Predictive value of impedance of leadless pacemaker during implantation on trend changes of pacing threshold / 中华心血管病杂志

Objective: To explore the predictive value of the impedance measured during leadless pacemaker Micra implantation on the trend of changes of pacing threshold post implantation. Methods: This is a retrospective cross-sectional study. Patients who received implantation of leadless pacemaker Micra at the Second Xiangya Hospital of Central South University from December 2019 to August 2020 were enrolled. The clinical data and the intraoperative electrical parameters during leadless pacemaker implantation were collected. The impedance and pacing threshold data were analyzed at three time points: immediate release, 5-10 min after release, and after traction test. Receiver operating characteristic (ROC) curves and the area under the curve (AUC) were used to analyze the value of the impedance at immediate release on predicting the trend of changes of pacing threshold post implantation. Results: A total of 21 patients (mean age: (72.2±12.5) years, 12 males) were included. The impedance of 21 patients was (798.1±35.3) Ω immediately after implantation, (800.9±35.6) Ω after 5-10 minutes of release, and (883.6±31.7) Ω after traction test. Impedance was similar between the three time points (P>0.05). The threshold was (0.97±0.11) V/0.24 ms immediately after implantation, (0.95±0.12) V/0.24 ms at 5-10 min after the release, and (0.59±0.06) V/0.24 ms after the traction test. The threshold was significantly lower after the traction test than that immediately after release (P=0.003) and than that at 5-10 minutes after release (P=0.008), suggesting a decreased tendency of the threshold over time. According to the analysis of the ROC curve, the immediate impedance after the release ≥680 Ω could predict the ideal pacing threshold after the traction test (AUC=0.989, 95%CI 0.702-0.964, P<0.001), the prediction sensitivity was 87%, and the specificity was 100%. The pacing threshold would be not ideal with the immediate impedance ≤ 520 Ω (95%CI 0.893-1.000, P<0.001), the sensitivity was 100%, and the specificity was 80%. Conclusions: The impedance immediately after the release has predictive value for the changing trend of threshold post leadless pacemaker Micra implantation. Impedance ≥680 Ω immediately after release is often related with ideal pacing threshold after the traction test. In contrast, the impedance ≤ 520 Ω pacing is often related with unsatisfactory threshold after the traction test, therefore, it is recommended to find a new pacing site to achieve the impedance ≥680 Ω immediately after release during leadless pacemaker Micra implantation.

Comparison of heart failure and COVID-19 in chest CT features and clinical characteristics / 中华心血管病杂志

Objective: To identify the characteristics including clinical features and pulmonary computed tomography (CT) features of heart failure and COVID-19. Methods: This study was a retrospective study. A total of 7 patients with heart failure and 12 patients with COVID-19 in the Second Xiangya Hospital of Central South University between December 1, 2019 and February 15, 2020 were enrolled. The baseline clinical and imaging features of the two groups were statistically analyzed. Results: There was no significant difference in age and sex between the two groups(both P>0.05), but the incidence of epidemiological contact history, fever or respiratory symptoms in the COVID-19 group was significantly higher than that in the heart failure group (12/12 vs. 0, P<0.001; 12/12 vs. 4/7, P=0.013). While the proportion of cardiovascular diseases and impaired cardiac function was significantly less than that of the heart failure group(2/12 vs.7/7, P<0.001；0 vs.7/7, P<0.001). For imaging features, both groups had ground-glass opacity and thickening of interlobular septum, but the ratio of central and gradient distribution was higher in patients with heart failure than that in patients with COVID-19 (4/7 vs. 1/12, P=0.04). In heart failure group, the ratio of the expansion of pulmonary veins was also higher (3/7 vs. 0，P=0.013), and the lung lesions can be significantly improved after effective anti-heart failure treatment. Besides, there were more cases with rounded morphology in COVID-19 group（9/12 vs. 2/7, P=0.048）. Conclusions: More patients with COVID-19 have epidemiological history and fever or respiratory symptoms. There are significant differences in chest CT features, such as enlargement of pulmonary veins, lesions distribution and morphology between heart failure and COVID-19.

Lead aVL in combination with lead V1:A new method for identifying premature ventricular contractions originating from aortic sinus cusp / 中国介入心脏病学杂志

Objective To explore the validity of lead aVL in combination with lead V1 for identifying idiopathic outflow tract premature ventricular contractions(PVCs)originating from aortic sinus cusp(ASC).Methods This study consecutively enrolled 102 idiopathic outflow tract PVCs patients who underwent radiofrequency catheter ablation at the Second Xiangya Hospital,Central South University between January 2015 and August 2017.We compared the QRS wave amplitudes in the surface twelve leads electrocardiography between PVCs originating from ASC and right ventricular outflow tract(RVOT).Results(1)The origin sites of PVCs were ASC(n=28,27.5％)and RVOT(n=74,72.5％).The lead V1R/S wave amplitude ratio and lead aVL S wave amplitude were significantly higher in the ASC group than in the RVOT group[(1.14±1.32)vs.(0.16±0.18),P＜0.001;(0.99±0.36)mV vs.(0.56±0.26)mV,P＜0.001].The areas under the receiver operating characteristic curve(AUCs)and 95％confidence intervals of V1R/S wave amplitude ratio and aVL S wave amplitude had relatively larger AUCs which were 0.894(0.824-0.964)and 0.831(0.749-0.912),with the cut-offs of 0.25 and 0.80 respectively.(2)The sensitivity,specificity and accuracy of the lead V1R/S wave amplitude ratio＞0.25 to identify ASC originating PVCs were 78.9％,83.7％and 82.4％,respectively.The sensitivity,specificity and accuracy of the lead aVL S wave amplitude＞0.80 mV were 78.6％,85.1％and 83.3％,respectively.The lead aVL S wave amplitude＞0.80 mV in combination with the lead V1R/S wave amplitude ratio＞0.25 was applied to developed a new diagnostic approach and the sensitivity,specificity and accuracy were 60.7％,93.2％and 84.3％,respectively.Conclusions Lead aVL in combination with lead V1 could be applied to develop a more accurate method for identifying ASC originating PVCs.

Treatment of pulmonary sinus cusp-derived ventricular arrhythmia with reversed U-curve catheter ablation / 中国介入心脏病学杂志

Objective To summarize the ablation methods,and to provide experience reference for the treatment of pulmonary since cusp(PSC)-derived ventricular arrhythmia(VA)with ablation. Methods A retrospective analysis of the clinical data of 19 patients undergoing catheter ablation for PSC-derived VA in Cardiac Intervention Therapy Center,The Second Xiangya Hospital of Central South University between January 2013 and March 2016 was conducted. Results Among the 19 patients,PSC-derived VA originated from the lower regions of the pulmonary sinuses,generating from the right,left,and anterior sinuses of the PSC were identified in 5,7,and 7 patients,respectively. Twelve patients with PSC-derived VAs originating from the right and anterior sinuses underwent successful reversed U-curve catheter ablation,while the other 7 patients with arrhythmias originating from the left sinus underwent successful ablation with the conventional method(non-reversed U-curve catheter ablation). All the patients were followed-up for 6 to 31 months,and no recurrence of VA or complications were recorded. Conclusions Reversed U-curve catheter ablation is suitable for VA originating from the right and anterior PSCs,while conventional ablation can be used for those originating from the left PSCs.

Neuroendocrine mechanisms of left ventricular dysfunction stimulated by anger stress in rats with atherosclerosis--a putative role of natriuretic peptide

OBJECTIVE@#To investigate the role of natriuretic peptide in the process of left ventricular dysfunction caused by emotional stress.@*METHODS@#Adult male SD rats (n=30) and Wistar rats (n=60) were selected in this study. Atherosclerosis models were induced with high-fat diet and excess VD3 injection (eight consecutive weeks), and anger stress models were prepared by resident-intruder stress experiment (two consecutive weeks). Furthermore, left ventricular functions were examined by high-resolution echocardiograph, after which left ventricular myocardium and coronary arteries were prepared for pathological section and observed with electron microscope. At the same time, the hypothalamus, medulla oblongata and left ventricular myocardium were also prepared for pathological sections to detect the localization and expression of ANP, BNP and NPR-A with immunofluorescence and western blot.@*RESULTS@#We found that left ventricular functions of atherosclerosis or emotional stress modeled rats were both inferior to the healthy ones and superior to the combined (atherosclerosis and emotional stress) modeled ones (P<0.05). We also found that atherosclerosis and emotional stress could both cause morphological changes of left ventricular cells and capillary which contribute to apoptosis and hyperblastosis. Further more, there was NPR-A distributed in hypothalamus, medulla oblongata, as well as left ventricular tissues with the same express trend between groups, with atherosclerosis modeled rats the highest and the healthy rats the lowest.@*CONCLUSIONS@#The results of our study suggest that anger stress could cause an excess consumption of ANP, BNP and NPR-A in nervous and cardiovascular system which inhibit the compensatory self-repair function of atherosclerosis rats, leading to a promotion of fibrosis and lipid peroxidation, offering insight into the neuroendocrine mechanisms of left heart function obstacle.

Changes of AFP and beta-hCG in testicular tumors analyzed by a function method / 中华男科学杂志

<p><b>OBJECTIVE</b>To establish a new function method for the analysis of a-fetoprotein (AFP) and beta-hCG in testicular tumors.</p><p><b>METHODS</b>We reexamined the serum levels of AFP and beta-hCG after radical orchiectomy, and calculated the measured coordinate, with the abscissa representing the number of the half-lives of tumor markers, and the ordinate representing the measured value of tumor markers. Referring to the measured value of tumor markers before surgery as a, the number of half-lives as x, and their theoretical value over a period of x elimination half-lives as y (logarithm to the base 2 of y), we calculated the predicted coordinate according to the formula y = log2(a/2x) ==> x + y = log2a (function 1). Then we assessed tumor residue and metastasis by analyzing the relationship between the measured and predicted coordinates.</p><p><b>RESULTS</b>The pathological examination of case 1 revealed a germ cell tumor of a mixed histological pattern of syncytiotrophoblast and yolk sac tumor. The measured coordinates of AFP and beta-hCG were (2.22, 6.21) and (10, 8.38), and the predicted coordinates (2.22, 6.34) and (10, 4.41) , indicating the elimination of the yolk sac tumor and metastasis of the syncytiotrophoblast tumor. Case 2 demonstrated the mixed pathological nature of teratocarcinoma and yolk sac tumor. The measured coordinates of AFP and beta-hCG were (2.67, -1.03) and (12, -3.32), and the predicted coordinates (2.67, 1.41) and (12, -5.80). But the review times of AFP and beta-hCG were out of the effective range of half-lives, with the measured values below the normal, which suggested no tumor residue or metastasis. Case 3 was found to be embryonal carcinoma. The measured coordinate of AFP was (0.22, 9.25) , and the predicted coordinate (0.22, 9.55) , indicating the elimination of tumor.</p><p><b>CONCLUSION</b>The change of the tumor markers predicted by the function method coincided with the natural course of disease in the three cases. The coincidence of the measured with the predicted coordinate after radical orchiectomy indicates no metastasis, while their disagreement suggests possible residue and metastasis of the tumor.</p>

Dural modulation effects of mesenchymal stem cells implantation on myocardial collagen remodeling in a rat model of myocardial infarction / 中华心血管病杂志

<p><b>OBJECTIVE</b>To investigate the modulation effects of mesenchymal stem cells (MSCs) implantation on the collagen remodeling in myocardial infarction.</p><p><b>METHODS</b>Acute myocardial infarction (AMI) was induced in SD rats by left anterior descending coronary artery ligation, and the animals were assigned randomly into the Sham group, MI + PBS group and MI + MSCs group. Echocardiography and hemodynamic examinations were performed to evaluate the cardiac function. HE staining and Masson trichrome staining were used to evaluate the myocardial infarction size. Infarcted area and infarcted expansion index were calculated. The expression of collagens in infarcted hearts was evaluated by immunohistochemistry, RT-PCR and Western blot.</p><p><b>RESULTS</b>(1) Infarct area was significantly reduced post MSCs transplantation [MI + MSCs vs. MI + PBS: (38.27 ± 2.70)% vs. (46.20 ± 3.17)%, P < 0.001]. (2) Cardiac function was significantly improved post MSCs transplantation [MI + MSCs vs. MI + PBS: FS(%): 29.98 ± 4.50 vs. 23.43 ± 3.34, P = 0.005; LVSP (mm Hg, 1 mm Hg = 0.133 kPa): 113.63 ± 10.81 vs. 99.25 ± 16.76, P < 0.05; LVEDP (mm Hg): 12.10 ± 4.28 vs. 20.08 ± 4.26, P < 0.05; +dp/dtmax (mm Hg/s): 4616.63 ± 363.34 vs. 3912.75 ± 248.79, P < 0.05; -dp/dtmax (mm Hg/s): 4254.63 ± 324.34 vs. 3530.88 ± 309.71, P < 0.05]. (3) Collagen synthesis was enhanced in infarcted area and decreased in non-infarcted area post MSCs transplantation (P < 0.05).</p><p><b>CONCLUSIONS</b>MSCs transplantation could enhance the collagen synthesis in infarcted area while decrease the deposition of collagen in non-infarcted area in this MI model. This may be one of the mechanisms by which ventricular remodeling is attenuated post MSCs transplantation.</p>

Prevalence and risk factors of peri-procedure electrical storm in acute myocardial infarction patients underwent emergency percutaneous coronary intervention / 中华心血管病杂志

<p><b>OBJECTIVE</b>To determine the prevalence and to identify risk factors of peri-procedure electrical storm (ES) in patients with acute myocardial infarction (AMI) underwent emergency percutaneous coronary intervention (PCI).</p><p><b>METHODS</b>The clinical data of 228 AMI patients underwent emergency PCI were retrospectively analyzed and patients were divided into ES group (n = 39) and non-ES (n = 189) group. ES was referred to spontaneous ventricular tachycardia or ventricular fibrillation occurring twice or more within 24 h and requiring emergency treatment including anti-arrhythmic medicine and/or cardioversion or defibrillation.</p><p><b>RESULTS</b>ES was diagnosed in 39 out of 228 patients (17.1%) during peri-procedure stage. The incidence of ES in patients with various infarct related arteries (IRA) was as follows: 55.6% with left main artery (LM), 23.7% with right coronary artery (RCA), 12.4% with anterior descending branch (LAD) and 0 with left circumflex artery (LCX). Older age, lager diameter of IRA, higher concentration of CK-MB and cTnT, higher incidence of reperfusion arrhythmia (RA), lower grade of TIMI after PCI and higher mortality were associated with increased risks of ES (The P value was 0.043, 0.012, 0.036, 0.018, 0.001, 0.049, respectively). Gender, systolic pressure, diastolic pressure, random blood glucose level, white blood count and concentration of hs-CRP were similar between ES and non-ES patients. Logistic analysis showed that the diameter of IRA (OR 2.381, 95%CI 1.127-5.028, P = 0.023), TIMI grade of IRA after PCI (OR 4.744, 95% CI 1.773-12.691, P = 0.002) and RA (OR 12.680, 95% CI 4.360-36.879, P = 0.000) were the independent risk factors of per-procedure ES in AMI patients underwent emergency PCI.</p><p><b>CONCLUSIONS</b>The AMI patients with LM as IRA had the highest incidence of ES during emergency PCI and the diameter of IRA, TIMI grade of IRA after PCI and RA were independent risk factors for the development of ES during peri-PCI stage.</p>

Analysis on an early diagnosis grading model for acute aortic dissection / 中华心血管病杂志

<p><b>OBJECTIVE</b>To investigate the value of an early diagnosis grading model derived from the clinical manifestation, laboratory and imaging data for the diagnosis of aortic dissection (AD).</p><p><b>METHODS</b>An early diagnosis grading model was established based on the clinical manifestation, laboratory and imaging data from 182 AD patients who admitted to our department during the last 3 years, 184 patients with chest and back pain served as controls.</p><p><b>RESULTS</b>The sensitivity and specificity of diagnosing AD with the score of 5 is 96.7% and 81.0%, respectively.</p><p><b>CONCLUSION</b>The emergency diagnose of AD could be improved based on the established early grading model based on the stabbing and severe pain, rapid blood pressure increase, asymmetry of the blood pressure and/or the pulse, widened aortic knob, mediastinum or descending aorta on X-ray, and significantly increased D-dimmer level.</p>

Inhibition of Nuclear Factor-?B Activity by Mesenchymal Stem Cells in Rats with Myocardial Infarction / 中华高血压杂志

Objective To investigate the effect of mesenchymal stem cells (MSC) on the activity of nuclear factor (NF)-?B in rats with myocardial infarction.Methods MSC were isolated from SD rats (120—150 g in weight).SD rats (180—200 g in weight) were subjected to MI by left coronary artery occlusion,and were allo- cated into three groups randomly:1)sham group (without ligation of the artery,n=8);2)injection of PBS solu- tion (n=8);3)injection of MSC (n=8).MSC or PBS solution was injected into myocardium from epicardium instantly after MI models were established.Four weeks after transplantation,cardiac function was evaluated u- sing physiological recorder.Western blot were performed to investigate the nuclear factor-? activity.The ex- pressions of tumor necrosis factor (TNF)-? and interleukin (IL)-6 were evaluated by RT-PCR and Western blot. Results 1)Mortality was 20%(2/10) in sham group,33.3%(4/12) in PBS group and 20%(2/10) in MSC group with no statistic differences between them(P=0.646).2) Hemodynamic measurements showed that MSC trans- plantation caused significant improvement in cardiac function,comparing with MI+PBS group.3) MSC inhibi- ted the activities of NF-?B in myocardium and down-regulated the expression of TNF-? and IL-6 in mRNA and protein level.Conclusion Transplantation of MSC improved cardiac function in MI rats,which may partly at- tribute to their immuno-inflammatory regulation mechanism.

Changes of plasma CD40L and PAPP-A in patients with acute coronary syndrome after the PCI operation / 中南大学学报(医学版)

OBJECTIVE@#To observe the changes and significance of plasma CD40L and pregnancy-associated plasma protein-A (PAPP-A) in acute coronary syndrome (ACS) patients after percutaneous coronary intervention (PCI) operation.@*METHODS@#According to the occurrence of primary heart events or restenosis 6 months after the PCI, 68 patients were divided into the ACS group and the stable angina pectoris (SAP) group. Plasma CD40L and PAPP-A after the PCI operation were measured and compared. Thirty-six patients underwent repeated angiography after the PCI. Their baseline and follow up angiograms were compared by quantitative coronary angiography to assess the incidence of restenosis.@*RESULTS@#CD40L and PAPP-A after the PCI operation were higher in the ACS group than that in the SAP group.The group having primary heart events within 6 months had higher level of PAPP-A after the PCI. The group having restenosis 6 months had higher level of PAPP-A after the PCI. The change of later loss index of coronary artery lumen diameter was correlated with PAPP-A level after the PCI.@*CONCLUSION@#CD40L and PAPP-A were higher in the ACS group, indicating the possible mechanism by which CD40L facilitates the plaque rupture via up-regulating the PAPP-A expression.Plasma PAPP-A level after the PCI possibly for cases the occurrence of primary heart events or restenosis within 6 months.

Peripheral vascular complications after the cardiac catheterization / 中南大学学报(医学版)

OBJECTIVE@#To explore the cause, the clinical manifestation and the management of peripheral vascular complications after cardiac catheterization.@*METHODS@#Clinical data of patients with peripheral vascular complications were analyzed retrospectively.@*RESULTS@#Of the 4,531 patients, 122 (2.7%) had peripheral vascular complications, including local hematoma (86 cases, 1.90%), pseudoaneurysm (15 cases, 0.33%), arteriovenous fistula (8 cases, 0.18%), femoral venous thrombosis (5 cases, 0.11%), excessive hemorrhage (5 cases, 0.11%), femoral arterial thrombosis (2 cases, 0.04%), and femoral nerve malfunction (1 case, 0.02%). All complications were relieved after conservative therapy except that one case needed surgery.@*CONCLUSION@#Peripheral vascular complications are associated with anticoagulation, diabetes, and hypertension. Prognosis of overwhelming complications is good, as long as patients are treated timely and appropriately.

Characterizations of atrial contractions triggering paroxysmal atrial fibrillation and the effect of atrial fibrillation prevention pacing / 中南大学学报(医学版)

OBJECTIVE@#To evaluate the electrocardiographic characterizations of atrial contractions(AC) triggering paroxysmal atrial fibrillation(AF), and to explore the effects of AF prevention pacing on their electrocardiographic characterizations.@*METHODS@#Twenty-four patients with the implantation of AF therapy pacemaker(Vitatron 900E) were analyzed by AC triggering paroxysmal AF with Holter monitoring in the study. AC compluing interval, compensatory pause and frequency 2 minutes before the AF or during the AC were compared between the induced paroxysmal AF group and noinduced paroxysmal AF group, and the preventive effect of AF on the post-PAC response program was investigated.@*RESULTS@#There was significant difference in the AC compluing interval [(352.3 +/-30.4) vs (421.8 42.5)ms], compensatory pause [(963 +/-109) vs (733 +/-124) ms], and frequency [(34.8 +/-18.9) vs (12.7 +/-8.7)/min] 2 minutes before the AF or during the AC in the induced paroxysmal AF group, compared with those in the noinduced paroxysmal AF group (all P<0.05). The AF of 7 patients were controlled by atrial overdrive pacing therapy, 17 patients by post-AC-response or/and post-exercise control therapy, 6 patients by the above therapy combining with cordarone (0.2g/d).@*CONCLUSION@#AC triggering paroxysmal AF is related to the compluing interval, compensatory pause and frequency 2 minutes before the paroxysmal AF or during the AC, AF prevention pacing may be helpful for the paroxysmal AF induced by AC.

Treatment of postcatheterization femoral arteriovenous fistulas with simple prolonged bandaging / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>The methods for the treatment of postcatheterization femoral arteriovenous fistulas (AVF-s) - simple observation, ultrasound guided compression, covered stents implantation and coil embolization have poor outcome. Surgery is the standard method for treatment of femoral AVFs, but it is a traumatic operation. In this study, we report the results of the treatment of postcatheterization femoral AVFs by simple prolonged compressing bandage.</p><p><b>METHODS</b>To treat iatrogenic femoral AVFs caused by transfemoral catheterization, prolonged binding with elastic or common bandage was applied in 16 cases. Catheterization was performed in 7 cases for radiofrequency current catheter ablation, in 4 for occlusion of congenital heart disease, in 3 for percutaneous coronary intervention, in 1 for coronary angiography and in 1 for right heart catheterization.</p><p><b>RESULTS</b>All iatrogenic femoral AVFs were healed after simple binding with elastic or common bandage for 4 - 46 days (mean (15 +/- 10) days). During the period of binding, local skins ulceration occurred at puncture site in two cases and femoral vein thrombus was found in one patient. During 6 - 24 months (mean (11.8 +/- 3.6) months) followup with colour Doppler ultrasonography, no recurrent arteriovenous shunting or other complications were observed.</p><p><b>CONCLUSION</b>The results suggest that simple prolonged bandaging for postcatheterization femoral AVFs is an effective and economical procedure.</p>

Effect of atrial pacing on the sleep apnea syndrome in elderly patients / 中南大学学报(医学版)

OBJECTIVE@#To evaluate the efficacy of atrial pacing to increase the heart rate during sleep in elderly patients with sleep apnea syndrome.@*METHODS@#Sixteen elderly patients with central type or obstructive type sleep apnea received permanent atrial-synchronous ventricular pacemakers for symptomatic sinus bradycardia were analysed in this study. All patients received polysomnographic evaluations for 3 consecutive nights. All patients were evaluated at the base-line, and then were randomly divided into 2 groups at the first night. In the following 2 nights, one group was monitored in spontaneous rhythm model and the other in dual-chamber pacing model with atrial overdrive (increasing by 15 beats per minute on the basic rate of the mean nocturnal sinus), and then the two groups were switched at the third night. The total duration and number of episodes of sleep apnea or hypopnea were analyzed, and compared between the two models.@*RESULTS@#The mean 24 h sinus rate in the spontaneous rhythm mode was 55+/-9 beats per minute at the base line, as compared in the 72+/-4 beats per minute in the atrial overdrive pacing model. There was statistic significant difference between the 2 models (P0.05 ]. The hypopnea index reduced from 9+/-3 in the spontaneous rhythm model to 3+/-3 in the atrial overdrive pacing model (P<0.01). The index of apnea and hypopnea was 28+/-21 in the spontaneous rhythm model, as compared with 10+/-13 in the atrial overdrive pacing model (P<0.01).@*CONCLUSION@#Atrial overdrive pacing can significantly reduce the number of episodes of central type or obstructive type sleep apnea, but doesn't decrease the total sleep time in elderly patients with sleep apnea syndrome.