[Show abstract][Hide abstract] ABSTRACT: Background:
Guinea pig ventricular cardiomyocytes display the rapid component of the delayed rectifier potassium current (Ikr) that contributes to ventricular repolarization and promotes stress-induced arrhythmias. Adrenergic stimulation favors ventricular arrhythmogenesis but its effects on Ikr are poorly understood.
Adrenergic modulation of Ikr was studied in isolated guinea pig ventricular cardiomyocytes using whole-cell patch clamping.
We found that the Ikr amplitude was reduced to 0.66±0.02 and 0.62±0.03 in response to 0.1 µM phenylephrine (PE), an α1AR agonist, and 10 µM isoproterenol (ISO), a βAR agonist, respectively. The effect of PE can be blocked by the selective α1A-adrenoceptor antagonist 5-methylurapidil, but not by the α1B-adrenoceptor antagonist chloroethylclonidine or α1D-adrenoceptor antagonist BMY7378. Additionally, the effect of ISO can be blocked by the β1-selective AR antagonist CGP-20712A, but not by the β2-selective AR antagonist ICI-118551. Although PE and ISO was continuously added to cells, ISO did not decrease the current to a greater extent when cells were first given PE. In addition, PE's effect on Ikr was suppressed by β1AR stimulation.
Ikr can by regulated by both the α1 and β ARs system, and that in addition to direct regulation by each receptor system, crosstalk may exist between the two systems.
Preview · Article · Mar 2014 · Molecular Medicine Reports
[Show abstract][Hide abstract] ABSTRACT: To report the single-center clinical experience of catheter ablation of epicardial accessory pathway associated with coronary sinus musculature.
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].
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.
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.
No preview · Article · May 2013 · Zhonghua xin xue guan bing za zhi [Chinese journal of cardiovascular diseases]
[Show abstract][Hide abstract] ABSTRACT: Quinone reductase 2 (NQO2) is a flavoprotein that catalyzes the metabolic reduction of quinines, but its biological mechanism in vascular smooth muscle cells (VSMCs) is unclear. The aim of this study was to evaluate the role of NQO2 on VSMCs proliferation and the neointimal formation in balloon injured rat carotid artery.
Left common carotid arteries from Sprague-Dawley rats were injured by a balloon catheter, and the injured arteries were incubated with 50 μL solution of NQO2-siRNA-GFP lentiviral vectors, NC-siRNA-GFP lentiviral vectors or PBS for 1 h. The rats were euthanized for morphometric and immunohistochemical analysis, real-time PCR and western blot analysis at 2 weeks after balloon injury and gene transfer. The cultured rat VSMCs transduced with NQO2-siRNA-GFP or NC-siRNA-GFP lentiviral vectors were used for cell proliferation assay, real-time PCR and western blot analysis. In order to detect the vascular or intracellular ROS level, the lentiviral vectors without GFP were used to transfect the injured common carotid arteries and the cultured rat VSMCs.
Lentiviral vectors bearing NQO2 siRNA could reduce NQO2 protein level and suppress NQO2 mRNA expression in balloon injured artery walls and cultured rat VSMCs. Downregulation of NQO2 significantly suppressed VSMCs proliferation and intimal formation. NQO2 siRNA treatment could reduce vascular or intracellular ROS level and decrease the phosphorylation of the ERK1/2 in balloon injured artery walls and cultured rat VSMCs.
Our study suggests that downregulation of NQO2 significantly suppresses VSMCs proliferation and progression of neointimal formation after vascular injury.
No preview · Article · Apr 2012 · Cellular Physiology and Biochemistry
[Show abstract][Hide abstract] ABSTRACT: To explore the topographic distribution and long-term outcome of catheter ablation for focal atrial tachycardia (AT).
The data of 207 patients who underwent electrophysiologic study for AT were retrospectively analyzed.
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).
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.
No preview · Article · Mar 2012 · Zhonghua xin xue guan bing za zhi [Chinese journal of cardiovascular diseases]
[Show abstract][Hide abstract] ABSTRACT: To summarize the clinical characteristics of congenital ventricular aneurysm and diverticula in inland China.
To identify the literature of congenital aneurysm and diverticula from Wanfang, China National Knowledge Infrastructure (CNKI) and PubMed databases, and to analyze the clinical characteristics of congenital aneurysm and diverticula from January of 2001 to December of 2009.
A total of 116 patients [78 men, 1 - 80 (33.5 ± 21.3) years old] with congenital aneurysm or diverticula were included in 109 articles. Twenty-five patients (13 men) were congenital ventricular aneurysm, including a family of 4 patients. Ninety-one patients (65 men) were congenital ventricular diverticula. One hundred patients were detected by echocardiography during medical examination, 34 patients combined with other cardiac anomalies, 4 of which with extracardiac structures. There were 8 patients with ventricular arrhythmia, 8 patients with thrombosis, 2 patients died of cardiac rupture, 4 patients died of sudden death, surgical operation was performed in 46 patients and 3 patients received ablation procedure. All patient did not receive implantable cardioverter defibrillator (ICD) implantation.
Congenital ventricular aneurysm or diverticulum is a rare cardiac malformation. Most congenital left ventricular aneurysms and diverticula are asymptomatic and detected by echocardiography. Congenital ventricular aneurysm or diverticulum may cause ventricular tachycardia, ventricular wall rupture, systemic embolization or sudden death, which had to be treated individually.
No preview · Article · Sep 2011 · Zhonghua xin xue guan bing za zhi [Chinese journal of cardiovascular diseases]
[Show abstract][Hide abstract] ABSTRACT: To explore the effectiveness of the metoprolol dosage adjustment on reducing the incidence of electrical-storm (ES) in patients with Implantable Cardioverter Defibrillators (ICDs).
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.
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.
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.
No preview · Article · Aug 2011 · Zhonghua xin xue guan bing za zhi [Chinese journal of cardiovascular diseases]
[Show abstract][Hide abstract] ABSTRACT: Premature ventricular contraction (PVC) is one of the most common kinds of arrhythmias for which the treatment falls into dilemma. Previous clinical application showed that the traditional Chinese Medicine Shensongyangxin (SSYX) capsule is efficacious for the treatment of PVCs. This randomized clinical trial aimed to further evaluate the efficacy and safety of SSYX capsule on treating PVC.
The subjects who had frequent PVCs with or without organic heart disease and normal cardiac function were enrolled in the study. The primary endpoint was the change of PVC numbers after eight-week medication with SSYX capsule. The secondary endpoints included change of clinical symptoms related to PVCs and the safety evaluation of SSYX capsule. Totally 188 PVC patients were randomly enrolled in the non-organic heart disease PVCs trial and orally took either SSYX capsules or analogues (three times per day, 4 capsules one time). A total of 671 PVCs patients were randomly enrolled in the organic heart disease PVCs trial, and orally took either SSYX capsules (three times per day, 4 capsules one time) or mexiletine tablet (three times per day, 150 mg one time). The PVCs were monitored and calculated with 24-hour Holter electrocardiogram. Routine blood, liver and kidney function were tested before and after medication with SSYX capsule.
SSYX capsules significantly decreased the PVCs numbers and alleviated the related symptoms in patients with or without organic heart disease. In non-organic heart disease group, SSYX capsules and the placebos decreased the PVCs from 12,561.34 ± 9,777.93 to 4,806.87 ± 6,507.17, and 12,605.69 ± 8,736.34 to 10,364.94 ± 9,903.41, respectively. The total effective rate was 74.2% and 28.9% in SSYX and placebo groups (P < 0.001). In organic heart disease group, SSYX capsule and mexiletine decreased the PVCs from 8,641.01 ± 8,923.57 to 3,853.68 ± 7,096.42, 8,621.61 ± 8,367.74 to 5,648.29 ± 8,667.38, respectively. The total effective rate was 65.8% and 50.7% in SSYX and mexiletine groups (P < 0.001). In addition, SSYX capsule significantly alleviated PVCs-related symptoms such as palpitations, chest tightness, insomnia, fatigue, and night sweats. No adverse cardiac events were observed except some slight gastrointestinal side effects during the study.
Compared with placebo or mexiletine, SSYX capsules have significant therapeutic efficacy in reducing PVCs numbers and alleviate PVCs-related symptoms.
Preview · Article · Jan 2011 · Chinese medical journal
[Show abstract][Hide abstract] ABSTRACT: Objective: To assess the correlations of left ventricular scar burden and cardiac dyssynchrony with CRT efficacy. Methods: We analyzed the left ventricular scar burden and cardiac dyssynchrony evaluated by SPECT-MPI-PA in 31 CRT patients, who were divided into a CRT-response group (18 pts, 8 males) and a CRT-nonresponse group (13 pts, 10 males). The CRT response is defined as the LVEF improvement by more than 5% or no rehospitalization. The nonresponse is defined as the LVEF improvement by less than 5% or at least one admission to hospital. The LV scar burden and cardiac dyssynchrony were determined by SPECT-MPI-PA. The cardiac dyssynchrony parameters include phase standard deviation (PSD) and phase histogram bandwidth (PHB). Results: Thirty one patients were followed up with an average of 23 months. The average LVEF improvement was 16.0% and −1.2% in response and nonresponse group, respectively (p<0.01). The average of PSD and PHB was 25.8 degrees and 80.7 degrees in response group, while 55.4 degrees and 177.2 degrees in nonresponse group (p<0.01). The scar burden was 27.7% and 39.2% in response group and nonresponse group, respectively (p<0.05). Conclusion: Cardiac dyssynchrony and myocardial scar burden assessed by SPECT-MPI-PA is associated with CRT efficacy, which may provide identifications of CRT responders.
No preview · Article · Jan 2011 · Journal of Arrhythmia
[Show abstract][Hide abstract] ABSTRACT: Only a few algorithms for predicting the site of origin of focal atrial tachycardia (AT) have been reported. We aimed to develop a new and more effective algorithm.
Surface 12-lead electrocardiograms were collected during tachycardia and sinus rhythm in 61 patients who received successful radiofrequency ablation. P-wave polarities, durations, and amplitudes were analyzed. Predictive values of the most significant parameters were determined. An algorithm was then developed and prospectively evaluated in 30 new consecutive AT patients.
Thirty-six percent (22/61) of the foci were located at the ostium of coronary sinus (CS). Other common foci included pulmonary veins (PVs, n = 15), right atrial appendage (RAA, n = 7), parahisian area (n = 7), and crista terminalis (CT, n = 3). Positive P waves in inferior leads (II, III, and aVF) and a negative P wave in lead aVR indicated high atrial origins (high CT, superior PVs, and RAA, defined as Area A), with a sensitivity of 95% and a specificity of 90%. Negative P waves in inferior leads and a positive P wave in lead aVR suggested right low septal origins (CS ostium and inferior tricuspid annulus, defined as Area B), with good sensitivity and specificity (88% and 89%, respectively). This new P-wave diagnostic algorithm correctly identified the site of origin in 90% of AT cases.
Combination of data from multiple leads and regrouping of sites of origin provides a better predictive value.
No preview · Article · Nov 2010 · Pacing and Clinical Electrophysiology
[Show abstract][Hide abstract] ABSTRACT: Endogenous digitalis-like compound (EDLC) is an endogenous ligand of the digitalis receptor and can remarkably inhibit Na+/K+-ATPase activity. Antidigoxin antiserum (ADA), a selective EDLC antagonist, may lessen myocardial reperfusion injury; however, the molecular mechanisms underlying the effect remain unclear. Therefore, this study investigated whether ADA may prevent myocardial reperfusion injury and modulate gene expression of sodium pump alpha isoforms. Cardiac function was examined in isolated rat hearts subjected to ischemia and reperfusion (I/R). The infarct size, EDLC level, Na+/K+-ATPase activity, and the levels of mRNA for sodium pump alpha isoforms were measured in vivo I/R rat hearts in the presence or absence of ADA. It was found that ADA significantly improved the recovery of cardiac function, decreased infarct size, decreased EDLC level, and recovered Na+/K+-ATPase activity in I/R hearts. Further studies showed that sodium pump alpha1, alpha2, and alpha3 isoform mRNA levels were significantly reduced in I/R hearts, and pretreatment with ADA induced a large increase in the mRNA levels. These results indicate that EDLC may participate in depressing Na+/K+-ATPase activity and sodium pump alpha isoform gene expression in I/R heart. It is suggested that treatment with ADA may prevent EDLC-mediated reperfusion injury via modulating sodium pump isoform gene expression.
Preview · Article · Jan 2010 · Canadian Journal of Physiology and Pharmacology
[Show abstract][Hide abstract] ABSTRACT: To investigate the prevalence of Epsilon wave in patients with arrhythmogenic right ventricular cardiomyopathy (ARVC).
The epsilon wave was detected in 32 patients [24 men, mean age (42.3 +/- 13.3) years] with ARVC using three different electrocardiography (ECG) recording methods: standard twelve leads ECG (S-ECG), right precordial leads ECG (R-ECG) and Fontaine bipolar precordial leads ECG (F-ECG). The Epsilon wave was defined as wiggler, small spike wave and smooth potential between the end of the QRS complex and the beginning of the ST segment.
Epsilon wave was detected in 37.5%, 37.5% and 50.0% patients with ARVC by S-ECG, R-ECG and F-ECG respectively. The detection rates derived from the three recording methods were similar (P > 0.05). The Epsilon wave was only detectable by S-ECG in one case, by R-ECG in three cases, and by F-ECG in five cases. The detection rate of Epsilon wave was 50.0% by combined use of S-ECG and R-ECG (SR-ECG), 56.3% by combined use of S-ECG and F-ECG (SF-ECG), and 65.6% by combined use of the three recording methods (SRF-ECG). The detection rate was significantly higher by SF-ECG (56.3%) and SRF-ECG (65.6%) than by S-ECG alone (37.5%, all P < 0.05). Most Epsilon waves detected by the S-ECG, R-ECG and F-ECG were small spiked waves.
Combined use of S-ECG, F-ECG and R-ECG could increase the detection rate of Epsilon wave in patients with ARVC.
No preview · Article · May 2009 · Zhonghua xin xue guan bing za zhi [Chinese journal of cardiovascular diseases]
[Show abstract][Hide abstract] ABSTRACT: 1. The purpose of the present study was to explore the relationship between electrocardiogram (ECG) patterns of right ventricular outflow tract (RVOT) premature ventricular contractions and the three-dimensional distribution of the target sites. 2. Thirty-three consecutive patients were included in the study. The target sites were identified by non-contact mapping and confirmed by successful ablation. The distribution of the target sites in the three-dimensional reconstructed geometry of the RVOT was classified in three directions: (i) anterior (A)/posterior (P); (ii) free wall (F)/septal (Se); and (iii) superior (Su)/inferior (I). The ECG characteristics were then analysed according to the three-dimensional distribution of the target sites. 3. The following indices were helpful to identify the position of the target site: (i) QRS duration (> or = 150 msec = F; < 150 msec = Se; P < 0.05); (ii) the R wave pattern in the inferior leads (RR' or Rr' = F; R = Se; P < 0.05); (iii) the R wave amplitude in the inferior leads (high = Se; low = F; P < 0.05); (iv) the initial r wave width in lead V(1) (wide = F; narrow = Se; P < 0.05); (v) the QS wave amplitude in aVR and aVL (if aVR < aVL, A; if aVR > or = aVL, P; P < 0.05); and (vi) the initial r wave amplitude in lead V(1) and V(2) (if V(1) > or = 0.15 mV and V(2) > or = 0.3 mV, Su; if V(1) < 0.15 mV or V(2) < 0.3 mV, I; P < 0.05). 4. In conclusion, the ECG characteristics were associated with target site locations in all three directions.
No preview · Article · Mar 2009 · Clinical and Experimental Pharmacology and Physiology
[Show abstract][Hide abstract] ABSTRACT: Ventricular tachyarrhythmias are often precipitated by physical or emotional stress, indicating a link between increased adrenergic stimulation and cardiac ion channel activity. Human ether-a-go-go related gene (hERG) potassium channels conduct the rapid component of delayed rectifier potassium current, I(kr), a crucial component for action potential repolarization. To evaluate the correlation between increased alpha(1)-adrenergic activity and the rapid component of cardiac I(kr), whole-cell patch-clamp recording was performed in isolated guinea-pig ventricular myocytes. Stimulation of alpha(1)-adrenoceptors using phenylephrine (0.1 nM-100 microM) reduced I(kr) current in a dose-dependent manner at 37 degrees C. Phenylephrine (0.1 microM) reduced I(kr) current to 66.83+/-3.16%. Chelerythrine (1 microM), a specific inhibitor of protein kinase C (PKC) completely inhibited the changes in I(kr) trigged by 0.1 microM phenylephrine. KT5720 (2.5 microM), a specific inhibitor of protein kinase A (PKA) partially inhibited the current decrease induced by 0.1 microM phenylephrine. Both chelerythrine and KT5720 drastically reduced the phenylephrine-induced effects, indicating possible involvement of PKC and PKA in the alpha(1)-adrenergic inhibition of I(kr). Our data suggest a link between I(kr) and the alpha(1)-adrenoceptor, involving activation of PKC and PKA in arrhythmogenesis.
No preview · Article · Mar 2009 · European journal of pharmacology
[Show abstract][Hide abstract] ABSTRACT: 1. Resveratrol, a polyphenol in red wine, has a cardioprotective effect. Resveratrol-targeting protein (RTP) has been purified using a resveratrol affinity column (RAC) and has been identified as quinone reductase type 2 (NQO2). We hypothesize that NQO2 is the target protein of resveratrol in vascular smooth muscle cells (VSMC) and that resveratrol inhibits proliferation of VSMC through its action on NQO2. In the present study, we investigated the correlation between NQO2 regulation and cell proliferation in VSMC in response to resveratrol treatment. 2. The RTP was purified using RAC and was detected with a NQO2 polyclonal antibody. The VSMC were incubated with resveratrol (1, 10 and 50 micromol/L) for 24, 48 and 72 h. Cell proliferation was detected by cell counting and bromodeoxyuridine (BrdU) assay. A lentiviral vector incorporating NQO2 short interference (si) RNA of short hairpin design was constructed and transduced into VSMC. Real-time quantitative polymerase chain reaction was used to measure NQO2 mRNA levels; NQO2 expression was determined by western blot analysis. 3. Using RAC, we extracted a 26 kDa protein from aortic smooth muscle, which was referred to as RTP-26. Proliferation of VSMC was inhibited by resveratrol in a concentration- and time-dependent manner. The mRNA and protein expression of NQO2 was also repressed by resveratrol in a concentration- and time-dependent manner. A similar pattern of inhibition was observed for cells treated with resveratrol (25 micromol/L) as for cells transduced with a lentiviral vector containing siRNA sequences against NQO2. 4. Collectively, these data indicate that the suppression of VSMC proliferation mediated by resveratrol correlates with NQO2 downregulation.
No preview · Article · Aug 2008 · Clinical and Experimental Pharmacology and Physiology
[Show abstract][Hide abstract] ABSTRACT: Brugada syndrome is linked to sodium channel mutations and could induce arrhythmias that even lead to sudden death. The purpose of this study was to detect if there was gene mutation of SCN5A in 7 patients with Brugada syndrome and explore the molecular genetic characteristics of this disease.
Genomic DNA was extracted from peripheral blood of all 7 patients with Brugada syndrome and 41 pairs of PCR primers were designed to amplify all the 28 exons of SCN5A.
There was no novel mutation in exons of Gene SCN5A in these patients with Brugada syndrome.
Brugada syndrome might associated gene mutation or other mechanisms independent of SCN5A gene mutation.
No preview · Article · Jun 2008 · Zhonghua xin xue guan bing za zhi [Chinese journal of cardiovascular diseases]
[Show abstract][Hide abstract] ABSTRACT: 1. It has been well established that oestrogens can increase the number of endothelial progenitor cells (EPC) by anti-apoptotic effects. Resveratrol, a polyphenolic phytoalexin extracted from grapes and wine, has been reported to act as an oestrogen receptor agonist. We hypothesize that putative phyto-oestrogen may promote EPC proliferation and survival in vitro. 2. Endothelial progenitor cells were isolated from human peripheral blood and identified immunocytochemically. Endothelial progenitor cells were incubated with resveratrol (1, 10, 25 and 50 mmol/L) or control for specified times. Cell proliferation, migration and in vitro vasculogenesis were assayed using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetra-zolium bromide (MTT) assay, modified Boyden chamber assay and in vitro vasculogenesis detection, respectively. 3. Resveratrol increased the number of EPC and promoted EPC proliferation, adhesion and migration in a dose- and time-dependent manner. Cell number peaked at 50 mmol/L resveratrol after incubation for 24 h compared with vehicle control (61.3 +/- 5.8 vs 112.8 +/- 7.2, respectively; P < 0.01). 4. Furthermore, cell cycle analysis showed that 50 mmol/L resveratrol significantly increased the S phase and decreased the G(0)/G(1) phase of EPC. In addition, resveratrol increased vascular endothelial growth factor production and further induced vasculogenesis in vitro. 5. In conclusion, resveratrol significantly induces EPC proliferation, migration and further promotes angiogenesis in vitro.
No preview · Article · Nov 2007 · Clinical and Experimental Pharmacology and Physiology
[Show abstract][Hide abstract] ABSTRACT: To evaluate the possible association between Tpeak-Tend (Tp-e) interval in surface standard ECG and cardiac events in patients with Brugada syndrome (BrS).
Tp-e interval in surface standard ECG was compared between BrS patients (n = 23, all males) and paroxysmal supraventricular tachycardia (PSVT) patients (n = 20, all males) as well as between BrS patients with (n = 16) or without (n = 7) cardiac events.
There was significant difference in Tp-e interval between BrS patients and PSVT patients [(109.57 +/- 22.86) ms vs. (88.50 +/- 13.08) ms, P < 0.05]. Tp-e interval was also significantly longer in BrS patients with cardiac events (syncope, clinical ventricular fibrillation and induced VF during electrophysiological study) than BrS patients without cardiac events [(118.12 +/- 20.40) ms vs. (90.00 +/- 15.27) ms, P < 0.05] while Tp-e interval was similar between BrS patients without cardiac events and PSVT patients (P > 0.05).
The prolongation of Tp-e (> or = 120 ms) was associated with higher cardiac events in BrS patients.
No preview · Article · Jul 2007 · Zhonghua xin xue guan bing za zhi [Chinese journal of cardiovascular diseases]
[Show abstract][Hide abstract] ABSTRACT: To report the electrophysiological findings and the ablation strategies in patients with atrial tachyarrhythmias (ATAs) or atrial fibrillation (AF) recurrence after left atrial circumferential ablation (LACA) in the treatment of AF.
91 patients with AF had LACA procedure from April 2004 to May 2006, 19 of which accepted the second ablation procedure due to ATAs or AF recurrence. In all the 19 patients [17 male, 2 female, age 25 - 65 (53 +/- 12) years], 11 presented with paroxysmal AF before the first ablation procedure, 2 with persistent AF and 6 with permanent AF. Pulmonary vein potentials (PVP) were investigated in both sides in all the patients.
Delayed PVP was identified inside the left circular line in 5 patients, in the right in 1 and both in 2 during sinus rhythm. "Gap" conduction was found and successfully closed guided by circular mapping catheter. In 3 cases, irregular left atrial tachycardia was caused by fibrillation rhythm inside the left ring via decremental "gap" conduction. Reisolation was done successfully again guided by 3-D mapping and made the left atrium in sinus rhythm but the fibrillation rhythm was still inside the left ring. Pulmonary vein tachycardia with 1:1 conduction to the left atrium presented in one case and reisolation stopped the tachycardia. No PVP was discovered in both sides in 4 patients but other tachycardias could be induced, including two right atrial scar related tachycardias, two supraventricular tachycardias mediated by concealed accessory pathway, one cavo-tricuspid isthmus dependent atrial flutter and one focal atrial tachycardia near the coronary sinus ostium. All the tachycardias in these 4 patients were successfully ablated with the help of routine and 3-D mapping techniques. In the rest 3, which were in AF rhythm, LACA was successfully done again. After a mean follow-up of 4 - 26 (11.5 +/- 8.5) months, 16 patients were symptom free without anti-arrhythmic drug therapy; 1 of them had frequent palpitation attack with Holter recording of atrial premature contractions; 2 of them with permanent AF became paroxysmal in one, and still in AF in the other.
Reconduction between the left atrium and the pulmonary veins is the dominant factor for post-LACA ATAs and AF recurrence. Other forms of atrial tachycardias or supraventricular tachycardias may coexist with AF or sometimes trigger AF. LACA can not sufficiently modify AF substrate in some permanent AF patients.
No preview · Article · Mar 2007 · Zhonghua xin xue guan bing za zhi [Chinese journal of cardiovascular diseases]
[Show abstract][Hide abstract] ABSTRACT: To investigate whether hypoxia reoxygenation induces premature senescence in neonatal Sprague-Dawley (SD) rat cardiomyocytes.
Cardiomyocytes were isolated from neonatal SD rat heart and identified by immunohistochemistry. The control cultures were incubated at 37 degree centigrade in a humidified atmosphere of 5% CO(2) and 95% air. The hypoxic cultures were incubated in a modular incubator chamber filled with 1% O(2), 5% CO(2), and balance N2 for 6 h. The reoxygenated cultures were subjected to 1% O(2) and 5% CO(2) for 6 h, then 21% oxygen for 4, 8, 12, 24, and 48 h, respectively. Cell proliferation was determined using bromodeoxyuridine labeling. The ultrastructure of cardiomyocytes was observed by using an electron microscope. beta-Galactosidase activity was determined by using a senescence beta-galactosidase Staining Kit. p16( INK4a ) and telomerase reverse transcriptase (TERT) mRNA levels were measured by real time quantitative PCR. TERT protein expression was determined by immunohistochemistry. Telomerase activities were assayed by using the Telo TAGGG Telomerase PCR ELISAplus kit.
The initial cultures consisted of pure cardiomyocytes identified by immunohistochemistry. The proportion of BrdU positive cells was reduced significantly in the hypoxia reoxygenation-treated group (P< 0.01). Under the condition of hypoxia reoxygenation, mitochondrial dehydration appeared; p16( INK4a ) and TERT mRNA levels, beta-galactosidase activity, TERT protein expression and telomerase activities were all significantly increased (P< 0.01 or P< 0.05).
These data indicate that premature senescence could be induced in neonatal SD rat cardiomyocytes exposed to hypoxia reoxygenation. Although TERT significantly increased, it could not block senescence.
Preview · Article · Jan 2007 · Acta Pharmacologica Sinica