彩色室壁运动多巴酚丁胺试验在冠心病诊断中的应用

目的：探讨彩色室壁运动（CK）技术与多巴酚丁胺负荷试验（DSE）结合在冠心病诊断中的应用价值。方法：受检者48例,其中冠心病30例,正常对照组18例,全部进行CK－DSE检查,实验结果与冠脉造影结果对照。结果：CK－DSE诊断冠心病的敏感性、特异性和准确性分别为83％、94％和87％;诊断单支、双支及三支病变的敏感性分别为73％、83％和100％;诊断中度狭窄（50％－75％）和重度狭窄（＞75％）的敏感性分别为71％和94％。实验中无严重并发症发生。结论：CK－DSE诊断冠心病直观、敏感,具有重要的临床实用价值。     

Dobutamine-stress electrocardiographically gated positron emission tomography for detection of viable but dysfunctional myocardium

PURPOSE: This study was performed to determine whether low-dose dobutamine stress electrocardiography (ECG)-gated fluorine-18 fluorodeoxyglucose (FDG)-positron emission tomography (PET) can assess wall motion and identify myocardium without contractile reserve despite preserved FDG uptake. METHODS: Fifty-three patients with myocardial infarction and normal sinus rhythm underwent ECG-gated FDG-PET and transthoracic echocardiography. Wall motion of 10 segments of the left ventricle was graded as normal, hypokinetic, or akinetic/dyskinetic. RESULTS: In 365 (76%) of 480 segments, assessment of wall motion was concordant between the 2 modalities. In 30 patients dobutamine-stress ECG-gated FDG-PET was performed. In 13 (50%) of 26 dysfunctional segments with normal FDG uptake, 16 (36%) of 44 dysfunctional segments with mildly reduced FDG uptake and 12 (25%) of 48 dysfunctional segments with moderately reduced FDG uptake, wall motion was improved by dobutamine infusion. CONCLUSION: Assessment of left ventricular wall motion with ECG-gated FDG-PET is feasible, and dobutamine stress ECG-gated FDG-PET can simultaneously identify metabolic viability and contractile reserve.     

定量实时心肌声学造影结合小剂量多巴酚丁胺负荷检测存活心肌

目的评价定量实时心肌声学造影（RT-MCE）联合小剂量多巴酚丁胺负荷超声心动图（LD-DSE）检测存活心肌的临床价值。方法22例经彩色超声检查存在左心室壁节段运动障碍的冠心病患者,进行RT-MCE、RT-MCE联合LD-DSE、冠状动脉造影（CAG）及介入治疗（PCI）,所有狭窄病变均行完全血运重建。RT-MCE图像按美国心脏超声协会16节段划分法获得各运动异常节段心肌灌注显影,用QLab软件定量分析法求出各节段的p值及A·p值。术后1、3、6个月时分别复查心脏超声,以冠状动脉血运重建后室壁节段收缩功能改善为判断存活心肌的金标准。结果普通RT-MCE各节段A值以3.78、β值以0.38和A·β值以1.39为截断点,诊断存活心肌的灵敏度、特异度及准确度分别是70.2％、68.5％、70.2％和87.4％、78.9％、83.1％及80.6％、89.5％、83.8％;联合LD-DSE后,各节段A值以3.84、β值以0.49和A·β值以1.74为截断点,诊断存活心肌的灵敏度、特异度及准确度分别是72.4％、67.8％、71.2％和87.4％、89.5％、88.1％及90.3％、82.5％、86.2％。联合LD-DSE后,RT-MCE β值定量法检测存活心肌的特异度和A·β值定量法检测存活心肌的灵敏度均有明显提高（89.5％ vs 78.9％;90.3％ vs 80.6％,P值均〈0.05）。结论RT-MCE β值及A·β值定量分析法检测存活心肌有较高的临床价值,联合小剂量多巴酚丁胺负荷可提高其检测价值。     

多巴酚丁胺负荷心肌声学造影的临床研究

目的 探讨多巴酚丁胺负荷心肌声学造影的临床应用价值。方法 10例正常人、1例冠脉旁路移植术和10例陈旧性心肌梗死患者共21例受试者分别于多巴酚丁胺负荷试验（DST）前后行经静脉心肌灌注显像（MCE）检查。采用能量谐波方法显像,16节段半定量记分法目测评分。梗死室壁色泽得分＝梗死室壁各节段得分总和／总节段数。多巴酚丁胺负荷心肌声学造影后梗死节段显像较前增加1分以上为心肌具有存活性。结果 10例正常人和1例冠脉旁路移植术患者大剂量多巴酚丁胺负荷心肌声学造影前后室壁节段显像记分间差异均无显著性意义。10例陈旧性心肌梗死患者进行了小剂量多巴酚丁胺负荷心肌声学造影估测心肌存活的研究,60个室壁节段,23个异常节段（不显像11节段;稀疏显像12节段）,负荷后12节段（不显像4节段,稀疏显像8节段）得到1分以上的改善,显色缺损较不显色节段可能具有更多的存活心肌（P＜0．05）。结论 多巴酚丁胺负荷心肌声学造影增加冠脉心肌血流量,使能量谐波状态下的心肌声学造影图像质量更好,可评估冠脉储备能力和估测梗死区的存活心肌。     

小剂量多巴酚丁胺负荷超声心动图试验对可逆性功能障碍心肌预测的新指标

目的：探讨小剂量多巴酚丁胺负荷超声心动图（DSE）试验中左心室功能EF值的变化,即ΔEF这一量化指标预测急性心肌梗死（AMI）后患者的功能障碍心肌是否可逆及其可恢复程度。方法：入选患者25例, 接受小剂量DSE检查,测定负荷试验各阶段的收缩功能EF值,25例患者亦接受冠脉造影,并择期行经皮经腔太动脉成形术（PTCA）治疗,根据病变血管的情况植入支架,在术后3．5－13个月之间复查小剂量DSE试验。结果：以小剂量DSE过程中EF增加值,即ΔEF大于等于15％作为衡量标准,预测可逆性功能障碍心肌的敏感性,特性和准确性分别为70．6％,75％和72％,此预测改善值与无改善值之间的差异有显著性意义（P＜0．05）,结论：ΔEF可以作为准确评价可逆性功能障碍心肌的指标,并且是一种定量测定方法。     

多巴酚丁胺心电图与~（99m）Tc－MIBI心肌显像对冠心病诊断价值比较

目的：比较多巴酚丁胺心电图（Ｄｏｂｕ－ＥＣＧ）与￣（９９ｍ）Ｔｃ－ＭＩＢＩ心肌显像（Ｄｏｂｕ－ＥＣＴ）诊断冠心病的价值。方法：对６９例拟诊冠心病而无心肌梗塞患者在行冠状动脉造影时进行多巴酚丁胺心肌显像检查。结果：Ｄｏｂｕ－ＥＣＴ诊断冠心病的敏感性和准确度优于Ｄｏｂｕ－ＥＣＧ（９１．７％对４７．２％，Ｐ＜０．０１８，５．５％对６６．７％，Ｐ＜０．０５），特异性二者之间无差异。诊断冠状动脉单支、双支、三支病变的敏感性Ｄｏｂｕ－ＥＣＴ优于Ｄｏｂｕ－ＥＣＧ。诊断前降支、右冠状动脉的敏感性，Ｄｏｂｕ－ＥＣＴ高于Ｄｏｂｕ－ＥＣＧ。在研究中无一例出现严重副作用。结论：Ｄｏｂｕ－ＥＣＴ对识别冠心病存在与否及冠心病冠脉病变程度和范围均优于Ｄｏｂｕ－ＥＣＧ。     

Potentiation of the effects of enoximone by a dobutamine infusion

Enoximone is a new inotropic agent, which acts by the inhibition of the type III phosphodiesterase (PDE) enzyme. The present report describes a 81-year-old female patient with severe heart failure following aortic valve replacement. Her cardiac activity was paced. The addition of enoximone (two doses of 0.5 mg/kg) to an intravenous infusion of dobutamine (8 mcg/kg/min) and sodium nitroprusside significantly increased cardiac output (CO) from 3.2 to 3.9 l/min and decreased pulmonary artery occlusive pressure (PAOP) from 22 to 16 mmHg. Another dose of enoximone 12 h later had similar effects. However, another two successive injections of 0.5 mg/kg of enoximone were totally ineffective (CO from 2.6 to 2.5 l/min, PAOP 23 mmHg). When the dobutamine infusion was restarted (at 8 mcg/kg/min), the positive effects of 0.5 mg/kg of enoximone were again present (CO from 3.0 to 3.6 l/min, PAOP from 19 to 14 mmHg). This observation underscores the therapeutic value of the combination of PDE inhibitors such as enoximone with adrenergic agents such as dobutamine in the management of severe heart failure.     

The evolving approach to the evaluation of low-gradient aortic stenosis

Severe aortic stenosis (AS) is typically identified by a low valve area (≤1.0?cm²) and high mean gradient (≥40?mm?Hg). A subset of patients are found to have a less than severe mean gradient (<40?mm?Hg) despite a low valve area. These latter types can present as either low ejection fraction with low-gradient AS (stage D2) or normal ejection fraction with low-gradient AS (stage D3). Determining the true severity of disease within these categories has proved difficult. In this review we illustrate both traditional and novel techniques that can be used for further valvular assessment. We also propose a simple algorithm that can be used to evaluate low-gradient AS.     

Relation of myocardial histomorphometric features and left ventricular contractile reserve assessed by high-dose dobutamine stress echocardiography in patients with idiopathic dilated cardiomyopathy

BACKGROUND: This study was designed to determine the relationship between histomorphometric features and contractile reserve assessed by high-dose dobutamine stress echocardiography in patients with idiopathic dilated cardiomyopathy. METHODS: Twenty-four consecutive patients (21 men, aged 43.4+/-8.7 years) with idiopathic dilated cardiomyopathy underwent dobutamine stress echocardiography. Wall motion score index, ejection fraction, cardiac power output and end-systolic pressure/volume ratio were used as indices of left ventricular contractility. Left ventricular endomyocardial biopsy specimens (3-5 per patient) were routinely processed and stained with Masson trichrome, interstitial fibrosis and myocyte diameter were calculated quantitatively. RESULTS: Myocyte diameter and interstitial fibrosis showed strongest correlation with change in wall motion score index (r=-0.667, p<0.001, and r=-0.567, p=0.004, respectively), followed by change in ejection fraction (r=-0.603, p=0.002, and r=-0.467, p=0.021, respectively). Interstitial fibrosis showed no correlation with change of cardiac power output and end-systolic pressure/volume ratio, whereas myocyte diameter was associated with change of both indices (r=-0.565, p=0.004, and r=-0.455, p=0.025). CONCLUSIONS: Contractile reserve elicited by high-dose dobutamine is strongly related to the degree of histological disruption in patients with idiopathic dilated cardiomyopathy.     

应变率成像评价负荷试验中冠心病患者右室局部功能

目的探讨在多巴酚丁胺负荷试验下应变率成像评价心肌缺血对右室心肌局部功能的影响。方法选取冠心病患者,其中左前降支病变（LAD）15例,右冠状动脉病变（RCA）10例和健康对照者15例,测量各级负荷状态下右室游离壁中段收缩期（SRS）、舒张早期（SRE）及舒张晚期峰值应变率（SRA）。结果与基础状态相比,小剂量10μg/（kg·min）时,LAD组、RCA组及正常组的SRS、SRE增高。峰值剂量40μg/（kg·min）时,正常组的SRS及SRE增高,达最大,LAD组及RCA组的SRS及SRE均降低,但RCA组的SRS及SRE降低更为明显。SRA略降低,其差异无统计学意义。结论心肌缺血时右室的局部SR降低,应变率可用于负荷状态下右室功能的评价。