Re-entry hypothesis testing within ligament of Marshall as a mechanisma for sustaining atrial fibrillation in dogs / 中华胸心血管外科杂志

Objective To explore the mechanisms of ligament of Marshall (LOM) initiat and sustain atrial fibrillation (AF).Methods The electrophysiologic properties of canine LOM were investigated using multipolar catheter mapping(normal canines,n =4,group A;AF canines,n =5,group B).The programmed stimulation were performed in the LOM,PV-left atrium(LA)junction and LA,respectively.Activations maps of LOM were analyzed from episodes of spontaneous onset of AF and initiation of induced AF by a single extrastimulus.The effectives refractory period of each part was compared and statistically analyzed among three parts in each group and between the two groups.LOM were cutted with surgical incision technology.The inducing rate of AF and the mapping rate of double potential and fragmented electrocardiogram were compared and statistically analyzed pro and post isolation of LOM.Results The incidence of abnormal potential of LOM in the two groups was significantly different(P ＜0.01),re-entry cycle(group A 25％ vs.B group 80％),tachycardia(group A 25％ vs.B 100％),double potential(group A 25％ vs.group B 80％),fragmentation potential(group A 25％ vs.group 80％).There was a significant difference in the rate of LOM tachycardia induction before and after LOM intervention in group B (P ＜ 0.05,before 100％ vs.after 20％).Conclusion There are two possible mechanisms of LOM involved in the occurrence and maintenance of AF:one is that LOM induces AF through spontaneous excitation,the other is that LOM participates in the reentry of left atrium and pulmonary vein in the form of bypass to induce and maintain AF.

Coronary microvascular resistance and its relevant factors in patients with moderate coronary stenosis and chest pain / 中华内科杂志

Objective To evaluate the impact of cardiovascular risk factors on index of microvascular resistance (IMR)and coronary flow reserve (CFR) and to explore the characteristics of IMR and CFR and the relationship between IMR and angiographic features in patients with intermediate coronary stenosis and chest pain.Methods Fractional flow reserve (FFR),CFR,and IMR were measured in patients who underwent invasive coronary angiography with 40％-70％ stenosis by visual assessment.All patients with FFR＞0.75 were enrolled and grouped with the cut-off points of IMR≥25 and CFR≤2.0.Patients with IMR≥25 were group H,including two sub-groups (high IMR-low CFR,group H1 and high IMR-high CFR,group H2),while those with IMR＜25 were group N.The thrombolysis in myocardial infarction (TIMI) frame were counted.Results A total of 34 patients with FFR＞0.75 were enrolled with 61.8％(21 cases) of males and 38.2％ (13 cases) of females.The mean age was (57.3±8.1) years old.High IMR accounted for 47.1％ of all cases.There was significant difference between group H and N in TIMI frame (33.0 vs.20.8,P=0.031).There were significant differences between group H1 and H2 in homocysteine (17.8 μmol/L vs.12.0 μmol/L,P=0.005) and IMRcorr (58.0 vs.36.1,P=0.002).IMRcorrwas correlated to TIMI frame (r=0.40,P=0.012) for all cases.The sensitivity and specificity of inferring IMR≥35.3 by TIMI frame were 0.75 and 0.65 (P=0.049) with TIMI frame over 40.5.Conclusions High IMR may be one of the reasons for chest pain in patients with intermediate coronary stenosis.There is no correlation between vascular risk factors and IMR or CFR,while there is positive correlation between TIMI frame and IMR.The specificity is 65％ for inferring IMR rise with TIMI frame over 40.5.

Application of domestic snare in retrograde percutaneous coronary intervention for coronary chronic total occlusion lesions / 中国介入心脏病学杂志

Objective To evaluate the safety and efficiency of domestic snare applied during retrograde percutaneous coronary intervention (PCI) for chronic total occlusion (CTO) lesions.Methods A total of 27 patients who underwent retrograde PCI for CTO and used domestic snare during the procedure were enrolled in our study from March 2012 to November 2016.Clinical data, angiographic characteristics and PCI details were collected.Clinical data, characteristics of CTO lesion, effect of the domestic snare and snaring time were retrospectively analyzed.Special complications related to the domestic snare and major adverse cardiovascular events (MACE) were also documented.Results Domestic snare was used in all the procedures, which included facillitating the micro-catheter to pass through the CTO lesions in 6 patients and assisting the RG3/rotational guide-wire externalization in all the 27 patients.Mean snaring time was 3.5±5.4 minutes.Stents were successfully implanted in 26 patients except in 1 patient who failed to receive stent implantation for severe coronary calcification.No complications including coronary dissection, fracture of guide-wire and unreleased snare happened during the procedures and no MACE occurred during hospitalization.Conclusions Domestic snare facilitates retrograde micro-catheter crossing CTO lesions and retrograde guide-wire entering the guiding catheter and externalization.It is a simple, safe and efficient method.

Prevalence of depressive and anxiety disorders in cardiovascular outpatients from 14 tertiary general hospitals of 5 Chinese cities / 中华心血管病杂志

<p><b>OBJECTIVE</b>To explore the prevalence of depression and (or) anxiety disorders among cardiovascular outpatients of tertiary general hospitals of five Chinese cities.</p><p><b>METHODS</b>A hospital-based cross-sectional survey was conducted in the cardiovascular out-patient departments of 14 tertiary general hospitals in five Chinese cities. The patients aged 18 years and over were recruited consecutively, who were conscious and with informed consent, and can finish the questionnaire independently. All the subjects were screened with Hospital Anxiety Depression Scale (HADS). The subjects with HADS score of 8 and over were interviewed and diagnosed by psychiatrists using mini international neuropsychiatric interview (MINI). The physicians made the diagnosis and management without knowing the results of MINI and HADS score. Subjects who refused MINI were defined as the case of loss of follow-up.</p><p><b>RESULTS</b>A total 2 123 subjects were included in the survey. The adjusted prevalence rate of depressive and anxiety disorder was 4.05% (86/2 123), the depressive and/or anxiety disorder was 14.27 % (303/2 123), depressive and anxiety disorder and mixed depressive or anxiety disorder was 14.37% (305/2 123) according to MINI. The adjusted prevalence of lifetime depressive and anxiety disorder was 5.37% (114/2 123), depressive and/or anxiety disorder was 16.91% (359/2 123), depressive and anxiety disorder and mixed depressive-anxiety disorder was 17.00% (361/2 123).</p><p><b>CONCLUSION</b>There is a high prevalence of depressive and anxiety disorder among cardiovascular outpatients from tertiary general hospitals in China. Therefore, doctors must pay attention to this disorder and try to reduce the impact of this disorder in cardiovascular patients.</p>

Study of the influence of uniform transverse magnetic field on the dose distribution of high energy electron beam using Monte Carlo method / 生物医学工程学杂志

In the present work, Monte Carlo simulations were employed to study the characteristics of the dose distribution of high energy electron beam in the presence of uniform transverse magnetic field. The simulations carried out the transport processes of the 30 MeV electron beam in the homogeneous water phantom with different magnetic field. It was found that the dose distribution of the 30 MeV electron beam had changed significantly because of the magnetic field. The result showed that the range of the electron beam was decreased obviously and it formed a very high dose peak at the end of the range, and the ratio of maximum dose to the dose of the surface was greatly increased. The results of this study demonstrated that we could change the depth dose distribution of electron beam which is analogous to the heavy ion by modulating the energy of the electron and magnetic field. It means that using magnetic fields in conjunction with electron radiation therapy has great application prospect, but it also has brought new challenges for the research of dose algorithm.

Comparison of drug eluting stent for treatment of intrastent restenosis and de novo lesion / 中国介入心脏病学杂志

Objective Compare the efifcacy and safety of drug eluting stent (DES) for treatment of in stent restenosis (ISR) and coronary de novo lesions. Methods Patients treated with DES for ISR and de novo lesions in Beijing Anzhen Hospital between October 2008 and December 2011 were followed up for 1 year. All lesions were divided into ISR and de novo group. Major adverse cardiovascular events (MACE) including all-cause death, myocardial infarction (MI) and clinical target lesion revascularization (TLR) were the primary endpoints. Results The study population consisted of 204 patients in the ISR group and 494 patients in the de novo group. Baseline clinical and angiographic parameters were comparable between the two groups. The rate of diabetic was higher in the ISR group than that in the de novo group (36.6%to 27.1%, P < 0.05). The diameter of coronary artery was smaller in the ISR group than that in the de novo group (2.72±0.36 to 3.08±0.54, P<0.01). The rate of TLR in the ISR group was higher than that in the de novo group (10.7%to 17.2%, P<0.05;14.2%to 21.1%, P<0.05),contributing to higher MACE in ISR group. Conclusions DES implantation is safe and effective for treatment of ISR lesions, but the rate of TLR is higher compared to treatment of de novo lesions.

Effect of ouabain on the pathogenesis of hypertension in rats / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Ouabain and digoxin are important cardiac glycoside and related to many cardiovascular diseases. The purpose of this study was to investigate the changes of sodium pump α-subunit expression in rats and compare the effects of ouabain (OUA) and digoxin (DIG) on the development of hypertension.</p><p><b>METHODS</b>In situ hybridization was performed. Specific sequence oligonucleotide probe tailing with a Dig-dUTP hybrid to target nucleic acids of the sodium pump α-subunit. According to counting positive particles sodium pump subunit expression was analyzed with statistical methods.</p><p><b>RESULTS</b>On day 16 of drug administration, the blood pressure of rats increased significantly in the OUA group. In the DIG group, the blood pressure revealed no significant difference when compared to the control group. In addition, the effects of OUA and DIG on sodium pump α-subunit RNA expression in tissues differed.</p><p><b>CONCLUSIONS</b>OUA and DIG can not only change the configuration of the sodium pump to depress their activity, but also influence their gene expression which is important in the mechanism of hypertension. This may be a key point in the pathogenesis of hypertension in the manner in which OUA differs from DIG and changes the sodium pump gene expression in the arteries and kidneys of rats.</p>

Ultrasound-mediated destruction of gene-loaded microbubbles enhanced the transfection of phospholamban antisense RNA into cardiac myocytes / 中华超声影像学杂志

Objective To explore whether ultrasound-mediated microbubbles destruction could enhance anti-sense RNA transfection and expression. Methods Phospholamban antisense RNA eukaryon vector PcDNA 4. 1-asPLB was successfully constructed and it was transfected into cardiac myocytes by various methods including calcium phosphate precipitation, ultrasound exposure and ultrasound-mediated microbubbles destruction. The expression of PLB and sarcoplasmic retculum Ca2+ ATPase (SERCA2a) in cardiac myocytes was tested by RT-PCR and western blot. Results The transfection and expression of PcDNA 4. 1-asPLB increased significantly in cells treated with ultrasound-mediated microbubbles destruction compared to other transfer groups( P ＜0.05). The expression of PLB was inhibited specifically after cardiac myocytes were transfected with PcDNA 4. 1-asPLB. There was no change of PLB expression after cardiac myocytes transfected with PcDNA 4. 1 ( P ＜0.05). Though the expression of SERCA2a never exhibited any changes after PcDNA 4. 1-asPLB transfection, the PLB/SERCA2a ratio decreased markedly. Conclusions As a highly effective antisense RNA transfer method, ultrasound-mediated microbubbles destruction can enhance the transfection and expression of the PcDNA 4. 1-asPLB significantly. The PcDNA4. 1-asPLB transfection inhibits the expression of PLB and result in decrease of PLB/SERCA2a ratio in cardiac myocytes.

Follow-up study on application of radiofrequency ablation combined with magnetic navigation assistance system in elderly patients with atrioventricular node reentrant tachycardia / 中华老年医学杂志

Objective To explore the safety, efficacy and 1-year follow-up outcome of radiofrequency ablation combined with magnetic navigation assistance system in elderly patients with atrioventricular node reentrant tachycardia (AVNRT). Methods Forty cases of patients with AVNRT identified by the electrophysiological test were enrolled in the study. Twenty cases were ablated with magnetic navigation system. The other 20 cases underwent the conventional catheters operation. With the cardiodrive, the 8 Frablation magnetic Helios I (Stereotaxis Inc, USA) was advanced to the Koch triangle area from the inferior caval vein (IVC). With the assistance of magnetic navigation (AXIOM Artis, Siemens, Germany), the direction of tip and the advancement or retraction of the catheters were regulated. The success rate, the time of procedure, the fluoroscopy time and the 1-year follow-up outcome were analyzed, and the complications of procedure were recorded. Results Forty cases with AVNRT underwent radiofrequency ablation successfully. In magnetic navigation group, 19/20 cases underwent magnetic catheter operation. The cases who failed to finish magnetic catheter operation underwent successfully conventional catheter operation. There was no perforation complication and no significant statistic difference in the success rate between two groups. No recurring case was found in the two groups 1 year later. The total of fluoroscopy time in magnetic navigation group was more than that in standard ablation group [(16.4±2.7) min vs. (11.1±1.0)rain, P<0.01], but the decreasing trend of fluoroscopy time in magnetic navigation group was showed. The operator's fluoroscopy time in magnetic navigation group was obviously less than that in standard ablation group [(4.5±0.6) min vs. (11.1±1.0) min, P<0.01]. Conclusions The radiofrequeney ablation combining with magnetic navigation system has the similar safety and efficacy to the conventional ablation in elderly patients with AVNRT, but the operator's fluoroscopy time was significantly decreased.

Content determination of tannin in Nodus Nelumbinis Rhizomatis / 中华中医药杂志

Objective: To establish a method for the content determination of tannin in Nodus Nelumbinis Rhizomatis. Methods: The content of tannin in Nodus Nelumbinis Rhizomatis was detected by molybdophosphate colorimetric method. Results: The content of tannin in Nodus Nelumbinis Rhizomatis from different drugstores varied from 0.2537% to 1.637%. Conclusion: This method was simple, accurate and can be used for the quality control of Nodus Nelumbinis Rhizomatis.

Evaluation of transisthmus conduction interval in predicting bidirectional block after ablation of typical atrial flutter / 中华医学杂志(英文版)

<p><b>OBJECTIVE</b>To determine whether the extent of prolongation of the transisthmus interval after ablation predicts complete bidirectional block.</p><p><b>METHODS</b>Since 1996 to 2002, 30 consecutive patients underwent ablation procedures for isthmus-dependent atrial flutter. There were 23 males and 7 females [mean age (47.85 +/- 9.35) years]. With the use of fluoroscopic view of anatomy, radiofrequency ablation was performed during coronary sinus pacing at a cycle length of 600 ms.</p><p><b>RESULTS</b>Bidirectional block was achieved with ablation in 29 (97%) of 30 patients. The transisthmus intervals before ablation and after complete transisthmus block were (73.82 +/- 13.01) ms and (140.47 +/- 20.48) ms, respectively, in the clockwise direction (P < 0.0001), and (77.63 +/- 8.36) ms and (138.17 +/- 15.55) ms, respectively, in the counterclockwise direction (P < 0.0001). A period of incomplete isthmus block was observed during 17 (58%) of the 29 ablation procedures. The clockwise transisthmus intervals during incomplete block [(107.65 +/- 21.33) ms] were (45.5 +/- 8.7)% longer than the baseline transisthmus intervals. An increase in the transisthmus interval by > or = 50% in both directions after ablation predicted complete bidirectional block with 100.0% sensitivity and 83.3% specificity. The positive and negative predictive values were 90.6% and 100.0%, respectively. The diagnostic accuracy of a > or = 50% prolongation in the transisthmus interval was 83.3%.</p><p><b>CONCLUSION</b>The analysis of transisthmus interval is a valuable method for determining complete bidirectional isthmus block.</p>