Rossetti E, Fragasso G, Mellone R, Vanzulli A, Del Maschio A, Chierchia S L
Divisione di Cardiologia, Istituto Scientifico H San Raffaele, Milano.
Cardiologia. 1999 Jul;44(7):653-9.
The syndrome of angina and normal coronary arteries (syndrome X) comprises a heterogeneous group of patients with typical chest pain, a positive exercise test, angiographically smooth coronary arteries and no evidence of spasm. Magnetic resonance imaging (MRI) has been used to detect areas of myocardial ischemia and/or recent necrosis both in animal and human studies. Most of these studies have been conducted after intravenous administration of the paramagnetic contrast medium gadolinium-DTPA (Gd-DTPA), that is considered a sensitive marker of extracellular, probably ischemic in origin, edema. On the basis of these data, we used MRI to evaluate the possibility of myocardial Gd-DTPA deposition at rest in patients with syndrome X, and to assess the effects of oral treatment with atenolol.
We have studied 24 patients with syndrome X, 10 patients with coronary artery disease and 10 age-matched control subjects. The protocol was similar in all study subjects. Exercise testing and MRI were undertaken off therapy after coronary arteriography. Following MRI, patients underwent a 10 day treatment period with atenolol and repeated exercise stress test and MRI while on therapy.
In all patients with syndrome X and coronary artery disease were observed effort diagnostic ST-segment changes that were associated with angina in 9 (37%) and 7 (70%) patients, respectively. Of 24 patients with syndrome X, 16 (66.6%) showed areas of myocardial enhancement after Gd-DTPA in comparison to the precontrast imaging. In 4 out of 10 patients with coronary artery disease (40%), Gd-DTPA accumulation was documented. Finally, focal Gd-DTPA myocardial enhancement was not observed in any normal control subject. After beta-blockade, 22 (92%) patients with syndrome X and 2 (20%) with coronary artery disease did not show any ischemic ST-segment changes on effort; 14 syndrome X patients (88%) and 2 coronary artery disease patients (50%) showed complete disappearance of the previously Gd-DTPA enhanced areas on MRI.
Patients with syndrome X often exhibit regional accumulation of Gd-DTPA on MRI. The agent is believed to trace interstitial water accumulation as occurs during ischemia and its accumulation is reduced or abolished by treatment with atenolol, probably by different mechanisms. It is likely that an overactivation of the sympathetic outflow to the cardiovascular system can induce most of the abnormalities observed in syndrome X patients. In this context, beta-blockers probably represent the mainstay of the medical treatment of this condition.
心绞痛合并冠状动脉正常综合征（X综合征）包括一组异质性患者，这些患者有典型胸痛、运动试验阳性、冠状动脉造影显示血管光滑且无痉挛证据。在动物和人体研究中，磁共振成像（MRI）已被用于检测心肌缺血和/或近期坏死区域。这些研究大多在静脉注射顺磁性造影剂钆喷替酸葡甲胺（Gd-DTPA）后进行，Gd-DTPA被认为是细胞外水肿（可能起源于缺血）的敏感标志物。基于这些数据，我们使用MRI评估X综合征患者静息时心肌Gd-DTPA沉积的可能性，并评估阿替洛尔口服治疗的效果。
我们研究了24例X综合征患者、10例冠状动脉疾病患者和10例年龄匹配的对照者。所有研究对象的方案相似。冠状动脉造影后，在未进行治疗的情况下进行运动试验和MRI检查。MRI检查后，患者接受为期10天的阿替洛尔治疗，并在治疗期间重复进行运动负荷试验和MRI检查。
在所有X综合征患者和冠状动脉疾病患者中均观察到运动试验诊断性ST段改变，分别有9例（37%）和7例（70%）患者的改变与心绞痛相关。在24例X综合征患者中，16例（66.6%）与注射造影剂前成像相比，Gd-DTPA注射后显示心肌强化区域。在10例冠状动脉疾病患者中有4例（40%）记录到Gd-DTPA蓄积。最后，在任何正常对照者中均未观察到局灶性Gd-DTPA心肌强化。β受体阻滞剂治疗后，22例（92%）X综合征患者和2例（20%）冠状动脉疾病患者运动时未出现任何缺血性ST段改变；14例（88%）X综合征患者和2例（50%）冠状动脉疾病患者MRI上先前Gd-DTPA强化区域完全消失。
X综合征患者MRI上常表现为Gd-DTPA区域蓄积。该药物被认为可追踪缺血时出现的间质水蓄积，其蓄积可通过阿替洛尔治疗减少或消除，可能是通过不同机制。心血管系统交感神经输出过度激活可能导致X综合征患者出现大多数异常表现。在此背景下，β受体阻滞剂可能是该病药物治疗的主要手段。
