Servicio de Cardiologia, Area del Corazon, Hospital Universitario Vall d'Hebron, Universidad Autonoma de Barcelona, Pg. Vall d'Hebron, 119-129, 08035 Barcelona, Spain.
Rev Esp Cardiol. 2010 Feb;63(2):181-9. doi: 10.1016/s1885-5857(10)70036-0.
To investigate negative contractile responses in the left ventricle during low-dose dobutamine (LDD) gated single-photon emission computed tomography (SPECT) in patients with ischemic cardiomyopathy.
Sixty-eight consecutive patients (mean age, 60 + or - 11 years; 7 male) with ischemic cardiomyopathy (i.e., left ventricular ejection fraction [LVEF] < or = 40%) were evaluated using gated-SPECT at rest and during LDD infusion. Associations between a negative contractile reserve (i.e., a > or = 1-grade improvement in wall thickening score with LDD infusion) and scintigraphic viability criteria and coronary angiography findings were analyzed.
Some 42.6% (29/68) of patients had a negative contractile reserve in one or more segments. In 14.7% (n=10), the LVEF decreased by > or = 4% with LDD. These patients had more segments with a negative contractile reserve (2.8 + or - 2.5 vs. 0.87 + or - 0.40; P=.042), and the cut-off value on receiver operating characteristic curve analysis was > or =2 segments with a negative contractile reserve (sensitivity 70%, specificity 74%, positive likelihood ratio 2.71, negative likelihood ratio 0.40). Some 94% (74/79) of segments with a negative contractile reserve were in viable myocardium (i.e. normal or viable on scintigraphy). Twelve of 17 segments with akinesia or severe hypokinesia and a negative contractile reserve satisfied scintigraphic viability criteria, with the majority (10/12) lying in territories supplied by a patent coronary artery.
A negative contractile reserve was not uncommon in patients with ischemic cardiomyopathy and was associated with a general decrease in left ventricular systolic function. It was observed mainly in myocardial segments that appeared viable on scintigraphy and were supplied by a patent coronary artery.
探讨在缺血性心肌病患者中左心室在低剂量多巴酚丁胺（LDD）门控单光子发射计算机断层扫描（SPECT）期间出现负性收缩反应的情况。
对 68 例连续的缺血性心肌病患者（平均年龄 60±11 岁；男性 7 例）在静息和 LDD 输注期间进行门控 SPECT 评估。分析了负性收缩储备（即 LDD 输注时壁增厚评分增加≥1 级）与闪烁扫描存活标准和冠状动脉造影结果之间的相关性。
约 42.6%（29/68）的患者在一个或多个节段存在负性收缩储备。在 14.7%（n=10）的患者中，LDD 使 LVEF 下降≥4%。这些患者的负性收缩储备节段更多（2.8±2.5 与 0.87±0.40；P=.042），而在受试者工作特征曲线分析中，负性收缩储备节段≥2 个为截断值（敏感性 70%，特异性 74%，阳性似然比 2.71，阴性似然比 0.40）。有负性收缩储备的 79%（74/79）的节段为存活心肌（即闪烁扫描正常或存活）。17 个运动减弱或严重运动低下且负性收缩储备的节段中有 12 个满足闪烁扫描存活标准，其中大多数（10/12）位于有开放冠状动脉供应的区域。
在缺血性心肌病患者中，负性收缩储备并不罕见，与左心室收缩功能普遍下降有关。它主要出现在闪烁扫描上表现为存活的心肌节段和由开放的冠状动脉供应的区域。
