Diabetic cardiomyopathy (DCM), a common consequence of longstanding diabetes mellitus, is initiated by death of cardiomyocyte. Hyperglycemia-induced reactive oxygen species (ROS) overproduction is a major contributor of the chronic low-grade inflammation that characterizes as the DCM. ROS may promote the activation of nucleotide-binding oligomerization domain like receptor (NLR) pyrin domain containing 3 (NLRP3) inflammasome, a novel regulator of inflammation and cell death, by nuclear factor-kB (NF-κB) and thioredoxin interacting/inhibiting protein (TXNIP). NLRP3 inflammasome regulates the death of cardiomyocyte and activation of fibroblast in DCM, which is involved in the structural and functional disorder of DCM. However, comprehensive understanding of molecular mechanisms linking NLRP3 inflammasome and disorder of cardiomyocyte and fibroblast in DCM is lacking. Here, we review the molecular mechanism(s) of NLRP3 inflammasome activation in response to hyperglycemia in DCM.

No abstract

Background Oxidative stress and inflammatory processes are responsible for the pathogenesis of AF, but their relationship with the sizes of the LA and PVs in AF patients remains unclear. Hypothesis Oxidative stress and inflammatory processes are associated with the sizes of the LA and PVs in AF patients. Methods 82 AF patients were compared to 30 control patients by using a case‐control study design. Oxidative stress, inflammatory biomarkers and the sizes of the LA and PVs were detected. Results (1) Hs‐CRP, IL‐6, IL‐8, TNF‐α, MDA and ox‐LDL were higher, and SOD was lower in AF patients than in control patients. Hs‐CRP, MDA and ox‐LDL were higher in permanent AF patients than in paroxysmal and persistent AF patients. (2) CsA of LSPV, RSPV, RIPV, LAA and LAV were statistically higher in AF patients than in control patients. CsA of RSPV, LSPV, LIPV and LAV were higher in permanent AF patients than in paroxysmal and persistent AF patients. (3) In the AF group, hs‐CRP and TNF‐α were positively correlated with LAV; MDA was positively correlated with CsA of LAA, LSPV and LAV; SOD was passively correlated with CsA of LAA and LAV; ox‐LDL was positively correlated with CsA of LAA and LAV. Multivariate logistic regression analysis showed hs‐CRP, ox‐LDL, RSPV CsA, LIPV CsA and LAV were associated with AF. Conclusions Oxidative stress, inflammatory biomarkers and the sizes of the LA and PVs were significantly increased in AF patients. Hs‐CRP, ox‐LDL, RSPV CsA, LIPV CsA and LAV were associated with AF persistence.

BackgroundProlonged electrocardiogram QRS durations are often present in hypertensive patients. Small increases in QRS duration serve as independent risk factors for both increased cardiovascular and all-cause mortality. Aortic stiffness is associated with increases in central aortic systolic blood pressure (CASP). However CASP and ECG QRS duration interactions have not been established in rural community populations. Our aims are to determine if QRS duration > 100 msec is associated with an elevated CASP measure in an Australian rural population.MethodsA retrospective cross sectional population was obtained from the CSU Diabetes Screening Research Initiative data base where 68 participants had both central aortic pressure recorded and ECG derived QRS duration. Central aortic pressure was determined by directly recording radial arterial tonometry and brachial cuff pressure (HealthStats, Singapore). Resting 12-lead electrocardiograms were obtained from each subject using a Welch Allyn PC-Based ECG system.ResultsThe population had a mean CASP of 137.8 mmHg, higher than previously reported in other population studies. In 8/68 subjects with a prolonged cardiac QRS duration >120 msec, CASP ranged from 129 mmHg – 182 mmHg. When subgroup analysis was stratified on the basis QRS duration <100 msec and ≥100 msec significant differences (p = 0.036) were observed for mean CASP, 130.6 mmHg ± 15.6 (SD) versus 140.6 mmHg ± 16.8 (SD), respectively.ConclusionsOur results suggest that an arbitrary CASP reading greater than a value 140 mmHg raises suspicion of a prolonged QRS duration. QRS durations ≥100 msec in an aging rural population are associated with higher CASP measures. Our results also suggest in aging Australian rural populations CASP is likely to be elevated, possibly due to age related aortic stiffening.

SummaryRadiofrequency catheter ablation (RFCA) in the treatment of AF is currently based on pulmonary vein isolation (PVI). Some studies have investigated the efficacy of empiric SVC isolation (SVCI) in addition to conventional PVI in order to improve success rates and reduce recurrence rates. However, the results of the studies have given conflicting data.We performed a meta-analysis to evaluate the efficacy and safety of the empiric SVCI compared with conventional SVCI for paroxysmal atrial fibrillation (PAF) ablation.We searched MEDLINE, EMBASE, the Web of Science, and the Cochrane Database from the period January 1986 to August 2016 and identified qualified studies. The primary clinical outcome was the recurrence rate of atrial tachyarrhythmias, and the secondary clinical outcomes were procedure time, fluoroscopy time, and complications.We identified 3 randomized controlled trials (RCTs) and one nonrandomized, observational study (nROS) involving 245 patients with empiric SVCI and 269 patients with conventional SVCI. The empiric SVCI group had a lower recurrence rate of atrial tachyarrhythmia after a single procedure compared with the conventional SVCI group (16.7% versus 29.4%, OR: 0.48, 95%CI: 0.31 to 0.74, P = 0.0009). There was no significant difference in fluoroscopic time (P = 0.22), procedure time (P = 0.32), or clinical complications (P = 0.33) between the two groups.Empiric SVCI is more effective than conventional SVCI in terms of the long-term outcomes of PAF patients after a single PVI procedure, with the same fluoroscopic time, procedure time, and clinical complications. (Int Heart J 2017; 58: 500-505) Key words: Arrhythmia, Pulmonary vein, Atrial fibrillation, Meta R adiofrequency catheter ablation (RFCA) is an effective treatment option for patients with atrial fibrillation (AF). At present, RFCA in the treatment of AF is based on pulmonary vein isolation (PVI), whether it is segmental PVI or circumferential PVI.1,2) AF can be also initiated by nonpulmonary vein ectopic beats such as in the superior vena cava (SVC), coronary sinus ostium, left atrial posterior wall, crista terminalis, and ligament of Marshall.3) Despite initial positive results of the PVI strategy, RFCA that targeted the pulmonary vein alone showed a significant recurrence rate after the first procedure with the reconnection of the pulmonary vein or with the emergence of non-PV ectopic foci including the SVC.3-5) Some researchers have investigated the efficacy of empiric SVC isolation (SVCI) in addition to conventional SVCI (performing SVCI only for patients who have triggers in the SVC) 6) in order to improve success rates and reduce recurrence rates in patients with AF. 7-9) However, some studies also have provided conflicting data indicating that there was no statistical significance for these two strategies after the initial AF ablation.10,11) Therefore, we believed a meta-analysis of published data was needed to assess the efficacy of empiric isolation and conventional isolation of SVC in patients with paroxysmal AF (PAF).

Homocysteine levels in the low to moderate range for cardiovascular risk have been previously associated with left ventricular cardiac hypertrophy (LVH). Electrocardiogram (ECG) derived QRS duration has also been used as an epidemiological screening marker for cardiac hypertrophy risk. QRS duration cut offs have not been previously modeled to assess homocysteine levels in community populations. Our aims are to determine if QRS duration is associated with an elevated homocysteine level in a cross-sectional Australian aging rural population.A retrospective study design utilizing a rural health diabetic screening clinic database containing observational data from the period January 9, 2002 till September 25, 2012. One hundred seventy-eight individuals (>21 years of age) from the database were included in the study. Inclusion criteria included being nondiabetic and having both a QRS duration measure and a matching homocysteine level within the same subject. All participants were from the Albury-Wodonga area, with a mean age of >64 years for both sexes.Mean population homocysteine plasma levels were 10.4 μmol/L (SD = 3.6). The mean QRS duration was 101.8 ms (SD = 17.4). Groups were stratified on the basis of QRS duration (≤120 ms [n = 157] and >120 ms [n = 21]). QRS duration subgroup (≤120 ms vs >120 ms) mean differences across homocysteine levels were 10.1 μmol/L (SD = 3.3) and 12.2 μmol/L (SD = 4.7), respectively (P = 0.016). Other ECG parameters (PQ interval, QTc interval, and QT dispersion) measurements were not significantly associated with differences in plasma homocysteine (P = not significant).We conclude that in community populations homocysteine may be moderately elevated when QRS durations are >120 ms. Small additional increases in homocysteine levels may suggest a risk factor for ECG diagnosis of LVH.

At present, little is known about the influence of mesenchymal stem cell (MSC) transplantation on connexin43 (Cx43) and connexin45 (Cx45) remodeling in the ischemic heart. In this study, we investigated the effect of MSC transplantation on Cx43 and Cx45 remodeling in the ischemic heart. Wistar rats were subjected to left anterior descending artery ligation to induce myocardial infarction (MI) and then randomly allocated to receive an intramyocardial injection of PBS (MI group) or 5-azacytidine-induced MSCs (MSCs group). Histological examination and western blotting were performed 4 weeks after cell transplantation. We found that the MSCs exhibited plasticity by differentiating into cardiomyocyte-like cells. Gap junction remodeling after MI was characterized by a decrease in Cx43 expression and an increase in Cx45 expression. MSC transplantation modulated the MI-induced abnormalities by up-regulating Cx43 and down-regulating Cx45 expression. MSCs exhibited plasticity by differentiating into cardiomyocyte-like cells and modulated abnormal Cx43 and Cx45 remodeling following MI.

Background Micro-reentry tachycardia usually emerges in scar tissues related to post-atrial fibrillation ablation and cardiomyopathy. It is difficult to identify the micro-reentry circuit accurately by conventional mapping method. Case summary A 74-year-old man presented with paroxysmal atrial tachycardia (AT) presenting as palpitations. He was evaluated by an electrophysiological examination using a high-density CARTO mapping system. The mapping results showed the AT with a cycle length of 184 ms was focused on his right atrial fossa ovalis (FO). In this small area, the high-density mapping demonstrated a significant micro-reentrant tachycardia. Radiofrequency ablation at the centre of the micro-reentrant circuit successfully terminated the AT. No recurrences were observed during a 12-month follow-up. Discussion This case demonstrated a micro-reentrant AT originates from the FO without cardiomyopathy or previous ablation with specific loops. This is an unusual location for AT though and can cause difficulty for operators if it terminates or is non-sustained. High-density mapping using a PentaRay catheter can effectively characterize micro-reentrant circuits and determine the real target for ablation therapy.