Relationship between the activity for photocatalytic H_(2)O overall splitting(HOS)and the electron occupancy on d orbits of the active component in photocatalysts shows volcanic diagram,and specially the d^(10)electro...Relationship between the activity for photocatalytic H_(2)O overall splitting(HOS)and the electron occupancy on d orbits of the active component in photocatalysts shows volcanic diagram,and specially the d^(10)electronic configuration in valley bottom exhibits inert activity,which seriously fetters the development of catalytic materials with great potentials.Herein,In d^(10)electronic configuration of In_(2)O_(3)was activated by phosphorus atoms replacing its lattice oxygen to regulate the collocation of the ascended In 5p-band(Inɛ5p)and descended O 2p-band(Oɛ2p)centers as efficient active sites for chemisorption to*OH and*H during forward HOS,respectively,along with a declined In 4d-band center(Inɛ4d)to inhibit its backward reaction.A stable STH efficiency of 2.23%under AM 1.5 G irradiation at 65°C has been obtained over the activated d^(10)electronic configuration with a lowered activation energy for H_(2)evolution,verified by femtosecond transient absorption spectroscopy,in situ diffuse reflectance infrared Fourier transform spectroscopy and theoretical calculations of dynamics.These findings devote to activating d^(10)electronic configuration for resolving the reaction energy barrier and dynamical bottleneck of forward HOS,which expands the exploration of high-efficiency catalytic materials.展开更多
An ishemic ventricular tachyarrhythmias canine model was established in open-chest dogs subjected to programmed electrical stimulation (PES)for 5-8 days after acute myocardial infarction. The electrophysiologic effect...An ishemic ventricular tachyarrhythmias canine model was established in open-chest dogs subjected to programmed electrical stimulation (PES)for 5-8 days after acute myocardial infarction. The electrophysiologic effects of neferine (Nef) and procainamide (PA) were observed in this model. With routine methods of PES,ventricular tachycardia (VT)and ventricular fibrillation (VF) could be reproducibly initiated. Both drugs lengthened the QTc interval (P【0.01) and effective refractory period(ERP)of normal and ischemic ventricular myocardia (NERP and IERP) respectively (P【0.01), decreased the dispersion of ERP in ischemic myocardium and the dispersion of ERP in left ventricle (P【0.01), and increased the diastolic excitability threshold of normal and ischemic ventricular myocardia (P【0.01). The two compounds prevented the PES-induced VT or VF (Nef group P【0.01, PA group P【0.05) and ischemia-induced VF (P【0.05). The results indicated that neferine and procainamide may be effective in preventing the onset of reentrant ventricular tachyarrhythmias after myocardial ischemic damage in dogs.展开更多
Objective To establish a canine model of electrophysiologic - electropharmacology as assessed by programmed electrical stimulation (PES),and to observe the electrophysiologic effects of Procainamide(PA) on normal and...Objective To establish a canine model of electrophysiologic - electropharmacology as assessed by programmed electrical stimulation (PES),and to observe the electrophysiologic effects of Procainamide(PA) on normal and ischemic myocardium in case of ischemic ventricular tachyarrhythmia in this model. Methods A ishemic ventricular tachyarrhythmias canine model was established in open-chest dogs subjected to programmed electrical stimulation(PES)for 5-8 days after acute myocardial infarction. The electrophysiologic effects of procainamide were observed in this model. With routine methods of PES,ventricular tachycardia(VT) and ventricular fibrillation (VF) could be reproducibly initiated. Results Procainamide distinctly lengthened the QTc interval (P【0.01) and effective refractory period(ERP) of normal and ischemic ventricular myocardium(NERP and IERP) respectively (P【0.01), decreased the dispersion of ERP in ischemic myocardium and the dispersion of ERP in left ventricle (P【0.01), and increased the diastolic excitability threshold of normal and ischemic ventricular myocardium remarkably (P【0.01). Procainamide effectively prevented the PES-induced VT or VF (P【0.05) and ischemia-induced VF (P【0.05). Conclusion The results indicated that PES-induced VT/VF were highly reproducible and reliable, this canine model is a worthy and reliable one, procainamide may be effective in preventing the onset of VT and VF after myocardial ischemic damage, and deserves further attention as an antifibrillatory agent.展开更多
Hydrogen sulfide (H2S) is the third gaseous signaling molecule discovered in recent years, and plays an important physiological role in the cardivascular system. To explore the effects of different doses of exogenou...Hydrogen sulfide (H2S) is the third gaseous signaling molecule discovered in recent years, and plays an important physiological role in the cardivascular system. To explore the effects of different doses of exogenous H2S on the electrocardiogram (ECG) of rats generally anesthetized by zoletil, different doses of NariS solution were used for the intervention of intraperitoneal injection 20 rain before the zoletil anesthesia. The ECGs of rats from each treatment group during the time range of 10^th-50^th min were determined under general anesthesia, and then were compared with those from the control group. The results showed that exogenous H2S could significantly reduce the Q-T interval time limit, thus played a role in slowing tachycardia or arrhythmia and other anomalies, thereby protecting the heart. S-T segment and T segment evaluation values were significantly reduced, which might be associated with bradycardia.展开更多
A canine model of ischemic ventricular tachyarrhythmias was established in open-chest dogs subjected to programmed electrical stimulation (PES) for 5 ̄8 days after acute myocardial infarction. The electrophysiologic e...A canine model of ischemic ventricular tachyarrhythmias was established in open-chest dogs subjected to programmed electrical stimulation (PES) for 5 ̄8 days after acute myocardial infarction. The electrophysiologic effects of sophoridine (Sop) and procainamide (PA) were observed in this canine model. With routine methods of PES, ventricular tachycardia (VT) and ventricular fibrilation (VF) could be reproducibly initiated in this model. Both drugs distinctly lengthened the QTc interval ( P <0.01) and the effective refractory period (ERP) in normal and ischemic ventricular myocardium ( P <0.01), decreased the dispersion of ERP in ischemic myocardium and the dispersion of ERP in left ventricle (P <0.05), and increased the diastolic excitability threshold of normal and ischemic ventricular myocardium remarkably ( P <0.01). Both drugs effectively prevented the PES-induced VT or VF and ischemia-induced VF ( P <0.05). The results indicated that this canine model is a good and reliable one, sophoridine and procainamide may be effective in preventing the onset of reentrant ventricular tachyarrhythmias after myocardial ischemic damage.展开更多
Objective Early researches found that different heartbeat perceivers have different heartbeat evoked potential (HEP)waves.Two tasks were considered in our experiments to get more details about the differences betwee...Objective Early researches found that different heartbeat perceivers have different heartbeat evoked potential (HEP)waves.Two tasks were considered in our experiments to get more details about the differences between good and poor heartbeat perceivers at attention and resting state.Methods Thirty channels of electroencephalogram(EEG)were recorded in 22 subjects,who had been subdivided into good and poor heartbeat perceivers by mental tracking task. Principal component analysis(PCA)was applied to remove cardiac field artifact(CFA)from the HEP.Results(1)The good heart-beat perceivers showed difference between attention and resting state in the windows from 250 ms to 450 ms after R wave at C3 location and from 100 ms to 300 ms after R wave at C4 location;(2)The difference waveforms between good and poor heartbeat perceivers was a positive waveform at FZ from 220 ms to 340 ms after R wave,which was more significant in attention state.Conclusion Attention state had more effect on the HEPs of good heartbeat perceivers than that of poor heartbeat perceivers;and perception ability influenced HEPs more strongly in the attention state than in the resting state.展开更多
Objective: Myocardial infarction (MI) is the main cause of heart failure, but the relationship between the extent of MI and cardiac function has not been clearly determined. The present study was undertaken to investi...Objective: Myocardial infarction (MI) is the main cause of heart failure, but the relationship between the extent of MI and cardiac function has not been clearly determined. The present study was undertaken to investigate early changes in the electrocardiogram associated with infarct size and cardiac function after MI. Methods: MI was induced by ligating the left anterior descending coronary artery in rats. Electrocardiograms, echocardiographs and hemodynamic parameters were assessed and myocardial infarct size was measured from mid-transverse sections stained with Masson抯 trichrome. Results: The sum of pathological Q wave amplitudes was strongly correlated with myocardial infarct size (r = 0.920, P < 0.0001), left ventricular ejection fraction (r = -0.868, P < 0.0001) and left ventricular end diastolic pressure (r = 0.835, P < 0.0004). Furthermore, there was close relationship between MI size and cardiac function as assessed by left ventricular ejection fraction (r = -0.913, P < 0.0001) and left ventricular end diastolic pressure (r = 0.893, P < 0.0001). Conclusion: The sum of pathological Q wave amplitudes after MI can be used to estimate the extent of MI as well as cardiac function.展开更多
Physicians previously thought that heart disease was rare in patients with end stage liver disease. However, recent evidence shows that the prevalence of ischemic heart disease and cardiomyopathy is increased in trans...Physicians previously thought that heart disease was rare in patients with end stage liver disease. However, recent evidence shows that the prevalence of ischemic heart disease and cardiomyopathy is increased in transplant candidates compared to most other surgical candidates. Investigators estimate that up to 26% of all liver transplant candidates have at least one critical coronary artery stenosis and that at least half of these patients will die perioperatively of cardiac complications. Cardiomyopathy also occurs in greater frequency. While all patients with advanced cardiac disease have defects in cardiac performance, a larger than expected number of patients have classical findings of dilated, restrictive and hypertropic cardiomyopathy. This may explain why up to 56% of patients suffer from hypoxemia due to pulmonary edema following transplant surgery. There is considerable controversy on how to screen transplant candidates for the presence of heart disease. Questions focus upon, which patients should be screened and what tests should be used. This review examines screening strategies for transplant candidates and details the prognostic value of common tests used to identify ischemic heart disease. We also review the physiological consequences of cardiomyopathy in transplant candidates and explore the specific syndrome of "cirrhotic cardiomyopathy".展开更多
A 78-year-old man with a history of mitral valve prolapse underwent echocardiography during his cardiological check-up examination in 2011 in a symptom-free stage. Echocardiography revealed akinesis of the inferior se...A 78-year-old man with a history of mitral valve prolapse underwent echocardiography during his cardiological check-up examination in 2011 in a symptom-free stage. Echocardiography revealed akinesis of the inferior septum and inferobasal free wall as a novel finding suggesting a distal right coronary artery (RCA) lesion (Figure 1). The systolic left ventricular function was normal. Earlier echocardiographies did not show wall motion abnormalities.展开更多
Objective To describe the clinical characteristics of idiopathic ventricular fibrillation (IVF) with fragmented QRS complex (f-QRS) and J wave in resting electrocardiogram. Methods We reviewed data from 21 case su...Objective To describe the clinical characteristics of idiopathic ventricular fibrillation (IVF) with fragmented QRS complex (f-QRS) and J wave in resting electrocardiogram. Methods We reviewed data from 21 case subjects in our hospital who were resuscitated after cardiac arrest due to IVF and assessed the prevalence of f-QRS and J wave in resting electrocardiogram (ECG). All the case subjects were classified among three groups based on the electrocardiographic morphology: group I, both f-QRS and J wave were observed (n = 6), group II, only J wave was observed (n = 9), group III, neither f-QRS nor J wave was observed (n = 6). Population characteristics, history of syncope or sudden cardiac arrest, incidence of ventricular fibrillation (VF), and circumstance of VF were evaluated among the three groups. Results The incidence of index events (syncope, survived cardiac arrest and VF episodes recorded in implantable cardioverter defibrillator (ICD) or pacemakers) was 13.4 ~ 5.6 per-year in group I, 10.8 ~ 3.9 per-year in group II, and 9.8 -4- 4.2 per-year in group HI. There were significant differences in incidences among the three groups, the most frequent index events were observed in group I. The hazard ratio for incidence was 3.2 (95%CI, 1.1-7.9; P = 0.01). The history and circumstance of the index events were different among the groups. In group I, all the index events occurred during sleep in early morning. In group II, four subjects suffered VF during strenuous physical activities or agitation state, two during sleep in early morning, three in usual activity. In group III, one subject suffered VF during sleep in early morning, one in agitation state, four in usual activity. Conclusions This study suggests that the IVF patients with the combined appearance of f-QRS and J wave in the resting ECG suffer an increased risk of VF, this subgroup of IVF patients has a unique clinical feature.展开更多
In the present paper, effects of electroacupuncture (EA) of 3 points of the Heart Meridian and other 3 points of the Lung Meridian on changes of electrocardiogram (ECG), small intestinal electrogram (SIG) and electroe...In the present paper, effects of electroacupuncture (EA) of 3 points of the Heart Meridian and other 3 points of the Lung Meridian on changes of electrocardiogram (ECG), small intestinal electrogram (SIG) and electroencephalogram (EEG) in intravenous drip of pituitrin induced myocardial ischemia rabbits. The three points of the Heart Meridian are "Shenmen" (HT 7), "Lingdao" (HT 4) and one point between HT 7 and HT 4, the 3 points of the Lung Meridian are "Taiyuan"(LU 9), Lieque (LU 7) and one point between LU 9 and LU 7. These points are punctured with filiform needles and stimulated electrically by setting the parameters being frequency of 2.5 Hz, dense sparse waves and duration of 10 min. Results display that the regulative effect of EA of the Heart Meridian is superior to that of EA of the Lung Meridian on the three indexes, showing a closer correlation between the whole Heart Meridian and activities of ECG, SIG and EEG.展开更多
Cardiac resynchronization therapy (CRT) is associated with a favorable outcome only in patients with left bundle branch block (LBBB) pattern and in patients with a QRS duration 〉 150 ms, in patients with non-LBBB...Cardiac resynchronization therapy (CRT) is associated with a favorable outcome only in patients with left bundle branch block (LBBB) pattern and in patients with a QRS duration 〉 150 ms, in patients with non-LBBB pattern with a QRS duration of 120-150 ms usually is not beneficial. After adjusting for QRS duration, QRS morphology was no longer a determinant of the clinical response to CRT. In contrast to the mainstream view, we hypothesized that the unfavorable CRT outcome in patients with non-LBBB and a QRS duration of 120-150 ms is not due to the QRS morphology itself, but to less dyssynchrony and unfavorable patient characteristics in this subgroup, such as more ischemic etiology and greater prevalence of male patients compared with patients with LBBB pattern. Further, the current CRT technique is devised to eliminate the dyssynchrony present in patients with LBBB pattern and inappropriate to eliminate the dyssynchrony in patients with non-LBBB pattern. We also hypothesized that electrocardiography may also provide information about the presence of interventricular and left intraventricular dyssynchrony and the approximate location of the latest activated left ventricular (LV) region. To this end, we devised new ECG criteria to estimate interventricular and LV intraventricular dyssynchrony and the approximate location of the latest activated LV region. Our preliminary data demonstrated that the latest activated LV region in patients with nonspecific intraventricular conduction disturbance (NICD) pattern might be at a remote site from that present in patients with LBBB pattern, which might necessitate the invention of a novel CRT technique for patients with NICD pattern. The application of the new interventricular and LV intraventricular dyssynchrony ECG criteria and a potential novel CRT technique might decrease the currently high nonresponder rate in patients with NICD pattern.展开更多
Cardiac arrhythmia is an abnormal rate and/or rhythm of a heart due to its abnormal electrical impulse origination and/or propagation. Various etiologies can cause arrhythmias. Heart failure (HF) is a clinical syndr...Cardiac arrhythmia is an abnormal rate and/or rhythm of a heart due to its abnormal electrical impulse origination and/or propagation. Various etiologies can cause arrhythmias. Heart failure (HF) is a clinical syndrome due to an impaired heart that can not pump sufficient blood to meet the systemic metabolic needs.展开更多
Objective. To study the mechanism and effects of blood perfusion to the acute ischemic region of myocardium through Ho-YAG laser channels with myocardial contrast echocardiography. Methods. To produce the model of acu...Objective. To study the mechanism and effects of blood perfusion to the acute ischemic region of myocardium through Ho-YAG laser channels with myocardial contrast echocardiography. Methods. To produce the model of acute myocardial ischemia,we partially ligated the left anterior decending(LAD)coronary artery of canine hearts between lst.and 2nd.diagonal branches and then performed transmyocardial revascularization in this region with Ho-YAG laser.Myocardial contrast echocardiography was made with a new generation of ultrasound contrast agent and second harmonic imaging of this region before,after ischemia and after laser revascularization.Pictures were taken with “R” wave trigger skill. Results.Acoustic density derterming in the ischemia region (anterior wall)with MCE(myocardial contrast echocardiography)was obviously decreased(540±181) after the LAD was ligated,as compared with before(1169±161, P<001).It was increased remarkably after transmyocardial laser revascularizatuon(TMLR)(112±201, P<001)as compared with that when ischemia and approximated to that before ischemia(P>005).There were no differences in acoustic density in the lateral wall(as control)among these comprehensive three periods(P>005).Contrast in the laser region developed one cardiac cycle ahead of that in the non-ischemic normal region. Conclusion.Acute ischemic myocardium can be perfused by oxygenated blood from the left ventricle through Ho-YAG laser channels.Evidence of blood perfusion through laser channels during systolic phase was detected,and myocardial contrast ultrasonography using intravenous perfluorocarbon-exposed sonicated dextrose albumin rnay be regarded as a reliable method in the study of transmyocardial revascularization.展开更多
One hundred and twenty-five patients with cardiovascular disease were examined by biplanar transesophageal echocardiography (BTEE), including 67 with rheumatic heart disease (7 monitored during operation), 22 with ao...One hundred and twenty-five patients with cardiovascular disease were examined by biplanar transesophageal echocardiography (BTEE), including 67 with rheumatic heart disease (7 monitored during operation), 22 with aortic diseases, 20 with congenital heart diseases. and 16 with other kinds of heart disease. The results showed that BTEE was not influenced by corpulent and pulmonary emphysema and was better than transthoracic echocardiography at imaging the interatrial septum, left atrium and left atrial appendage, thoracic aorta, and mitral artificial valve and at intraoperative monitoring. BTEE was also better than single-plane transesophageal echocardiography,because BTEE could be used to observe the heart and thoracic aorta in transverse and longitudinal planes, thus enlarging the transmission 'window' as well as allowing the entire lesion to be imaged.This study suggests that BTEE will have good prospects in clinical application.展开更多
Objective To explore the infarct sites in patients with inferior wall acute myocardial infarction (AMI) concomitant with ST segment elevation in leads V1-V3 and leads V3R-V5R. Methods Five patients diagnosed as inf...Objective To explore the infarct sites in patients with inferior wall acute myocardial infarction (AMI) concomitant with ST segment elevation in leads V1-V3 and leads V3R-V5R. Methods Five patients diagnosed as inferior, right ventricular, and anteroseptal walls AMI at admission were enrolled. Electrocardiographic data and results of isotope ^99mTc-methoxyisobutylisonitrile (MIBi) myocardial perfusion imaging and coronary angiography (CAG) were analyzed. Results Electrocardiogram showed that ST segment significantly elevated in standard leads Ⅱ, Ⅲ, aVF, and leads V1-V3, V3R-V5R in all five patients. The magnitude of ST segment elevation was maximal in lead V1 and decreased gradually from lead V1 to V3 and from lead V1 to V3R-V5R. There was isotope ^99mTc-MIBI myocardial perfusion imaging defect in inferior and basal inferior-septal walls. CAG showed that right coronary artery was infarct-related artery. Conclusions The diagnostic criteria for basal inferior-septal wall AMI can be formulated as follows: ( 1 ) ST segment elevates ≥2 mm in lead V1 in the clinical setting of inferior wall AMI; (2) the magnitude of ST segment elevation is the tallest in lead V1 and decreases gradually from lead V1 to V3 and from lead V1 to V3R-V5R. With two conditions above, the basal inferior-septal wall AMI should be diagnosed.展开更多
ObjectiveTo investigate the diagnostic value of 18F-fluorodeoxyglucose positron emission tomography (18F-FDG PET) in the as-sessment of myocardial viability in patients with known coronary artery disease (CAD) whe...ObjectiveTo investigate the diagnostic value of 18F-fluorodeoxyglucose positron emission tomography (18F-FDG PET) in the as-sessment of myocardial viability in patients with known coronary artery disease (CAD) when compared to99mTc single photon emission computed tomography (SPECT) and echocardiography, with invasive coronary angiography as the gold standard.MethodsThirty patients with diagnosed CAD met the selection criteria, with 10 of them (9 men, mean age 59.5 ± 10.5 years) undergoing all of these imaging proce-dures consisting of SPECT and PET, echocardiography and invasive angiography. Diagnostic sensitivity of these less invasive modalities for detection of myocardial viability was compared to invasive coronary angiography. Inter- and intra-observer agreement was assessed for di-agnostic performance of SPECT and PET.ResultsOf all patients with proven CAD, 50% had triple vessel disease. Diagnostic sensitivity of SPECT, PET and echocardiography was 90%, 100% and 80% at patient-based assessment, respectively. Excellent agreement was achieved between inter-observer and intra-observer agreement of the diagnostic value of SPECT and PET in myocardial viability (k= 0.9). Conclusion18F-FDG PET has high diagnostic value in the assessment of myocardial viability in patients with known CAD when com-pared to SPECT and echocardiography. Further studies based on a large cohort with incorporation of18F-FDG PET into patient management are warranted.展开更多
Background Cardiac implantable electronic devices (CIEDs) greatly improve survival and life quality of patients. However, there are gender differences regarding both the utilization and benefit of these devices. In ...Background Cardiac implantable electronic devices (CIEDs) greatly improve survival and life quality of patients. However, there are gender differences regarding both the utilization and benefit of these devices. In this prospective CIED registry, we aim to appraise the gender differences in CIED utilization in China. Methods Twenty centers from 14 provinces in China were included in our registry study. All patients who underwent a CIED implantation in these twenty centers between Jan 2015 and Dec 2016 were included. Results A total of 8570 patients were enrolled in the baseline cohort, including 7203 pacemaker, 664 implantable cardiac defibrillators (ICD) implants and 703 cardiac resynchronization therapy device (CRT/D). Totally, 4117 (48.0%) CIED patients were female, and more than 59% pacemaker patients were female, but women account only one third of ICD or CRT/D implantation in this registry. There were significant differences between genders at pacemaker and ICD indications. Female was more likely received a pacemaker due to sick sinus syndrome (SSS) (63.9% vs. 51.0%, P 〈 0.001). Female patients receiving an ICD were more likely due to cardiac ion channel disease (29.2% vs. 4.2%, P 〈 0.001). The percentage of utilization of dual-chamber pacemaker in female patients was significantly higher than male (85.3% vs. 81.1%, P 〈 0.001). But male patients were more likely received a cardiac resynchronization therapy devices with defibrillator than female (56.5% vs. 41.9%, P = 0.001). In pacemaker patient, male was more likely to have structure heart disease (31.3% vs. 28.0%, P = 0.002). In ICD patient, male patients were more likely to have ischemic heart disease (48.2% vs. 29.2%, P 〈 0.001). The mean age of women at the time of CRT/D implantation was older than men (P = 0.014). Nonischemic cardiomyopathy (70.9%) was the most common etiology in the patients who underwent the treat?ment of CRT/D, no matter male or female. Conclusions In real-world setting, female do have different epidemiology, pathophysiology and clinical presentation of many cardiac rhythm disorders when compared with male, and all these factors may affect the utilization of CIED implantation. But it also possibility that cultural and socioeconomic features may play a role in this apparent discrimination.展开更多
文摘Relationship between the activity for photocatalytic H_(2)O overall splitting(HOS)and the electron occupancy on d orbits of the active component in photocatalysts shows volcanic diagram,and specially the d^(10)electronic configuration in valley bottom exhibits inert activity,which seriously fetters the development of catalytic materials with great potentials.Herein,In d^(10)electronic configuration of In_(2)O_(3)was activated by phosphorus atoms replacing its lattice oxygen to regulate the collocation of the ascended In 5p-band(Inɛ5p)and descended O 2p-band(Oɛ2p)centers as efficient active sites for chemisorption to*OH and*H during forward HOS,respectively,along with a declined In 4d-band center(Inɛ4d)to inhibit its backward reaction.A stable STH efficiency of 2.23%under AM 1.5 G irradiation at 65°C has been obtained over the activated d^(10)electronic configuration with a lowered activation energy for H_(2)evolution,verified by femtosecond transient absorption spectroscopy,in situ diffuse reflectance infrared Fourier transform spectroscopy and theoretical calculations of dynamics.These findings devote to activating d^(10)electronic configuration for resolving the reaction energy barrier and dynamical bottleneck of forward HOS,which expands the exploration of high-efficiency catalytic materials.
文摘An ishemic ventricular tachyarrhythmias canine model was established in open-chest dogs subjected to programmed electrical stimulation (PES)for 5-8 days after acute myocardial infarction. The electrophysiologic effects of neferine (Nef) and procainamide (PA) were observed in this model. With routine methods of PES,ventricular tachycardia (VT)and ventricular fibrillation (VF) could be reproducibly initiated. Both drugs lengthened the QTc interval (P【0.01) and effective refractory period(ERP)of normal and ischemic ventricular myocardia (NERP and IERP) respectively (P【0.01), decreased the dispersion of ERP in ischemic myocardium and the dispersion of ERP in left ventricle (P【0.01), and increased the diastolic excitability threshold of normal and ischemic ventricular myocardia (P【0.01). The two compounds prevented the PES-induced VT or VF (Nef group P【0.01, PA group P【0.05) and ischemia-induced VF (P【0.05). The results indicated that neferine and procainamide may be effective in preventing the onset of reentrant ventricular tachyarrhythmias after myocardial ischemic damage in dogs.
文摘Objective To establish a canine model of electrophysiologic - electropharmacology as assessed by programmed electrical stimulation (PES),and to observe the electrophysiologic effects of Procainamide(PA) on normal and ischemic myocardium in case of ischemic ventricular tachyarrhythmia in this model. Methods A ishemic ventricular tachyarrhythmias canine model was established in open-chest dogs subjected to programmed electrical stimulation(PES)for 5-8 days after acute myocardial infarction. The electrophysiologic effects of procainamide were observed in this model. With routine methods of PES,ventricular tachycardia(VT) and ventricular fibrillation (VF) could be reproducibly initiated. Results Procainamide distinctly lengthened the QTc interval (P【0.01) and effective refractory period(ERP) of normal and ischemic ventricular myocardium(NERP and IERP) respectively (P【0.01), decreased the dispersion of ERP in ischemic myocardium and the dispersion of ERP in left ventricle (P【0.01), and increased the diastolic excitability threshold of normal and ischemic ventricular myocardium remarkably (P【0.01). Procainamide effectively prevented the PES-induced VT or VF (P【0.05) and ischemia-induced VF (P【0.05). Conclusion The results indicated that PES-induced VT/VF were highly reproducible and reliable, this canine model is a worthy and reliable one, procainamide may be effective in preventing the onset of VT and VF after myocardial ischemic damage, and deserves further attention as an antifibrillatory agent.
文摘Hydrogen sulfide (H2S) is the third gaseous signaling molecule discovered in recent years, and plays an important physiological role in the cardivascular system. To explore the effects of different doses of exogenous H2S on the electrocardiogram (ECG) of rats generally anesthetized by zoletil, different doses of NariS solution were used for the intervention of intraperitoneal injection 20 rain before the zoletil anesthesia. The ECGs of rats from each treatment group during the time range of 10^th-50^th min were determined under general anesthesia, and then were compared with those from the control group. The results showed that exogenous H2S could significantly reduce the Q-T interval time limit, thus played a role in slowing tachycardia or arrhythmia and other anomalies, thereby protecting the heart. S-T segment and T segment evaluation values were significantly reduced, which might be associated with bradycardia.
文摘A canine model of ischemic ventricular tachyarrhythmias was established in open-chest dogs subjected to programmed electrical stimulation (PES) for 5 ̄8 days after acute myocardial infarction. The electrophysiologic effects of sophoridine (Sop) and procainamide (PA) were observed in this canine model. With routine methods of PES, ventricular tachycardia (VT) and ventricular fibrilation (VF) could be reproducibly initiated in this model. Both drugs distinctly lengthened the QTc interval ( P <0.01) and the effective refractory period (ERP) in normal and ischemic ventricular myocardium ( P <0.01), decreased the dispersion of ERP in ischemic myocardium and the dispersion of ERP in left ventricle (P <0.05), and increased the diastolic excitability threshold of normal and ischemic ventricular myocardium remarkably ( P <0.01). Both drugs effectively prevented the PES-induced VT or VF and ischemia-induced VF ( P <0.05). The results indicated that this canine model is a good and reliable one, sophoridine and procainamide may be effective in preventing the onset of reentrant ventricular tachyarrhythmias after myocardial ischemic damage.
基金the National Natural Science Foundation of China(No.30400105);the National Basic Research Development Program(973)(No. 2003CB716106);the National Science Fund for Distinguished Young Scholars of China(No.30525030).
文摘Objective Early researches found that different heartbeat perceivers have different heartbeat evoked potential (HEP)waves.Two tasks were considered in our experiments to get more details about the differences between good and poor heartbeat perceivers at attention and resting state.Methods Thirty channels of electroencephalogram(EEG)were recorded in 22 subjects,who had been subdivided into good and poor heartbeat perceivers by mental tracking task. Principal component analysis(PCA)was applied to remove cardiac field artifact(CFA)from the HEP.Results(1)The good heart-beat perceivers showed difference between attention and resting state in the windows from 250 ms to 450 ms after R wave at C3 location and from 100 ms to 300 ms after R wave at C4 location;(2)The difference waveforms between good and poor heartbeat perceivers was a positive waveform at FZ from 220 ms to 340 ms after R wave,which was more significant in attention state.Conclusion Attention state had more effect on the HEPs of good heartbeat perceivers than that of poor heartbeat perceivers;and perception ability influenced HEPs more strongly in the attention state than in the resting state.
文摘Objective: Myocardial infarction (MI) is the main cause of heart failure, but the relationship between the extent of MI and cardiac function has not been clearly determined. The present study was undertaken to investigate early changes in the electrocardiogram associated with infarct size and cardiac function after MI. Methods: MI was induced by ligating the left anterior descending coronary artery in rats. Electrocardiograms, echocardiographs and hemodynamic parameters were assessed and myocardial infarct size was measured from mid-transverse sections stained with Masson抯 trichrome. Results: The sum of pathological Q wave amplitudes was strongly correlated with myocardial infarct size (r = 0.920, P < 0.0001), left ventricular ejection fraction (r = -0.868, P < 0.0001) and left ventricular end diastolic pressure (r = 0.835, P < 0.0004). Furthermore, there was close relationship between MI size and cardiac function as assessed by left ventricular ejection fraction (r = -0.913, P < 0.0001) and left ventricular end diastolic pressure (r = 0.893, P < 0.0001). Conclusion: The sum of pathological Q wave amplitudes after MI can be used to estimate the extent of MI as well as cardiac function.
文摘Physicians previously thought that heart disease was rare in patients with end stage liver disease. However, recent evidence shows that the prevalence of ischemic heart disease and cardiomyopathy is increased in transplant candidates compared to most other surgical candidates. Investigators estimate that up to 26% of all liver transplant candidates have at least one critical coronary artery stenosis and that at least half of these patients will die perioperatively of cardiac complications. Cardiomyopathy also occurs in greater frequency. While all patients with advanced cardiac disease have defects in cardiac performance, a larger than expected number of patients have classical findings of dilated, restrictive and hypertropic cardiomyopathy. This may explain why up to 56% of patients suffer from hypoxemia due to pulmonary edema following transplant surgery. There is considerable controversy on how to screen transplant candidates for the presence of heart disease. Questions focus upon, which patients should be screened and what tests should be used. This review examines screening strategies for transplant candidates and details the prognostic value of common tests used to identify ischemic heart disease. We also review the physiological consequences of cardiomyopathy in transplant candidates and explore the specific syndrome of "cirrhotic cardiomyopathy".
文摘A 78-year-old man with a history of mitral valve prolapse underwent echocardiography during his cardiological check-up examination in 2011 in a symptom-free stage. Echocardiography revealed akinesis of the inferior septum and inferobasal free wall as a novel finding suggesting a distal right coronary artery (RCA) lesion (Figure 1). The systolic left ventricular function was normal. Earlier echocardiographies did not show wall motion abnormalities.
文摘Objective To describe the clinical characteristics of idiopathic ventricular fibrillation (IVF) with fragmented QRS complex (f-QRS) and J wave in resting electrocardiogram. Methods We reviewed data from 21 case subjects in our hospital who were resuscitated after cardiac arrest due to IVF and assessed the prevalence of f-QRS and J wave in resting electrocardiogram (ECG). All the case subjects were classified among three groups based on the electrocardiographic morphology: group I, both f-QRS and J wave were observed (n = 6), group II, only J wave was observed (n = 9), group III, neither f-QRS nor J wave was observed (n = 6). Population characteristics, history of syncope or sudden cardiac arrest, incidence of ventricular fibrillation (VF), and circumstance of VF were evaluated among the three groups. Results The incidence of index events (syncope, survived cardiac arrest and VF episodes recorded in implantable cardioverter defibrillator (ICD) or pacemakers) was 13.4 ~ 5.6 per-year in group I, 10.8 ~ 3.9 per-year in group II, and 9.8 -4- 4.2 per-year in group HI. There were significant differences in incidences among the three groups, the most frequent index events were observed in group I. The hazard ratio for incidence was 3.2 (95%CI, 1.1-7.9; P = 0.01). The history and circumstance of the index events were different among the groups. In group I, all the index events occurred during sleep in early morning. In group II, four subjects suffered VF during strenuous physical activities or agitation state, two during sleep in early morning, three in usual activity. In group III, one subject suffered VF during sleep in early morning, one in agitation state, four in usual activity. Conclusions This study suggests that the IVF patients with the combined appearance of f-QRS and J wave in the resting ECG suffer an increased risk of VF, this subgroup of IVF patients has a unique clinical feature.
文摘In the present paper, effects of electroacupuncture (EA) of 3 points of the Heart Meridian and other 3 points of the Lung Meridian on changes of electrocardiogram (ECG), small intestinal electrogram (SIG) and electroencephalogram (EEG) in intravenous drip of pituitrin induced myocardial ischemia rabbits. The three points of the Heart Meridian are "Shenmen" (HT 7), "Lingdao" (HT 4) and one point between HT 7 and HT 4, the 3 points of the Lung Meridian are "Taiyuan"(LU 9), Lieque (LU 7) and one point between LU 9 and LU 7. These points are punctured with filiform needles and stimulated electrically by setting the parameters being frequency of 2.5 Hz, dense sparse waves and duration of 10 min. Results display that the regulative effect of EA of the Heart Meridian is superior to that of EA of the Lung Meridian on the three indexes, showing a closer correlation between the whole Heart Meridian and activities of ECG, SIG and EEG.
文摘Cardiac resynchronization therapy (CRT) is associated with a favorable outcome only in patients with left bundle branch block (LBBB) pattern and in patients with a QRS duration 〉 150 ms, in patients with non-LBBB pattern with a QRS duration of 120-150 ms usually is not beneficial. After adjusting for QRS duration, QRS morphology was no longer a determinant of the clinical response to CRT. In contrast to the mainstream view, we hypothesized that the unfavorable CRT outcome in patients with non-LBBB and a QRS duration of 120-150 ms is not due to the QRS morphology itself, but to less dyssynchrony and unfavorable patient characteristics in this subgroup, such as more ischemic etiology and greater prevalence of male patients compared with patients with LBBB pattern. Further, the current CRT technique is devised to eliminate the dyssynchrony present in patients with LBBB pattern and inappropriate to eliminate the dyssynchrony in patients with non-LBBB pattern. We also hypothesized that electrocardiography may also provide information about the presence of interventricular and left intraventricular dyssynchrony and the approximate location of the latest activated left ventricular (LV) region. To this end, we devised new ECG criteria to estimate interventricular and LV intraventricular dyssynchrony and the approximate location of the latest activated LV region. Our preliminary data demonstrated that the latest activated LV region in patients with nonspecific intraventricular conduction disturbance (NICD) pattern might be at a remote site from that present in patients with LBBB pattern, which might necessitate the invention of a novel CRT technique for patients with NICD pattern. The application of the new interventricular and LV intraventricular dyssynchrony ECG criteria and a potential novel CRT technique might decrease the currently high nonresponder rate in patients with NICD pattern.
文摘Cardiac arrhythmia is an abnormal rate and/or rhythm of a heart due to its abnormal electrical impulse origination and/or propagation. Various etiologies can cause arrhythmias. Heart failure (HF) is a clinical syndrome due to an impaired heart that can not pump sufficient blood to meet the systemic metabolic needs.
文摘Objective. To study the mechanism and effects of blood perfusion to the acute ischemic region of myocardium through Ho-YAG laser channels with myocardial contrast echocardiography. Methods. To produce the model of acute myocardial ischemia,we partially ligated the left anterior decending(LAD)coronary artery of canine hearts between lst.and 2nd.diagonal branches and then performed transmyocardial revascularization in this region with Ho-YAG laser.Myocardial contrast echocardiography was made with a new generation of ultrasound contrast agent and second harmonic imaging of this region before,after ischemia and after laser revascularization.Pictures were taken with “R” wave trigger skill. Results.Acoustic density derterming in the ischemia region (anterior wall)with MCE(myocardial contrast echocardiography)was obviously decreased(540±181) after the LAD was ligated,as compared with before(1169±161, P<001).It was increased remarkably after transmyocardial laser revascularizatuon(TMLR)(112±201, P<001)as compared with that when ischemia and approximated to that before ischemia(P>005).There were no differences in acoustic density in the lateral wall(as control)among these comprehensive three periods(P>005).Contrast in the laser region developed one cardiac cycle ahead of that in the non-ischemic normal region. Conclusion.Acute ischemic myocardium can be perfused by oxygenated blood from the left ventricle through Ho-YAG laser channels.Evidence of blood perfusion through laser channels during systolic phase was detected,and myocardial contrast ultrasonography using intravenous perfluorocarbon-exposed sonicated dextrose albumin rnay be regarded as a reliable method in the study of transmyocardial revascularization.
文摘One hundred and twenty-five patients with cardiovascular disease were examined by biplanar transesophageal echocardiography (BTEE), including 67 with rheumatic heart disease (7 monitored during operation), 22 with aortic diseases, 20 with congenital heart diseases. and 16 with other kinds of heart disease. The results showed that BTEE was not influenced by corpulent and pulmonary emphysema and was better than transthoracic echocardiography at imaging the interatrial septum, left atrium and left atrial appendage, thoracic aorta, and mitral artificial valve and at intraoperative monitoring. BTEE was also better than single-plane transesophageal echocardiography,because BTEE could be used to observe the heart and thoracic aorta in transverse and longitudinal planes, thus enlarging the transmission 'window' as well as allowing the entire lesion to be imaged.This study suggests that BTEE will have good prospects in clinical application.
文摘Objective To explore the infarct sites in patients with inferior wall acute myocardial infarction (AMI) concomitant with ST segment elevation in leads V1-V3 and leads V3R-V5R. Methods Five patients diagnosed as inferior, right ventricular, and anteroseptal walls AMI at admission were enrolled. Electrocardiographic data and results of isotope ^99mTc-methoxyisobutylisonitrile (MIBi) myocardial perfusion imaging and coronary angiography (CAG) were analyzed. Results Electrocardiogram showed that ST segment significantly elevated in standard leads Ⅱ, Ⅲ, aVF, and leads V1-V3, V3R-V5R in all five patients. The magnitude of ST segment elevation was maximal in lead V1 and decreased gradually from lead V1 to V3 and from lead V1 to V3R-V5R. There was isotope ^99mTc-MIBI myocardial perfusion imaging defect in inferior and basal inferior-septal walls. CAG showed that right coronary artery was infarct-related artery. Conclusions The diagnostic criteria for basal inferior-septal wall AMI can be formulated as follows: ( 1 ) ST segment elevates ≥2 mm in lead V1 in the clinical setting of inferior wall AMI; (2) the magnitude of ST segment elevation is the tallest in lead V1 and decreases gradually from lead V1 to V3 and from lead V1 to V3R-V5R. With two conditions above, the basal inferior-septal wall AMI should be diagnosed.
文摘ObjectiveTo investigate the diagnostic value of 18F-fluorodeoxyglucose positron emission tomography (18F-FDG PET) in the as-sessment of myocardial viability in patients with known coronary artery disease (CAD) when compared to99mTc single photon emission computed tomography (SPECT) and echocardiography, with invasive coronary angiography as the gold standard.MethodsThirty patients with diagnosed CAD met the selection criteria, with 10 of them (9 men, mean age 59.5 ± 10.5 years) undergoing all of these imaging proce-dures consisting of SPECT and PET, echocardiography and invasive angiography. Diagnostic sensitivity of these less invasive modalities for detection of myocardial viability was compared to invasive coronary angiography. Inter- and intra-observer agreement was assessed for di-agnostic performance of SPECT and PET.ResultsOf all patients with proven CAD, 50% had triple vessel disease. Diagnostic sensitivity of SPECT, PET and echocardiography was 90%, 100% and 80% at patient-based assessment, respectively. Excellent agreement was achieved between inter-observer and intra-observer agreement of the diagnostic value of SPECT and PET in myocardial viability (k= 0.9). Conclusion18F-FDG PET has high diagnostic value in the assessment of myocardial viability in patients with known CAD when com-pared to SPECT and echocardiography. Further studies based on a large cohort with incorporation of18F-FDG PET into patient management are warranted.
文摘Background Cardiac implantable electronic devices (CIEDs) greatly improve survival and life quality of patients. However, there are gender differences regarding both the utilization and benefit of these devices. In this prospective CIED registry, we aim to appraise the gender differences in CIED utilization in China. Methods Twenty centers from 14 provinces in China were included in our registry study. All patients who underwent a CIED implantation in these twenty centers between Jan 2015 and Dec 2016 were included. Results A total of 8570 patients were enrolled in the baseline cohort, including 7203 pacemaker, 664 implantable cardiac defibrillators (ICD) implants and 703 cardiac resynchronization therapy device (CRT/D). Totally, 4117 (48.0%) CIED patients were female, and more than 59% pacemaker patients were female, but women account only one third of ICD or CRT/D implantation in this registry. There were significant differences between genders at pacemaker and ICD indications. Female was more likely received a pacemaker due to sick sinus syndrome (SSS) (63.9% vs. 51.0%, P 〈 0.001). Female patients receiving an ICD were more likely due to cardiac ion channel disease (29.2% vs. 4.2%, P 〈 0.001). The percentage of utilization of dual-chamber pacemaker in female patients was significantly higher than male (85.3% vs. 81.1%, P 〈 0.001). But male patients were more likely received a cardiac resynchronization therapy devices with defibrillator than female (56.5% vs. 41.9%, P = 0.001). In pacemaker patient, male was more likely to have structure heart disease (31.3% vs. 28.0%, P = 0.002). In ICD patient, male patients were more likely to have ischemic heart disease (48.2% vs. 29.2%, P 〈 0.001). The mean age of women at the time of CRT/D implantation was older than men (P = 0.014). Nonischemic cardiomyopathy (70.9%) was the most common etiology in the patients who underwent the treat?ment of CRT/D, no matter male or female. Conclusions In real-world setting, female do have different epidemiology, pathophysiology and clinical presentation of many cardiac rhythm disorders when compared with male, and all these factors may affect the utilization of CIED implantation. But it also possibility that cultural and socioeconomic features may play a role in this apparent discrimination.