Varga A, Ostojic M, Djordjevic-Dikic A, Sicari R, Pingitore A, Nedeljkovic I, Picano E
CNR, Institute of Clinical Physiology, Pisa, Italy.
Eur Heart J. 1996 Apr;17(4):629-34. doi: 10.1093/oxfordjournals.eurheartj.a014918.
Low (0.56 mg.kg-1 over 4 min) and high (0.84 mg.kg-1 over 10 min) doses of dipyridamole can identify viable myocardium through the contractile recovery of basally dyssynergic regions; however, it also induces ischaemia in susceptible patients. The aim of this study was to assess the potential of an "infra-low' dose of dipyridamole to selectively identify myocardial viability, independently evaluated by low dose dobutamine. Forty patients with resting dyssynergy and angiographically assessed coronary artery disease (1-vessel in 18, 2-vessel in 12, and 3-vessel in 10 patients) separately underwent a low dose dobutamine (5-10 micrograms.kg-1.min-1 for 3 min) echo test and an infralow dose (0.28 mg.kg-1 over 4 min) dipyridamole echo test. Systolic blood pressure (rest: 131 +/- 19 mmHg) changed slightly after dobutamine (137 +/- 21, P < 0.05 vs rest) and remained stable after dipyridamole (130 +/- 17, P = ns vs rest). Heart rate (rest: 68 +/- 13 beats.min-1) was also unchanged after dipyridamole (69 +/- 12, P = ns vs rest) and increased slightly after dobutamine (71 +/- 15, P < 0.05 vs rest and vs dipyridamole). No patient developed echocardiographic or electrocardiographic signs of ischaemia after either dipyridamole or dobutamine. Of the 243 segments with baseline dyssynergy, 70 were responders (i.e. they showed an improvement of 1 grade or more, from 1 = normal/hyperkinetic to 4 = dyskinetic in a 16-segment model of the left ventricle) by both dipyridamole and dobutamine, 157 were non-responders (i.e. they showed no change) by both dipyridamole and dobutamine, and 16 showed discordant results (five responders by dipyridamole only; 11 by dobutamine only). The overall concordance of dipyridamole and dobutamine was 93%. An echocardiographic follow-up could be obtained > 6 weeks after successful revascularization (achieved with angioplasty in 17, with by pass surgery in 3) in 19 patients and showed an improvement of one grade or more in 50 segments (viable) and no improvement in 50 segments (necrotic). The sensitivity of dobutamine and dipyridamole for predicting recovery was 76 and 78% respectively (P = ns); the specificity of both tests was 94%. In conclusion, infra-low dose dipyridamole is a haemodynamically neutral stress test which does not affect either heart rate or systolic blood pressure; it allows myocardial viability to be explored selectively, without eliciting ischaemia; it shows excellent overall concordance with low dose dobutamine and has good sensitivity and excellent specificity for predicting functional recovery following successful revascularization.
低剂量（4分钟内0.56毫克/千克）和高剂量（10分钟内0.84毫克/千克）的双嘧达莫可通过基础运动不协调区域的收缩恢复来识别存活心肌；然而，它也会在易感患者中诱发缺血。本研究的目的是评估“超低”剂量双嘧达莫选择性识别心肌存活能力的潜力，心肌存活能力通过低剂量多巴酚丁胺独立评估。40例静息时运动不协调且经血管造影评估为冠状动脉疾病的患者（18例单支血管病变、12例双支血管病变、10例三支血管病变）分别接受了低剂量多巴酚丁胺（5 - 10微克/千克·分钟，持续3分钟）超声心动图检查和超低剂量（4分钟内0.28毫克/千克）双嘧达莫超声心动图检查。收缩压（静息时：131±19毫米汞柱）在多巴酚丁胺给药后略有变化（137±21，与静息时相比P<0.05），在双嘧达莫给药后保持稳定（130±17，与静息时相比P=无显著差异）。心率（静息时：68±13次/分钟）在双嘧达莫给药后也无变化（69±12，与静息时相比P=无显著差异），在多巴酚丁胺给药后略有增加（71±15，与静息时和双嘧达莫相比P<0.05）。双嘧达莫或多巴酚丁胺给药后，无患者出现超声心动图或心电图缺血征象。在243个基线运动不协调节段中，70个节段对双嘧达莫和多巴酚丁胺均有反应（即它们在左心室16节段模型中显示改善1级或更多，从1级=正常/运动亢进到4级=运动障碍），157个节段对双嘧达莫和多巴酚丁胺均无反应（即无变化），16个节段结果不一致（5个节段仅对双嘧达莫有反应；11个节段仅对多巴酚丁胺有反应）。双嘧达莫和多巴酚丁胺的总体一致性为93%。19例患者在成功血运重建（17例通过血管成形术，3例通过搭桥手术）>6周后可进行超声心动图随访，结果显示50个节段（存活）改善1级或更多，50个节段（坏死）无改善。多巴酚丁胺和双嘧达莫预测恢复的敏感性分别为76%和78%（P=无显著差异）；两种检查的特异性均为94%。总之，超低剂量双嘧达莫是一种血流动力学中性的负荷试验，不影响心率或收缩压；它能选择性地探索心肌存活能力，不诱发缺血；它与低剂量多巴酚丁胺总体一致性极佳，对成功血运重建后功能恢复的预测具有良好的敏感性和出色的特异性。
