PDF(Pubmed)
Abstract：
UNASSIGNED: Detection of myocardial bridge (MB) at angiography suggests it has a role in ischaemic-related symptoms in patients with angina without obstructive coronary artery disease. However, evidence that MB may cause myocardial ischaemia is limited.
UNASSIGNED: We studied 41 patients with MB of the left anterior descending coronary artery and otherwise normal coronary arteries. Fourteen patients with normal coronary arteries and without MB served as controls. All subjects underwent a maximal treadmill exercise stress test (EST) under ECG monitoring. Standard and speckle-tracking echocardiography were performed at baseline and immediately after peak EST.
UNASSIGNED: EST duration and peak heart rate and systolic pressure were similar in the two groups. A positive EST (ST-segment depression .1 mm) was found in 18 patients in the MB group (43.9%) and none in the control group (p=0.001). No abnormalities in both left ventricle systolic and diastolic function were found between the two groups in the standard echocardiographic evaluation. Global and segmental (anterior, inferior) longitudinal strain (LS) did not differ at baseline between the groups. There was a small increase in global LS during EST in MB patients but not in the control group (p=0.01). Similar trends were found for regional LSs, with differences being significant for the medium (p=0.028) and apical (p=0.032) anterior segments. No differences in echocardiographic parameters and both global and segmental LSs were observed between MB patients with ischaemic ECG changes during EST versus those without.
UNASSIGNED: Our findings do not support the notion that MB results in significant degrees of myocardial ischaemia during maximal myocardial work.
UNASSIGNED: We studied 41 patients with MB of the left anterior descending coronary artery and otherwise normal coronary arteries. Fourteen patients with normal coronary arteries and without MB served as controls. All subjects underwent a maximal treadmill exercise stress test (EST) under ECG monitoring. Standard and speckle-tracking echocardiography were performed at baseline and immediately after peak EST.
UNASSIGNED: EST duration and peak heart rate and systolic pressure were similar in the two groups. A positive EST (ST-segment depression .1 mm) was found in 18 patients in the MB group (43.9%) and none in the control group (p=0.001). No abnormalities in both left ventricle systolic and diastolic function were found between the two groups in the standard echocardiographic evaluation. Global and segmental (anterior, inferior) longitudinal strain (LS) did not differ at baseline between the groups. There was a small increase in global LS during EST in MB patients but not in the control group (p=0.01). Similar trends were found for regional LSs, with differences being significant for the medium (p=0.028) and apical (p=0.032) anterior segments. No differences in echocardiographic parameters and both global and segmental LSs were observed between MB patients with ischaemic ECG changes during EST versus those without.
UNASSIGNED: Our findings do not support the notion that MB results in significant degrees of myocardial ischaemia during maximal myocardial work.
摘要：
■在血管造影术中检测到心肌桥（MB）表明，它在没有阻塞性冠状动脉疾病的心绞痛患者的缺血相关症状中起作用。然而,MB可能导致心肌缺血的证据有限.
■我们研究了41例冠状动脉左前降支和其他正常冠状动脉的MB患者。14例冠状动脉正常且无MB的患者作为对照。所有受试者均在ECG监测下进行了最大跑步机运动压力测试（EST）。在基线和峰值EST后立即进行标准和斑点追踪超声心动图检查。
■两组的EST持续时间和峰值心率和收缩压相似。在MB组的18例患者（43.9％）中发现了阳性的EST（ST段下降0.1mm），而在对照组中没有发现（p=0.001）。在标准超声心动图评估中，两组之间均未发现左心室收缩和舒张功能异常。全局和节段(前，劣等）纵向应变（LS）在基线组间没有差异。在MB患者的EST期间，全局LS略有增加，而对照组则没有（p=0.01）。在区域LS中也发现了类似的趋势，中（p=0.028）和根尖（p=0.032）前段差异显着。在EST期间有缺血性ECG变化的MB患者与没有缺血性ECG的MB患者之间，未观察到超声心动图参数以及整体和节段性LS的差异。
■我们的发现不支持在最大心肌做功期间，MB导致显著程度的心肌缺血。
■我们研究了41例冠状动脉左前降支和其他正常冠状动脉的MB患者。14例冠状动脉正常且无MB的患者作为对照。所有受试者均在ECG监测下进行了最大跑步机运动压力测试（EST）。在基线和峰值EST后立即进行标准和斑点追踪超声心动图检查。
■两组的EST持续时间和峰值心率和收缩压相似。在MB组的18例患者（43.9％）中发现了阳性的EST（ST段下降0.1mm），而在对照组中没有发现（p=0.001）。在标准超声心动图评估中，两组之间均未发现左心室收缩和舒张功能异常。全局和节段(前，劣等）纵向应变（LS）在基线组间没有差异。在MB患者的EST期间，全局LS略有增加，而对照组则没有（p=0.01）。在区域LS中也发现了类似的趋势，中（p=0.028）和根尖（p=0.032）前段差异显着。在EST期间有缺血性ECG变化的MB患者与没有缺血性ECG的MB患者之间，未观察到超声心动图参数以及整体和节段性LS的差异。
■我们的发现不支持在最大心肌做功期间，MB导致显著程度的心肌缺血。
