[Show abstract][Hide abstract] ABSTRACT: To analyze the association between T393C single nucleotide polymorphism (SNP) of GNAS1 gene and non-valvular atrial fibrillation (AF) in Chinese Han patients.
Ninety patients with non-valvular AF and 90 healthy subjects were examined for T393C SNP of GNAS1 gene using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). The allele genotypes and the distribution of allele frequencies were analyzed and compared between the two groups. The relationship between allele frequency distribution characteristics and the heart rate variability (HRV) were also studied for analysis of the association between T393C SNP of GNAS1 gene and the autonomic nervous activation in non-valvular AF.
The two groups showed a significant difference in the frequencies of genotypes of T393C SNP of GNAS1 gene and allele frequencies (P<0.01). CC genotype and T393C allele frequency were significantly increased in the case group. pNN50, LF, or LF/HF showed no significant difference between different genotypes (P<0.05).
The T393C SNP of GNAS1 gene is closely associated with non-valvular AF in Chinese Han patients.
No preview · Article · Oct 2013 · Nan fang yi ke da xue xue bao = Journal of Southern Medical University
[Show abstract][Hide abstract] ABSTRACT: To investigate the clinical characteristics of a Chinese pedigree with cardiac conductive disease complicated by atrial fibrillation and the therapeutic effect of the treatments.
All the family members including the proband were screened with routine examination, electrocardiography, echocardiograpy, Holter recording, chest X-ray, blood biochemistry tests and autoantibody test. The proband received dual chamber pacemaker implantation combined with oral amiodarone treatment for 3 months. The patient was monitored for thyreoid function and chest X-ray during the treatments, and was followed up for another 3 months.
Clinical evidence of organic heart disease was found in none of the family members. The proband showed recurrent dizziness and chest distress, which exacerbated after exercise, and ECG showed atrial fibrillation and severe A-V block. The proband's uncle was found to have atrial fibrillation and III degree A-V block after a syncope episode at the age of 30, and received a pacemaker treatment. Her grandpa died from a heart attack without detailed clinical documentations. No other family members showed abnormal ECG or a history of any heart events. The proband's condition was improved by treatments, after which ECG and Holter recording showed pace rhythm without atrial fibrillation.
Cardiac conductive disease with atrial fibrillation can present in one family, and can be managed effectively and safely with implantation of dual chamber pacemaker combined with oral amiodarone.
No preview · Article · Jan 2012 · Nan fang yi ke da xue xue bao = Journal of Southern Medical University
[Show abstract][Hide abstract] ABSTRACT: Guanfu base A (GFA) and Guanfu base G (GFG) are chemicals isolated from Aconitum coreanum. The potassium channel encoded by the human ether-a-go-go related gene (HERG) plays an important role in repolarization of the cardiac action potential. The purpose of the present study was to investigate the effects of GFA and GFG on the HERG channel and its structure-function relationship.
The effects of GFA and GFG were investigated in human embryonic kidney 293 (HEK293) cells transiently transfected with HERG complementary DNA using a whole-cell patch clamp technique.
GFA and GFG inhibited HERG channel current in concentration-, voltage-, and time-dependent manners. The IC50 for GFA and GFG was 1.64 mM and 17.9 μM, respectively. Both GFA and GFG shifted the activation curve in a negative direction and accelerated channel inactivation but showed no effect on the inactivation curve. Moreover, GFG also accelerated channel recovery from inactivation.
Both GFA and GFG blocked HERG channel current. This effect was stronger after GFG treatment rather than GFA treatment. This blockade was dependent on open and inactivated channel states. These results indicate that GFA could be a rather promising antiarrhythmic drug without severe side effects, whereas GFG could cause QT prolongation and requires further research.
No preview · Article · Sep 2011 · Journal of cardiovascular pharmacology
[Show abstract][Hide abstract] ABSTRACT: To assess the efficacy and safety of radiofrequency catheter ablation for verapamil-sensitive ventricular tachycardia (VT).
A total of 18 patients with a diagnosis of verapamil-sensitive VT were enrolled in this study. Radiofrequency catheter ablation was administered after underwent examinations on admission to rule out structural heart disease. the ablation catheter was placed around the left posterior intermediate septum and left anteroseptal in the left ventricular to searching for the Purkinje potential (P potential). When the Purkinje potential preceded the surface QRS by ≥ 20 ms, it was considered as an ideal target for ablation. Ablation at 25 - 35 W, 60°C was often carried out at the point where the Purkinje potential was earliest. After ablation, perform programmed stimulation to measured the effects. The patients received routine postoperative treatment and care. And the follow-up period was 3 - 6 months after discharge.
17 patients diagnosed as ventricular raise from left posterior fascicle and 1 patient raise from left anterior fascicle were got to the radiofrequency end point and failed to elicit ventricular tachycardia again. In this patients, the Purkinje potential advanced to the starting point of QRS 20 ms were recognized as ideal point of radiofrequency. The length as the Purkinje potential advanced to the starting point of QRS are (24.0 ± 3.5) ms. the more length, the less times of radiofrequency. No postoperative complications were noted except for 2 patients who had mild hematoma at the site of puncture. During the follow-up period, 2 patients were found to have relapsed (recurrence rate = 11.1%) and showed transient resistance to verapamil. The remaining patients had no previous history of tachycardia.
With a low recurrence rate, radiofrequency ablation is a safe and efficacious cure for verapamil-sensitive VT. Despite some efficacies in the treatment of VT.
No preview · Article · Sep 2011 · Zhonghua yi xue za zhi
[Show abstract][Hide abstract] ABSTRACT: to investigate the clinical characteristics in two families with early repolarization syndrome (ERS) and recurrent syncope.
all family members including the probands were screened with routine clinical examination, electrocardiography, echocardiography, Holter recording, chest x-ray, head-up tilt test and blood biochemistry.
there was no clinical evidence of organic heart disease in all members from the two families. Proband 1 showed recurrent syncope, ERS and repeated torsade de pointes ventricular tachycardia and ventricular fibrillation were documented with resting ECG. ERS was detected in one brother, one nephew and one son from him and all were free of cardiac events including syncope, cardiac arrest and sudden cardiac death. Proband 2 showed recurrent syncope, ERS and ST segment arched upward elevation in V(1)-V(3) were documented by ECG. His father suffered sudden cardiac death at the age of 65 and asymptomatic ERS was detected in one of his nephew.
ERS is not always linked with benign clinical course and can sometimes lead to repeated syncope, torsade de pointes ventricular tachycardia and ventricular fibrillation. Pedigree research is of importance for ERS.
No preview · Article · Sep 2010 · Zhonghua xin xue guan bing za zhi [Chinese journal of cardiovascular diseases]
[Show abstract][Hide abstract] ABSTRACT: To investigate the association of ATP binding cassette transporter A1 (ABCA1) gene R219K polymorphisms with atrial fibrillation (AF) in Chinese population.
A total of 250 patients with AF and 250 control subjects were selected. Polymerase chain reaction-restricted fragments length polymorphism (PCR-RFLP) was used to determine the ABCA1 genotype, and the serum concentration of C-reactive protein (CRP) and high-density lipoprotein cholesterol (HDL-C) were measured in all the subjects.
The frequency of the RR , RK , KK , allele R , allele K genotype of ABCA1 in AF group and control group was 42.0%, 42.8%, 15.2%, 34.0%, 43.2% and 22.8%, 63.4%, 36.6%, 55.6%, 44.4%, respectively. The frequency of the KK genotype was significantly higher in the control group than in the case group (P=0.03), and the frequency of the allele K genotype was significantly different between the two groups (P=0.012). The serum CRP concentrations was significantly higher in AF group than in the control group (P=0.004), but serum HDL-C level showed no difference between the two groups. The serum CRP concentrations were significantly higher in patients with RR genotype than in those with KK genotype (P=0.013), and patients with RR genotype had significantly lower HDL-C level than those with RK and KK genotypes (P=0.009 and 0.027, respectively).
Patients with AF have elevated serum CRP level in comparison with healthy individuals, and the K allele of R219K polymorphism is an independent protective factor against AF.
No preview · Article · Apr 2009 · Nan fang yi ke da xue xue bao = Journal of Southern Medical University
[Show abstract][Hide abstract] ABSTRACT: To investigate the optimal atrioventricular delay (AVD) in using dual-chamber pacemaker.
Thirty patients with atrioventricular conduction block, aged 62 +/- 12, implanted for were implanted with DDD pacemakers. Program controller was used to program the AVD. Two-dimensional echocardiography was used to measure the hemodynamic parameters: cardiac output (CO), cardiac output index (CI), stroke volume (SV), left ventricular ejection fraction (LVEF), left ventricular end-systolic diameter (LVESd), left ventricular end-diastolic diameter (LVEDd), peak systolic velocity (Vs), and peak systolic time of the basic segment at inter-ventricular septum and left ventricular under the pattern of tissue velocity imaging at different values of AVD. For each patient, the AVD was prolonged to 250 ms stepwise by 30 ms starting from 100 ms.
Cardiac function changed with different AVD. When the AVD was 160 ms, the maximal values were reached for CO (5.5 L/min+/-1.1 L/min, P<0.05), CI (3.5 Lxmin(-1)xm(-2)+/-0.8 Lxmin(-1)xm(-2), P<0.05), SV (78 ml+/-13 ml, P<0.05), LVEF (67%+/-7%, P<0.05), LVEDd (121 mm+/-29 mm, P<0.05), and Vs. LVESd reached its minimal value (37 mm+/-16 mm, P<0.05) and the Vs values of different ventricular walls reached the minimal too (all P<0.05).
When the optimal AVD is selected the cardiac function can be significantly improved. Tissue Doppler echocardiography is useful in evaluating cardiac function and determining the optimal AVD.
No preview · Article · Apr 2007 · Zhonghua yi xue za zhi
[Show abstract][Hide abstract] ABSTRACT: To analyze the clinical features idiopathic ventricular tachycardia (IVT) and evaluate the effect of radiofrequency ablation therapy for their management.
An retrospective analysis was conducted in 165 IVT patients who received radiofrequency ablation therapy. IVT was classified into 3 types according to the site of origin, namely the right ventricular outflow tract (RVOT-IVT, 86 cases), left ventricular septum (LV-IVT, 75 cases), and left Valsalva sinus (4 cases).
RVOT-IVT was more frequent in female patients than in male patients (60 vs 26, M/F ratio of 0.43). In LV-IVT, male patients prevailed (54 vs 21, M/F ratio of 2.57), suggesting a gender difference in the incidence of IVT. IVT occurred mainly in young and middle-age patients. Most RVOT-IVT occurred in the third to fourth decade of life (mean 36-/+12 years), and LV-IVT occurred at a younger age than did RVOT-IVT (mean 26-/+15 years, P<0.01). Twelve-lead ECGs revealed left bundle branch block morphology in RVOT-IVT, and most of them presented with frequent premature ventricular contraction and/or non-sustained ventricular tachycardia. All the RVOT-IVT patients were successfully ablated by radiofrequency energy in pace mapping. LV-IVT patients with right bundle branch block morphology presented sustained ventricular tachycardia for most of the time, and 97% of the patients were successfully managed with radiofrequency ablation in activation mapping. Four IVT patients were characterized by atypical bundle branch block, an inferior axis, and an R/S ratio >1 in lead V3 or V2, and their tachycardia was ablated successfully in the left sinus of Valsalva using pace mapping. Radiofrequency ablation is currently an effective procedure for IVT management.
No preview · Article · Aug 2006 · Nan fang yi ke da xue xue bao = Journal of Southern Medical University
[Show abstract][Hide abstract] ABSTRACT: A retrospective analysis of 21 cases of Brugada syndrome treated between 1997 and 2004 was conducted to examine the clinical characteristics of these patients and the relations between fever and Brugada syndrome. Of the 21 patients including one female patient, 4 male patents with Brugada syndrome were confirmed to develop ventricular arrhythmias due to febrile disease, suggesting that fever, one of the common causes for triggering cardiac events in Brugada syndrome, should receive due attention in clinical practice.
No preview · Article · May 2005 · Di 1 jun yi da xue xue bao = Academic journal of the first medical college of PLA
[Show abstract][Hide abstract] ABSTRACT: To evaluate the protective effect of losartan, an angiotensin II type 1 (AT1) receptor antagonist, against myocardial ischemic reperfusion in intact canine.
Sixteen dogs were divided into model group(n=8) with left anterior descending coronary artery occlusion for 30 min followed by reperfusion for 30 min and losartan group (n=8) with 5 mg/(kg x d) intragastric losartan administration for 2 weeks before the ischemic-reperfusion model establishment. Monophasic action potential recording technique was employed to observe the incidence of early after depolarization (EAD) and reperfusion arrhythmias.
In the model group, 5 dogs (62.5%) developed EAD and reperfusion arrhythmia while 3 (37.5%) developed the symptoms in losartan group, showing significant difference between the two groups (P<0.05). No ventricular tachycardia or ventricular fibrillation was observed in losartan group (P<0.01).
Losartan can suppress the occurrence of EAD during reperfusion following myocardial ischemia to reduce the incidence of reperfusion arrhythmias, suggesting its protective effect against myocardial ischemic injury.
No preview · Article · May 2005 · Di 1 jun yi da xue xue bao = Academic journal of the first medical college of PLA
[Show abstract][Hide abstract] ABSTRACT: To perform PCR-based site-directed mutagenesis of a new SCN5A mutation (K317N) identified in a Chinese family with Brugada syndrome and construct the recombinant expression plasmid pRc/CMV-Hh1 containing the human cardiac sodium channel alpha subunit (hH1), mutant cDNA.
A pair of primers was designed according to the restricted sites Sse 8387I and Age I of the SCN5A sequence with the mismatches introduced into primers. Mutagenesis was performed in a single-step PCR, and the fragments amplified by PCR containing the mutation site were subcloned into the pRc/CMV-hH1 vector.
Sequence analysis confirmed the presence of the desired mutation site, and a mutation from K (Lys) to N (Asn) in codon 317 was identified in the SCN5A gene, indicating the successful induction of the mutation at K317N of the SCN5A gene.
PCR site-directed mutagenesis is accurate and highly efficient, and the successfully constructed recombinant expression plasmid pRc/CMV-hH1 (K317N) may provide a molecular basis for further functional and genomic investigation of SCN5A.
No preview · Article · Dec 2003 · Di 1 jun yi da xue xue bao = Academic journal of the first medical college of PLA
[Show abstract][Hide abstract] ABSTRACT: To explore the differential diagnosis of early repolarization syndrome (ERS) in patients with ST-segment elevation and its clinical significance.
Five patients with ESR were clinically observed and followed up after discharge from hospital.
All the patients complained of chest distress or chest pain, accompanied by ST-segment elevation in the precordial electrocardiogram leads.
ESR is often misdiagnosed as acute myocardial infarction, acute coronary syndrome, Brugada syndrome or other diseases that may involve elevated ST-segment, and careful examination of the ECGs, echocardiogram, troponin I and the patients' history of heart diseases may help differentiate ESR from these diseases.
No preview · Article · Dec 2002 · Di 1 jun yi da xue xue bao = Academic journal of the first medical college of PLA