Gradient-echo magnetic resonance imaging during incremental dobutamine infusion for the localization of coronary artery stenoses

Dobutamine pharmacological stress testing in conjunction withgradient-echo magnetic resonance imaging (MRI) may be a usefultool for the assessment of haemodynamically significant coronaryartery stenoses. Therefore, 28 patients without previous myocardialinfarction but significant proximal stenoses (70% diameter stenosis)of one or more coronary arteries were selected for dobutamine-MRI.Each patient underwent MRJ at rest and during incremental dobutamineinfusion (5, 10, 15 and 20 µg. kg^–1. min^–1).Additionally, all patients were submitted to exercise stresselectrocardiography (EST). A total of 72 segments per patient obtained from identical shortaxis and transverse tomograms at rest and during dobutamineinfusion were evaluated by two observers. Each segment was gradedas normal, hypokinetic, akinetic or dyskinetic. Dobutamine-MRIwas considered pathological if segmental wall motion deterioratedby at least one grade after dobutamine infusion. For comparisonwith coronary angiography, segmental wall motion gradings wererelated to the respective coronary artery territories. Peakrate-pressure product during steady-state dobutamine infusion(18·493 ± 4·315 mmHg. min^–1) wassignificantly lower (P<0·01) than during EST (21·316± 4·937 mmHg. min^–1). Dobutanine-inducedwall motion abnormalities were observed in 22/26 (85%) MR studiesand 20/26 (77%) patients had a pathological EST. Regional asynergyinduced by dobutamine-MRI occurred in 11/15 (73%) patients withsingle and 11/11 (100%) with multi-vessel disease. Sensitivityand specificity for the detection of a stenosed coronary arterywere 87% and 100% for the left anterior descending, 62% and93% for the left circumflex and 78% and 88% for the right coronaryartery respectively. In conclusion, dobutamine-MRI is a well tolerated, non-exercisedependent test for the detection and localization of hzaemodynamicallysignificant coronary artery stenoses with a diagnostic accuracysimilar to that previously reported for high-dose dipyridamoleMRI but with a better control of stress intensity and duration.     

心率变异性及高敏C反应蛋白与冠状动脉病变程度及预后的相关性研究

目的：探讨心率变异性（HRV）和血浆高敏C反应蛋白（hs-CRP）水平与冠心病患者血管病变程度及预后的相关性。方法：选择行冠状动脉（冠脉）造影的患者306例,根据改良Gensini评分值将患者分为正常组（62例）以及病变轻度组（64例）、中度组（92例）、重度组（88例）,术前测定hs-CRP水平并行24h动态心电图检查,比较不同程度冠脉病变组间hs-CRP及HRV的差异,并随访至少12个月,记录主要不良心脑血管事件（MACCE）发生情况。结果：（1）与正常组比较,病变组hs-CRP水平均明显升高（P〈0．05,P〈0．01）,轻、中、重度3组间比较差异具有统计学意义（P〈0．05,P〈0．01）;（2）正常R-R间期的标准差（SDNN）和连续5min窦性心搏R-R间期均值的标准差（SDANN）参数在中、重度组明显降低,与正常组和轻度组比较差异有统计学意义（P〈0．05,P〈0．01）;相邻正常R-R间期差值的均方根（Rmssd）、24h内相邻窦性心搏R。R间期差值≥50ms的心搏数占正常心搏总数的百分比（PNN50）、高频成分（HP）、低频成分（LP）等参数重度组明显低于其它3组（P〈0．05,P〈0．01）;（3）随访期间冠脉病变组中发生MACCE与无MACCE患者比较,HRV和hs-CRP指标无明显差异。结论：HRV及血清hs-CRP水平与冠脉病变程度相关,对预测和评估冠脉病变严重程度可能具有一定的价值。     

平板运动试验诊断冠心病的临床价值

目的通过与冠脉造影（CAG）结果对比,探讨运动平板试验（TET）对冠心病的诊断价值。方法以CAG为诊断冠心病（冠脉狭窄≥50%）的＂金标准＂,对同期先后行TET和CAG检查的150例疑似冠心病患者进行回顾性分析,将其TET的结果与CAG进行比较。结果 TET检出冠心病的敏感性80.5%,特异性63.3%,准确性为72.7%,阳性预测值为72.5%,阴性预测值72.9%。冠心病患者中TET诊断阳性率与病变血管支数无明显相关性（r=0.482,p=0.68）,TET诊断结果阳性与阴性仅与血管狭窄程度≥75%狭窄的节段数目有统计学差异（p〈0.05）。结论 TET检出冠心病的特异性较低,但敏感性较高,能较准确评价冠心病的缺血情况。     

长期应用阿替洛尔致血脂代谢异常的临床分析

［目的］探讨长期口服阿替洛尔患者血脂水平的变化及其临床意义［方法］给５４例高血压及 冠状动脉硬化性心脏病患者连续口服阿替洛尔３个月，观察用药前后甘油三酯、总胆固醇和高密度脂蛋 白的水平［结果］阿替洛尔可使血甘油三酯升高，高密度脂蛋白降低，且随着时间的延长，差异更为明 显，总胆固醇无明显变化．［结论］长期服用阿替洛尔时应动态监测血脂水平，而不要局限于该值是否正 常，从预防与治疗动脉硬化角度来看，应选用有内源性拟交感作用的β肾上腺素能受体阻滞剂．