Dobutamine stress echocardiography and cardiac troponin T for the detection of significant coronary artery disease and predicting outcome in renal transplant candidates.

AIMS: Ischaemic heart disease is the leading cause of mortality and morbidity in patients with end-stage renal disease (ESRD) and after renal transplantation. However, the optimal non-invasive test for coronary artery disease (CAD) diagnosis in this population has yet to be established. The aim of this study was to assess the diagnostic accuracy of dobutamine stress echocardiography (DSE) and baseline plasma cardiac troponin T (cTnT) for detecting significant CAD and predicting adverse cardiac events in patients referred for renal transplantation. METHODS: Coronary angiography, DSE, and baseline cTnT measurements were performed in 118 consecutive patients (mean age 52+/-12 years, 75 male) with ESRD (mean creatinine 608+/-272 micromol/L) referred for renal transplantation. The mean follow-up period was 1.32+/-0.48 years. Significant CAD was defined as a reduction in luminal diameter >70% by visual estimation in at least one major epicardial vessel. An abnormal DSE result defined as the development of a new regional wall motion abnormality in one or more normal resting segments or a deterioration of wall motion in one or more resting hypokinetic segments. A baseline cTnT>0.1 microg/L was taken as positive. RESULTS: Significant CAD in at least one vessel was present in 35 patients (30%). The number of patients with significant 3 vessel and 2 vessel disease was 6 and 7, respectively. An abnormal DSE result was present in 36 (31%) patients. Thirty-one (26%) had cTnT>0.1 microg/L. Sixty-four (54%) patients were on dialysis and 46 (39%) were diabetic. The sensitivity, specificity, positive and negative predictive values for DSE in detecting significant coronary artery disease were 88%, 94%, 86% and 95%, respectively. The same values for a raised cTnT were 54%, 62%, 40% and 74%, respectively. The combination of an abnormal DSE result and raised cTnT gave values of 61%, 91%, 76%, and 80%, respectively. Over the follow-up period, mortality was significantly higher in those with a raised baseline cTnT but not those with an abnormal DSE result or significant CAD. CONCLUSION: DSE is an accurate technique for the detection of significant CAD in renal transplant candidates. An elevated cTnT does not predict significant CAD in this population and when used in conjunction with DSE, reduces the sensitivity of the combined tests. cTnT is an important marker of prognosis in renal transplant candidates.     

多巴酚丁胺负荷试验QTcd对冠心病的诊断价值

目的探讨多巴酚丁胺负荷试验前、后冠心病与非冠心病患者QTc散离度(QTcd)的变化,评估多巴酚丁胺负荷试验QTcd对冠心病的诊断价值。方法测量选择性冠脉造影证实的30例冠心病与20例非冠心病患者试验前、后QTcd值,并比较分析。结果冠心病组多巴酚丁胺负荷试验终点QTcd明显高于试验前QTcd(P<0.01),非冠心病组无明显差异(P>0.05)。多巴酚丁胺负荷试验终点QTcd≥55ms诊断冠心病的敏感性、特异性、准确性分别为83.3%、85%、84%,QTcd≥10ms(86.7%、85%、86%)高于传统试验ST段压低诊断冠心病的价值(56.7%、50%、54%)(P<0.05)。结论多巴酚丁胺负荷试验QTcd、QTcd可提高冠心病的诊断价值,是一种安全、简便、有效的无创检查方法。     

Prognostic value of left ventricular volume response during dobutamine stress echocardiography

AIMS: An abnormal left ventricular volume response during dobutamineechocardiography identified patients with severe coronary arterydisease. The aim of the study was to assess the prognostic valueof left ventricular volume changes during dobutamine stressechocardiography in 136 patients. MEHTODS AND RESULTS: Endpoints were defined as spontaneous cardiac events at follow-up.Left ventricular end-diastolic and end-systolic volume changes(abnormal response: >10% and >20> decrease, respectively)were compared with other clinical and stress test variables.During 18±7 months of follow-up, 31 cardiac events occurred:12 hard events (cardiac death [n=6 myocardial infarction [n=6])and 19 soft events (unstable angina [n=16] congestive heartfailure [n=3] End-diastolic volume response (P=0·006),diabetes (P=0·008), inducible wall motion abnormalities(P=0·024), end-systolic volume response (P=0·039)and inducible angina (P=0·038) were related to a greaterlikelihood of cardiac events. The Cox regression analysis revealedend-diastolic volume response (odds ratio: 3·0; CI 1·44–6·32)and diabetes (odds ratio: 2·7; CI 1·28–5·69)to be independent predictors of spontaneous cardiac events.Diabetes (odds ratio: 4·0; CI 1·26–12·80)and >40% baseline ejection fraction (odds ratio: 2·21;CI 1·14–4·29) were independent predictorsof hard events. CONCLUSIONS: An abnormal end-diastolic volume response during dobutaminestress echocardiography identifies patients with an unfavourableoutcome; they should be considered for more accurate prognosticstratification.     

多巴酚丁胺在肥厚型心肌病激发试验的应用

目的 评价多巴酚丁胺激发试验在肥厚型心肌病激发试验中的安全性及有效性,比较潜在型肥厚型梗阻与静息型肥厚型梗阻性心肌病的临床特点. 方法 对22例确诊肥厚型心肌病患者(左心室流出道压力阶差正常或轻度增加)进行多巴酚丁胺激发试验,以5 μg·min-1·kg-1为起始剂量静脉泵人多巴酚丁胺,每隔5 min增加5 μg·min-1·kg-1,最大剂量20 μg·min-1·kg-1.每一次剂量泵入2 min后进行超声心动图检查,并对其临床特点与57例静息型肥厚型梗阻性心肌病患者进行比较. 结果 入选22例患者激发状态时左心室流出道流速峰值为(5.39±1.60)m/s,左心室流出道压力阶差(LVOTPG)峰值为(125.7±62.4)mm Hg(1 mm Hg=0.133 kPa);达到峰值时多巴酚丁胺给药平均速率为(13.9±6.85)μg·min-1·kg-1.16例(72.7%)患者达到阳性标准;6例(27.3%)患者虽达到阴性标准,但LVOTPG也有显著升高.潜在型梗阻患者的年龄、性别、各房室腔内径、左心室射血分数、室间隔厚度、LVOTPG等与静息型梗阻患者比较,差异均无统计学意义,但二尖瓣前向运动(SAM)现象发生率较低(62.5%比100%),Maron Ⅱ型较多[50.0%(8/16)比29.8(17/57)]. 结论 在肥厚型心肌病激发试验中,小剂量多巴酚丁胺负荷超声是一种较为安全和敏感性高的方法.潜在型较静息型肥厚型梗阻性心肌病患者的SAM现象发生率低,Maron Ⅱ型占优势.     

Diagnostic accuracy of dobutamine stress echocardiography for detection of coronary heart disease in hypertensive patients

To compare the diagnostic accuracy between dobutamme echocardiographyand treadmill exercise electrocardiography in detecting coronaryartery disease in hypertensive patients, 43 patients withoutelectrocardiographic evidence of left ventricular hypertrophyand basal ST-T changes, who had also undergone coronary angiography,were further evaluated by dobutamine echocardiography. The patientsalso underwent treadmill exercise echocardiography. Left ventricularmass index was calculated by echocardiography. Twenty-nine patientshad coronary artery disease, of whom 22 had multi-vessel diseaseand 14 a normal coronary anatomy. Twenty-eight patients hadan increased left ventricular mass index. The sensitivitiesof dobutaniine echocardiography and exercise electrocardiographyfor detecting coronary artery disease were 93% and 72% (P=0·08)respectively, and the specificities were 100% and 29%(P<0·005),respectively. Logistic regression analysis showed exercise electrocardiographyto be a poor predictor of coronary artery disease (P<0·09)but dobutamine echocardiography was significantly better (P<0·00l).When patients with increased left ventricular mass index wereexcluded, prediction of coronary anatomy by exercise electrocardiographyimproved only marginally (P=0·4) while dobutamine echocardiographywas significantly better (P<0·00l). Thus dobutamineechocardiography is superior to exercise electrocardiographyfor diagnosis of coronary artery disease in hypertensive patients.     

注射用益气复脉（冻干）联合多巴胺/多巴酚丁胺治疗心源性休克临床研究

目的 探讨注射用益气复脉（冻干）联合多巴胺/多巴酚丁胺治疗心源性休克的临床疗效。方法 选取郑州市中医院2018年1月-2019年12月收治的心源性休克患者120例为研究对象,采用随机数字法最终分为对照组（54例）和观察组（52例）。对照组患者在常规治疗的基础上给予大剂量盐酸多巴胺注射液5~20 μg/（kg·min）和盐酸多巴酚丁胺注射液5~15 μg/（kg·min）治疗。观察组在对照组治疗基础上静滴注射用益气复脉（冻干）2.6~5.2 g/次,加入5%葡萄糖注射液或0.9%氯化钠注射液250~500 mL中,1次/d。疗程为7~14 d。观察两组患者的临床疗效和不良反应情况,同时比较两组治疗前后的血压和尿量水平。结果 治疗后,观察组患者总有效率为94.2%,显著高于对照组的81.5%,两组比较差异有统计学意义（P<0.05）。治疗后,两组血压和尿量水平均明显改善,同组治疗前后比较差异有统计学意义（P<0.05、0.01）,观察组的血压和尿量水平显著高于对照组,两组比较差异有统计学意义（P<0.05、0.01）。两组不良反应发生率差异无统计学意义。结论 注射用益气复脉（冻干）联合多巴胺/多巴酚丁胺治疗心源性休克患者具有一定的临床疗效,能够显著改善血压和尿量水平。     

Cyclic adenosine monophosphate modulation of contractility via slow Ca2+ channels in chick heart

The catecholamines exert a positive inotropic effect associated with elevated tissue cyclic AMP levels and possibly with increase in the number of membrane slow cationic channels available for voltage activation. In the present study, catecholamines (isoproterenol, dopamine and dobutamine) were tested for their ability to affect the maximum upstroke velocity (+ V_max) of the slow action potentials, the first derivative ($\text{d}\text{T}\text{d}\text{t}$) of developed tension accompanying the slow responses, and the tissue cyclic AMP levels in the ventricular myocardium of isolated perfused chick hearts. To study the slow channels exclusively, the fast Na⁺ channels were voltage inactivated by elevated (25 mm) K⁺. In this condition of functional removal of the fast channels, the heart could not be excited by intense electrical stimulation. It was found that these catecholamines induced slow action potentials accompanied by contractions. Elevation of the concentration of these agents produced increases in + V_max, $\text{d}\text{T}\text{d}\text{t}$, and cyclic AMP in a dose-dependent fashion; a close correlation was obtained between the cyclic AMP level, + V_max and $\text{d}\text{T}\text{d}\text{t}$. These results support the hypothesis that the increases in + V_max of the slow action potentials and in contraction are explained by increase in the number of available slow channels mediated by intracellular cyclic AMP levels, and the resulting increase in the Ca²⁺ influx.     

多巴酚丁胺负荷试验结合脉冲组织多普勒二尖瓣环运动定量评估心肌梗死患者心肌存活

目的研究脉冲多普勒组织成像技术(DTI-PW)中二尖瓣环速度检测存活心肌的可行性及价值.方法 40例陈旧性心肌梗死患者室壁按照硝酸甘油(NTG)介入99Tcm-MIBI SPECT 结果分为有存活心肌组、无存活心肌组,采用小剂量多巴酚丁胺负荷超声心动图试验,测量相应梗死壁二尖瓣环多巴酚丁胺(Dobutamine,Dob)负荷前及每级Dob负荷试验时的收缩期峰值速度Vs、射血前期PEP、射血期ET;另选20例年龄匹配的正常人为对照组,测量6个室壁二尖瓣环Vs、PEP、ET.结果 Dob 5μg/(kg·min)时,以Vs增加量≥2 cm/s为临界值,则检测存活心肌的敏感度为75%,特异度为76%,准确度为75%,以PEP/ET变化率2(Dob 5μg/(kg·min)时PEP/ET与Dob负荷前PEP/ET的比值)≥100%作为诊断无存活心肌的临界值,则敏感度为73%,特异度为85%,准确度为79%;以Dob 10 μg/(kg·min)时Vs增加量≥3 cm/s为临界值,则检测存活心肌的敏感度增加到83%,特异度为79%,准确度增加到81%,以PEP/ET变化率3(Dob 10μg/(kg·min)时PEP/ET与Dob负荷前PEP/ET的比值)≥100%作为诊断非存活心肌的临界值,则敏感度为82%,特异度为85%,准确度为84%.结论 Dob负荷时二尖瓣环Vs、PEP/ET可用于检测存活心肌,方法简单、可靠.