Post-ejection thickening as a marker of viable myocardium. An echocardiographic study in patients with chronic coronary artery disease

Summary The study aim was to assess whether post-ejection thickening (PT) is an useful marker of viable myocardium in patients with chronic coronary artery disease. Twenty-three patients with critical coronary stenoses were submitted to dobutamine and dipyridamole stress-echocardiographies and dipyridamole-early-redistribution ²⁰¹TI SPECT within 15 days from coronary arteriography. They were selected for the presence of PT in segments that could be optimally studied by M-mode echocardiography and were hypo-akinetic in basal conditons. PT (occurring between end-ejection and mitral valve opening) was found in 58% of dysfunctional critically perfused regions. Ninety-eight percent of the regions with PT and 6% of those without PT improved during low-dose dobutamine stress-echocardiography. Segments with PT had, respectively, higher and lower SPECT early-redistribution thallium activity than dysfunctional segments without PT and normokinetic regions. Therefore, regions with PT were viable and had a moderate decrease in coronary perfusion. Akinetic segments without PT did not show any inotropic reserve. After revascularization almost all the segments with PT improved. In conclusion, PT is a pattern of myocardial contraction easily detected by M-mode echocardiography in the clinical setting. If the results of this study are further confirmed, PT may become a sign for the recognition of myocardial viability. Received: 18 November 1996, Returned for 1. revision: 20 December 1996, 1. Revision received: 30 March 1997, Returned for 2. revison: 21 May 1997, 2. Revision received: 11 August 1997, Returned for 3. revision: 9 September 1997, 3. Revision received: 26 February 1998, Accepted: 25 March 1998  

银杏达莫注射液对急性心肌梗死血小板聚集的影响

目的 :探讨银杏达莫注射液对急性心肌梗死 (AMI)溶栓后血小板聚集的影响。方法 :将AMI溶栓治疗判为临床再通者 64例分为对照组 ( 3 2例 )及银杏达莫组 ( 3 2例 )。银杏达莫组在对照组基础上予以银杏达莫静脉输注。统计 2h内心电图ST段抬高指数(∑STI)下降≥ 5 0 %率与ST段完全回落率。测量溶栓前即刻及溶栓后 2h、10h血小板聚集率。结果 :银杏达莫组与对照组比较 :①心电图∑STI下降≥ 5 0 %率、ST段完全回落率均显著提高 ( 96.9%∶71.8% ,P <0 .0 5 ;87.5 %∶5 3 .1% ,P <0 .0 5 ) ;②溶栓后2h两组血小板聚集率银杏达莫组明显低于对照组 [( 3 1±18) %∶ ( 4 5± 2 2 ) % ,P <0 .0 1] ,10h两组相同 [( 15±7) %∶( 13± 6) % ,P >0 .0 5 ]。结论 :银杏达莫液能通过迅速抑制血小板功能 ,减轻心肌再灌注损伤。  

Selection of the optimal stress test for the diagnosis of coronary artery disease

Objective—To compare the value and limitations of exercise testing, dipyridamole echocardiography, dobutamine-atropine echocardiography, and MIBI-SPECT (technetium-99m methoxyisobutyl nitrile single photon emission computed tomography) during dobutamine infusion in the diagnosis of coronary artery disease.
Design—The performance of these four tests was assessed in random order on a consecutive cohort of patients. The presence or absence of coronary artery disease was confirmed by coronary angiography.
Setting—Two tertiary care and university centres.
Patients—102 consecutive patients with chest pain and no previous history of coronary artery disease. Ten patients with left bundle branch block were excluded for further analysis of exercise testing and scintigraphy results.
Results—MIBI-SPECT was the most sensitive (87%) but the least specific test (70%). Exercise stress testing had a sensitivity of 66%, which increased to 80% when patients with inconclusive results were excluded. Dipyridamole and dobutamine echocardiography had similar sensitivity (81%, 78%) and specificity (94%, 88%). All four tests had similar accuracy and positive and negative predictive values. Agreement between the echocardiographic techniques was excellent (detection of coronary artery disease 87%, κ = 0.72; regional analysis 93%, κ = 0.72; diagnosis of the "culprit" vessel 95%, κ = 0.92), and it was good between echocardiographic techniques and MIBI-SPECT (diagnosis of the culprit vessel 90%, κ = 0.84 with dobutamine and 92%, κ = 0.85 with dipyridamole).
Conclusions—Exercise stress testing has a sensitivity comparable to other tests in patients capable of exercising and with no basal electrical abnormalities. The greatest sensitivity is offered by MIBI-SPECT and the greatest specificity is obtained with stress echocardiography. Redundant information is obtained with dipyridamole echocardiography, dobutamine echocardiography, and MIBI-SPECT.

Keywords: coronary artery disease;  dipyridamole;  dobutamine;  scintigraphy  

双哌达莫和腺苷对小鼠肺纤维化的干预作用

目的　通过腺苷 (ADO)受体拮抗剂 茶碱 (TH) ,探讨ADO、双哌达莫 (DPM)对小鼠肺间质纤维化过程的干预作用。方法　 1 0 0只小鼠经气道注入博莱霉素 (BLM ,8.5mg/kg)制备肺纤维化动物模型 ,随机分成BLM、DPM、ADO和TH 4组 ,分别给予生理盐水 (1 0 0 μl/d)、DPM (50mg·kg- 1 ·d- 1 )、ADO(50mg·kg- 1 ·d- 1 )、DPM和TH (50mg·kg- 1 ·d- 1 ) ,共 7天 ,第 4～ 30天内处死动物 ,观察肺超微结构与病理变化。结果　BLM组肺泡上皮细胞坏死多 ,内皮伸出许多长棘突呈现肺组织缺氧 ,1 0天后间质出现大量成纤维细胞 ,因胶原增加伴炎症细胞浸润导致肺泡隔增宽 ;第 2 0天后DPM和ADO两组与BLM组比较 ,坏死肺泡上皮细胞少 ,第 4～ 30天活跃的肺泡巨噬细胞 (AM)数量增多 ,胞质内含大量溶酶体与吞饮小泡 ,第 30天塌陷肺泡与成纤维细胞均减少 ;TH组坏死肺泡上皮细胞很多 ,毛细血管闭锁、因肺组织缺血 ,间质内浸润的单核细胞发育成巨噬细胞延迟 ,成纤维细胞很少。结论　BLM能损伤肺泡上皮细胞致缺氧是成纤维细胞大量增生的重要因素之一 ,DPM与ADO通过改善微循环 ,促进AM发育和肺泡腔重建 ,以抑制成纤维细胞的增生  

Enhanced sensitivity for detection of coronary artery disease by addition of atropine to dipyridamole echocardiography

Dipyridamole echocardiography test (DET) has gained acceptancedue to its safety, feasibility, diagnostic accuracy and prognosticpower. The main limitation of the test is a less than idealsensitivity in some patient subsets, such as those with limitedcoronary artery disease. Atropine with dipyridamole might theoreticallycombine to become a synergistic ischaemic stress test, by increasingmyocardial oxygen demand through chronotropic stress and byreducing flow supply through a shortening of the diastolic intervalunder maximal coronary vasodilation. The aim of this study wasto assess the effects of the addition of atropine to DET. Threehundred and twenty-one patients (age=58±9 years), referredfor testing in the echo lab, were initially studied by DET.Of these, 151 were stopped during or within the 2 min followingdipyridamole infusion because of achievement of a predeterminedend-point: obvious echocardiographic positivity (n = 137), severechest pain (n = 3), diagnostic ST segment changes (n = 7) orlimited side effects (n = 4). In another three cases, atropinewas not given due to a history of glaucoma or severe prostatichypertrophy. In the remaining 167 patients with a negative DETtest, atropine (0.25 mg intravenously, repeated every min upto a maximum of 1 mg, if necessary) was added, starting 3 minafter the end of the dipyridamole infusion. The dipyridamole-atropineecho test (DETA) was positive in 32 and negative in 135 patients,and no major side effects occurred in any patient. The peakheart rate was significantly higher during DETA than with DETalone (108±16 vs 86±14 beats . min^–1; P<0.0001).In the subset of 178 patients who were studied while not takingantianginal therapy, who had no prior myocardial infarctionor revascularization procedure and who underwent coronary catheterization,independently of the test results, coronary angiography showednormal coronary arteries in 48 patients and significant coronaryartery disease (CAD) ( 50% luminal reduction in at least onemajor coronary vessel by quantitative coronary arteriography)in 130 patients—with single-, double- and triple-vesseldisease in 56, 47 and 27 patients, respectively. The sensitivitywas 96/130 for DET and 110/130 for DETA (72 vs 85%, P<0.01)while the specflcity was 96% and 92% (P=ns), respectively. Theaddition of atropine to dipyridamole, which causes further chronotropicstress to the myocardium already challenged by flow maldistribution,is well tolerated and safe, and increases the sensitivity ofthe test for the detection of coronary artery disease with noloss in specificity.  

缺血性卒中二级预防中的抗血小板治疗

抗血小板治疗是缺血性卒中二级预防的重要措施之一。在缺血性卒中二级预防中，阿司匹林仍然是最常用的抗血小板药。氯吡格雷的疗效优于阿司匹林，但因其价格昂贵，目前仅在阿司匹林不能耐受或阿司匹林无效者中使用。联合用药只推荐缓释型双嘧达莫加小剂量阿司匹林。  

潘生丁试验与冠状动脉造影结果对比分析

目的 探讨潘生丁试验（DP－1）在冠心病诊断中的价值。方法 应用DP－T及冠脉造(CAG）对可疑冠心病患者进行自身对比研究。结果 DP－T敏感性为81．8％，特异性为60．0％。结论 在不能开展冠脉造影的医院，DP－T作为非创伤性检查手段在冠心病诊断中具有重要价值。  

潘生丁试验中QT间期离散度增加对冠心病诊断价值的探讨

目的观察冠心病患者潘生丁试验前后心电图ST段、校正QT间期(QTc)及QT间期离散度(QTd)的变化，以探讨潘生丁试验时诊断冠心病的更敏感及特异的指标。方法对30例冠心病患者(冠心病组)及32例正常者(对照组)进行潘生丁试验，记录试验前后12导联同步心电图，测量其ST段，QTc及QTd的改变。根据受试者作业特征曲线(ROC曲线)求出QTc及QTd的阳性分界点，结合传统诊断标准ST段下移≥0．1mV，分别计算其特异性及敏感性。并与“并联诊断”方法进行比较。结果以潘生丁试验诊断冠心病时，如分别以ST段下移≥0．1mv、QTc≥440ms、QTd≥40ms为标准，其特异性分别为100％、68．8％、93．8％；敏感性分别为53．3％、83．3％和87．6％。如采用“并联诊断”方法，分别以ST段下移≥0．1mV和QTc≥440ms、ST段下移≥0．1mV和QTd≥40ms、QTc≥440ms和QTd≥40ms为标准，其特异性分别为68．8％、93．8％、68．8％。敏感性分别为70．0％、96．8％、90．0％。结论在潘生丁试验时，如以传统的诊断标准(ST段下移≥0．1mV)，结合QTd≥40ms，可明显提高其诊断的敏感性而不影响其特异性，QTd≥40ms可作为潘生丁试验时诊断冠心病的一项重要参考指标。  

Detection of patients with restenosis after PTCA by dipyridamole-atropine-stress-echocardiography

Stress-echocardiography (SE) has been proven to be a valuable method for the diagnosis of coronary artery disease. For patients who cannot exercise, pharmacological stress-echocardiography represents an alternative method for the induction of cardiovascular stress. Few studies exist concerning the value of dipyridamole-SE for the detection of restenosis in patients after primary successful PTCA. It has been demonstrated that the addition of atropine can significantly increase the diagnostic potential of dipyridamole-SE, especially in patients with 1- or 2-vessel disease. The purpose of our study was to investigate the diagnostic value of high-dose dipyridamole-SE plus atropine (DASE) for the detection of restenosis after primary successful PTCA. We investigated 65 patients 3–6 months after PTCA before a control angiography was performed. Restenosis was defined as > 70% lumen narrowing, determined by quantitative coronary angiography. In 20/27 patients with restenosis the DASE was pathologic (sensitivity 74%), in 34/38 patients without restenosis the DASE was normal or showed no induced WMA (specificity 89%). Patients with tight restenosis (> 90%) were always correctly detected by DASE. Concerning the different vessels, restenosis of the LAD was correctly predicted by DASE in 11/12 patients, restenosis of the LCX in 6/9 patients and restenosis of the RCA in 8/11 patients. Conclusions: From our results of our study we conclude that DASE is a reliable diagnostic method for the non-invasive evaluation of patients after PTCA. DASE can identify patients with relevant restenosis after PTCA and help to select those patients who will probably benefit from further coronary interventions.  

Dipyridamole echocardiography

Intravenous dipyridamole is a potent coronary vasodilator that has been extensively investigated over the past several years in the noninvasive assessment of patients with suspected coronary artery disease when exercise cannot be performed or is suboptimal. As an alternative to exercise studies, dipyridamole has been used in combination with different cardiac imaging techniques such as echocardiography, thallium scintigraphy, and radionuclide ventriculography. Extensive experience has been obtained with dipyridamole thallium-201 imaging for coronary artery disease screening, risk stratification, and prognosis after an acute coronary event. However, experience with the use of dipyridamole in combination with two-dimensional echocardiography has been limited. Dipyridamole increases coronary blood flow in nondiseased coronary vessels relative to coronary vessels with significant luminal narrowings. These provide the basis for detecting regional differences in flow by using different cardiac imaging techniques. Two-dimensional echocardiography would show regional wall-motion abnormalities in response to those regional differences in coronary blood flow. In this article, the most commonly used protocols, safety, and practicability of dipyridamole echocardiography are reviewed. As an alternative to exercise, dipyridamole echocardiography shares all the indications of a standard exercise test. Clinical applications of dipyridamole echocardiography include coronary artery disease screening, suspected coronary artery spasm, postmyocardial infarction risk stratification, evaluation of percutaneous transluminal coronary angioplasty results, and prognosis following an acute coronary event. Compared to conventional (ECG) exercise testing, dipyridamole echocardiography appears to be equally sensitive but more specific. Compared to atrial pacing, dipyridamole provokes ischemia at a lower rate pressure product and results in a greater ST segment depression suggesting that dipyridamole induces more profound myocardial ischemia than atrial pacing. Dipyridamole thallium and exercise thallium have shown to be equally sensitive and specific in the assessment of coronary artery disease. High dose dipyridamole echocardiography appeared to be equally sensitive and more specific. Experimental studies have demonstrated that dobutamine appears to be a more powerful pharmacological agent in inducing wall-motion abnormalities. Dipyridamole echocardiography as compared to stress echocardiography offers the advantage of obtaining better quality postintervention images. With regard to sensitivity and for coronary artery disease diagnosis, both techniques appear to render similar results. Although further studies are needed, the available data indicates that cardiac ultrasound imaging prior to and following the intravenous administration of dipyridamole may be an attractive alternative to thallium perfusion imaging in the clinical setting, particularly when radionuclide capabilities are not present.