不同程度狭窄病变冠心病患者介入治疗后心肌灌注变化及临床意义

目的利用经冠状动脉超声心肌声学造影（MCE）比较单支血管不同程度狭窄病变冠心病患者经皮冠状动脉介入术（PCI）后心肌灌注的变化,并探讨其临床意义。方法62例进行PCI治疗的住院患者根据选择性冠状动脉造影结果,按血管狭窄程度分组:A组,血管狭窄75%95%;B组,血管狭窄>95%;C组,急性血管闭塞。PCI前及术后15 min进行经冠状动脉MCE,检测心肌灌注状况。其中,MCE有关定量参数分别为:造影剂峰值密度反映心肌血容量;峰值时间反映心肌灌注速度;曲线下面积反映心肌血流量。结果所有患者PC I后均达到TIMIⅢ级血流;A组术后心肌血流量较术前增加（P<0.05）;B组心肌血容量及血流量也较术前增加（P<0.05）;而C组心肌血容量、血流量及灌注速度较术前增加更显著（P<0.01）。结论不同狭窄程度病变冠心病患者,PCI后心肌灌注均得到不同程度改善,其中,以急性闭塞病变改善最明显,该类患者为PCI治疗的最大获益者。     

无创性冠脉血流储备用于分析不稳定型心绞痛患者冠脉缺血和冠脉狭窄的关系

目的 探究无创性冠脉血流储备（coronary flow reserve,CFR）用于分析不稳定型心绞痛（UAP）患者心肌缺血和冠脉狭窄关系。 方法 选取2016年1月至2018年12月收入UAP患者180例,共计冠脉病变94支,冠脉血流显像模式开展下,获取前降支、回旋支及右冠脉中远端静息时血流频谱图,ATP注射前、停药后5min内冠脉扩张后血流频谱图获取,用于测定静息状态下最大冠状舒张时峰值流速,并计算CFR。结果 冠脉狭窄组CFR为（1.17 ± 0.21）,非冠脉狭窄组为（2.61 ± 0.32）,冠脉狭窄组显著低于非冠脉狭窄组,差异具有统计学意义（P < 0.01）;CFR ≤ 1.8诊断为冠脉狭窄,敏感度为98%（92/94）、特异度为99%（85/86）,准确度为98%（177/180）。冠脉狭窄率 > 70%,CFR为（0.84 ± 0.12）,冠脉狭窄率50%~70%,CFR为（1.91 ± 023）,差异具有统计学意义（P = 0.01）,CFR以1.0作为截断值,冠脉狭窄率 > 70%,CFR ≤ 1.0例数为35例,冠脉狭窄率50%~70%,CFR ≤ 1.0例数为5例,差异具有统计学意义（P < 0.01）,当冠脉狭窄率增高,则CFR减低,二者呈负相关（r = ?0.803,P<0.05）。两组左心室舒张、收缩功能指标比较差异均无统计学意义。Pearson相关分析结果显示CFR与各心脏功能指标无相关性。与用药前比较,给药5 min、停药5 min后心率、收缩压、舒张压、呼吸高于用药前,差异有意义（P < 0.05, P < 0.01）。 结论 UAP患者开展无创CFR,可用于评估冠脉狭窄及其严重程度,但是冠状狭窄和患者心肌缺血发生并无明显相关性。     

血流储备分数指导经皮冠状动脉介入治疗术中非罪犯中度狭窄血管治疗策略的研究

目的：通过测量血流储备分数（FFR）,决定是否对不稳定型心绞痛多支血管病变患者经皮冠状动脉介入治疗（PCI）术中非罪犯中度狭窄血管行介入治疗,并观察临床转归。方法本研究入选不稳定型心绞痛多支血管病变患者,首先对已明确的罪犯血管行PCI治疗后,针对非罪犯中度狭窄血管按照单双号分为对照组（非支架组）和观察组（FFR指导下行PCI组）。其中,观察组FFR＜0.8的患者对中度狭窄血管行PCI治疗,术后再次行FFR检测,确保FFR≥0.95。观察终点事件为全因死亡、非致死性心肌梗死、再次血运重建发生率以及心绞痛临床表现。结果共纳入71例患者,对照组35例;观察组36例,其中FFR≥0.8的患者23例,FFR＜0.8的患者13例。两组患者无主要终点事件和再次血运重建生存率分别比较,差异均有统计学意义（P＜0.05）;无全因死亡与非致死性心肌梗死生存率分别比较,差异均无统计学意义。针对靶血管不良事件的统计学分析显示,两组再次血运重建（观察组5.6%,对照组31.4%）及非致死性心肌梗死（观察组5.6%,对照组28.6%）发生率分别比较,差异均有统计学意义（P＜0.05）。结论不稳定型心绞痛患者中,使用压力导丝测出的FFR值来决定是否对非罪犯中度病变进行血运重建是安全的。FFR结合冠状动脉造影指导PCI治疗较单纯冠状动脉造影指导PCI的不良事件发生率显著减少,尤其在再次血运重建方面,并且心绞痛临床表现显著缓解。     

Severe coronary tortuosity or myocardial bridging in patients with chest pain, normal coronary arteries, and reversible myocardial perfusion defects

We reviewed patients with normal or near-normal coronary angiograms enrolled in the SPAM contrast stress echocardiographic diagnostic study in which 400 patients with chest pain syndrome of suspected cardiac origin with a clinical indication to coronary angiography were enrolled. Patients underwent dipyridamole contrast stress echocardiography (cSE) with sequential analysis of wall motion, myocardial perfusion, and Doppler coronary flow reserve before elective coronary angiography. Ninety-six patients with normal or near-normal epicardial coronary arteries were screened for the presence of 2 prespecified findings: severely tortuous coronary arteries and myocardial bridging. Patients were divided in 2 groups based on the presence (false-positive results, n = 37) or absence (true-negative results, n = 59) of reversible myocardial perfusion defects during cSE and compared for history and clinical and angiographic characteristics. Prevalence of severely tortuous coronary arteries (35% vs 5%, p <0.001) or myocardial bridging (13% vs 2%, p <0.05) was 7 times higher in patients who demonstrated reversible perfusion defects at cSE compared to those without reversible perfusion defects. No significant differences were found between the 2 groups for the main demographic variables and risk factors. Patients in the false-positive group more frequently had a history of effort angina (p <0.001) and ST-segment depression at treadmill electrocardiography (p <0.001). In conclusion, we hypothesize that patients with a positive myocardial perfusion finding at cSE but without obstructive epicardial coronary artery disease have a decreased myocardial blood flow reserve, which may be caused by a spectrum of causes other than obstructive coronary artery disease, among which severely tortuous coronary arteries/myocardial bridging may play a significant role.     

The effect of coronary artery lesions on the relationship between coronary perfusion pressure and myocardial blood flow during cardiopulmonary resuscitation in pigs

In subjects without coronary disease, coronary perfusion pressure generated with closed-chest cardiopulmonary resuscitation (CPR) bears a direct relationship to myocardial blood flow. The effect of coronary lesions on this relationship was studied in an experimental porcine model not requiring thoracotomy. Coronary stenoses (a 50% reduction in coronary cross-sectional area) or total coronary occlusions were created by percutaneous, transarterial catheter placement of a Teflon cylinder in the left anterior descending artery of 21 swine (30 to 60 kg). Coronary perfusion pressure, defined as the aortic diastolic pressure minus right atrial diastolic pressure, was correlated with myocardial blood flow measured with nonradioactive, colored microspheres during external chest compression CPR. Complete occlusion of the left anterior coronary artery resulted in essentially no CPR-generated blood flow to the anterior myocardium distal to the site of occlusion. Coronary perfusion pressure showed a positive correlation with myocardial blood flow above the area of occlusion (r = 0.783; p less than 0.01) but did not correlate with myocardial blood flow below the occlusion site (r = 0.239). In the presence of a patent coronary artery stenosis, coronary perfusion pressure correlated with myocardial blood flow both above (r = 0.841; p less than 0.001) and below (r = 0.508; p less than 0.05) the stenosis. During closed-chest CPR producing coronary perfusion pressures between 30 and 60 mm Hg, anterior myocardial blood flow was 109 +/- 16 ml/min/100 gm above a patent stenosis and 66 +/- 13 ml/min/100 gm below the stenosis (p less than 0.005). Over a wide range of coronary perfusion pressures, myocardial blood flow below a coronary lesion was significantly less than that above the lesion. Coronary occlusions and stenoses can substantially affect the amount of CPR-generated coronary perfusion pressure needed to produce distal myocardial blood flow.     

Relative coronary flow velocity reserve improves correlation with stress myocardial perfusion imaging in assessment of coronary artery stenoses

STUDY OBJECTIVE: To evaluate the angiographic and coronary flow velocity parameters that best correlate with the results of stress myocardial perfusion imaging. DESIGN: Criterion standard. SETTING: Tertiary care center. PATIENTS: Forty-eight patients undergoing diagnostic coronary angiography for angina or silent ischemia. INTERVENTIONS: We performed angiographic and coronary flow velocity measurements at rest and during hyperemia at the post-stenotic segment and in the adjacent angiographically normal branch of the left coronary artery. Relative coronary flow velocity reserve (RCFVR) was calculated as the ratio of post-stenotic to reference vessel coronary flow velocity reserve (CFVR). The best cutoff points for reversible perfusion defects were calculated using receiver operating characteristic curves. MEASUREMENTS AND RESULTS: Post-stenotic CFVR showed fairly good correlations with minimal lumen diameter and percentage of diameter stenosis (r = 0.57 and r = 0.55, respectively; p < 0.001). RCFVR showed stronger correlations with these angiographic indexes of stenosis severity (r = 0.66 and r = 0.68, respectively; p < 0.0001). Based on receiver operating characteristic cutoff values (1.67 for post-stenotic CFVR and 0.64 for RCFVR), RCFVR had better agreement with myocardial perfusion imaging results, compared to post-stenotic CFVR (92% vs 75%, respectively). This agreement was more meaningful in patients with moderate coronary artery stenoses (50 to 75%). The area under the curve was 0.65 (not significant) for post-stenotic CFVR and 0.88 (p < 0.01) for RCFVR. CONCLUSIONS: RCFVR describes better than post-stenotic CFVR the functional significance of coronary artery stenoses.     

Impact of exercise-induced coronary vasomotion on anti-ischemic therapy

Coronary vasomotion has an important role in the regulation of myocardial perfusion. During dynamic exercise, normal coronary arteries dilate, whereas stenotic arteries constrict. This exercise-induced vasoconstriction has been associated with the occurrence of myocardial ischemia and has been believed to be the result of endothelial dysfunction, with a reduced release or production of EDRF, increased sympathetic stimulation, enhanced platelet aggregation with release of thromboxane A2 and serotonin, or a passive collapse of the disease-free wall segment within the stenosis (the Bernoulli effect), or a combination of any of these. More recently, it has been realized that pharmacological treatment might prevent exercise-induced vasoconstriction and, thus, reduce myocardial ischemia and the occurrence of angina pectoris. Vasodilators such as nitrates, calcium antagonists or alpha-receptor blockers dilate the coronary arteries and prevent coronary stenosis narrowing during exercise. In contrast, beta-blocking agents are associated with coronary vasoconstriction at rest, but--conversely--can induce coronary vasodilatation during exercise. Pharmacological treatment in patients with stable angina pectoris may improve myocardial ischemia by reducing pre- and afterload, myocardial contractility, oxygen consumption, and vasomotor tone. However, coronary collateral perfusion can modify these effects by shunting blood from the non-ischemic to the ischemic region (collateral flow) or by shunting blood from the ischemic to the non-ischemic zone (coronary steal phenomenon). Typically, a steal phenomenon has been reported in patients receiving either dipyridamole or calcium antagonists, whereas a reversed steal has been described after beta-blockade, with an increase in contralateral tone shunting blood from the non-ischemic to the ischemic zone (reverse steal phenomenon).     

Comparison between regional myocardial perfusion reserve and coronary flow reserve in the canine heart

Diameter stenosis and flow reserve are indices of morphologicaland functional severity of coronary artery stenosis. Flow reservecan be determined at coronary arterial or at myocardial level.In the presence of functional collateral circulation, coronaryflow reserve and myocardial perfusion reserve may differ. We studied coronary flow, coronary flow reserve and myocardialperfusion reserve in an open chest dog model with intact collateralcirculation, before and after induction of coronary artery stenosis.Coronary flow was determined with perivascular ultrasonic flowprobes and myocardial perfusion reserve from digital angiographicimages, in the stenotic as well as the adjacent non-stenoticcoronary arteries. Before induction of a stenosis, a significant correlation existedbetween coronary flow reserve and myocardial perfusion reserveof the left anterior descending (r=0·59; P<0·005)and the left circumflex arteries (r=0·84, P<0·005).In stenotic arteries, coronary flow reserve and myocardial perfusionreserve decreased significantly (P<0·005), but inthe adjacent non-stenotic arteries coronary flow reserve wasnot affected Myocardial perfusion reserve in the non-stenoticadjacent left anterior descending artery decreased significantly(P<0·05) and no correlation was found between coronaryflow reserve and myocardial perfusion reserve, whereas in theadjacent non-stenotic left circumflex artery there was no statisticallysignificant decrease (4·1 ± 1·6 3·5± 1·4) but there was a good correlation betweencoronary flow reserve and myocardial perfusion reserve (r=0·85;P<0·005). This study demonstrates that, in the presence of a stenosisand functioning collateral circulation, coronary flow reserveis not a reliable predictor of myocardial perfusion reserve;both parameters provide mutually complementary information.     

Effect of oral nitroglycerin and cold stress on myocardial perfusion in areas subtended by stenosed and nonstenosed coronary arteries

Physical obstruction and coronary vasoconstriction mediated by adrenergic stress are believed to be responsible for episodes of myocardial hypoperfusion and angina. Nitroglycerin relieves symptoms by reducing preload and dilating epicardial vessels. The net perfusion change and relation to stenosis severity of nitroglycerin and adrenergic stress have been debated. This study aimed to evaluate whether oral nitroglycerin and adrenergic stress alters perfusion in myocardial segments subtended by stenosed and nonstenosed coronary arteries. Myocardial perfusion was quantified (using N-13-ammonia positron emission tomography [PET]) at rest, after oral nitroglycerin 400 microg, and after cold stress in 25 patients with coronary artery disease (62 +/- 9 years, 21 men) and in 30 controls (34 +/- 9 years, 22 men). Myocardial perfusion was quantified in areas supplied by stenosed (>70%) and nonstenosed (<30%) coronary arteries. The cold pressor test did not significantly alter myocardial perfusion in any of the groups. However, when normalized for rate-pressure product, the response in stenosed areas showed a significantly more pronounced reduction compared with nonstenosed areas (0.78 +/- 0.18 vs 0.64 +/- 0.19 ml/g/min, p <0.005 and 0.86 +/- 0.19 vs 0.73 +/- 0.24 ml/g/min, p <0.05, p <0.05) for intergroup comparison. In both stenosed areas and nonstenosed areas nitroglycerin increased perfusion (0.51 +/- 0.14 vs 0.60 +/- 0.17 ml/g/min, p <0.05 and 0.56 +/- 0.14 vs 0.61 +/- 0.17 ml/g/min, p <0.05). Nitroglycerin did not alter myocardial perfusion in the control group. There was a negative correlation between the cold pressor test response and stenosis severity (r(2) = 0.17, p <0.046), whereas this was not the case for nitroglycerin. In patients with coronary artery disease, myocardial segments supplied by stenosed coronary arteries showed an altered perfusion response to adrenergic stress. Oral nitroglycerin increased myocardial perfusion irrespective of the presence of a stenosis.     

冠状动脉二支主干堵塞行介入治疗完全血运重建

目的：本研究探讨对16例冠状动脉二支主干堵塞者采用分步和分次冠状动脉介入治疗术（PCI）完全血运重建的有效性和安全性。方法：（1）对5例急性心肌梗死（AMI）,采取一次性分步直接PCI术完成血运重建;（2）对11例不稳定型心绞痛（UAP）,采取多次性分步PCI术达到完全血运重建,首先解除本次发病罪犯血管的堵塞;（3）恰当使用XB导引导管、Crossit硬导丝和Maverick球囊以及主动脉内球囊反搏（IABP）支持。结果：（1）5例AMI二支堵塞冠状动脉均成功植入支架,并首先使左前降支（LAD）再通。（2）11例UAP中21／22支冠状动脉二支主干堵塞处经球囊预扩张后,均成功植入支架,所有堵塞冠脉均获得TIMI-Ⅲ级血流。（3）16例患者术后心电图显示心肌缺血明显改善,心脏超声显示左室射血分数较术前明显改善,由（42±34）％升至（51±44）％。经过平均18个月随访,患者生活质量明显提高,未发生严重心血管事件。结论：冠状动脉二支主干堵塞者行PCI术完全血运重建安全可行;对AMI者优先开通LAD的一次性PCI术安全高效;对慢性堵塞UAP者,优先开通近期罪犯病变的多次性PCI术既可达到完全血运重建,又符合临床实际。     

Assessment of coronary stenosis by myocardial scintigraphy with thallium-201 after dipyridamol infusion

After a 4 minute i.v. dipyridamole infusion (0.14 mg/Kg/min) serial Thallium-201 scans were obtained in 45 patients, without myocardial necrosis, undergoing coronarography. Twelve patients had effort angina, 6 rest angina, 14 effort associated with rest angina, 13 had atypical chest pain. Thirty-two patients had a 50% or greater stenosis of 1 or more coronary artery (8 had three vessels disease, 7 two vessels, 17 one vessel); 13 patients had no significant coronary stenosis ("control group"). The test induced electrocardiographic signs of ischemia in 18 patients, all with significant coronary stenosis, 15 of them experienced angina too. Sensitivity of Thallium-201 for detecting coronary artery stenosis was 94% (30 of 32) and specificity was 85% (11 of 13). In the group of the 17 patients with one vessel disease we obtained a sensitivity and specificity of 100% (17 of 17). We conclude that Thallium-201 myocardial imaging after pharmacologic vasodilatation with dipyridamole is a highly sensitive and specific test for detecting coronary artery stenoses without necessary overt ischemia. In fact dipyridamole, as consequence of its important coronary vasodilatation, produces differences in myocardial perfusion with relative perfusion defects detectable with Thallium-201 imaging.     

Assessment of percutaneous coronary intervention on regional and global left ventricular function in patients with chronic total occlusions

BACKGROUND: The improvement of regional and global ventricular function following percutaneous coronary intervention (PCI) with reperfusion of the artery supplying the infarct area in acute myocardial infarction is well-described. However, little is known of the potential effects of late recanalization of chronic coronary artery occlusion on left ventricular function. OBJECTIVE: To determine whether PCI improves regional and global left ventricular function in patients with chronic coronary artery occlusions. PATIENTS AND METHODS: Thirty-five patients having at least one coronary artery occluded for six weeks or longer were included in the present prospective study. Exercise thallium-201 myocardial perfusion scintigraphy, multiple-gated acquisition ventriculography and two-dimensional echocardiography were performed in 19 patients (16 men; mean age of 58+/-5 years) who underwent a successful PCI to assess both regional and global left ventricular function before and six weeks following the procedure. RESULTS: The mean ejection fractions before and after reperfusion were 51+/-7% and 58+/-6% using Simpson's method (P<0.001) by echocardiography, and 45+/-1% and 53+/-1% (P=0.01) by multiple-gated acquisition ventriculography, respectively. The echocardiographic wall motion score was 24+/-9 before and 15+/-6 after PCI (P<0.001). The exercise perfusion score (21+/-1 and 14+/-1 [P=0.01]), rest perfusion score (15+/-1 and 12+/-1 [P=0.02]) and reinjection perfusion score (14+/-1 and 11.1+/-1 [P=0.07]) also improved after PCI. The presence of angina was strongly associated with an improvement in left ventricular function and wall motion score (P<0.01). CONCLUSIONS: PCI significantly improved the regional and global left ventricular function in patients with chronic total coronary occlusion. This procedure may provide symptom benefits in selected patients.     

Quantitative assessment of myocardial perfusion during graded coronary artery stenoses by intravenous myocardial contrast echocardiography

OBJECTIVES: The purpose of this study was to examine whether coronary stenoses of variable severity could be quantitatively assessed by analysis of myocardial perfusion as determined by intravenous (IV) myocardial contrast echocardiography. BACKGROUND: Recently, new contrast agents and imaging technology have been developed that may enable improved assessment of myocardial perfusion by IV contrast injection. METHODS: Variable obstruction of the left anterior descending (LAD) coronary artery in dogs was produced by a screw occluder. Coronary artery flow was measured with a transit time flowmeter during baseline, pharmacological vasodilation, a non-flow-limiting stenosis at rest in conjunction with vasodilation, a flow-limiting stenosis, and total occlusion. Myocardial contrast echocardiography was performed after IV injection of the contrast agent NC 100100. Time-intensity curves were obtained off-line for the LAD risk area and the adjacent left circumflex (LCx) territory, and peak background-subtracted video intensity was determined. Fluorescent microspheres were injected at each intervention for determination of regional myocardial blood flow. RESULTS: During non-flow-limiting stenosis, flow limiting stenosis and total occlusion, LAD/LCx ratios of peak myocardial videointensity and blood flow decreased proportionately. Both LAD/LCx ratios of video intensity and blood flow identified the non-flow-limiting and the flow-limiting stenoses as well as total occlusion of the LAD artery. A significant correlation between LAD/LCx video intensity and blood flow ratios was observed (r = 0.83, p < 0.0001). CONCLUSIONS: The degree of blood flow mismatch between ischemic and normal myocardial regions during graded coronary stenoses can be estimated in the dog by quantitative assessment of myocardial perfusion produced by IV myocardial contrast echocardiography.     

Augmented myocardial perfusion reserve after coronary angioplasty quantified by positron emission tomography with H2(15)O

Effects of coronary angioplasty on myocardial flow reserve have been difficult to characterize noninvasively because conventional imaging techniques cannot quantitate blood flow in absolute terms. The effects of coronary angioplasty on myocardial perfusion and perfusion reserve were delineated with positron emission tomography and oxygen-15-labeled water (H2(15)O) in 13 patients before and after single vessel angioplasty. In 11 patients, angioplasty was successful (minimal cross-sectional area increased from 0.60 +/- 0.59 to 3.45 +/- 1.09 mm2, p less than 0.001). In these patients, regional H2(15)O radioactivity (the ratio of nutritional perfusion in regions distal to the stenosis compared with regions supplied by angiographically normal arteries) at rest before angioplasty was 55 +/- 22% of peak myocardial radioactivity and did not increase significantly afterward (70 +/- 16%, p = NS). However, after administration of intravenous dipyridamole, hyperemic perfusion in regions distal to a stenosis averaged only 39 +/- 18% of peak myocardial counts before angioplasty, but increased to 66 +/- 22% after angioplasty (p less than 0.02). Perfusion reserve in the two patients in whom angioplasty was angiographically unsuccessful showed no change. Quantitative estimates of perfusion in absolute rather than relative terms were obtained with positron emission tomographic data from seven of the patients with successful angioplasty. At rest, perfusion in regions distal to a stenosis was not different from the values in regions supplied by normal coronary arteries (1.54 +/- 0.54 compared with 1.46 +/- 0.38 ml/g per min, p = NS).(ABSTRACT TRUNCATED AT 250 WORDS)     

Effects of oral testosterone treatment on myocardial perfusion and vascular function in men with low plasma testosterone and coronary heart disease

Intracoronary testosterone infusions induce coronary vasodilatation and increase coronary blood flow. Longer term testosterone supplementation favorably affected signs of myocardial ischemia in men with low plasma testosterone and coronary heart disease. However, the effects on myocardial perfusion are unknown. Effects of longer term testosterone treatment on myocardial perfusion and vascular function were investigated in men with CHD and low plasma testosterone. Twenty-two men (mean age 57 +/- 9 [SD] years) were randomly assigned to oral testosterone undecanoate (TU; 80 mg twice daily) or placebo in a crossover study design. After each 8-week period, subjects underwent at rest and adenosine-stress first-pass myocardial perfusion cardiovascular magnetic resonance, pulse-wave analysis, and endothelial function measurements using radial artery tonometry, blood sampling, anthropomorphic measurements, and quality-of-life assessment. Although no difference was found in global myocardial perfusion after TU compared with placebo, myocardium supplied by unobstructed coronary arteries showed increased perfusion (1.83 +/- 0.9 vs 1.52 +/- 0.65; p = 0.037). TU decreased basal radial and aortic augmentation indexes (p = 0.03 and p = 0.02, respectively), indicating decreased arterial stiffness, but there was no effect on endothelial function. TU significantly decreased high-density lipoprotein cholesterol and increased hip circumference, but had no effect on hemostatic factors, quality of life, and angina symptoms. In conclusion, oral TU had selective and modest enhancing effects on perfusion in myocardium supplied by unobstructed coronary arteries, in line with previous intracoronary findings. The TU-related decrease in basal arterial stiffness may partly explain previously shown effects of exogenous testosterone on signs of exercise-induced myocardial ischemia.     

经皮冠状动脉介入术后心肌灌注评价方法的比较

目的比较经冠状动脉超声心肌声学造影(MCE)与校正的心肌梗死溶栓临床试验(TIMI)帧数计数(CTFC)及冠状动脉血流速度方法对经皮冠状动脉介入术(PCI)后心肌灌注的评价,并探讨相关临床意义。方法68例住院患者根据选择性冠状动脉造影结果,按血管狭窄程度分组A组,正常对照组;B组,血管狭窄75%~95%;C组,血管狭窄>95%;D组,急性血管闭塞。对各病变血管均进行PCI治疗,并恢复TIMI3级血流。采用定量经冠状动脉MCE、CTFC及冠状动脉血流速度方法对术后心肌灌注状况进行检测。其中,经冠状动脉MCE有关定量参数分别为造影剂峰值密度(A)反映心肌血容量;峰值时间(TP)反映心肌灌注速度;曲线下面积(AUC)反映心肌血流量。结果PCI后心外膜血管恢复正常血流的前提下,各狭窄病变血管组CTFC与对照组差异无统计学意义;而闭塞血管组冠状动脉血流速度较对照组低;在MCE检测中,C组的心肌血容量及血流量较对照组低,而D组反映心肌灌注的3个参数值均较对照组差异均有统计学意义。结论经冠状动脉MCE通过多个参数进行定量分析,较其他两种方法能更精确地评价PCI后心肌灌注状况。     

经桡动脉穿刺冠状动脉造影后即刻经桡动脉介入治疗

目的探讨冠心病心绞痛患者经桡动脉穿刺冠状动脉造影术后即刻选择经桡动脉行冠状动脉介入治疗的可行性、并发症以及近期疗效。方法选择临床诊断为冠心病心绞痛经桡动脉造影显示明确的冠状动脉病变后即刻采取经桡动脉介入治疗(PCI)的患者117例(桡动脉组),与同期经股动脉途径造影后即刻PCI者(股动脉组,共409例)进行比较,分析两组靶血管病变特征、疗效和并发症,并随访术后1月内心绞痛复发、心肌梗死、死亡等主要心血管事件的发生率。结果桡动脉组PCI成功率为94.0%,与股动脉组(97.6%)相比无明显差异(P>0.05)。桡动脉组造影显示明显病变(管腔狭窄程度≥70%)的血管数量累计为210支,其中182支作为靶血管进行了成功的PCI,病变血管的血运重建率为86.7%,低于股动脉组(93.4%),差异具有显著性(P<0.01)。而且成功PCI者中慢性闭塞病变的所占的比例也明显低于股动脉组,差异具有显著性(P<0.05)。桡动脉组术后与穿刺有关的总的并发症的发生率明显低于股动脉组(P<0.01)。术后平均卧床时间和平均住院天数均明显短于股动脉组。随访PCI术后1个月期间主要心血管事件两组之间无明显差异(P>0.05)。结论经桡动脉穿刺冠状动脉造影术后即刻行冠状动脉介入治疗的成功率较高,并发症少,具有可行性。但对于复杂病变选择经股动脉途径PCI     

应用腺苷负荷心肌灌注显像随访老年冠状动脉介入术后患者的临床研究

目的 观察腺苷负荷心肌灌注显像对老年经皮冠状动脉介入治疗(PCI)患者疗效评估包括心肌血运恢复及心功能恢复情况。 方法 选择怀疑冠心病和已明确诊断老年冠心病患者,常规完成冠状动脉造影,53例行PCI,于PCI前、后6个月进行腺苷负荷心肌灌注显像检查,并同时进行心血管主要不良事件随访,完成随访40例。腺苷负荷心肌灌注显像把心肌分为16节段,计算核素扫描总积分及测定心功能。 结果 心肌扫描总积分与冠状动脉总狭窄指数呈正相关(r=0.675,P＜0.01);PCI后心肌扫描总积分与治疗前比较明显减低,分别为（2.2±2.3）与（4.5±1.9）分,差异有统计学意义(t=7.348,P＜0.01);PCI术后心肌灌注改善总有效率86.8％(40/53);PCI术后左心室射血分数较术前明显改善,分别为(58.3±10.5)％与（53.8±10.3）％,差异有统计学意义(t=3.497,P＜0.01)。 结论腺苷负荷心肌灌注显像作为一种无创的检测方法可以准确判定老年PCI术后血流恢复及心功能恢复情况,对老年人PCI术后疗效评价具有一定优势。     

Differential value of adenosine myocardial contrast echocardiography and dobutamine stress echocardiography in evaluating functional significance of coronary artery stenosis in a porcine model

Aim Myocardial contrast echocardiography (MCE) during adenosine induced hyperemia is an experimental method that detects flow limiting coronary artery stenosis by visualizing myocardial perfusion defects. Noninvasive detection of flow limiting coronary artery stenosis in clinical routine is a frequent domaine of dobutamine stress echocardiography (DSE) visualizing ischemia related regional wall motion abnormalities. This study investigated the values of adenosine MCE and DSE in the detection of functionally significant coronary artery stenosis in an experimental open chest pig model. Methods A total of 28 proximal LAD stenoses were instrumented in 12 animals. Reduction of coronary blood flow reserve (Δ CFR [%]) was calculated as a marker of functional significance of coronary artery stenosis (mild to moderate stenosis: Δ CRF ≤ 50%; severe stenosis: Δ CFR > 50%). Fractional area shortening (FAS) and wall thickening (WT) were calculated to evaluate regional wall motion. Peak myocardial contrast intensities (PCI) were measured following aortic root injections of Levovist' to detect myocardial perfusion defects. Results As a group, severe stenosis significantly reduced wall motion response to dobutamine (Δ FAS: 12.0 ± 3.0%, vs. 20 ± 3.0% without stenosis, p < 0.05; Δ WT: 2.2 ± 0.9 mm vs. 0.0 ± 0.8 mm without stenosis, p < 0.05) and diminished myocardial opacification during hyperemia (PCI: 59 ± 8 units vs. 143 ± 16 units without stenosis, p < 0.05). Mild to moderate stenosis did not influence wall motion but reduced myocardial opacification (PCI 89 ± 14 units vs. 143 ± 16 units). PCI correlated more closely with alterations in CFR (r = −0.7, p < 0.0001) than did FAS (r = −0.5, p < 0.002) or WT (r = −0.2, p = 0.3). Conclusion Adenosine myocardial contrast echocardiography detects flow limiting coronary artery stenosis and compares favorably to regional wall motion analysis during dobutamine infusion. Received: 22 May 2000 / Returned for 1. revision: 26 June 2000 / 1. Revision returned: 11 September 2000 / Returned for 2. revision: 11 October 2000 / 2. Revision returned: 21 December 2000 / Accepted: 15 January 2001     

延迟支架置入术在高血栓负荷急性ST段抬高型心肌梗死患者急诊冠状动脉介入治疗中的应用

目的观察高血栓负荷急性ST段抬高型心肌梗死(STEMI)患者直接经皮冠状动脉介入治疗(PCI)后靶病变的变化及延迟支架置入情况。方法入选48例高血栓负荷STEMI患者,急诊予单纯球囊扩张和(或)冠状动脉血栓抽吸,梗死相关动脉前向血流心肌梗死溶栓试验(TIMI)血流分级3级,7 d后复查冠状动脉造影(CAG),根据靶病变血管狭窄情况必要时置入支架治疗。观察靶病变变化的相关数据,包括狭窄程度、长度、近端参考血管直径、远端参考血管直径,比较老年患者(≥60岁)和中青年患者(<60岁)支架置入比例。结果 7 d后复查CAG显示靶病变直径狭窄程度较直接PCI时减轻(35.5%±14.1%比48.8%±11.0%,P<0.01)、病变长度缩短[(15.69±5.36)mm比(18.94±5.37)mm,P<0.01],靶病变近端参考血管直径[(3.29±0.33)mm比(3.24±0.32)mm,P=0.02]和远端参考血管直径[(3.18±0.33)mm比(3.08±0.33)mm,P<0.01]增大;其中,39.6%(19/48)患者因靶病变狭窄>50%置入支架,老年患者和中青年患者置入支架比例分别是56%(9/16)、31%(10/32)(P=0.04)。结论对于中青年高血栓负荷不适宜直接支架置入术的STEMI患者急诊予单纯球囊扩张和(或)血栓抽吸即时开通梗死相关动脉,再延迟必要时支架置入治疗策略是安全、有效的。