Home About us Contact
|
Home About us Contact | ||
|
|
||
Major Coronary Artery (major + coronary_artery)
Selected AbstractsWhole-heart coronary magnetic resonance angiography at 3 Tesla in 5 minutes with slow infusion of Gd-BOPTA, a high-relaxivity clinical contrast agentMAGNETIC RESONANCE IN MEDICINE, Issue 1 2007Xiaoming Bi Abstract T1 -shortening contrast agents have been used to improve the depiction of coronary arteries with breath-hold magnetic resonance angiography (MRA). The spatial resolution and coverage are limited by the duration of the arterial phase of the contrast media passage. In this study we investigated the feasibility of acquiring free-breathing, whole-heart coronary MRA during slow infusion of the contrast media (0.3 ml/s) for prolonged blood signal enhancement time. Ultrashort TR (3 ms) and parallel data acquisition were used to allow the whole-heart MRA in approximately 5 min. A newly approved gadolinium (Gd)-based high T1 relaxivity contrast agent, gadobenate dimeglumine ([Gd-BOPTA]2,), was used and coronary MRA was performed on a whole-body 3 Tesla (T) system to improve the signal-to-noise ratio (SNR). Results from eight volunteers demonstrate that this coronary MRA method is capable of imaging the whole heart in 4.5 ± 0.6 min. Major coronary arteries are well depicted with high SNR (42.4 ± 12.5) and contrast-to-noise ratio (CNR; 27.1 ± 7.6). Magn Reson Med 58:1,7, 2007. © 2007 Wiley-Liss, Inc. [source] Magnetic resonance imaging for ischemic heart diseaseJOURNAL OF MAGNETIC RESONANCE IMAGING, Issue 1 2007Hajime Sakuma MD Abstract Cardiac MRI has long been recognized as an accurate and reliable means of evaluating cardiac anatomy and ventricular function. Considerable progress has been made in the field of cardiac MRI, and cardiac MRI can provide accurate evaluation of myocardial ischemia and infarction (MI). Late gadolinium (Gd)-enhanced MRI can clearly delineate subendocardial infarction, and the assessment of transmural extent of infarction on late enhanced MRI has been shown to be useful in predicting functional recovery of dysfunctional myocardium in patients after MI. Stress first-pass contrast-enhanced (CE) myocardial perfusion MRI can be used to detect subendocardial ischemia, and recent studies have demonstrated the high diagnostic accuracy of stress myocardial perfusion MRI for detecting significant coronary artery disease (CAD). Free-breathing, whole-heart coronary MR angiography (MRA) was recently introduced as a method that can provide visualization of all three major coronary arteries within a single three-dimensional (3D) acquisition. With further improvements in MRI techniques and the establishment of a standardized study protocol, cardiac MRI will play a pivotal role in managing patients with ischemic heart disease. J. Magn. Reson. Imaging 2007;26:3,13. © 2007 Wiley-Liss, Inc. [source] The association between effort,reward imbalance and coronary atherosclerosis in a Chinese sampleAMERICAN JOURNAL OF INDUSTRIAL MEDICINE, Issue 7 2010Weixian Xu MD Abstract Background Previous studies of job strain and coronary heart disease (CHD) have produced mixed findings. We aimed to examine the association between job stress evaluated by the effort,reward imbalance (ERI) model and coronary atherosclerosis assessed by coronary angiography in a Chinese sample. Methods Three-hundred twenty participants accepting coronary angiography for the first time were enrolled in series. Job stressors were evaluated by the ERI model. The presence and severity of CHD were assessed by measuring the coronary artery stenosis (the presence of >50% luminal stenosis in one or more major coronary arteries). The association between job stressors and CHD was examined by multivariate analysis. Results Compared with the low-level group, high-level effort, overcommitment, and ERI increased CHD risk with odds ratio (OR) 2.5 (95% confidence interval (CI): 1.2,5.0), 2.5 (95% CI: 1.2,5.0), 2.4 (95% CI: 1.2,4.9), respectively, after adjustment for confounders. They were also significantly positively correlated with the complexity of coronary artery lesions, respectively. Dose,response relationships were observed. Conclusions ERI was associated with coronary artery lesions in a sample of Chinese workers. Longitudinal research and interventional designs are needed to confirm the mechanism and to provide evidence for the prevention of CHD. Am. J. Ind. Med. 53:655,661, 2010. © 2010 Wiley-Liss, Inc. [source] Effect of dantrolene in an in vivo and in vitro model of myocardial reperfusion injuryACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 2 2000B. Preckel Background: In skeletal muscle, dantrolene reduces free cytosolic calcium by inhibiting calcium release from the sarcoplasmic reticulum. A similar effect in ischemic-reperfused heart cells would protect myocardial tissue against reperfusion injury. We tested the hypothesis that dantrolene infusion during reperfusion protects the heart against reperfusion injury. Methods: Isovolumetric beating rat hearts were subjected to 30 min of ischemia followed by 60 min of reperfusion. Left ventricular (LV) developed pressure (LVDP) and creatine kinase release (CKR) were determined as indices of myocardial performance and cellular injury, respectively. In the treatment groups, dantrolene (25 (DAN25) or 100 (DAN100) ,mol l,1) was infused during the first 15 min of reperfusion; control hearts received the respective concentration of the vehicle (mannitol (CON25, CON100), each group n=7). To investigate the effects of dantrolene on reperfusion injury in vivo, 18 chloralose-anesthetized rabbits were subjected to 30 min occlusion and 180 min reperfusion of a major coronary artery. LV pressure (LVP), cardiac output (CO), and infarct size were determined. During the last 5 min of ischemia, nine rabbits received 10 mg kg,1 dantrolene intravenously (DAN). Another nine rabbits received the vehicle (dimethylsulfoxide) and served as controls (CON). Results: In isolated rat hearts, there was no recovery of LVDP in any group. Total CKR during 1 h of reperfusion was 845±76 (CON100) and 550±81 U g,1 dry mass (DAN100, P<0.05). In rabbits in vivo, hemodynamic baseline values were similar between groups (CON vs. DAN: LVP, 99±6 (mean±SEM) vs. 91±6mm Hg, P=0.29; CO, 252±26 vs. 275±23 ml min,1, P=0.53). During coronary artery occlusion, LVP and CO were reduced in both groups (CON: LVP, 89±3%; CO, 90±5% of baseline values) and LVP did not recover to baseline values during reperfusion (51±5% (CON) vs. 67±7% (DAN) of baseline, P=0.10). Infarct size was 41±4% of the area at risk in controls and 37±6% in dantrolene treated hearts (P=0.59). Conclusions: Dantrolene reduced CKR, indicating an attenuation of lethal cellular reperfusion injury in isolated rat hearts. However, in the rabbit in vivo, there was no effect on the extent of reperfusion injury after regional myocardial ischemia. [source] Haplotype Analysis of the Stromelysin-1 (MMP3) and Gelatinase B (MMP9) Genes in Relation to Coronary Heart DiseaseANNALS OF HUMAN GENETICS, Issue 4 2009Naqiong Wu Summary The functional genetic polymorphisms present in the promoters of stromelysin-1 (MMP3) and gelatinase B (MMP9) have been shown to be associated with angiographically measured atherosclerosis; however, haplotype analysis of the genetic polymorphisms occurring in the promoters and coding regions of MMP3 and MMP9 has been infrequently performed in the past. The aim of this study was to analyze the occurrence of the -1612 5A/6A, -376C/G, and Glu45Lys polymorphisms of MMP3 and the -1562C/T and R279Q polymorphisms of MMP9 and their relation to the risk of coronary heart disease (CHD; stenosis ,50% of the diameter in at least one major coronary artery) in a Chinese Han population. The present study involved 1373 patients with CHD and 695 healthy controls. The Glu45Lys polymorphism of MMP3 was significantly associated with an increased risk of CHD. Compared with the 45Glu homozygotes, 45Lys allele carriers had a significantly elevated risk of CHD (adjusted OR = 1.50; 95%CI 1.11,2.03; p= 0.008). Moreover, haplotype analysis identified both the 6A-C-Lys (-1612 6A, -376C, 45Lys) haplotype and the 6A-G-Lys (-1612 6A,-376G, 45Lys) haplotype of MMP3 as associated with an increased risk of CHD. Our study suggests that common genetic variations in the MMP3 gene may affect the risk of CHD in the Chinese population. [source] Frequency of Acute Coronary Syndrome in Patients with Normal Electrocardiogram Performed during Presence or Absence of Chest PainACADEMIC EMERGENCY MEDICINE, Issue 6 2009Samuel D. Turnipseed MD Abstract Objectives:, The authors hypothesized that patients with active chest pain at the time of a normal electrocardiogram (ECG) have a lower frequency of acute coronary syndrome (ACS) than patients being evaluated for chest pain but with no active chest pain at the time of a normal ECG. The study objective was to describe the association between chest pain in patients with a normal ECG and the diagnosis of ACS. Methods:, This was a prospective observational study of emergency department (ED) patients with a chief complaint of chest pain and an initial normal ECG admitted to the hospital for chest pain evaluation over a 1-year period. Two groups were identified: patients with chest pain during the ECG and patients without chest pain during the ECG. Normal ECG criteria were as follow: 1) normal sinus rhythm with heart rate of 55,105 beats/min, 2) normal QRS interval and ST segment, and 3) normal T-wave morphology or T-wave flattening. "Normal" excludes pathologic Q waves, left ventricular hypertrophy, nonspecific ST-T wave abnormalities, any ST depression, and discrepancies in the axis between the T wave and the QRS. Patients' initial ED ECGs were interpreted as normal or abnormal by two emergency physicians (EPs); differences in interpretation were resolved by a cardiologist. ACS was defined as follows: 1) elevation and characteristic evolution of troponin I level, 2) coronary angiography demonstrating >70% stenosis in a major coronary artery, or 3) positive noninvasive cardiac stress test. Chi-square analysis was performed and odds ratios (ORs) are presented. Results:, A total of 1,741 patients were admitted with cardiopulmonary symptoms; 387 met study criteria. The study group comprised 199 males (51%) and 188 females (49%), mean age was 56 years (range, 25,90 years), and 106 (27%) had known coronary artery disease (CAD). A total of 261 (67%) patients experienced chest pain during ECG; 126 (33%) patients experienced no chest pain during ECG. There was no difference between the two groups in age, sex, cardiac risk factors, or known CAD. The frequency of ACS for the total study group was 17% (67/387). There was no difference in prevalence of ACS based on the presence or absence of chest pain (16% or 42/261 vs. 20% or 25/126; OR = 0.77, 95% confidence interval = 0.45 to 1.33, p = 0.4). Conclusions:, Contrary to our hypothesis concerning patients who presented to the ED with a chief complaint of chest pain, our study demonstrated no difference in the frequency of acute coronary syndrome between patients with chest pain at the time of acquisition of a normal electrocardiogram and those without chest pain during acquisition of a normal electrocardiogram. [source] Relationship of carotid intima-media thickness, pulse wave velocity, and ankle brachial index to the severity of coronary artery atherosclerosisCLINICAL CARDIOLOGY, Issue 11 2004Yoshihiro Matsushima M.D. Abstract Background: Carotid intima-media thickness (IMT), pulse wave velocity (PWV), and the ankle brachial index (ABI) are widely used noninvasive modalities for evaluating atherosclerosis. Hypothesis: The aim of this study was to determine the relationship of carotid IMT, PWV, and ABI with the severity of coronary artery disease (CAD), expressed as the Gensini score, and the presence of coronary risk factors. Methods: We examined 205 consecutive patients (mean age 65 ± 12 years) who were clinically suspected of having CAD and were scheduled to undergo coronary angiography. Carotid intima-media thickness, brachial-ankle PWV (baPWV), and ABI were measured in all subjects before they underwent coronary angiography. Results: Of the 205 patients, 124 patients were diagnosed as having CAD based on the presence of > 50% stenosis in a major coronary artery; the remaining 81 patients did not have CAD. A relatively good correlation was obtained between carotid IMT and the Gensini score (R = 0.411, p < 0.0001), whereas baPWV correlated only weakly with the Gensini score (R = 0.203, p = 0.0035), and ABI did not correlate with it. A multiple regression analysis revealed that the Gensini score correlated significantly and independently with age, male gender, and carotid IMT. Conclusions: Of the three noninvasive methods, carotid IMT may be more useful for determining coronary artery atherosclerosis than baPWV or ABI. [source] | ||||||||||