Gambelli G, Donati R, Mezzanotte R, Pozzar F, Cesario A S, Schiavo B, Pau F
Divisione di Cardiologia, Ospedale G.B. Grassi, Roma.
G Ital Cardiol. 1998 Mar;28(3):249-58.
The impairment of intracellular calcium homeostasis is an important biochemical alteration in stunned and hibernating myocardium. These different forms of viable myocardium frequently occur after myocardial infarction and their recognition may modify the therapeutic program and prognosis. Experimental studies and experiences on male subjects have demonstrated that calcium-channel blockers exert a protective action on myocardial reperfusion injury and reduce infarct size.
The aim of the present study was to evaluate the efficacy of i.v. diltiazem (i.e. a calcium-channel blocker with negative inotropic effect) in enhancing the contractility of viable akinetic myocardium in patients after myocardial infarction.
Sixty patients (52 males and 8 females, age 57 +/- 10 years) with the first acute myocardial infarction were evaluated with dobutamine-echocardiography 9 +/- 2 days after admission and on the following day with diltiazem-echocardiography. Diltiazem was administered i.v. using repeated boluses of 0.25 mg/kg up to the maximum dose of 1 mg/kg. Before and during the infusion, left ventricular regional function was scored and the Wall Motion Score Index (WMSI) was calculated; ECG and arterial blood pressure were also monitored. Results were compared with low-dose dobutamine-echocardiography. In a subset of 13 patients who underwent myocardial revascularization (7 coronary artery by-pass graftings and 6 percutaneous transluminal angioplasties), post-procedure echocardiograms were performed to evaluate whether regional left ventricular function had improved.
Low-dose dobutamine and diltiazem enhanced regional left ventricular contractility in 28 and 31 patients, respectively; both tests were positive in 26 cases. Conversely, dobutamine-test was negative in 32 patients and diltiazem in 29, with concordance in 27. A good correlation was found between diltiazem and dobutamine WMSI at the basal evaluation (r = 0.91; p < 0.000) as well as during the pharmacological test (r = 0.86; p < 0.000). In patients who underwent myocardial revascularization, the same good correlation was found between diltiazem-WMSI and WMSI evaluated after the procedure (r = 0.91; p < 0.000).
Acute i.v. administration of diltiazem about ten days after myocardial infarction may enhance the contractility of viable akinetic ventricular wall segments, as evaluated with echocardiography. The results of this study may have some physiopathological and therapeutical implications that could lead to reconsidering the use of calcium-channel blockers, particularly diltiazem, in selected patients after myocardial infarction.
细胞内钙稳态受损是顿抑心肌和冬眠心肌重要的生化改变。这些不同形式的存活心肌常见于心肌梗死后，对它们的识别可能会改变治疗方案和预后。针对男性受试者的实验研究和经验表明，钙通道阻滞剂对心肌再灌注损伤具有保护作用，并可减小梗死面积。
本研究旨在评估静脉注射地尔硫䓬（一种具有负性肌力作用的钙通道阻滞剂）对心肌梗死后患者存活的运动不能心肌收缩力的增强效果。
60例首次发生急性心肌梗死的患者（52例男性，8例女性，年龄57±10岁）在入院9±2天后接受多巴酚丁胺超声心动图检查，并于次日接受地尔硫䓬超声心动图检查。静脉注射地尔硫䓬，以0.25mg/kg的剂量重复推注，最大剂量为1mg/kg。在输注前和输注过程中，对左心室局部功能进行评分并计算室壁运动评分指数（WMSI）；同时监测心电图和动脉血压。将结果与小剂量多巴酚丁胺超声心动图检查结果进行比较。在13例行心肌血运重建的患者（7例行冠状动脉搭桥术，6例行经皮腔内血管成形术）亚组中，术后进行超声心动图检查以评估左心室局部功能是否改善。
小剂量多巴酚丁胺和地尔硫䓬分别使28例和31例患者的左心室局部收缩力增强；两种检查均为阳性的有26例。相反，多巴酚丁胺试验阴性的有32例患者，地尔硫䓬试验阴性的有29例患者，两者一致的有27例。在基础评估时（r = 0.91；p < 0.000）以及药理试验期间（r = 0.86；p < 0.000），地尔硫䓬和多巴酚丁胺的WMSI之间存在良好的相关性。在接受心肌血运重建的患者中，地尔硫䓬-WMSI与术后评估的WMSI之间也存在同样良好的相关性（r = 0.91；p < 0.000）。
心肌梗死后约10天急性静脉注射地尔硫䓬可增强存活的运动不能室壁节段的收缩力，这通过超声心动图评估得出。本研究结果可能具有一些生理病理和治疗意义，可能会促使重新考虑在特定心肌梗死患者中使用钙通道阻滞剂，尤其是地尔硫䓬。
