[心肌梗死后检测存活心肌的超声-硝酸盐试验：与延迟采集铊闪烁扫描术的比较]

[The echo-nitrate test for the detection of viable myocardium after a myocardial infarct: a comparison with delayed-acquisition thallium scintigraphy].

作者信息

Pontillo D, Capezzuto A, Achilli A, Guerra R, Carboni G P

机构信息

Divisione di Cardiologia e U.T.I.C., Ospedale Belcolle, Viterbo.

出版信息

G Ital Cardiol. 1993 Dec;23(12):1187-94.

PMID:8174869

Abstract

BACKGROUND

The aim of this study was to evaluate the ability of echocardiography, associated with nitroglycerin infusion, in the detection of myocardial viability in patients with recent infarction.

PATIENTS AND METHODS

Fourteen patients (11 male, 3 female, mean age 59 +/- 8 years) with first acute myocardial infarction (12 Q wave, 2 non-Q wave) underwent predischarge (18 +/- 3 days) nitrate echocardiography. All patients underwent delayed planar thallium scintigraphy within four weeks from AMI. Nitrate echocardiography was performed with a nitroglycerin infusion starting from 0.4 mcg/Kg/min every 5 minutes up to 2.0 mcg/Kg/min; the test was terminated with an improvement of wall motion abnormalities or with a drop of systolic blood pressure > or = 20%. Wall motion abnormalities were evaluated with a 16-segment wall motion score index (WMSI). Thallium was performed after a symptom-limited exercise test, after 3 and 24 hours. The left ventricle was divided in 15 regions. Thallium was considered the gold standard for myocardial viability.

RESULTS

Basal echo identified 59 dyssynergic segments: of these, 12 (20%-6 patients) showed improvement in contractility during nitrate echocardiography at a mean dose of 0.9 +/- 0.3 mcg/Kg/min. WMSI decreased from 1.42 +/- 0.22 to 1.27 +/- 0.13 (p = 0.022), with no significant change of haemodynamic data (mean systolic blood pressure from 125 to 112 mmHg; mean heart rate from 66 to 76 beats/min; mean rate/pressure product from 8415 to 8848; all p = ns). Thallium scintigraphy showed 40 fixed defects (19%-7 patients) and 10 (4.7%-7 patients) late reversible defects. 20% of the 3-hour fixed defects improved at 24-hour imaging. 5/7 patients with echo improvement had 24-hour reversible defects, while 6/7 with no WMSI improvement had 24-hour fixed defects. Therefore, nitrate echocardiography demonstrated 71% sensitivity, 86% specificity, 83% positive predictive value, 75% negative predictive value and 78% accuracy.

CONCLUSIONS

Nitrate echocardiography may be a feasible and low cost method in the detection of myocardial viability after myocardial infarction, but awaits further validation.

摘要

背景

本研究旨在评估超声心动图联合硝酸甘油输注在近期心肌梗死患者心肌存活性检测中的能力。

患者与方法

14例首次发生急性心肌梗死的患者（男11例，女3例，平均年龄59±8岁）（12例Q波心肌梗死，2例非Q波心肌梗死）在出院前（18±3天）接受硝酸酯类超声心动图检查。所有患者在急性心肌梗死发生后4周内接受延迟平面铊闪烁扫描。硝酸酯类超声心动图检查时，从0.4μg/kg/min开始输注硝酸甘油，每5分钟增加一次剂量，直至2.0μg/kg/min；当室壁运动异常改善或收缩压下降≥20%时终止检查。采用16节段室壁运动评分指数（WMSI）评估室壁运动异常。在症状限制性运动试验后、3小时和24小时后进行铊扫描。左心室分为15个区域。铊扫描被视为心肌存活性的金标准。

结果

基础超声心动图识别出59个运动失调节段：其中12个节段（20%，6例患者）在平均剂量为0.9±0.3μg/kg/min的硝酸酯类超声心动图检查期间收缩性改善。WMSI从1.42±0.22降至1.27±0.13（p = 0.022），血流动力学数据无显著变化（平均收缩压从125 mmHg降至112 mmHg；平均心率从66次/分钟增至76次/分钟；平均心率/压力乘积从8415增至8848；所有p值均无统计学意义）。铊闪烁扫描显示40个固定缺损（19%，7例患者）和10个（4.7%，7例患者）延迟可逆缺损。3小时固定缺损中有20%在24小时成像时改善。超声心动图改善的5/7例患者有24小时可逆缺损，而WMSI未改善的6/7例患者有24小时固定缺损。因此，硝酸酯类超声心动图的敏感性为71%，特异性为86%，阳性预测值为83%，阴性预测值为75%，准确性为78%。