ISSN 1671-5411 CN 11-5329/R

2009 Vol. 6, No. 3

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Left ventricular hypertrophy in relation to systolic blood pressure and the angiotensin converting enzyme I/D polymorphism in Chinese
Alexander P. Headley, Yan Li, Yi Zhang, Ji-Yong Ge, Qi-Fang Huang, Ji-Guang Wang
2009, 6(3): 131-136.
Objective There is little population-based data on the prevalence and the environmental or genetic determinants of left ventricular hypertrophy (LVH) in China. The purpose of this paper is to study LVH in relation to systolic blood pressure and the angiotensin converting enzyme (ACE) insertion/deletion(I/D) polymorphism in Chinese. Methods We recorded 12-lead ECG (CardioSoft, v4.2) in 1365 residents in the Jingning County, Zhejiang Province, China. LVH was defined according to the gender-specific Sokolow-Lyon and Cornell product ECG criteria. Results Regardless of whether the Sokolow-Lyon or Cornell product ECG criteria was used, the prevalence of LVH (20.7% and 4.8%, respectively) significantly (P<0.0001) increased with male gender (odds ratio [OR] 2.33 and 7.15) and systolic blood pressure (per 10 mm Hg increase, OR 1.46 and 1.33). If the Sokolow-Lyon criteria was used, the prevalence of LVH was also influenced by alcohol intake (OR 1.44, P=0.03) and body mass index (OR 0.83, P=0.0005). The association between the Sokolow-Lyon voltage amplitude and the ACE I/D polymorphism was dependent on antihypertensive therapy (P=0.01). In 1262 untreated subjects, but not 103 patients on antihypertensive medication, the ACE DD compared with II subjects had significantly higher Sokolow-Lyon voltage amplitudes (29.8±0.6 vs. 28.0±0.5 mV, P=0.02) and higher risk of LVH (OR 1.74, 95% CI: 1.12-2.69, P=0.01). Conclusion LVH is prevalent in Chinese, and is associated with systolic blood pressure and the ACE D allele. The genetic association might be modulated by antihypertensive therapy.
Does high altitude increase risks of the elderly patients with coronary artery disease?
Tian-Yi Wu, Zhong-Yan Zhan, Qin-Li Wu, Suo-Lung Baomu, Yu-Ling Jie, Min Sun
2009, 6(3): 137-141.
Objective To assess the effect of altitude hypoxia on the elderly patients with coronary artery disease (CAD). Methods Three subject groups were surveyed during their train trip on the highest railroad——the Qinghai-Tibet Railway: 22 elderly individuals with documented CAD, 20 healthy elderly controls, and 20 healthy young controls, all of whom from Beijing near the sea level (76 m). Survey questions addressed clinical features of their healthy conditions and aspects of their coronary disease. The baseline study was performed at Xining at an altitude of 2261m, and then during acute exposure to altitudes of 2808 m, 4768m, 5072 m and 4257 m by train for 24 hours. Resting pulse rate, blood pressure, oxygen saturation, electrocardiograph (ECG), and cardiac work estimated by the heart rate-blood pressure double product were obtained five times in each subject at different altitudes. Results On arrival to altitudes between 4768 m and 5072 m, the older passengers, especially those with preexisting coronary disease, had higher HR, higher BP, and lower SaO2, as well as more frequent abnormalities on ECG, as compared to the younger healthy subjects. As compared with the healthy elderly controls, incomplete right bundle branch block, left ventricular hypertrophy, and ST segment depression were more frequently seen in the elderly coronary patients (P<0.01). Cardiac work in group 1 was increased by 13% 12 hours after arrival to altitudes between 2808 m and 5072 m. Oxygen saturation decreased significantly with the altitude increasing by train ascent but improved after inhalation of oxygen. Most of the older subjects tolerated their sojourn at high altitude well except one who developed angina repeatedly with a significant ST segment depression. Conclusions Coronary events and ECG signs of myocardial ischemia are rare in elderly individuals with CAD who travel from sea level to moderate altitudes of 1500m to 2800 m. Patients with CAD who are well compensated at sea level generally tolerate this moderate altitude well. However, it would be prudent for patients with CAD going to altitude above 3000 m. The patients should consult their physician before undertaking a trip to such altitude.
Continuation of cardiopulmonary resuscitation in a Chinese hospital after unsuccessful EMS resuscitation
Xiao-Bo Yang, Yan Zhao, Fei Wang
2009, 6(3): 142-146.
Objective To evaluate the efficacy of the continuation of cardiopulmonary resuscitation (CPR) following transportation to the emergency department in a Chinese hospital after unsuccessful emergency medical services (EMS) CPR. Methods From January 2002 to December 2007, emergency records of non-traumatic patients who were transported to a tertiary teaching hospital after unsuccessful EMS CPR were reviewed. Results Eigty-five patients were included, and 13 patients (15%) accomplished restoration of spontaneous circulation in our emergency department. Resuscitative possibility reached zero at around 23 minutes. One patient was discharged with a favourable neurologic outcome. Conclusions This study shows that the continuation of CPR is not futile and may improve outcomes. The outcomes should be re-evaluated in the future when prehospital information can be combined with in-hospital information.
Cardiac response to exercise in mild-to-moderate chronic obstructive pulmonary disease
Hao-Yan Wang, Qiu-Fen Xu, Yao Xiao
2009, 6(3): 147-150.
Objective Chronic obstructive pulmonary disease (COPD) increases the risk of cardiovascular problem.The symptom of dyspnea on exertion may be associated with pulmonary dysfunction or heart failure, or both. The study objective was to determine whether cardiac dysfunction adds to the mechanism of dyspnea caused mainly by impaired lung function in patients with mild-tomoderate COPD. Methods Patients with COPD and healthy controls performed incremental and constant work rate exercise testing. Venous blood samples were collected in 19 COPD patients and 10 controls before and during constant work exercise for analysis of Nterminal-pro-BNP (NT-pro-BNP). Results Peak oxygen uptake and constant work exercise time (CWET) were significantly lower in COPD group than in control group (15.81±3.65 vs 19.19±6.16 ml/min kg, P=0.035 and 7.78±6.53 min vs 14.77±7.33 min, P=0.015, respectively). Anaerobic threshold, oxygen pulse and heart rate reserve were not statistically significant between COPD group and control group. The NT-pro-BNP levels both at rest and during constant work exercise were higher in COPD group compared to control group, but without statistical significance. The correlations between CWET and NT-proBNP at rest or during exercise in patients with COPD were not statistically significant. Conclusions Heart failure does not contribute to exercise intolerance in mild-to-moderate COPD.
Prevalence of left ventricular dyssynchrony in patients with heart failure assessed by a novelprogrammer-cardioGRAF
Can-Zhan Zhu, Naoto Takahashi, Akira Yamamoto, Masahira Ishikawa, Naomi Kawaguchi, Takahiro Uchida, Kazuo Munakata
2009, 6(3): 151-156.
Objectives Left ventricular systolic dyssynchrony is the most important determinant of response to cardiac resynchronization therapy (CRT), playing a vital role to predict improvement of systolic function or LV reverse remodeling. CardioGRAF is a novel programmer based on the ECG gated single photon emission computed tomography (G-SPECT) imaging to detect LV systolic and diastolic dyssynchrony simultaneously. This study was to investigate the prevalence of systolic and diastolic left ventricular (LV) dyssynchrony in patients with heart failure. Methods We retrospectively studied 69 patients with heart disease, including 31 patients who had symptoms of heart failure (NYHA classⅡ- Ⅲ), and 38 patients who had no symptoms of heart failure (NYHA classⅠ). GSPECT data were analyzed by cardiaGRAF, and measurements included the time to end systole (TES), the time to peak ejection (TPE), the time to peak filling (TPF), TES+TPF and maximal difference (MD) of each parameters were obtained. using the 95th percentile of the control group as a cutoff of 150 ms for MD-TES, 139 ms for MD-TPE, 345 ms for MD-TPF and 315 ms for MD-TES+TPF. Results The prevalence of LV systolic dyssynchrony was significantly higher in heart failure patients with reduced LV ejection fraction (LVEF)<45% (72% for MD-TES; 64% for MD-TPE) compared with heart failure patients with preserved LVEF=45% (14% for both MD-TES and MD-TPE; P=0.002, P=0.005, respectively); The prevalence of MD-TES<150 ms was higher in NYHA class Ⅲ patients (64%) compared with NYHA class Ⅱpatients (27%, P=0.049). However, the prevalence of the LV diastolic dyssynchrony were high but not difference between NYHA class Ⅲ(47% for both MD-TPF and MD-TES+TPF) and class Ⅲ(63% for MD-TPF; 69% for MD-TES+TPF; P=NS) patients as well as between patients with preserved LVEF (43% for both MD-TPF and MD-TES+TPF) and patients with reduced LVEF(64% for MD-TPF; 72% for MD-TES+TPF; P=NS). Conclusions The prevalence of LV systolic dyssynchrony was high in heart failure patients with reduced LVEF. Diastolic dyssynchrony was common in patients with heart failure. CardioGRAF maybe a useful method to detect LV dyssynchrony.
Firebird stent for the treatment of patients with coronary heart disease: short-term clinical outcome
Hai-Ying Wang, Jin-Bo Wang, Feng Liang, Da-Yi Hu, Chu-Zhong Tang, Ming-Ying Wu, Tian-Chang Li, Ji-Yun Wang, Chang-Lin Lu
2009, 6(3): 157-161.
Objective The sirolimus-eluting stent (SES) has dramatically reduced the rate of restenosis in comparison to that with the baremetal stent (BMS).This study aimed to evaluate the short-term efficacy and safety of Firebird stent implantation for patients with coronary heart disease (CHD). Methods From April 2006 through July 2007, 155 patients (mean age 58.93±10.27 years ) with CHD were implanted with Firebird stent or Cypher select stent at Daxing Hospital. Patients were followed up for one year. All-cause mortality, major adverse cardiac events (MACE, including cardiac death, myocardial infarction, recurrence of angina pectoris, heart failure, revascularization, and adverse arrhythmia) and stent thrombosis were compared between the 2 groups. Results Of the 155 consecutive patients, 147 patients were revascularized completely. Of these patients, 48 (with 59 lesions) were treated with Firebird stent, 59 patients (with 75 lesions) with Cypher select stent. The demographic characteristics were similar in the 2 groups. All the angiographic and procedural results were not significantly different between the 2 groups. All-cause mortality, myocardial infarction, recurrence of angina pectoris, MACE and stent thrombosis were almost identical between the 2 groups before discharge, at 6 months and at one year .Conclusion The short-term efficacy and safety of Firebird stent are similar to that of the cypher select stent for the treatment of patients with CHD.
Predictors of atrial fibrillation after coronary artery bypass graft: a meta-analysis
Liang Yin, Zhi-Nong Wang, Yi-Feng Wang, Wen-Tao Wang, Guang-Yu Ji, Xin-Wei Yang, Zhi-Yun Xu
2009, 6(3): 162-167.
Objectives Postoperative atrial fibrillation (AF) has been associated with less favorable outcomes in patients undergoing coronary artery bypass graft surgery (CABG) and may result in increased post-operative morbidity and mortality. A systematic review and meta-analysis of published studies was conducted to examine the risk factors of occurrence AF after CABG. Methods Using the Medline database, the Cochrane clinical trials database and online clinical trial databases, we reviewed all randomized controlled trials (RCTs) and observational studies examining the risk factors of occurrence of AF after CABG. We searched for literature published April 2009 or earlier. Results Our review identified 8 studies (observational studies), involving 14548 patients, that examined the risk factors of occurrence of AF after CABG. Although studies provide conflicting results, the overall outcomes suggests that advanced age, previous hypertension, numbers of bridge vessels may increase the occurrence of AF after CABG, while no significant difference of diabetes, preoperative myocardial infarction, and preoperative medication of β-Blocker have been observed between the AF patients and no-AF patients. Conclusions Patients with advanced age, previous hypertension and more numbers of bridge vessels had higher risk for the occurrence of AF after CABG, and perioperative medication and care must be intensified to decrease the postoperative occurrence of AF.
N-acetylcysteine blocked hypoxia-reoxygenation induced apoptosis through ROS-p38 MAPK signaling pathway in neonatal rat cardiomyocytes
Feng-Xiang Zhang, Ming-Long Chen, Bing Yang, Ke-Jiang Cao
2009, 6(3): 168-172.
Objective Previous investigations have shown that N-acetylcysteine (NAC) could regulate diverse cell type’s apoptosis. The purpose of this study was to evaluate the mechanism of NAC reversed apoptosis of cardiomyocytes induced by hypoxia-reoxygenation (H/R). Methods Cardiomyocytes were treated with hypoxia 6 h and reoxygenation 72 h in the absence and presence of NAC (100μmol/L). The ROS was assayed by using Image-iTTM LIVE green reactive oxygen species detection kit. The viability of cell was assayed with trypan blue. Early stages of apoptosis were assessed by flow cytometry using Annexin V, and late stages of apoptosis were assessed using TUNEL system. Bcl2 and bax mRNA levels were determined by real-time quantitative PCR. Bcl2, bax, p38 and pp38 protein levels were determined by western blot. Results We found that H/R could markedly increase ROS generation and induce the apoptosis of cardiomyocytes (P<0.01). NAC (100μmol/L) significantly reduced the generation of ROS and apoptosis (P all <0.01). NAC also significantly reduced the protein ratio of pp38 and p38 and increased the RNA and protein ratio of bcl2 and bax (P all <0.01). Conclusion The results showed that NAC significantly reduced apoptosis through inhibiting the phosphorylation of p38 signal pathway, which has potential value for clinical cardiac diseases
Valsartan prevents the development of rabbit’s heart failure by restoring calcium uptake ofsarcoplasmic reticulum
Cao Zou, Zhi-Hua Liu, Fu-Zheng Qu, Bin Jiang, Jian-Ping Song, Jie Hui, Xu-Jie Cheng, Lian-Hua Han, Wen-Ping Jiang
2009, 6(3): 173-177.
Objective Clinical evidence has suggested that AT1 receptor blocker (ARB) could prevent the development of heart failure. Decreased sarcoplasmic reticulum(SR) Ca2+ content, which is due to reduced SR calcium reuptake by SERCA2a, is responsible for defective systolic function in failing heart. To better understand how ARB could improve cardiac systolic dysfunction, we studied the effects of Valsartan on calcium reuptake of SR and its regulatory proteins in heart failure rabbits. Methods Thirty rabbits were divided into three groups:sham rabbits(controls, n=11), rabbits with heart failure treated with Valsartan (n=11) and rabbits with heart failure but without Valsartan treatment (n=8).Rabbit heart failure model was established by volume plus pressure overload. Cardiac function was measured by echocardiography. SR calcium uptake was determined by measuring extra vesicular free [Ca2+] changes in a fluorescence spectrophotometer. SERCA2a, Ser16-phosphorylated phospholamban (p-PLB), PKA and PP1á protein abundance were determined by use of Western blot analysis. Results Compared to control rabbits, the ejection fractions in the HF rabbits were significantly decreased (P<0.05), these changes could be significantly attenuated by Valsartan treatment (P<0.05).Calcium reuptake of SR, activity of SERCA2a and PKA decreased in heart failing myocytes (P<0.05), with down regulations of p-PLB, SERCA2a and PKA, but up regulation of PP1αin ventricular samples from the failing rabbits (P<0.05). All of these changes were attenuated by Valsartan treatment (all P<0.05). Conclusion Valsartan improved cardiac function in volume plus pressure overload induced heart failure of rabbits possibly by restoring the SR calcium uptake resulted from attenuating the activities and expressions of SERCA2a and its regulatory proteins.
In situ observation of surface structures of cardiovascular endothelial cells with atomic force microscope
Tong Yin, Yu-Sheng Zhao, Shi-Wen Wang, Jin Luo, Ya-Min Ma, Xiao-Long Ji
2009, 6(3): 178-181.
Objective To observe the surface structures of cardiovascular endothelial cells in situ with atomic force microscope (AFM). Methods Fresh aorta and aortic valve were dissected from 10 healthy male New Zealand white rabbits. Before fixed in 1% formaldehyde, the fresh tissues were washed in the buffer phosphate solution. Under general microscope, the fixed aorta or valve was spread on the double side stick tape which had already been stuck on the glass slide. The intima of aorta or the aorta side of valve was towards upside. Then the specimen was dried under 37 degrees centigrade in an attemperator and was washed with pure water. After dried again, the specimen was loaded on the platform of NanoScope IIIa AFM and was scanned in tapping mode with the scanning speed of 0.5 HZ. Results The surface structures of endothelial cell on the fixed and dried tissue could be observed clearly in situ with AFM. aortic endothelial cells were large, branched and arranged sparsely and parallel to the direction of blood flow, whereas endothelial cells on aorta valve surface were small, less branched and arranged intensively and vertical to the direction of blood flow. When the scanning range was dwindled, granular ultra-structures could be observed on the surface of endothelial cells, and, as the scanning range was dwindled further, fissure and convolution could be seen on the surface of granules from aortic endothelial cells. Centre cavity and surrounding swelling volcano-like structure could be seen on the surface of granules from endothelial cells of aortic valve. Conclusions It’s feasible to observe the surface ultra-structures of cardiovascular endothelial cells in situ with AFM and morphological information provided by AFM might be of clinical value in future histopathological diagnosis.
Role of 5-azacytidine in differentiation of human mesenchymal stem cell sinto cardiomyocytes in vitro
Fang-Ge Deng, Yu-Lin Li, Xiu-Ying Zhang
2009, 6(3): 182-188.
Objective 5-azacytidine could induce the differentiation of stem cells into cardiomyocytes (CMs). The aim of this study was to screen the optimal condition for 5-azacytidine inducing differentiation of human mesenchumal stem cells (hMSCs) into CMs, and the effect of 5-azacytidine on adherence, cell vigor and chromosome karyotype of hMSCs. Methods hMSCs were isolated from human bone marrow and cultured in vitro. The phenotypes of hMSCs were identified by flow cytometric analyses. MTT test was used to investigate the effect of different concentrations of 5-azacytidine on proliferation of hMSCs. Four weeks after 5-azacytidine induction, semi-quantitative RT-PCR, transmission electron microscopy (TEM), single-cell action potentials, detection of cardio-enzyme AST and LDH, cell adherence, cell viability and chromosome karyotype test were performed. Results The typical morphological features of hMSCs were fibroblast-like in shape. hMSCs expressed CD44 and CD105,and did not express CD34, CD45 and CD31. The optimal concentration of 5-azacytidine was 10μmol/L. The shape of hMSCs treated with 5-Azacytidine changed from fusiform to polygon or astrocyte gradually, and passaged cells were evenly arranged as polarity structure. Induced-hMSCs connected with neighbouring cells, forming myotube-like structures 4 weeks later. It was confirmed that induced hMSCs shaped myotubule-like structure and had some of micro-histologic structures of CMs by TEM. RT-PCR showed that induced hMSCs expressed cardiac specific product BNNP and early cardio-myogenesis specific transcription factor NKX2.5mRNA. Besides, induced-MSCs led to the weak action potential and secreted cardio-enzyme AST and LDH. There was no significant difference in cell adherence and viability before and after induction. Both hMSCs and induced-hNSCs kept stable normal diploid nucleus. Conclusion The optimal condition for inducing effect of 5-azacytidine is 10μmol/L and 24-hour incubation; and under this condition, the adherence, vigor and chromosome karyotype of hMSCs would not be affected.
Percutaneous coronary Intervention for ostial occlusion lesion of an anomalous right coronary artery
Shi-Wei Yang, Yu-Jie Zhou
2009, 6(3): 189-192.
Ostial lesions present many challenges for percutaneous coronary intervention (PCI). Coronary anomaly will further increase difficulties in performing PCI for the patient. We present such a case as ostial occlusion of an right coronary artery with high takeoff. A 77-year-old male was referred to our institution with a diagnosis of non-ST elevated acute myocardial infarction. Selective coronary angiography and nonselective ascending aortography could not identify the origin of the right coronary artery. Multi-slices computed tomography showed RCA ostial totally occluded. A successful PCI was performed and a perfect final result was achieved utilized with many tips and tricks, including “buddy wire” technique and “focused-force” angioplasty.