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Cong-xin Huang

Publications and source records attributed to Cong-xin Huang.

At least 19 recordsLinked to original sources
PubMed2006

Linear ablation of left atrium for the treatment of atrial fibrillation guided by double Lasso catheters and three dimensional electroanatomical mapping.

BACKGROUND: Linear ablation of left atrium (LA) guided by three dimensional (3-D) electroanatomical mapping (Carto) has been used in many centres worldwide for the treatment of atrial fibrillation (AF) instead of pure anatomical approaches. There were little data about linear ablation of LA guided by Carto and double Lasso catheters in China. We report the results of linear ablation of LA guided by both Carto and double Lasso catheters. METHODS: After the anatomical model of LA and all pulmonary veins (PVs) had been established, circumferential ablations of the left pulmonary vein antrum and the right pulmonary vein antrum were performed with 2 circumferential mapping catheters (Lasso) placed within the ipsilateral superior and inferior PVs. The endpoint of ablation was abolishment or dissociation of the pulmonary vein potentials (PVPs). Oral amiodarone or propafenone was taken for at least 3 months by patients with persistent AF, permanent AF or those whose PVPs had not been isolated completely. The recurrence of atrial tachyarrhythmias was observed 3 months after the procedure. RESULTS: There were 106 patients (mean age, 51.4 +/- 9.9 years). Seventy-eight patients had paroxysmal AF, 12 persistent AF and 16 permanent AF. Onset of atrial fibrillation occurred in 52 patients during ablation procedure. Thirty-two patients restored to sinus rhythm eventually after the procedure. Abolishment or dissociation of PVPs was accomplished during the procedure in 94 patients (88.7%). The duration of procedure and exposure to X-ray were (213 +/- 45) minutes and (32.5 +/- 12.8) minutes, respectively. Among the 87 patients followed up for over 3 months, 62 were free of atrial tachyarrhythmias (including 8 patients who were still taking oral amiodarone). The success rate was 71.3% in the first procedure. Two patients had pericardial effusion treated by pericardial puncture and effusion drainage. No pulmonary vein stenosis, atrioesophageal fistula, stroke or procedural death occurred. CONCLUSIONS: Combination of double Lasso catheters with 3-D electroanatomical mapping to guide the linear ablation of left atrium procedure can confirm the isolation of PVPs.

Adult↗
PubMed2006

Effect of nifekalant on acute electrical remodelling in rapid atrial pacing canine model.

BACKGROUND: Nifekalant may prevent atrial fibrillation (AF) and possibly be useful in treatment of atrial tachyarrhythmia in patients with severe heart failure. This study investigated the electophysiologic effect of nifekalant on the acute atrial remodeling in rapid atrial pacing (RAP) model of canine. METHODS: Twelve mongrel dogs subjected to rapid stimulation (400 beats/min) at left atrial appendage (LAA) for 24 hours, were randomized into the control group (rapid pacing only, n = 6) and the nifekalant group (intravenous nifekalant therapy immediately after RAP, n = 6). Atrial electrophysiological parameters were measured in right atrium, coronary sinus, LAA, posterior wall of left atrium (PWLA) and left superior pulmonary vein (LSPV), before and after the RAP. RESULTS: In the control group, the effective refractory periods (ERP) were shortened greatly at all sites, paced dogs had substantially shorter ERPs in the high right atrium, LAA, and LSPV, but fewer changes in the PWLA, the coefficient variation of ERP (COV ERP) was increased significantly. After rapid atrial stimulation, the inducibility of AF increased significantly [induction number: pre-RAP vs post-RAP, 1.00 +/- 0.89 vs 8.17 +/- 2.79, P < 0.01; duration of AF: pre-RAP vs post-RAP, (450.34 +/- 362.59) ms vs (9975.77 +/- 4376.99) ms, P < 0.01]. In the nifekalant group, although the ERPs were prolonged at all sites compared with those in pre-RAP state, only the value at LSPV differed significantly from that in pre-RAP state [pre-RAP vs post-RAP, (102.50 +/- 5.24) ms vs (132.51 +/- 5.20) ms, P < 0.01]; the COV ERP did not change statistically in this group. The inducibility of AF slightly increased but insignificantly after pacing [induction number: pre-RAP vs post-RAP, 0.83 +/- 0.75 vs 1.67 +/- 0.82, P = 0.19; duration of AF: pre-RAP vs post-RAP, (378.67 +/- 317.88) ms vs (1124.08 +/- 1109.77) ms, P = 0.06]. Conduction time values did not alter significantly in either of the two groups after RAP. CONCLUSIONS: In canine RAP model, nifekalant inhibited ERP shortening and ERP heterogeneity increasing, decreased AF induction. Nifekalant can reverse acute electrical remodeling effect in this model.

Animals↗
PubMed2006

[Effects of amiodarone versus sotalol in treatment of atrial fibrillation: a random controlled clinical study].

OBJECTIVE: To evaluate the effects and adverse reactions of amiodarone and sotalol in treatment of atrial fibrillation. METHODS: One hundred and two patients with atrial fibrillation, 56 males and 46 females, aged 56 +/- 11, were randomized into 2 equal groups: amiodarone group, taking amiodarone 600 mg/d for 7 days, 400 mg/d for 7 days, 200 mg/d for 7 days, and then 200 mg/d as maintenance dosage if conversion to sinus rhythm occurred; and sotalol group, taking sotalol 40-80 mg/d for one week, 160 mg/d for 2 weeks and then 40-80 mg/d as maintenance dosage if conversion to sinus rhythm occurred. If the cardiac rhythm failed to be converted to sinus rhythm after three week the medication was stopped. All the patients were followed up for 12-24 months and therapeutic effects were evaluated by echocardiography, electrocardiogram and Holter monitor. RESULTS: (1) Conversion to sinus rhythm occurred in 40 patients in the amiodarone group with an effective rate of 78.4%, and in 36 patients in the sotalol group with an effective rate of 70.6%. (2) Conversion to sinus rhythm occurred in the first week in 34 patients of the amiodarone group and in 10 patients of the sotalol group. (3) 67.5% of the patients with conversion to sinus rhythm in the amiodarone group and 41.7% of the patients with conversion to sinus rhythm in the sotalol group maintained sinus rhythm in the following 12 months; and 44.4% patients with conversion to sinus rhythm in the amiodarone group and 26.7% of the patients with conversion to sinus rhythm in the following 24 months. (4) 10 patients in the sotalol group taking a maintenance dosage of 80 mg/d showed atrial ventricular block and severe bradycardia during the follow-up of 6-2 months, then the medication was stopped, but there was no severe arrhythmia in amiodarone group. (5) It was difficult to maintain sinus rhythm when atrial fibrillation lasting longer than 12 months was a predictive factor of failure to maintain sinus rhythm. CONCLUSION: There is no significant difference between amiodarone and sotalol in converting atrial fibrillation to sinus rhythm. However, amiodarone is more effective in maintenance of sinus rhythm than sotalol. The adverse reaction of amiodarone on heart is less severe than that of sotalol.

Adult↗
PubMed2006

[Effect of losartan on sarcoplasmic reticulum Ca2+ handing proteins in heart failure rabbit].

OBJECTIVE: To investigate the effects of losartan on mRNA expression of myocardial sarcoplasmic reticulum calcium handling proteins (SERCA2, RyR2 and PLB) and the role of which in prevention of chronic heart failure in rabbit. METHODS: After chronic heart failure was induced by ligation of the left anterior descending artery in rabbits, the animals were treated with losartan. At 8 weeks after ligation, left ventricular function, hemodynamic parameters, and SERCA2, RyR2, PLB mRNA expressions were observed. RESULTS: Compared with the control group (group C), LVEDP in the infarcted group (group I) increased (P < 0.01), while +dp/dt(max) and -dp/dt(max) decreased significantly (P < 0.01). LVEDP was lower but +dp/dt(max) and -dp/dt(max) significantly higher in the losartan treated group (group L) than those in group I (P < 0.05). SERCA2, RyR2, and PLB mRNA expressions in group I were remarkably lower than those in group L (P < 0.01) and group C (P < 0.01), respectively. CONCLUSION: Losartan can improve cardiac function, probably owing to its upregulating mRNA expressions of myocardial sarcoplasmic reticulum Ca(2+) handling proteins (RyR2, SERCA2 and PLB) in the prevention of heart failure.

Angiotensin II Type 1 Receptor Blockers↗
PubMed2005

Changes of IK, ATP current density and allosteric modulation during chronic atrial fibrillation.

BACKGROUND: Atrial fibrillation (AF) is the most common supraventricular arrhythmia in clinical practice. Chronic atrial fibrillation (CAF) is associated with ionic remodeling. However, little is known about the activity of ATP-sensitive potassium current (IK, ATP) during CAF. So we studied the changes of IK, ATP density and allosteric modulation of ATP-sensitivity by intracellular pH during CAF. METHODS: Myocardium samples were obtained from the right auricular appendage of patients with rheumatic heart disease complicated with valvular disease in sinus rhythm (SR) or CAF. There were 14 patients in SR group and 9 patients in CAF group. Single atrial cells were isolated using an enzyme dispersion technique. IK, ATP was recorded using the whole-cell and inside-out configuration of voltage-clamp techniques. In whole-cell model, myocytes of SR and CAF groups were perfused with simulated ischemic solution to elicit IK, ATP. In inside-out configuration, the internal patch membranes were exposed to different ATP concentrations in pH 7.4 and 6.8. RESULTS: Under simulated ischemia, IK, ATP current density of CAF group was significantly higher than in SR group [(83.5 +/- 10.8) vs. (58.7 +/- 8.4) pA/pF, P < 0.01]. IK, ATP of the two groups showed ATP concentration-dependent inhibition. The ATP concentration for 50% current inhibition (IC50) for the SR group was significantly different in pH 7.4 and pH 6.8 (24 vs. 74 micromol/L, P < 0.01). The IC50 did not change significantly in CAF group when the pH decreased from 7.4 to 6.8. CONCLUSIONS: During CAF, IK, ATP current density was increased and its allosteric modulation of ATP-sensitivity by intracellular pH was diminished.

Adenosine Triphosphate↗
PubMed2005

[Electrophysiology of cardiocytes in ligament of Marshall of canine].

OBJECTIVE: To investigate electrophysiology of cardiocytes in ligament of Marshall. METHODS: The single cardiocytes obtained from ligament of Marshall were direct observed under inverted microscope. The cardiocyte action potential and current density of I(Na), I(Ca), L, I(to), I(K) and I(K1) were researched by whole-cell patch-clamp techniques. RESULTS: There were two different cardiomyocytes in ligament of Marshall, one was rod shape, the other was short-rectangle shape. The short-rectangle myocyte was short and thick; the rod myocyte was long and thin. The short-rectangle myocyte was more than rod myocyte. The length/width rate of short-rectangle myocyte was less than that of rod myocyte (2.99 +/- 0.95 vs 12.05 +/- 2.41, P < 0.01). The action potential of ligament myocytes was similar to fast responsive cells. The action potential amplitude (APA) and duration (APD) of short-rectangle cells were less than those in rod cells. APA (mV), APD(50) (ms) and APD(90) (ms) were respectively 80.02 +/- 3.68 vs 91.72 +/- 7.56, 69.62 +/- 6.33 vs 83.14 +/- 3.66 and 107.55 +/- 4.25 vs 144.00 +/- 5.15, P < 0.05. The ion current density of I(Na), I(Ca), L, I(to), I(K1) was different between the two kind cells. CONCLUSIONS: There are two different cardiocytes in ligament of Marshall. The action potential and ion current density of I(Na), I(Ca), L, I(to), I(K1) are different between the two kind cardiocytes.

Action Potentials↗
PubMed2005

[The role of isoprenaline-induced, calcium-activated transient outward chloride current in atrial electrical remodeling of rabbit].

OBJECTIVE: To investigate the relationship between the changes of the L-type calcium current (I(Ca, L)) and the calcium-activated transient outward chloride current (I(Cl, Ca)), and the repolarization characteristic of action potential in phase 1 under isoprenaline (ISO) stimulation in atrium myocytes of rabbit. METHODS: Atrium myocytes were obtained by enzymatic dissociation from a section of atrial free wall. The membrane currents and action potential were recorded by the whole-cell patch-clamp technique. RESULTS: After recording I(Ca, L), atrium myocytes were perfused with ISO (1 micromol/L) immediately. Five minutes later, a transient outward current (I(to)) was significantly induced, and the peak of I(to) was gradually increased while I(Ca, L) gradually decreased with increasing in clamp voltage. The I(to) was resistant to 4-AP (3 mmol/L) but sensitive to DIDS (150 micromol/L, Cl(-) channel blocker). This current was blocked by CdCl(2) (200 micromol/L, Ca(2+) channel blocker). The elicited rate of I(to) was 91.67% (P < 0.05). (2) The shape of AP was like an inverse triangle with no plateau in Phase 2 after ISO (1 micromol/L) perfusion. Moreover, compared to the parameters of control group, APD(50) and APD(90) were significantly shortened from (65.4 +/- 4.2) ms and (95.8 +/- 3.8) ms to (12.8 +/- 3.8) ms and (27.0 +/- 4.7) ms, and reduced to 80.46% and 71.87%, respectively (P < 0.01, n = 12). 4-AP (3 mmol/L) had on obvious effect on the shape of AP, however, the plateau of AP in phase 2 was recovered by DIDS (150 micromol/L) perfusion, APD(50) and APD(90) were (41.1 +/- 4.5) ms and (79.6 +/- 3.4) ms respectively. Compared to the parameters of control group, there were no significant differences (P > 0.05, n = 12). These results indicated that ionic transport were changed by ISO perfusion in atrium myocytes and I(to) played an important role in the phase 1 repolarization of AP. CONCLUSIONS: Before ISO administration, we could only observe I(Ca, L) in atrium myocytes of rabbit. After isoproterenol intervention, certain intracellular ionic consistency and membrane ionic channels were changed. Calcium activated chloride channel and I(to2) revealed obvious predominance which shorten APD significantly. Action potential showed a triangle with no plateau, suggesting an electrical remodeling in atrium myocytes. The remodeling of ionic channel is related possibly with the opening of Ca(2+)-activated Cl(-) current, which maybe the electrophysiological base of reentrant atrial tachycardia.

Animals↗
PubMed2005

[Study on the intercellular molecule-1 polymorphisms in an Chinese population with myocardial infarction].

OBJECTIVE: To investigate the association between intercellular adhesion molecule-1 (ICAM-1) gene + 12959G/A and + 13848A/G polymorphism and myocardial infarction (MI). METHODS: Polymerase chain reaction-sequence specific primers (PCR-SSP) technology and PCR-restriction fragment length polymorphism(PCR-RFLP) were used for the detection of ICAM-1 genotypes in 165 patients with MI(including acute MI and old MI) and 199 healthy controls. Plasma lipid levels and hyper sensitive C reactive protein (quantitive ELISA method was used) levels were measured in all subjects. RESULTS: + 12959G/A polymorphism was not detected in our study. The frequencies of AA,AG and GG Genotypes of + 13848A/G were 58.2% and 45.7%, 37.0% among patients and 45.2%, 4.8% and 9.0% among controls,respectively. There were statistically significant differences in the distributions of the genotype frequencies (P<0.05) between two groups, and the relative risk suffered from MI of AA genotype was 1.651 times of the GG and GA genotype (OR = 1.651, 95% CI: 1.089-2.504). CONCLUSION: There was no + 12959G/A polymorphism found in Chinese people. The coding single nucleotide polymorphism + 13848 A/G in the exon 6 of ICAM-1 gene was associated to MI and the allele A might serve as a risk factor for MI in Chinese.

Asian People↗
PubMed2004

[Angiotensin II-induced podocyte apoptosis: role of the MAPK subtypes].

OBJECTIVE: To evaluate the role of the MAPK subtypes (p38MAPK, ERK and JNK) in ANG II-induced apoptosis of cultured human podocytes. METHODS: The cultured podocytes were incubated in media containing either vehicle, SB202190(5 micromol/L, an inhibitor of p38MAPK), PD98059 (1 micromol/L, an inhibitor of ERK), SP600125 (5 micromol/L, an inhibitor of JNK), ANG II (10(-8)mol/L) with or without SB202190 PD98059 and SP600125 for 18 hours; the cells were assayed for apoptosis by morphologic staining with H-33342 and propidium iodide and DNA fragmentation assays; the cell proteins were probed for phosphorylated MAPKs to determine the activation of specific MAPK subtypes. RESULTS: ANG II promoted podocyte apoptosis in a time- and dose-dependent manner; ANG II stimulated p38MAPK, but inhibited JNK; SB202190 inhibited both ANG II-induced podocyte apoptosis and p38MAPK phosphorylation; Inhibition of ERK by PD98059 had no effect on ANG II-induced cell apoptosis. CONCLUSION: ANG II-induced apoptosis through stimulation of p38MAPK and inhibition of JNK in human podocytes.

Angiotensin II↗
PubMed2004

[Study on the polymorphism of interleukin-1 gene and the susceptibility to essential hypertension].

OBJECTIVE: To make investigations on the polymorphism of interleukin-1 (IL-1)gene in Chinese Han population, on its association with essential hypertension, and on the relationship between the genotype of IL-1 and susceptibility to essential hypertension. METHODS: The polymorphisms of IL-1 gene in Han population of Hubei province, including polymorphisms of IL-1alpha (-889C/T), IL-1beta (-511C/T),IL-1beta (+3953C/T), IL-1Ra(+8006T/C) and IL-1Ra (variable number of tandem repeat, VNTR), were analyzed by polymerase chain reaction (PCR) and a combination of PCR-restriction fragment length polymorphism methods in 152 patients with essential hypertension and 168 healthy controls. RESULTS: The polymorphism distributions of IL-1alpha (-889C/T), IL-1beta (+3953C/T), IL-1Ra (+8006T/C) and IL-1Ra (VNTR) showed no differences between the essential hypertension group and control group, but the IL-1beta (-511C/T) exhibited a significant difference between the two groups. CT genotype carriers were at increased risk for essential hypertension (OR=2.54, 95%CI: 1.41-4.58), compared with healthy controls. CONCLUSION: The polymorphism of promotor region -511C/T in IL-1beta gene is probably associated with the susceptibility to essential hypertension.

Aged↗
PubMed2004

[Association between tumor necrosis factor-beta polymorphisms and coronary heart disease in a Chinese population].

OBJECTIVE: To investigate the association between tumor necrosis factor-beta (TNF-beta) gene polymorphisms and coronary heart disease (CHD). METHODS: Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and sequence specific primer-PCR (PCR-SSP) were used for the detection of TNF-beta genotype in 210 patients with CHD and 186 healthy controls. The serum TNF-beta levels were measured by enzyme-linked immunosorbent assay (ELISA). RESULTS: The frequencies of CC, CA and AA genotypes of C804A in patients and controls were 25.7% and 37.1%, 49.5% and 45.7%, 24.8% and 17.2%, respectively; there were statistically significant differences in the distributions of the genotypes (P<0.05) and the allele frequencies (P<0.05) between the two groups; the risk of suffering from CHD in those of AA and CA genotypes was 1.704 times that in those of CC genotype (OR=1.704, 95%CI: 1.109-2.617). However, there was no significant difference in the distribution of the genotype of G252A between the patients and controls, though significant difference was seen between the subgroups of the CHD group. The serum TNF-beta and high sensitive C-reactive protein (hsCRP) levels of the patients were significantly higher than those of the controls (P<0.05); however, there were no significant differences in regard to different TNF-beta genotypes among the patients and controls respectively. CONCLUSION: The single nucleotide polymorphism (SNP) at position 804 in the exon 3 of TNF-beta gene is associated with CHD and the allele A may be a risk factor for CHD in Chinese. The polymorphism of G252A may not play an important role in the pathogenesis of CHD.

Aged↗
PubMed2004

Factors associated with the extent of care-seeking delay for patients with acute myocardial infarction in Beijing.

BACKGROUND: Prehospital delay remains one of the main causes of reduced benefit of reperfusion therapy for patients with acute myocardial infarction (AMI). The largest proportion of prehospital delay involves the interval between the onset of symptoms and the decision to seek medical treatment. The purpose of this study was to examine the factors associated with the extent of care-seeking delay in Beijing for patients with AMI. METHODS: A structured interview was conducted in 102 patients with AMI in eight hospitals in Beijing. RESULTS: The mean decision time in patients with AMI was (204 +/- 43) minutes, and prehospital delay time was (311 +/- 54) minutes. Only 34% of patients sought medical care within one hour and a further 36% of patients presented to one of the eight hospitals within two hours after onset. Educational level, atypical presentation of AMI, and family members at the site where AMI occurred were associated with longer delay time in seeking medical assistance (P < 0.05, respectively), whereas the intensity of chest pain was inversely related to patients' delay time (P < 0.01). Patients who perceived their family relationship as good, attributed their symptoms to AMI origin, knew the time-dependent nature of reperfusion therapy, or used emergency medical service tended to seek medical care in a more rapid manner (P < 0.05, respectively). CONCLUSIONS: Patients with AMI in Beijing delay seeking medical care to a great extent. Health education to increase the level of awareness of the target population at increased risk of AMI, including patients and their family members, is probably beneficial to reduce patients' care-seeking delay.

Cognition↗