Objective To describe the new cognition of mapping, ablation and mechanism of typical atrial flutter using non-contact mapping system. Methods In 9 patients with typital AFL, the bi-directional conduction properties of isthmus, atrial activation sequence and reentrant circuit of AFL were mapped using the non-contact mapping system. Linear isthmus radiofrequency ablation was guided by navigation system without fluoroscopy, and isthmus bi-directional block was verified. Results A clockwise moving reentrant activation wavefront in 1 of the 9 patients was observed and a counter-clockwise rotating wavefront in 7 of the 9 patients, respectively. AFL was not inducible in one patient. The mean cycle length of AFL was (215?36) ms. The whole reentrant way and its relation with anatomical structure of right atrium (RA) were displayed by non-contact mapping. In each mapped AFL, the wavefront conducted through the crista terminalis (CT) and propagated slowly, which that indicated the smooth part of RA was involved in the reentrant circuit. In patients with recurrences, the gap in the line of block in the isthmus was identified and ablated, which was navigated by the system. Complete isthmus bi-directional conduction block was achieved at the end of the procedure except in two patients. No recurrences of AFL occurred during the follow-up of 12-36 months. Conclusion The whole activation circuit and its relation with RA anatomical structure of typical AFL can be directly visualized and its reentry mechanism was verified by non-contact mapping system. In recurred cases ,the gap of isthmus block was identified and ablated accurately. CT, which was previously supposed to be a complete posterior conduction barrier, was now proved to be of transverse slow conduction by non-contact mapping.

Objective Previous investigations have shown that N-aeetylcysteine (NAC) could regulate diverse cell type's apoptosis. The purpose of this study was to evaluate the mechanism of NAC reversed apoptosis ofcardiomyocytes induced by hypoxia-reoxygenation (H/R). Methods Cardiomyocytes were treated with hypoxia 6 h and reoxygenation 72 h in the absence and presence of NAC (100 μmol/ L). The ROS was assayed by using Image-iTTM LIVE green reactive oxygen species detection kit. The viability of cell was assayed with trypan blue. Early stages ofapoptosis were assessed by flow cytometry using Annexin V, and late stages ofapoptosis were assessed using TUNEL system. Bcl2 and bax mRNA levels were determincd by real-time quantitative PCR. Bcl2, bax, p38 and pp38 protein levels were determined by western blot. Results We found that H/R could markedly increase ROS generation and induce the apoptosis of cardiomyocytes (P<0.01). NAC (100 p tool/L) significantly reduced the generation of ROS and apoptosis (P all <0.01). NAC also significantly reduced the protein ratio of pp38 and p38 and increased the RNA and protein ratio of bcl2 and bax (P all <0.01). Conclusion The results showed that NAC significantly reduced apoptosis through inhibiting the phosphorylation of p38 signal pathway, which has potential value for clinical cardiac diseases.

Objective Chronic atrial fibrillation (AF) results in dedifferentiation of atrial cardiomyocytes that plays an important role in the perpetuation of AF.In this study,we aimed to investigate the changes of titin and α-smooth muscle actin (α-SMA) after long time of AF reversal.Methods Twenty-four goats were randomized into four groups:(1) sinus rhythm (SR),(2) 3 months AF (3-mo AF),(3) 3 months SR after 3 months AF (3-mo post AF),(4) 6 months SR after 3-mo AF (6-mo post AF),with 6 in each group.By pacing on the anterior bottom of left atria appendage (LAA),we established a goat model of chronic AF.Atria effective refractory period (AERP) was measured with electrophysiological methods.Ultra-structure was studied with echocardiography,light and electron microscopy.Titin and α-SMA protein expressions were determined by Western blot.Results The animals underwent high rate pacing on LAA for a mean of 42.23±21.70 days before presenting AF.Electrophysiological analysis revealed that AERP completely resumed in 3-mo post AF goats.Echocardiography displayed that the size of left atrium resumed almost in 6-mo post AF goats (P＜ 0.01).Pathological and electron microscopic examination revealed the disorder of myofibrils,augmentation of intercellular space,myolysis,accumulation of glycogen,and numerous bigger mitochondria among atrial cardiomyocytes in 3-mo AF goats.They recovered mostly in 6-mo post AF goats.Western blot showed that the band density of titin significantly reduced in 3-mo AF goats compared to SR ones [1826±319 vs 5012±854,P＜0.01].In 3-and 6-mo post AF goats,titin increased gradually and it reversed completely in 6-mo post AF goats (3841±601 and 4523±833 respectively,P ＜ 0.01).Conversely,the band density of α-SMA was significantly higher in 3-mo AF goats (5324±948) than in SR ones (1619± 271,P＜0.01).In 3-and 6-mo post-AF goats,α-SMA decreased gradually,and it recovered mostly in 6mo post AF goats (4437± 792 and 2205±540 respectively,P＜0.01,).Conclusions These data indicate that the reversal of dedifferentiation of atrial cardiomyocyts is a very slow process,and it is definitely essential for normal cardiac function.

Objective To study the mode and clinical implications of onset of spontaneous tosade de pointes in the congenital long QT syndrome. Methods We reviewed electrocardiograms (ECGs) of 55 patients with congenital QT syndrome for syncope. Documentation of the onset of tosade de pointes was available for 16 patients. All these patients had "definitive long QT syndrome" by accepted clinical and ECG criteria. Results One hundren and forty-nine runs of tosade de pointes were documented in 16 patients,of whom,there were 130 runs of pause-dependent tosade de pointes. Conclusion Our results show that the pause-dependent tosade de pointes,which has been recognized as a hallmark of tosade de pointes in the acquired long QT syndrome,plays a major role in the genesis of tosade de pointes in the congenital long QT syndrome.

Objective To appraise the clinical value of velocity vector imaging(VVI) by analyzing the peak systolic velocities,strain and strain rate of ventricular segments in patients with DDD pacing. Methods eventeen patients with DDD pacing were enrolled in this study. The peak systolic velocities, strain andstrain rate of ventricular segments were measured with VVI. The difference at baseline and after pacemaker implantation was analyzed. Results Left and right ventricular (LV and RV) longitudinal peak velocities at baseline and after DDD pacing were significantly decreasing from basal, mid to apical segments. But no significant difference was found in longitudinal strain,strain rate and radial motion characteristic of LV. The mean systolic velocities and strain rate at baseline and after pacemaker implantation and strain with pacing of RV posterior septum and free wall were higher than those of posterior septum and lateral segment of LV respectively. The mean strain and strain rate of RV after pacing were higher than that of LV. Compared with the values at baseline, mean strain of LV with pacing was lower significantly. Conclusions VVI can accurately assess ventricular systolic function in patients with DDD pacing, and can become a powerful means in assessing the regional myocardial function.

OBJECTIVETo observe the long-term outcome of implantable cardioverter-defibrillator (ICD) implantation in Brugada syndrome patients and to explore how to reduce the frequency of ICD nappropriate schocks.

METHODSThis study included 14 symptomatic patients (mean age (44.3 ± 8.3) years old; all males) with Brugada syndrome implanted with ICD in our hospital between 1998 and 2012, and these patients were followed up routinely every 6 months. The initial ICD parameters were set according o conventional experience. The ventricular tachycardia (VT) zone was programmed to ventricular rate 150-188 bpm/cycle length (CL) 400-320 ms and the ventricular fibrillation (VF) zone was programmed to ventricular rate ≥ 188 bpm/CL ≤ 320 ms. The total events were recorded by ICD. The ICD parameters revision was made by electrophysiological (EP) experts in case of inappropriate shocks.

RESULTSPatients were followed up for mean (43.0 ± 28.3) months. A total of 297 VF/VT events were recorded by ICD. Electrophysiological experts found that 90% (178/198) episodes were true VF ( CL 130-250 ms) among of 198 VF episodes and 147 VF episodes were terminated by one shock and 21 VF events were terminated by two or more shocks, and the rest 10 VF terminated spontaneously. Only 9% (9/99) VT events were true VT (CL 320-360 ms) among of 99 VT episodes. Eight VT episodes were converted by antitachycardia pacing therapy (ATP) and the other one terminated spontaneously. The rest 90 VT episodes (91%) were supraventricular arrhythmias (SVT, CL 340-390 ms). About 90% inappropriate shocks can be reduced by Wavelet discrimination function and optimal programming (VF zone ventricular rate ≥ 222 bpm/CL ≤ 270 ms and/or VT zone ventricular rate 167-222 bpm/CL 270-360 ms ) according to the characteristics of arrhythmia of individual patient.

CONCLUSIONICD can effectively prevent sudden cardiac death and syncope in high-risk patients with Brugada syndrome. The most common complication is inappropriate shock due to SVT. Optimal ICD programming with Wavelet discrimination function can effectively reduce the frequency of inappropriate shock rate.

Adult ; Brugada Syndrome ; Cardiac Conduction System Disease ; Death, Sudden, Cardiac ; Defibrillators, Implantable ; Humans ; Male ; Syncope ; Tachycardia, Ventricular ; Treatment Outcome ; Ventricular Fibrillation

Objective To understand diabetes prevalence and its factors is to provide the suggestion for diabetes prevention and control in Yongchuan district .Methods Residents aged above 18 years old from 3 towns and 1 street were sampled by stratified clustered random sampling method .Residents were investigated with the questionnaire and physical examination and taken blood sample to test fasting glucose ,2‐h glucose .The data were analyzed to calculate diabetes prevalence by SPSS17 .0 .The factors of dia‐betes was compared by chi‐square and the independent influencing factors of diabetes were identified by step backward logistic re‐gression .Results A total of 1 202 were investigated .The rate of cognition about diabetes was below 30% .21 .46% of residents smoke every day .31 .78% of them do exercise .The prevalence of overweight ,obesity and diabetes was 24 .63% ,6 .07% and 10 .48% .The result of multi‐variant logistic regression indicated that the independent influencing factors of diabetes prevalence in‐cluded age(OR=1 .41 ,95% CI=1 .24-1 .62) ,the rate of cognition about the dose of salt intake per person per day recommended by Chinese guideline of diet(OR= 2 .12 ,95% CI= 1 .13 -3 .96) ,smoking at present(OR= 1 .44 ,95% CI= 1 .10 -1 .89) ,body weight(OR=1 .06 ,95% CI= 1 .00 -1 .12) ,blood pressure(OR=0 .76 ,95% CI=0 .59 -0 .98) .Conclusion Diabetes prevalence was high in Yongchuan district .The risk factors such as unhealthy diet ,smoking ,physical inactivity were common .Government should take the major role for diabetes prevention and control .

Objective To understand the hypertension prevalence and its influencing factors in Yongchuan district of Chongqing to provide the suggestion for the prevention and control of hypertension .Methods The permanent residents aged above 18 years old were sampled from 3 towns and 1 street by adopting the stratified clustered random sampling method and performed the questionnaire survey ,physical examination and detection of fasting glucose and postprandial 2‐h glucose .The data were analyzed to calculate the hypertension prevalence by the SPSS16 .0 software .The influencing factors of hypertension were analyzed by chi‐square and the multivariate Logistic regression analysis .Results A total of 1 202 persons were investigated .The survey found that the cognition level on hypertension in the residents was below 30 .00% .21 .46% of residents smoked every day .31 .78% of them did exercise .The proportions of overweight and obesity were 24 .63% and 6 .07% respectively ,the hypertension prevalence rate was 23 .88% .The multivariate Logistic regression analysis results indicated that the independent influencing factors of hypertension prevalence included age (OR=1 .95 ,95% CI:1 .74-2 .17) ,cognition level on hypertension(OR=2 .11 ,95% CI:1 .18-3 .79) ,oil in‐take per person per day(OR=0 .80 ,95% CI:0 .64-0 .99) ,body weight(OR=1 .97 ,95% CI:1 .58-2 .46) and blood glucose(OR=0 .63 ,95% CI:0 .50 -0 .78) .Conclusion The hypertension prevalence among the residents in Yungchuan district is high .The knowledge about the prevention and treatment of hypertension is deficient .The high risk factors of smoking ,drinking ,irrational diet and insufficient body movement are common .The comprehensive prevention and treatment work of hypertension should be practi‐cally strengthened .

Objective To evaluate left ventricular(LV)myocardial contraction patterns and function when pacing in different right ventricular(RV)sites and discuss echocardiogarphic method to evaluate physiologcal pacing mode.Methods This study included 26 patients with paroxysmal supraventricular tachycardia without organic heart disease.Four pacing modes including right atrium pacing(AAI),RV apex pacing(VVI-RVA),RV septal pacing(VVI-IVS)and RV outflow tract pacing(VVI-RVOT)were performed on the patients in a random order after succussful radiofrequency ablation.The parameters measured in each pacing mode included(1)LV systolic function parameters:LV twist angle(Twist),aortic systolic velocity-time integral(VTIAo)and LV global strain(Gε)；(2)LV contracting pattern:segmental peak systolic strain(Sε),the time to peak value(TPε),and the distribution of segmental Sε,TPε in each layer or wall.The relationship between Sε,TPε of each wall was analyzed.[Results]Pacing from RV sites showed lower Twist,VTIAO and Gε than AAI mode.Gε demonstrated significant difference in three RV sites pacing mode(VVI-RVOT＞VVI-IVS＞VVI-RVA,P＜0.05).Compared with the AAI mode,the distribution of segmental Sε,TPε in the each layer or wall alerted significantly in three RV sites pacing mode,especially in VV1-RVA.The distribution pattern was similar in VVI-RVOT and VVI-IVS.Furthermore,the wall Sε collated negtively with wall TPε(r =-0.51,P＜0.001).[Conclusions]Compared with AAI mode,RV pacing,especially the VVI-RVA induced the alternation of LV contraction patterns and reduction of systolic function.Longitudinal strain parameters can be used to assess the myocardial contraction patterns and function in different pacing mode.

Objective To explore link of change of plasma C-reactive protein (CRP) and atrial fibrillation (AF). Method The hsCRP enzyme-linked immunosorbent assay (ELISA) methods were used to measure plasma CRP levels in 21 patients with lone paroxysmal AF (LPAF) during AF and 7 days after return to sinus rhythm ;28 patients with lone sustained atrial fibrillation(LSAF) and 27 patients with rheumatic heart disease and chronic AF(RHD).Levels of plasma CRP were compared to levels in 32 patients with paroxysmal supraventricular tachycardia(PSVT) and 20 voluntary healthy subjects. Results Patients with LPAF,LPAF and RHD had high levels of CRP when compared with PSVT and the healthy subjects.No significant changes of CRP levels were found between the onset AF patients and those after 7 days of recovery.Patients with lone persistent AF and rheumatic heart disease with persistent AF had higher levels of CRP than those with LPAF,but have no significance.There were positive correlation between the duration of AF and the levels of CRP.But there were no relation with left atrial size on echocardiography,sex and ages. Conclusion These results indicate that elevated CRP levels in AF patients may play an important role in the occurrence and sustainment of AF.