药理学应激心肌灌注显像

阐述临床应用的三种药理学应激反应剂：潘生丁、腺苷和多巴酚丁胺在诊断试验中的显像方法、作用机理、血液动力学效应、临床诊断评价、副作用等，为临床药理学应激心肌灌注显像提供重要的参考资料。     

急性心肌梗塞患者应激性ST段抬高的放射性核素研究

急性心肌梗塞后应激性ST段抬高(△ST)的意义仍有争议,一些研究显示其与左室运动不协调有关,另一些则认为与缺血有关。目前尚无将同组病人的应激性缺血和不协调与△ST加以比较的报道。为此,对88例急性心肌梗塞16±4天后的病人进行了研究。在间歇1～2天的不同时间,分别对其进行多巴酚丁胺激发实验。在血压和心电图监测下,多巴酚丁胺输注量达40μg/kg/min。当多巴酚丁胺最大剂量及3～4小时后行~(201)TL单光子发射计算机断层照相,在静息状态和多巴酚丁胺最大剂量时进行平衡法放射性核素心室显像,计算全心脏和局部(运动减少区域)射血分数,ST     

组织多普勒结合多巴酚丁胺负荷试验对冠心病的研究

多巴酚丁胺负荷超声心动图主要用于冠心病的研究 ,可检测梗死心肌、心肌缺血后的存活心肌及冠状动脉血流储备等 ,具有较高的敏感性和特异性 ,但其图像分析采用半定量目测法 ,结果的分析判断需要一定的经验 ,并带有一定的主观性 .组织多普勒是近年发展起来的一项定量分析室壁运动的超声新技术 ,用于多巴酚丁胺负荷试验(DSE)可弥补其半定量目测法的不足     

组织多普勒结合多巴酚丁胺负荷试验对冠心病的研究

多巴酚丁胺负荷超声心动图主要用于冠心病的研究,可检测梗死心肌、心肌缺血后的存活心肌及冠状动脉血流储备等,具有较高的敏感性和特异性,但其图像分析采用半定量目测法,结果的分析判断需要一定的经验,并带有一定的主观性.组织多普勒是近年发展起来的一项定量分析室壁运动的超声新技术,用于多巴酚丁胺负荷试验(DSE)可弥补其半定量目测法的不足.     

小剂量多巴酚丁胺应激超声心动图预测扩张型心肌病左室收缩功能的改善

多巴酚丁胺应激超声心动图已广泛应用于局部缺血左室功能障碍患者心肌存活和预后的测定,然而其在非局部缺血左室功能障碍患者的价值尚不清楚,此研究目的是阐明多巴酚丁胺应激超声心动图是否可预测扩张型心肌病(DCM)左室收缩功能的改善。方法　以多巴酚丁胺应激超声心动图测定了18例DCM患者的心肌收缩储备力。平均年龄53±13岁,LVEF为28±10%,且与随访期15±8个月的LVEF作了比较。分析了输注多巴酚丁胺(5～20μg·kg-1·min-1)前及后的LVEF和短轴与四腔图共12段的局部左室室壁运动评分(0,正常;1,轻度运动减少;2,严重运动减少;3,无运…     

持续静滴多巴酚丁胺增加心衰患者死亡危险

目的　评价老年心衰患者接受持续静脉滴注多巴酚丁胺治疗,在国际各中心随机生存试验的临床特征和结果。方法　将北美和欧洲13个国家95个中心的471例NYHAb或级心力衰竭患者收入该研究,并在常规抗心衰治疗的基础上,随机将患者分为两组:80例持续静滴多巴酚丁胺为治疗组;对照组391例不用多巴酚丁胺。分别于分组前、分组后,1个月内每2周,之后每个月评价心脏事件发生情况,伴用药物不良反应,6min行走及生活质量测试等,发生临床事件如心衰恶化,加用机械辅助设备,猝死复苏成功,心梗及死亡为研究终点。结果　6个月临床事件发生率多巴酚丁胺组显著高…     

移动对心肌灌注模型断层与病人心肌灌注断层显像结果的影响比较初探

利用心肌灌注模型模拟人体进行心肌灌注断层显像,观察移动对显像结果的影响,并与心肌灌注显像检查病人移动的影响作比较,发现移动对显像结果影响极大,且病人移动造成的影响远比模型实验复杂和显著.     

移动对心肌灌注模型断层与病人心肌灌注断层显像结果的影响比较初探

利用心肌灌注模型模拟人体进行心肌灌注断层显像，观察移动对显像结果的影响，并与心肌灌注显像检查病人移动的影响作比较，发现移动对显像结果影响较大，且病人移动造成的影响远比模型实验复杂和显著。     

多巴酚丁胺负荷超声心动图诊断冠心病的研究和应用体会

探讨多巴酚丁胺负荷超声诊断冠心病的价值。方法　选择冠心病患者 2 5 2例 ,对照组 80例健康人。多巴酚丁胺从小剂量开始逐渐递增 ,持续观察并录像记录室壁运动 ,记录心电图 ,检测血压和心率。试验阳性标准 :出现新的室壁运动的异常或原有室壁运动异常加重 ,心电图ST段缺血型下移 0 .2mv ,典型心绞痛发作。结果　敏感性95 % ,特异性 10 0 %。     

多巴酚丁胺小剂量静滴治疗老年性心衰32例

多巴酚丁胺小剂量静滴治疗老年性心衰３２例周泉解放军４５１医院内二科关键词多巴酚丁胺，心衰，老年，治疗多巴酚丁胺（ＤＴ）是合成的异丙基肾上腺类衍生物，属儿茶酚胺类非洋地黄强心药ＤＴ用于反复心衰、顽固性心衰及长期使用洋地黄呈现洋地黄中毒者，均取得了较好的...     

静脉注射左西孟坦、多巴酚丁胺对脓毒症休克患者心肌抑制影响的对照性研究

目的 通过观察血流动力学指标以及机体炎症因子的改变探讨静脉注射左西孟坦对脓毒症休克患者心肌抑制的影响.方法 总共纳入2014年3月至2015年6月于我院治疗的脓毒症休克患者94例,在相同的基础治疗基础上,随机分为接受左西孟坦治疗组(观察组)和多巴酚丁胺治疗组(对照组);分别观察两组患者入组前、治疗3天以及7天各项指标的差异.结果 观察组和对照组在患者的平均年龄、性别构成以及基础病构成方面差异无统计学意义(P＞0.05);治疗前对两组患者的APACHE Ⅱ评分、GESVI以及血清PCT、BNP、以及Lac差异无统计学意义(P＞0.05).治疗3天以后:观察组BNP水平、Lac以及cTnl水平显著低于对照组,组间对比差异有统计学意义(P＜0.05).两组间GESVI对比差异无统计学意义(P＞0.05).连续治疗6d后,指标观测结果显示:观察组的GL以及GESVI水平显著高于对照组水平,BNP水平、Lac以及cTnl水平显著低于对照组,组间对比差异有统计学意义(P＜0.05).观察组与对照组相比,机械通气时间(P＜0.05)、住院时间较短(P＜0.05),并且APACHE Ⅱ观察组也较对照组低(P＜0.05).结论 应用左西孟坦治疗脓毒症休克患者的心肌抑制,有利于改善患者的心脏舒张和收缩功能,提高氧代谢,缩短机械通气时间和ICU住院时间,减轻机制的炎症反应,值得临床的推广应用.     

The effect of bisoprolol on perioperative mortality and myocardial infarction in high-risk patients undergoing vascular surgery. Dutch Echocardiographic Cardiac Risk Evaluation Applying Stress Echocardiography Study Group

BACKGROUND: Cardiovascular complications are the most important causes of perioperative morbidity and mortality among patients undergoing major vascular surgery. METHODS: We performed a randomized, multicenter trial to assess the effect of perioperative blockade of beta-adrenergic receptors on the incidence of death from cardiac causes and nonfatal myocardial infarction within 30 days after major vascular surgery in patients at high risk for these events. High-risk patients were identified by the presence of both clinical risk factors and positive results on dobutamine echocardiography. Eligible patients were randomly assigned to receive standard perioperative care or standard care plus perioperative beta-blockade with bisoprolol. RESULTS: A total of 1351 patients were screened, and 846 were found to have one or more cardiac risk factors. Of these 846 patients, 173 had positive results on dobutamine echocardiography. Fifty-nine patients were randomly assigned to receive bisoprolol, and 53 to receive standard care. Fifty-three patients were excluded from randomization because they were already taking a beta-blocker, and eight were excluded because they had extensive wall-motion abnormalities either at rest or during stress testing. Two patients in the bisoprolol group died of cardiac causes (3.4 percent), as compared with nine patients in the standard-care group (17 percent, P=0.02). Nonfatal myocardial infarction occurred in nine patients given standard care only (17 percent) and in none of those given standard care plus bisoprolol (P<0.001). Thus, the primary study end point of death from cardiac causes or nonfatal myocardial infarction occurred in 2 patients in the bisoprolol group (3.4 percent) and 18 patients in the standard-care group (34 percent, P<0.001). CONCLUSIONS: Bisoprolol reduces the perioperative incidence of death from cardiac causes and nonfatal myocardial infarction in high-risk patients who are undergoing major vascular surgery.     

Effects of dobutamine and salbutamol on haemodynamics and atrial natriuretic factor in patients with severe congestive heart failure.

The influence of two cardiac inotropic drugs, dobutamine and salbutamol, on plasma atrial natriuretic factor (ANF) was investigated in 20 patients with congestive heart failure. All were in New York Heart Association class-III or IV. The patients underwent right heart catheterization with determination of central pressures, cardiac output, and pulmonary arterial plasma ANF during incremental infusions with dobutamine or salbutamol. Fourteen patients completed the study. Both drugs induced comparable increases in cardiac index and decreases in total systemic vascular resistance (P less than 0.01) without significant changes in central pressures. Heart rate rose after salbutamol (P less than 0.05), but not after dobutamine. No changes in plasma ANF were observed after either of the drug infusions. ANF secretion rate was calculated from simultaneous measurements of ANF in right atrial and pulmonary arterial plasma before and after salbutamol infusion, and median values rose more than seven-fold (P less than 0.05). The results demonstrate that ANF secretion rate is augmented after beta-adrenergic agents, possibly by a direct beta 2-adrenergic stimulation, in patients with severe congestive heart failure, and that changes in plasma ANF are an insufficient measure of ANF release when patient samples are small.     

Comparative Therapeutic Effi cacy of Adenocin and Non-Glycoside Cardiotonic Drugs in Chronic Heart Failure at Rest and under Conditions of Heart Overload

Experiments were performed on the model of chronic heart failure. Functional capacity of myocardial structures under conditions of maximum pressure overload was within the upper limit of normal after treatment with Adenocin. The myocardial functional reserve and potential capacity index were shown to increase to normal under these conditions. Dobutamine, levosimendan, and milrinone increased functional capacity under conditions of maximum pressure overload. Treatment with adenocin restored diastolic function of the heart under conditions of maximum pressure overload. The end-diastolic pressure increased, but remained 1.7 times below the level observed in heart failure. After treatment with dobutamine and milrinone, the end-diastolic pressure (8th episode of ligation) did not differ from the level observed in heart failure, while after administration of levosimendan this parameter decreased by 31%. Contraction-relaxation coupling was completely restored under the infl uence of Adenocin in all episodes of ligation both before and after removal of the ligature. Nearly all animals with heart failure were resistant to 8 episodes of ligation after treatment with Adenocin (89 vs. 96% under normal conditions). Under these conditions, the survival rate of animals after administration of levosimendan, milrinone, and dobutamine was 65, 60, and 61%, respectively, (the mortality rate of animals with heart failure was 75%). Adenocin, a cardiotonic drug with cardioprotective properties, in contrast to other cardiotonic drugs, has a modulatory effect on the system of cell energy supply, restores myocardial reserves, and improves myocardial function under conditions of overload.     

Mortality and morbidity in patients receiving encainide, flecainide, or placebo. The Cardiac Arrhythmia Suppression Trial

BACKGROUND AND METHODS. In the Cardiac Arrhythmia Suppression Trial, designed to test the hypothesis that suppression of ventricular ectopy after a myocardial infarction reduces the incidence of sudden death, patients in whom ventricular ectopy could be suppressed with encainide, flecainide, or moricizine were randomly assigned to receive either active drug or placebo. The use of encainide and flecainide was discontinued because of excess mortality. We examined the mortality and morbidity after randomization to encainide or flecainide or their respective placebo. RESULTS. Of 1498 patients, 857 were assigned to receive encainide or its placebo (432 to active drug and 425 to placebo) and 641 were assigned to receive flecainide or its placebo (323 to active drug and 318 to placebo). After a mean follow-up of 10 months, 89 patients had died: 59 of arrhythmia (43 receiving drug vs. 16 receiving placebo; P = 0.0004), 22 of nonarrhythmic cardiac causes (17 receiving drug vs. 5 receiving placebo; P = 0.01), and 8 of noncardiac causes (3 receiving drug vs. 5 receiving placebo). Almost all cardiac deaths not due to arrhythmia were attributed to acute myocardial infarction with shock (11 patients receiving drug and 3 receiving placebo) or to chronic congestive heart failure (4 receiving drug and 2 receiving placebo). There were no differences between the patients receiving active drug and those receiving placebo in the incidence of nonlethal disqualifying ventricular tachycardia, proarrhythmia, syncope, need for a permanent pacemaker, congestive heart failure, recurrent myocardial infarction, angina, or need for coronary-artery bypass grafting or angioplasty. CONCLUSIONS. There was an excess of deaths due to arrhythmia and deaths due to shock after acute recurrent myocardial infarction in patients treated with encainide or flecainide. Nonlethal events, however, were equally distributed between the active-drug and placebo groups. The mechanisms underlying the excess mortality during treatment with encainide or flecainide remain unknown.     

Detrimental effects after dobutamine infusion on rat left ventricular function: mechanical work and energetics

We have previously reported that continuous infusion of dobutamine into the coronary artery induces positive inotropic effects but induces no detrimental effects in cross-circulated, excised normal rat hearts and even in Ca2+ overload-induced contractile failing rat hearts. However, we hypothesized that some detrimental effects on left ventricular (LV) function are induced after continuous dobutamine infusion and the following clearance of blood dobutamine, as is the case after beta-adrenergic receptor stimulation. To test this hypothesis, we investigated LV mechanical work and energetics in the same type of preparations that underwent continuous dobutamine infusion and clearance of blood dobutamine. We found that both mean end-systolic pressure and systolic pressure-volume area (PVA; a measure of total mechanical energy per beat) at midrange LV volume were significantly (P < 0.01) decreased. The mean myocardial oxygen consumption per beat intercept, which is composed of for the total Ca2+ handling in excitation-contraction coupling and basal metabolism, of the and PVA linear relation was also significantly (P < 0.05) decreased (n=8). The mean slope of the linear relation was unchanged in such hearts. Post-dobutamine basal metabolism was unchanged (n = 5 of the 8 hearts). The moderate proteolysis of a cytoskeleton protein, alpha-fodrin was identified (n = 7 of the 8 hearts with the decreased intercept), after clearance of blood dobutamine. In agreement with our hypothesis, the detrimental effect of the post-beta-adrenergic receptor stimulation was induced by a moderate concentration of dobutamine; we found systolic dysfunction due to the impairment of Ca2+ handling in excitation-contraction coupling in the rat LV and proteolysis of a cytoskeleton protein, alpha-fodrin.     

Effects of inotropic drugs on mechanical function and oxygen balance in postischemic canine myocardium: comparison of dobutamine, epinephrine, amrinone, and calcium chloride

Brief ischemic episodes that induce myocardial and coronary endothelial dysfunction may alter the responses to inotropic drugs. To determine the effects of inotropic drugs in stunned myocardium, the coronary blood flow (CBF), myocardial oxygen consumption (MVO2), and regional mechanical function in response to intracoronary dobutamine, epinephrine, amrinone, and calcium chloride (CaCl2) were measured before (normal) and 30 min after a 15-min-period occlusion of the left anterior descending artery (stunned) in an open-chest canine model. Percent segment shortening (%SS) and post-systolic shortening (%PSS) were determined. Myocardial extraction of oxygen (EO2) and lactate (E(lac)) was calculated. The inotropic drugs increased %SS, CBF, and MVO2 in normal myocardium. Epinephrine and amrinone decreased, while dobutamine and CaCl2 did not affect EO2. The ischemia and reperfusion itself significantly reduced %SS and E(lac), and increased %PSS. In stunned myocardium, the responses to inotropic drugs were not significantly altered, except that they progressively reduced %PSS and epinephrine did not affect EO2. These findings indicate that a brief episode of ischemia does not affect the mechanical and metabolic coronary flow responses to inotropic drugs, although it abolishes direct vasodilator responses to epinephrine.     

硝酸甘油酯介入^99mTc-MIBI心肌断层显像对急性心肌梗塞病人存活心肌测定的研究

采用口服硝酸甘油酯(NTG)与静态^99mTc-MIBI心肌灌注断层显像相结合的定量方法，对64例急性心肌梗塞病人进行了存话心肌的测定，静态心肌显像有44.3％(170／384)的节段灌注异常，口含NTG后有57．1%(97／170)的节段心肌灌注得到改善，其中14例接受PTCA的病人，于PTCA前静态显像有27个灌注缺损节段，口服NTG后有51.9%(14／27)的缺损节段得到改善，PTCA后有48．1％(13／27)的缺损节段得到改善，表明本法对心梗后存活心肌的判断是正确的。     

Coronary artery bypass grafting in patients with severe left ventricular dysfunction: a prospective randomized study on the timing of perioperative intraaortic balloon pump support

In this prospective trial the results of preoperative and intraoperative IABP in coronary artery bypass graft (CABG) patients with low left ventricular ejection fraction (LVEF) were compared. Sixty CABG patients with preoperative LVEF < or = 0.30 were enrolled: in group A patients (n=30) IABP was started within 2 hours preoperatively; in group B (n=30) it was instituted intraoperatively before weaning from cardiopulmonary bypass. Cardiac performance was assessed through Swan-Ganz catheter monitoring and daily echocardiography. Hospital survival, length of IABP support, intubation, ICU and hospital stay, need for postoperative inotropic drugs and incidence of myocardial infarction were compared between the two groups. Survival in group A patients proved significantly higher (P=0.047). Cardiac performance after myocardial revascularization improved in both groups with significantly better outcomes in group A patients (P<0.001). Doses of inotropic drugs (dobutamine, enoximone) were lower in group A (P=0.001; P=0.004) and duration shorter (P<0.001; P<0.001). No major IABP-related complication was observed.     

Prolonged strenuous exercise alters the cardiovascular response to dobutamine stimulation in male athletes

Prolonged strenuous exercise has been associated with transient impairment in left ventricular (LV) systolic and diastolic function that has been termed 'cardiac fatigue'. It has been postulated that cardiac β-adrenoreceptor desensitization may play a central role; however, data are limited. Accordingly, we assessed the cardiovascular response to progressive dobutamine stimulation after prolonged strenuous exercise (2 km swim, 90 km bike, 21 km run). Nine experienced male athletes were studied: PRE (2–3 days before), POST (after) and REC (1–2 days later). The cardiovascular response to progressive continuous dobutamine stimulation (0, 5, 20, and 40 μg kg⁻¹ min⁻¹) was assessed, including heart rate (HR), systolic blood pressure (SBP), LV cavity areas (two-dimensional echocardiography) and contractility (end-systolic elastance, SBP/end-systolic cavity area (ESCA)). POST there was limited evidence of myocardial necrosis (measured by troponin I), while catecholamines were elevated. HR was higher POST (mean ± s.d. ; PRE, 58 ± 9; POST, 79 ± 9; REC, 57 ± 7 beats min⁻¹; P < 0.05), while SBP was lower (PRE, 127 ± 15; POST, 116 ± 9; REC, 121 ± 12 mmHg; P < 0.05). A blunted HR, SBP and LV contractility (SBP/ESCA; PRE 29 ± 6 versus POST 20 ± 6 mmHg cm⁻²; P < 0.05) response to dobutamine was demonstrated POST, with values returning towards baseline in REC. Following prolonged strenuous exercise, the chronotropic and inotropic response to dobutamine stimulation is blunted. This study supports the hypothesis that beta-receptor downregulation and/or desensitization may play a major role in prolonged-strenuous-exercise-mediated cardiac fatigue.