularization on the incidence of AF in elderly patients with acute MI. RESULTS: AF was documented in 100 (11.53%) patients and the incidence of new-onset AF was 6.51% during hospitalization. History of old MI and cerebrovascular events were more common in patients with AF than in those without AF (P < 0.001, P < 0.01, respectively). The incidence of AF was higher in patients with non-ST elevated MI (P = 0.014), inferior wall MI (P = 0.004) and cardiac function of Killip class III or IV (P = 0.008). Patients with AF had more complication of pneumonia (P = 0.003) and longer hospital stay. Left circumflex coronary artery involvement was more common in patients with AF (compared with patients without AF, P < 0.001). Percutaneous coronary intervention or coronary artery bypass grafting significantly decreased the incidence of new-onset AF from 7.97% to 3.82% (P = 0.017). AF depended to heart failure, increased the in-hospital mortality. CONCLUSIONS: AF is common in elderly patients with acute MI and is associated with poorer clinical outcomes. Revascularization reduces the incidence of AF and thus improves the clinical outcomes in these patients.