Predictive values of left ventricular mechanical dyssynchrony for CRT response in heart failure patients with different pathophysiology.

BACKGROUND: Cardiac resynchronization therapy (CRT) patients with different pathophysiology may influence mechanical dyssynchrony and get different ventricular resynchronization and clinical outcomes. METHODS: Ninety-two dilated cardiomyopathy (DCM) and fifty ischemic cardiomyopathy (ICM) patients with gated single-photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI) were included in this retrospective study. Patients were classified based on the concordance between the left ventricular (LV) lead and the latest contraction or relaxation position. If the LV lead was located on or adjacent to both the latest contraction and relaxation position, the patient was categorized into the both match group; if the LV lead was located on or adjacent to the latest contraction or relaxation position, the patient was classified into the one match group; if the LV lead was located on or adjacent to neither the latest contraction nor relaxation position, the patient was categorized to the neither group. CRT response was defined as [Formula: see text] improvement of LV ejection fraction at the 6-month follow-up. Variables with P < .05 in the univariate analysis were included in the stepwise multivariate model. RESULTS: During the follow-up period, 58.7% (54 of 92) for DCM patients and 54% (27 of 50) for ICM patients were CRT responders. The univariate analysis and stepwise multivariate analysis showed that QRS duration, systolic phase bandwidth (PBW), diastolic PBW, diastolic phase histogram standard deviation (PSD), and left ventricular mechanical dyssynchrony (LVMD) concordance were independent predictors of CRT response in DCM patients; diabetes mellitus and left ventricular end-systolic volume were significantly associated with CRT response in ICM patients. The intra-group comparison revealed that the CRT response rate was significantly different in the both match group of DCM (N = 18, 94%) and ICM (N = 24, 62%) patients (P = .016). However, there was no significant difference between DCM and ICM in the one match and neither group. For the inter-group comparison, Kruskal-Wallis H-test revealed that CRT response was significantly different in all the groups of DCM patients (P < .001), but not in ICM patients (P = .383). CONCLUSIONS: Compared with ICM patients, systolic PBW, diastolic PBW and PSD have better predictive and prognostic values for the CRT response in DCM patients. Placing the LV lead in or adjacent to the latest contraction and relaxation position can improve the clinical outcomes of DCM patients, but it does not apply to ICM patients.

Epicardial Adipose Tissue Measured From Computed Tomography Predicts Cardiac Resynchronization Therapy Response in Patients With Non-ischemic Systolic Heart Failure.

Background: Epicardial adipose tissue (EAT) has been linked with the pathogenesis of heart failure (HF). Limited data have been reported about the clinical value of EAT for cardiac resynchronization therapy (CRT) in non-ischemic systolic HF. We aimed to explore the values of EAT measured from CT to predict the response to CRT in patients with non-ischemic systolic HF. Methods: Forty-one patients with CRT were consecutively recruited for our study. All patients received both gated resting Single Photon Emission CT (SPECT) myocardial perfusion imaging (MPI) and dual-source multi-detector row CT scans. EAT thickness was assessed on both the parasternal short and horizontal long-axis views. The area of EAT was calculated at the left main coronary artery level. Left ventricular systolic mechanical dyssynchrony (LVMD) was measured by phase standard deviation (PSD) and phase histogram bandwidth (PBW). The definition of CRT response was an improvement of 5% in left ventricular ejection fraction (LVEF) at 6 months after CRT implantation. Results: After 6 months of follow-up, 58.5% (24 of 41) of patients responded to CRT. A greater total perfusion deficit (TPD) was observed in the left ventricle, and a narrower QRS complex was observed in the nonresponse group than in the response group (p < 0.05). Meanwhile, the systolic PSD and systolic PBW were statistically greater in the CRT group with no response than in the response group (p < 0.05). Meanwhile, the baseline QRS duration, TPD, systolic PSD, systolic PBW, EAT thicknesses of the left ventricular (LV) apex, right atrioventricular (AV) groove, and left AV groove were all significantly related to the CRT response in the univariate logistic regression analysis. Furthermore, the QRS duration and EAT thicknesses of the right AV groove and left AV groove were independent predictors of CRT response in the multivariate logistic regression analysis. Conclusions: The EAT thickness of the left AV groove in patients with non-ischemic systolic HF is associated with the TPD of LV and LV systolic dyssynchrony. The EAT thickness of the AV groove has a good predictive value for the CRT response in patients with non-ischemic systolic HF.

Design and fabrication of an integrated heart-on-a-chip platform for construction of cardiac tissue from human iPSC-derived cardiomyocytes and in situ evaluation of physiological function.

In vitro model of the human cardiac tissues generated from human induced pluripotent stem cells (hiPSCs) could facilitate drug discovery and patient-specific studies of physiology and disease. However, the immature state of hiPSC-derived cardiomyocytes (hiPSC-CMs) compared to adult myocardium is a key defect that must be overcome to enable the potential applications of hiPSC-CMs in drug testing. For this purpose, we developed a heart-on-a-chip device that contains microfluidic channels for long-term dynamic culture of cells, platinum wire electrodes for electrical stimulation of hiPSC-CMs, and gold electrode arrays as acquisition electrodes for real-time recording electrophysiological signals of cardiac tissues. Human iPSC-CMs cultured on biocompatible hydrogels in the chip chamber can be electrically stimulated to prompt the maturation of cardiomyocytes (CMs) and generate functional cardiac tissues. Drug tests were performed with calcium transient measurements to evaluate drug responsiveness of electrical stimulated and unstimulated cardiac tissues. The results show that only the electrical-stimulated cardiac tissues respond correctly to drug treatment of verapamil and isoprenaline, indicating the reliability of this engineered cardiac tissues for drug testing. The above integrated heart-on-a-chip device provides a promising platform for drug efficacy testing and cardiactoxicity.

Acupuncture for persistent atrial fibrillation after catheter ablation: study protocol for a pilot randomized controlled trial.

BACKGROUND: Atrial fibrillation (AF) is a common arrhythmia, which is closely related to cardiovascular morbidity and mortality. Although acupuncture is used in the treatment of AF, the evidence is insufficient. The objective of this pilot trial is to evaluate the feasibility, preliminary efficacy, and safety of acupuncture in reducing AF burden for persistent AF after catheter ablation (CA). METHODS AND DESIGN: This will be a multi-center, 3-arm, pilot randomized controlled trial in China. Sixty patients in total will be randomly assigned to the specific acupoints group, the non-specific acupoints group, or the non-acupoints group in a 1:1:1 ratio. The whole study period is 6 months, including a 3-month treatment period and a 3-month follow-up period. All patients will receive 18 sessions of acupuncture over 12 weeks after CA and appropriate post-ablation routine treatment. The primary outcome is AF burden at 6 months after CA measured by electrocardiography patch that can carry out a 7-day continuous ambulatory electrocardiographic monitoring. The secondary outcomes include AF burden at 3 months after CA, recurrence of AF, quality of life, etc. The adverse events will also be recorded. DISCUSSION: This pilot study will contribute to evaluating the feasibility, preliminary efficacy, and safety of acupuncture in reducing AF burden for persistent AF after CA. The results will be used for the sample size calculation of a subsequent large-scale trial. TRIAL REGISTRATION: Chinese Clinical Trial Registry ChiCTR2000030576 . Registered on 7 March 2020.

Electrophysiologic effects and outcomes of sympatholysis in patients with recurrent ventricular arrhythmia and structural heart disease.

INTRODUCTION: Autonomic modulation has been used as a therapy to control recurrent ventricular arrhythmia (VA). This study was to explore stellate ganglion block (SGB) effect on cardiac electrophysiologic properties and evaluate the long-term outcome of cardiac sympathetic denervation (CSD) for patients with recurrent VA and structural heart disease (SHD). MATERIALS AND METHODS: Patients who had recurrent VA due to SHD were enrolled prospectively. Electrophysiologic study and ventricular tachycardia (VT) induction were performed before and after left and right SGB. VA burden and long-term outcomes were assessed for a separate patient group who underwent left or bilateral CSD for drug-refractory VA due to SHD. RESULTS: Electrophysiologic study of nine patients showed that baseline mean (SD) corrected sinus node recovery time (cSNRT) increased from 320.4 (73.3) ms to 402.9 (114.2) ms after left and 482.4 (95.7) ms after bilateral SGB (P = .03). SGB did not significantly change P-R, QRS, and Q-T intervals and ventricular effective refractory period, nor did the inducibility of VA. Nineteen patients underwent left (n = 14) or bilateral (n = 5) CSD. CSD reduced VA burden and appropriate ICD therapies from a median (interquartile range) of 2.5 (0.4-11.6) episodes weekly to 0.1 (0.0-2.4) episodes weekly at 6-month follow-up (P = .002). Three-year freedom from orthotopic heart transplant (OHT) and death was 52.6%. New York Heart Association functional class III/IV and VT rate less than 160 beats per minute were predictors of recurrent VA, OHT, and death. CONCLUSION: SGB increased cSNRT without changing heart rate. CSD was more beneficial for patients with mild-to-moderate heart failure and faster VA.

Electrical and histological remodeling of the pulmonary vein in 2K1C hypertensive rats: Indication of initiation and maintenance of atrial fibrillation.

OBJECTIVE: Hypertension is a significant risk factor for atrial fibrillation (AF). The role of pulmonary vein (PV) remodeling in the mechanistic association between hypertension and AF is not definitive. In this study, we aimed to identify changes in the electrophysiology and histology in PVs in two-kidney, one-clip (2K1C) hypertensive rats. METHODS: Fifty male Sprague-Dawley rats were classified into the 2K1C and sham-operated groups. The systolic blood pressure was measured every 2 weeks. The left atrial diameter was measured by transthoracic echocardiography. Left superior PV (LSPV) and left atrial (LA) fibrosis was evaluated by Masson's trichrome staining. The expression of fibrosis markers [angiotensin II (Ang II), transforming growth factor-ß1 (TGF-ß1), matrix metalloproteinase-2 (MMP-2), and collagen I (Col I)] and ion channels [Kir2.1, Kir2.3, Cav1.2, and Nav1.5] in LSVP was quantified by western blot. Conventional microelectrodes were used to record the action potential duration at 90% repolarization (APD90) and effective refractory period (ERP) in isolated LA. RESULTS: At 4 months, the 2K1C hypertensive rats developed LA dilation. Col deposition in LSPV and left atrium and expression of TGF-ß1, MMP-2, and Col I in LSPV were significantly increased in 2K1C hypertensive rats. In addition, hypertension reduced the expression of Nav1.5 and Kir2.1, although there were no significant differences in APD90; ERP; and expression of Ang II, Kir2.3, and Cav1.2 between the two groups. CONCLUSION: Hypertension may lead to changes in the electrophysiology and histology of rats PVs, which is characterized by significant reduction in the expression of Nav1.5 and Kir2.1 and increase in interstitial fibrosis. These observations may clarify the role of PVs in the mechanistic association between hypertension and AF.

Updating the evidence for the effect of radiofrequency catheter ablation on left atrial volume and function in patients with atrial fibrillation: a meta-analysis.

OBJECTIVES: To systematically review the effects of radiofrequency catheter ablation (RFCA) on left atrial (LA) size, volumes and function in patients with atrial fibrillation (AF). METHODS: We searched MEDLINE, EMBASE, ScienceDirect, Highwire, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews and the reference lists of retrieved reports in July 2012. SETTING: China. PARTICIPANTS: Twenty-six studies (enrolling 1821 patients) were included in the final analysis. MAIN OUTCOME MEASURES: Changes of LA size or volumes and/or function in patients with AF after RFCA. RESULTS: Compared to pre-ablation values, there were significant decreases in LA diameter and LA volumes at post-ablation follow-up. However, compared to pre-ablation values, there were no significant differences in LA ejection fraction/LA active emptying fraction and LA strain at post-ablation follow-up. Decreases in LA diameter and LA volumes remained significant in those without AF recurrence but not in those with AF recurrence. LA ejection fraction/LA active emptying fraction did not decrease in patients without AF recurrence, whereas they decreased in patients with AF recurrence. As for LA strain, it seems that LA strain increases in patients without AF recurrence, with less fibrosis and with more LA volumes decrease, but the differences were not significant. CONCLUSIONS: Successful RFCA in patients with AF significantly decreases LA size and volumes and does not seem to adversely affect LA function.

Cx43 in mesenchymal stem cells promotes angiogenesis of the infarcted heart independent of gap junctions.

Mesenchymal stem cells (MSCs) with elevated levels of connexin 43 (Cx43) have been shown to exhibit improved protection for ischemic hearts. However, it remains unclear whether Cx43 is involved in the paracrine actions of angiogenesis, the major mechanism of cell therapy. In the present study, an in vitro model with deprivation of oxygen and a murine myocardial infarction model with permanent ligation of the left anterior­descending (LAD) coronary artery were used to determine whether gap junctions in MSCs promote angiogenesis. It was observed that MSCs that overexpressed Cx43 (MSCs­Cx43), improve the cardiac function of infarcted myocardium as compared with control MSCs (MSCs­vector) and MSCs with Cx43 knocked down by small interfering RNA (MSCs­siCx43), accompanied with a reduction of infarct size and an increase in the vascular density and maturity. Increased levels of representative angiogenic factors [vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF)] were produced by MSCs­Cx43 compared with MSCs­siCx43 in vivo and in vitro. However, neither Cx43 formed gap junction specific inhibitor (Cx43 mimetic peptide) or gap junction opener (antiarrhythmic peptide) affected the production of VEGF and bFGF in MSCs under hypoxic stress. These data support the hypothesis that Cx43 in MSCs promotes angiogenesis in the infarcted heart, independent of gap junction formation.

[Clinical characteristics and long-term outcome of non-pulmonary vein foci ablation in patients with paroxysmal atrial fibrillation].

OBJECTIVE: To evaluate the clinical characteristics and long-term results of non-pulmonary veins (PV) trigger ablation in patients with paroxysmal atrial fibrillation (AF). METHODS: Eighty-six patients [48 men, mean age (52.3 ± 10.2) years] were included in the study. Circumferential pulmonary vein antrum isolation guided by a 3-D mapping system was performed. Aggressive high right atrium programmed stimulation and burst pacing were made before and after isoproterenol infusion. Additional ablation was performed if other trigger foci were found or other sustained tachycardias could be induced. RESULTS: PV triggers were observed in 59 patients (group I), and non-PV triggers were observed in 27 patients (group II), 12 non-PV triggers were identified during the first procedure. Among them, one was located in the roof of left atrium, 11 were originated from superior vena cava. After a mean follow-up of [37.1 ± 10.4 (range 15-60)] months, the AF recurrence rate was significantly higher in the Group II than in the Group I (55.5% vs. 20.3%, P = 0.001). The number of performed ablation was also significantly in group II than in group I higher difference (1.7 ± 0.8 vs. 1.1 ± 0.4, P < 0.001). In the group II, 15/15 (100%) patients had a repeated ablation procedure for AF recurrence, and 15 patients had new non-PV foci after isoproterenol infusion which were originated from the superior vena cava (n = 11) and coronary sinus (n = 2), respectively. After the second ablation procedure, AF recurrence was observed in three patients, two patients accepted third procedure, the non-PV triggers were located in left atrial septum and coronary sinus, and one patient accepted fourth procedure, the non-PV foci was located in left posterior wall. CONCLUSIONS: Non-PV foci may occur at any age and the main area is located in the super vena cava, Non-PV serves as a major cause of AF recurrence after successful PVAI.

[Catheter ablation of epicardial accessory pathway associated with coronary sinus musculature].

OBJECTIVE: To report the single-center clinical experience of catheter ablation of epicardial accessory pathway associated with coronary sinus musculature. METHODS: The data of 721 cases of left sided accessory pathway ablation were retrospectively analyzed. Ablation in the coronary sinus was performed in 17 (2.4 %) cases [11 males, mean age (37 ± 11) years]. RESULTS: Among the 17 cases, the accessory pathway was successfully ablated in middle cardiac vein and posterior lateral coronary sinus in 11 and 6 cases, respectively. Deverticulum of middle cardiac vein was seen in 2 cases. Mean time required to block the accessory pathway was (4.7 ± 2.7) s. An accessory pathway potential could be recorded at the target site in 10 out of 17 patients (59%). During a mean (21 ± 16) months follow up, only one patient experienced recurrence who was successfully cured by a second ablation session. No procedure related complication was reported. CONCLUSION: About 2.4% of left accessory pathway may have epicardial connection locating at middle cardiac vein or lateral part of the coronary sinus and require epicardial ablation. The epicardial ablation is safe and effective, warrants an excellent long-term results.

[Efficacy of catheter radiofrequency ablation for the treatment of ventricular arrhythmia storm post cardioverter-defibrillators implantation].

OBJECTIVE: To evaluate the acute and long-term effects of catheter radiofrequency ablation for the treatment of ventricular arrhythmia storm (VAS) post implantable cardioverter-defibrillators (ICD) implantation. METHODS: Acute and long-term effects of catheter radiofrequency ablation for the treatment of VAS post ICD implantation were retrospectively assessed in 11 patients from September 2008 to August 2011. RESULTS: A total of 15 ablation procedures were performed in 11 patients. Six ablation procedures were performed through epicardial approach. In 9 patients, 20 types of ventricular tachycardia (VT) (including 20% hemodynamically unstable VT) were induced during the procedures [mean cycle length (384 ± 141) ms] and polymorphic ventricular tachycardia were induced in 7 patients. The average X-ray fluoroscopy time and procedural time were (26 ± 17) min and (189 ± 60) min, respectively. Complete success, partial success, and failure rates immediately post catheter radiofrequency ablation were 46.7% (7/15), 26.7% (4/15) and 26.7% (4/15), respectively. All patients are alive at follow-up[(2.45 ± 9.6) months after the last catheter ablation] and the complete success, partial success, and failure rates during follow-up were 72.7% (8/11), 9.1% (1/11) and 18.2% (2/11), respectively. CONCLUSION: VAS can be effectively treated by catheter radiofrequency ablation in patients post ICD implantation.

ATP-binding cassette transporter A1 R219K polymorphism and coronary artery disease in Chinese population: a meta-analysis of 5,388 participants.

The ATP-binding cassette transporter A1 (ABCA1) R219K gene polymorphism has been suggested to lower the risk of coronary artery disease (CAD). However, research results remain debatable. Meta-analysis involving 2,730 CAD patients and 2,658 controls was performed to investigate the relationship between ABCA1 R219K gene polymorphism and CAD in Chinese population. A total of 14 studies which were obtained from electronic databases were analyzed. The pooled odds ratios (ORs) and their corresponding 95 % confidence intervals (95 % CIs) were estimated by a random effect model. A significant association between ABCA1 R219K gene polymorphism and CAD was found in the Chinese population under the following genetic models: an allelic genetic model (OR 0.70, 95 % CI 0.62-0.78, P < 0.00001), a recessive genetic model (OR 0.51, 95 % CI 0.41-0.64, P < 0.00001), an additive genetic model (OR 0.816, 95 % CI 0780-0.855, P = 0), a dominant genetic model (OR 1.326, 95 % CI 1.232-1.427, P = 0), a homozygote genetic model (OR 0.640, 95 % CI 0.575-0.712, P = 0), and a heterozygote genetic model (OR 0.640, 95 % CI 0.575-0.712, P = 0). The K allele of the ABCA1 R219K gene has a protective role for CAD risk in Chinese population and is possibly associated with decreased CAD susceptibility.

Endoplasmic reticulum (ER) stress inhibitor salubrinal protects against ceramide-induced SH-SY5Y cell death.

In the present study, we examined the mechanisms of ceramide-induced cell death in SH-SY5Y human neuroblastoma cells. Our results demonstrate a significant endoplasmic reticulum (ER) stress response in SH-SY5Y cells after short-chain ceramide (C6) treatment. Administration of ceramide (C6) to SH-SY5Y human neuroblastoma cells caused apoptotic cell death, which was inhibited by ER stress inhibitor salubrinal. Further, ceramide-induced cell death reduced significantly in stable SH-SY5Y cells expressing C/EBP homologous protein (CHOP) shRNA. Salubrinal inhibited ceramide-induced inositol-requiring enzyme 1α (IRE1α)/apoptosis signal regulating kinase 1 (ASK1)/c-Jun N-terminal kinase (JNK) phosphorylation. Taken together, these data suggest that ceramide-induced SH-SY5Y cell death may be linked to the ER stress-regulated intrinsic pathway, and proposed the potential protective effects of salubrinal.

[Catheter ablation of focal atrial tachycardia:the topographic distribution and long-term outcome].

OBJECTIVE: To explore the topographic distribution and long-term outcome of catheter ablation for focal atrial tachycardia (AT). METHOD: The data of 207 patients who underwent electrophysiologic study for AT were retrospectively analyzed. RESULTS: A total of 200 AT were identified in 185 patients. The most common site for AT was ostium of the coronary sinus (23.8%), followed by crista terminalis (20.5%), perinodal area (20.0%), cava vena (17.8%), annulus (13.0%), and appendage (10.3%). Eighty percent AT originated from the right atrium, 17.8% originated from the left atrium. AT originated from the left atrium was more common in male than in female (25.0% vs. 13.3%, P = 0.042), while AT originated from the right atrium was more common in female than in male (69.4% vs. 86.7%, P = 0.004). Among the 185 patients, acute success ablation rate was 93.5% (n = 173). The acute success rate in the conventional mapping group was lower than that in the three-dimensional mapping group (79.3% vs. 96.5%, P < 0.01). During a median of 36 months follow up, the AT recurred in 20 patients (success ablation rate 88.4%). Success ablation rate was similar between the conventional mapping group and the three-dimensional mapping group (P > 0.05). CONCLUSIONS: Focal AT commonly originates from ostium of coronary sinus, crystal terminalis, perinodal area, and cava veins. There is a gender related difference in the distribution of focal AT. The radiofrequency catheter ablation yields a satisfying success rate and very low complication rate and could be the first line choice for treating ATs in experienced electrophysiological center.

[Impact of metoprolol use in the treatment of patients with electrical-storm after cardioverter defibrillators implantation].

OBJECTIVE: To explore the effectiveness of the metoprolol dosage adjustment on reducing the incidence of electrical-storm (ES) in patients with Implantable Cardioverter Defibrillators (ICDs). METHODS: Data from patients with ICD implantation between Jan, 2003 and Jun, 2006 in our hospital were retrospectively analyzed. ES was defined as either ≥ 3 times of ventricular tachyarrhythmias (VTAs) resulting in ICD therapy or VTAs lasting more than 30 s detected by ICD without any therapy within 24 hours. RESULTS: During a follow-up period of (27.5 ± 21.2) months, ES was recorded in 39 cases [34 males, average age (52.0 ± 13.1) years] out of 119 patients (32.8%) and 9 patients died after ES. During the period of storm attack, ES was successfully controlled in 25/30 patients by various interventions, including predisposing factors corrected in 5 cases, ICD reprogramming and antiarrhythmic drugs therapy optimized in 16 cases (one received intravenous injection of metoprolol), and VTAs eliminated by catheter ablation in 4 cases. ES was spontaneously resolved in the remaining 5 cases. In the chronic phase, 2 patients with Brugada syndrome were treated with Quinidine mono-therapy while the dosage of metoprolol was adjusted in the remaining 23 patients and the dosage of metoprolol was increased gradually from (26.8 ± 13.9) mg/d to (88.9 ± 53.5) mg/d without any adverse effects (9 patients received also oral amiodarone 200 mg/d). Post dosage adjustment, the total VTA episodes [(1.9 ± 1.7) times/month vs. (0.8 ± 0.6) times/month, P = 0.004], incidence of antitachycardia pacing therapies [(4.2 ± 3.8) runs/month vs. (2.3 ± 2.0) runs/month, P = 0.003], as well as electrical cardioversion or defibrillation [(1.1 ± 0.9) times/month vs. (0.4 ± 0.2) times/month, P = 0.001] were significantly decreased. ES was not controlled until a extremely high dosage [225 - 300 (255.3 ± 41.7) mg/d] of metoprolol was reached in the remaining 5 patients. CONCLUSIONS: Metoprolol use is essential and its dosage should be individualized in the majority of ICD recipients with ES. In approximately 1/6 patients, the dosage of metoprolol should be higher than 200 mg/d.

Myocardial injury resulting from radiofrequency catheter ablation: comparison of circumferential pulmonary vein isolation and complex fractionated atrial electrograms ablation.

BACKGROUND: Radiofrequency catheter ablation (RFCA) necessarily produces an area of myocardial necrosis. However, the difference of the extent of myocardial injury between circumferential pulmonary vein isolation (CPVI) and complex fractionated atrial electrograms (CFAE) ablation in patients with atrial fibrillation (AF) has not been investigated before. METHODS: Twenty-nine consecutive male patients (n = 29) with either paroxysmal or persistent AF were selected for CPVI or CFAE ablation. The CPVI or CFAE ablation was performed with a three-dimensional electroanatomical mapping system (CARTO). Serum cardiac biomarkers, for example, cardiac troponin T (cTnT), aspartate transaminase (AST), lactate dehydrogenase (LDH), creatine kinase (CK), and creatine kinase myocardial bound (CKMB) were determined by the Elecsys STATE immunoassay. Cardiac structure and function were measured with echocardiography. RESULTS: Echocardiography showed that there was no significant difference of atrioventricular structure or function parameters between the CPVI group and the CFAE ablation group. Serum cTnT showed a significant increase in the CFAE ablation group over the CPVI group at 12 and 24 hours after the procedure (P < 0.05, respectively), and then it was reduced to a normal level after 48 hours. Serum AST showed a significant increase in the CFAE ablation group over the CPVI group at post-procedure, 4 and 12 hours after the procedure (P < 0.05, respectively), and then it reached to a normal level after 24 hours. There was no significant difference in LDH, CK, or CKMB levels between the CFAE ablation group and the CPVI group at any time point (P > 0.05). CONCLUSIONS: cTnT and AST other than LDH, total CK or CKMB activity significantly increased more in the CFAE ablation group than the CPVI group. However, the difference of the serum levels of cTnT, AST between two groups was temporary.

p21 WAF1 and hypoxia/reoxygenation-induced premature senescence of H9c2 cardiomyocytes.

We have previously reported on hypoxia/reoxygenation-induced premature senescence in neonatal rat cardiomyocytes. In this research, we investigated the effects of p21(WAF1) (p21) in hypoxia/reoxygenation-induced senescence, using H9c2 cells. A plasmid overexpressing wild type p21(WAF1) and a plasmid expressing small hairpin RNA (shRNA) targeting p21(WAF1) were constructed, and transfected into H9c2 cells to control the p21 expression. Hypoxia/reoxygenation conditions were 1% O2 and 5% CO(2), balancing the incubator chamber with N(2) for 6 h (hypoxia 6 h), then 21% oxygen for 8 h (reoxygenation 8 h). Cell cycle was examined using flow cytometry. Senescence was assessed using ß-galactosidase staining. The expression of p53, p21, p16(INK4a), and cyclin D1 was assayed using Western blotting. At hypoxia 6 h, cells overexpressing p21 had a larger G1 distribution, stronger ß-galactosidase activity, and lower cyclin D1 expression compared to control cells, while the opposite results and higher p53 expression were obtained in p21-knockdown cells. At reoxygenation 8 h, p21-silenced cells had a smaller percentage of G1 cells, weaker ß-galactosidase activity and lower 16(INK4a) expression, and higher cyclin D1 expression, but the overexpression group showed no difference. Taken together, this data implies that p21(WAF1) is important for the hypoxia phase, but not the reoxygenation phase, in the H9c2 senescence process.