[Zero-fluoroscopy catheter ablation for idiopathic premature ventricular contractions from the aortic sinus cusp].

OBJECTIVE: To compare the safety, feasibility, and efficacy of a completely nonfluoroscopic approach to radiofrequency catheter ablation (RFCA) using CARTO3 and ablation with conventional fluoroscopic guidance for treatment of idiopathic premature ventricular contractions from the aortic sinus cusp (ASC-PVCs). METHODS: From April 2013 to October 2015, we prospectively enrolled 52 consecutive patients with ASC-PVCs scheduled for either CARTO3 mapping-guided zero-fluoroscopy ablation (group A, n=23) or conventional fluoroscopic ablation (group B, n=29). The success rates, rates of complications, rates of recurrences, number of radiofrequency applications, procedure time, mapping time and fluoroscopy time were compared between the 2 groups. RESULTS: s No significant differences were found in the success rates between the 2 groups [22/23 (96%) vs 24/29 (83%), P=0.21]. No major complications occurred during the procedures in either group. There was no significant difference with regard to the procedure time between the two groups (79.6∓8.8 vs 77.4∓7.2 min, P=0.332). The procedure was completed without any fluoroscopy use in group A, while the mean fluoroscopy time in group B was 23.1∓6.0 min. Group A showed a shorter mapping time than group B (4.3∓1.7 vs 7.8∓2.6 min, P<0.01) with significantly fewer radiofrequency applications (4.8∓1.1 vs 7.9∓3.2, P<0.01). The recurrence rates were comparable between the two groups over a follow-up period of 5 to 20 months. CONCLUSION: Compared with the conventional fluoroscopic technique, the zero-fluoroscopy approach can shorten the total procedure time and the ablation time with significantly reduced RF applications to eliminate ionizing radiation exposure in RFCA. RFCA guided by CARTO3 system without fluoroscopy is feasible, safe, and effective for treatment of ASC-PVCs.

[Correlation of Tp-e interval and Tp-e/Q-T ratio with malignant ventricular arrhythmia in patients with implantable cardioverter-defibrillator for primary prevention].

OBJECTIVE: To investigate whether Tpeak-Tend interval (Tp-e) and Tp-e/QT ratio are associated with malignant ventricular arrhythmia in patients with implantable cardioverter-defibrillator (ICD) for primary prevention. METHODS: A cohort of 68 consecutive patients with chronic heart failure undergoing standard ICD for primary prevention indications (NYHA function class II-III, left ventricular ejection fraction ≤35%, systolic cardiomyopathy without prior malignant ventricular arrhythmia) were enrolled in this study. The patients were followed up for 18-48 months and were divided into high-risk group and low-risk group according to the occurrence of the endpoint events of sudden cardiac death (SCD), ventricular tachycardia (VT), or ventricular fibrillation (VF). Electrocardiographic and echocardiographic characteristics, Tp-e, and Tp-e/QT ratio were analyzed in all cases before ICD implantation. RESULTS: During the follow-up, ICD shock for sustained ventricular tachycardia or ventricular fibrillation occurred in 11 patients; nonsustained ventricular tachycardia (NSVT) that did not require therapy was detected by ICD in 7 patients (high-risk group, 18 cases). ICD did not detect ventricular tachycardia or ventricular fibrillation in 50 patients (low-rsk group). Compared with the low-rsik group, the high-risk group had an increased Tp-e/QT ratio (0.27±0.04 vs 0.22±0.05 P<0.01) and an increased Tp-e (105±15 vs 90±17 ms P<0.01). ROC analysis revealed that a Tp-e/QT ratio ≥0.255 had a sensitivity of 72.2% and a specificity of 65.9%, and a Tp-e ≥103 ms had a sensitivity of 66.7% and a specificity of 67.9% for predicting VT and VF in these patients. CONCLUSION: Increased Tp-e and Tp-e/QT ratio are associated with increased risks of ventricular arrhythmias in patients with ICD for primary prevention.

[Functional analysis of a novel SCN5A mutation G1712C identified in Brugada syndrome].

OBJECTIVE: To elucidate the molecular and electrophysiological mechanisms of Brugada syndrome through functional analysis of a novel SCN5A gene mutation G1712C. METHODS: A recombinant plasmid pRc

[Radiofrequency ablation for verapamil-sensitive ventricular tachycardia].

OBJECTIVE: To assess the efficacy and safety of radiofrequency catheter ablation for verapamil-sensitive ventricular tachycardia (VT). METHODS: 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. RESULTS: 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. CONCLUSION: 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.

[Early repolarization syndrome and recurrent syncope in two Chinese pedigrees].

OBJECTIVE: to investigate the clinical characteristics in two families with early repolarization syndrome (ERS) and recurrent syncope. METHOD: 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. RESULTS: 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. CONCLUSIONS: 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.

[Therapeutic effect of recombinant human brain natriuretic peptide for treatment of decompensated heart failure: comparison with nitroglycerin].

OBJECTIVE: To compare the therapeutic effect of recombinant human brain natriuretic peptide (rhBNP) and nitroglycerin on acute decompensated heart failure (ADHF). METHODS: Fifty ADHF patients were randomly divided into rhBNP group and nitroglycerin group. In all the patients, dyspnea and global clinical status were assessed before and at 30 min, 6 h and 24 h after drug administration, and the volume of fluid intake and urine along with hemodynamic parameters was recorded 24 h after drug administration. In the nitroglycerin group, the patients received an initial nitroglycerin dose of 5 microg/min, with subsequent dose increment of 5 microg/min every 3 to 5 min; the dose was adjusted individually according to the hemodynamics of the patients. The patients in rhBNP group were given rhBNP at the initial dose of 1.5 microg/kg by with an intravenous bolus injection followed by infusion at the rate of 0.0075 microg.kg(-1).min(-1) for 72 h. RESULTS: At 30 min and 6 h after drug administration, the patients in the rhBNP group showed significant greater improvement of dyspnea (P=0.042 and 0.019) and global clinical status (P=0.018 and 0.044) than those in the nitroglycerin group, but 24 h after drug administration, no significant difference was noted between the two groups (P=0.192 and 0.179). Twenty-four hours after drug administration, the mean urine volume was significantly greater in rhBNP group than in nitroglycerin group (1513.8-/+242.9 vs 1341.2-/+239.7 ml, P=0.015), and the ejection fraction increased and pulmonary arterial pressure and systolic blood pressure decreased at greater amplitude in the former group (P=0.001,0.000 and 0.002, respectively). At 72 h, the numbers of premature ventricular contraction and couplets premature beats and onset of paroxysmal ventricular tachycardia were significantly reduced in rhBNP group as compared with the nitroglycerin group (P=0, 0.001 and 0.002, respectively). CONCLUSION: RhBNP promotes urine excretion, decreases pulmonary arterial pressure and increases left ventricular ejection fraction to improve dyspnea and global clinical status and reduce the onset of ventricular arrhythmia in ADHF patients.

[Influence of atrioventricular delay of dual chamber pacemaker on cardiac function: evaluation by tissue Doppler echocardiography].

OBJECTIVE: To investigate the optimal atrioventricular delay (AVD) in using dual-chamber pacemaker. METHODS: 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. RESULTS: 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). CONCLUSION: 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.

[Clinical features of idiopathic ventricular tachycardia of various types and their radiofrequency ablation therapy].

OBJECTIVE: To analyze the clinical features idiopathic ventricular tachycardia (IVT) and evaluate the effect of radiofrequency ablation therapy for their management. METHODS: 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). RESULTS AND CONCLUSION: 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.

[Fever and Brugada syndrome: report of 21 cases].

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.

[Effects of recombinant human interleukin-10 on tumor necorsis factor-alpha-induced adventitial fibroblast proliferation in vitro].

OBJECTIVE: To observe the effects of recombinant human interleukin-10 (rhIL-10) on adventitial fibroblast proliferation induced by tumor necrosis factor-alpha TNF-alpha in vitro. METHODS: In this controlled study, NIH/3T3 cells cultured in vitro were treated with TNF-alpha and recombinant human interleukin-10 (rhIL-10), respectively, and the cell proliferation was determined by non-radioactive MTS/PES assay. Cell cycle analysis was performed using flow cytometry. RESULTS: Compared with the control cells, TNF-alpha significantly stimulated NIH/3T3 cell proliferation, wherea. rhIL-10 had no such effect. With TNF-alpha stimulation, rhIL-10 at the dose as low as 1 ng/ml inhibited the proliferation of NIH/3T3 cells (P<0.05). The number of cells in G(0)/G(1) phase treated with both TNF-alpha and rhIL-10 was higher than those treated with TNF-alpha alone (P<<0.05), as shown by flow cytometry. CONCLUSION: rhIL-10 can significantly inhibit the proliferation of adventitial fibroblasts induced by TNF-alpha in vitro.

[PCR-based site-directed mutagenesis and recombinant expression plasmid construction of a SCN5A mutation (K317N) identified in a Chinese family with Brugada syndrome].

OBJECTIVE: 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. METHODS: 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. RESULTS: 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. CONCLUSION: 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.

[Differential diagnosis of early repolarization syndrome in patients with ST-segment elevation: report of 5 cases].

OBJECTIVE: To explore the differential diagnosis of early repolarization syndrome (ERS) in patients with ST-segment elevation and its clinical significance. METHODS: Five patients with ESR were clinically observed and followed up after discharge from hospital. RESULTS: All the patients complained of chest distress or chest pain, accompanied by ST-segment elevation in the precordial electrocardiogram leads. CONCLUSION: 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.

Enzyme-linked immunosorbent assay for urinary aquaporin-2 water channel protein measurement.

OBJECTIVE: To develop an efficient and stable enzyme-linked immunosorbent assay (ELISA) for detecting urinary aquaporin-2 (AQP2) water channel protein. METHODS: Rat AQP2 C-terminal peptides (CELHSPQSLPRGSKA) were synthesized and linked to KLH to prepare rabbit anti-AQP2 polyclonal antibodies, and IgG of the antibodies were labeled with horseradish peroxidase (HRP). Rat models of congestive heart failure (CHF) was established by ligation of the left coronary artery, in which both direct and sandwich ELISA for urinary AQP2 detection were tested. RESULTS: Double antibody sandwich ELISA was able to detect urinary AQP2 as low as 15.625 pmol/ml with intra-and inter-assay coefficients of variance (CVs) of 4.65% and 14.05% respectively. Urinary AQP2 concentration determined by this assay showed significant positive relation to that by Western blot analysis in CHF rats. CONCLUSION: Double antibody sandwich ELISA was successfully established to detect urine AQP2 in CHF rats, which is more efficient and simpler than Western blot analysis.