Beneficial effect of enhanced myocardial carbohydrate utilisation after oxfenicine (L-hydroxyphenylglycine) in angina pectoris

Although the major myocardial energy supply comes from oxidationof lipid, carbohydrate requires less oxygen for the same energyyield. Oxfenicine has been shown experimentally to favour carbohydrateutilisation and its effect in a dose of 3–12 mg/kg wasstudied in 18 patients with obstructive coronary artery disease,both at rest and during angina induced by rapid atrial pacing.No major haemodynamic changes or side effects were observedafter the drug. The mean pacing time to angina was significantlyincreased from 289 ± 33 s to 360 ± 35 s (P <0.05) and during pacing, myocardial oxygen consumption fell.After the drug there was a significant increase in myocardialextraction of carbohydrate in the form of lactate, pyruvateand glucose during pacing and in contrast, the myocardial extractionof free fatty acids fell significantly. This increase in myocardialcarbohydrate extraction associated with a reduced myocardialoxygen consumption, is of potential value not only in the treatmentof angina pectoris, but also in the early phases of acute myocardialinfarction.     

Effect of aortocoronary bypass surgery on coronary circulation and myocardial metabolism during atrial pacing

Summary Eleven patients with coronary heart disease, in whom at least one of several bypass grafts to the left coronary artery was patent, were selected for the study. The hemodynamics, coronary sinus blood flow, myocardial oxygen consumption, and myocardial lactate metabolism were evaluated at rest and during atrial pacing stress test before and after surgery.There were no significant improvements in the cardiac index, pulmonary arterial end-diastolic pressure, and left ventricular ejection fraction after aortocoronary bypass surgery. However, significant improvement of coronary sinus blood flow, myocardial oxygen consumption, and myocardial lactate extraction and consumption were found during postoperative atrial pacing compared with the preoperative findings.These results suggest that successful bypass grafting may improve myocardial lactate metabolism in ischemic lesions and contribute to the postoperative relief of angina.     

Intracoronary papaverine induced myocardial lactate production in patients with angiographically normal coronary arteries

Although intracoronary papaverine has been widely used for the measurement of coronary flow reserve, little is known concerning whether papaverine may produce deleterious metabolic changes in humans. We investigated the effect of papaverine on lactate metabolism in 28 patients with normal coronary arteries. We continuously monitored phasic coronary flow velocity in the proximal left anterior descending coronary artery using Doppler guidewire. We also obtained paired samples of arterial and coronary sinus blood for the measurement of lactate at control and at 1 min after administration of 10 mg of intracoronary papaverine. There were no serious side effects during papaverine infusion. Sixteen patients showed ST-T abnormalities after papaverine. The QTc interval increased from 450 ± 42 msec to 571 ± 58 msec (P < 0.001). Average peak velocity increased significantly (% increase: 198.5 ± 87.8%, range: 27.8–374.1%) after papaverine. Although intracoronary papaverine produced no significant change in arterial lactate levels (8.5 ± 4.0–8.8 ± 5.0 mg/ml), it induced a significant increase in coronary sinus lactate levels (5.4 ± 3.2–15.3 ± 8.2 mg/ml, P < 0.001). Lactate extraction ratio decreased significantly (36.4 ± 18.4–-82.2 ± 58.4%, P < 0.001), and all patients showed net lactate production (-3.9–-198.0%) after papaverine. There was weak but significant correlation between lactate extraction ratio after papaverine and coronary flow reserve (R² = 0.15, P < 0.05). There was no correlation between lactate extraction ratio and QTc interval after papaverine. The mean value of lactate extraction ratio was not different in patients with ST-T abnormalities induced by papaverine compared to those without. These results demonstrate that intracoronary papaverine induces myocardial lactate production irrespective of the degree of coronary flow reserve and electrocardiographic changes in patients with normal coronary arteries. A safer and more reliable agent is needed for the measurement of coronary flow reserve. © 1996 Wiley-Liss, Inc.     

New signs characteristic of myocardial bridging demonstrated by intracoronary ultrasound and Doppler.

BACKGROUND: Large discrepancies exist concerning the incidence of myocardial bridging. This has been reported to be 0.5%-2.5% following coronary angiography but 15%-85% following autopsy. The purpose of the study was to use intravascular ultrasound and intracoronary Doppler to study the morphology and flow characteristics of myocardial bridging in order to find feasible parameters of this syndrome. METHODS AND RESULTS: Intravascular ultrasound was performed in 62/69 patients in whom typical angiographic 'milking effects' were present. In 48 patients, intracoronary Doppler was performed. A specific, echolucent 'half moon' phenomenon surrounding the myocardial bridge was found in all the patients. The thickness of the half moon area was 0.47 +/- 0.19 mm in diastole and 0.52 +/- 0.23 mm in systole. There was systolic compression of the myocardial bridge with a lumen reduction during systole of 36.4 +/- 8.8%. Using intracoronary Doppler, a characteristic early diastolic 'finger tip' phenomenon was observed in 42 (87%) of the patients. All patients showed no or reduced antegrade systolic flow. Coronary flow velocity reserve was 2.03 +/- 0. 54. After intracoronary nitroglycerin injection, retrograde systolic flow occurred in 37 (77%) of the 48 patients, with a velocity of -22. 2 +/- 13.2 cm. s(-1). Intravascular ultrasound revealed atherosclerotic involvement of the proximal segment in 61 (88%) of the 69 patients, with an area stenosis of 42 +/- 13%. No plaques were found in the bridge or distal segments in the 62 patients in whom it was possible to introduce the ultrasound catheter throughout the bridging segment. CONCLUSION: Myocardial bridging is characterized by the following morphological and functional signs: a specific, echolucent half moon phenomenon over the bridge segment, which exists throughout the cardiac cycle; systolic compression of the bridge segment of the coronary artery; accelerated flow velocity at early diastole (finger-tip phenomenon); no or reduced systolic antegrade flow; decreased diastolic/systolic velocity ratio; retrograde flow in the proximal segment, which is provoked and enhanced by nitroglycerin injection.     

心肌呈色分级评价急性心肌梗死急诊经皮冠状动脉介入治疗的近期疗效

目的以心肌呈色分级(MBG)评估急性心肌梗死(AMI)急诊冠状动脉介入治疗(PCI)后的心肌灌注状况。方法109例AMI患者给予急诊PCI治疗。各例于PCI后行冠状动脉造影,观察梗死相关动脉(IRA)前向血流,评估心肌灌注情况,并记录6个月心脏事件发生率。结果冠状动脉造影结果显示,无复流组(no-reflow,NR)22例患者,占所有直接PCI患者的20.2%,既往心肌梗死史和糖尿病、前壁梗死和多支血管病变的发生率方面明显多于非NR组。NR组MBG2和3级和ST段抬高下降≥50%者显著少于非NR组,根据心肌酶估测的心肌梗死范围扩大(磷酸肌酸激酶为43.45±5.34g比27.48±4.47g,P<0.05),左心室射血分数显著降低(0.39±0.11比0.62±0.13,P<0.01);NR组总死亡率较非NR组有增加趋势,但差异无统计学意义;非致死性心力衰竭(22.7%比5.7%,P<0.05)和复合终点事件(35.0%比13.8%,P<0.05)的发生率无论住院期间还是随访6个月均明显增加,而两组在不稳定型心绞痛、非致死性再次心肌梗死、缺血性靶血管重建及总的心脏性死亡的发生率方面差异无统计学意义。结论出现NR者心肌微循环灌注不良,梗死范围大,心功能降低,预后差。     

冠状动脉慢血流与心肌缺血的关系

目的:通过腺苷负荷心肌灌注显像(SPECT),评价冠状动脉慢血流现象(CSF)与心肌缺血的关系。方法:选择经冠状动脉造影(CAG)诊断为CSF者20例,CAG显示无管腔狭窄及无慢血流者20例为对照组。使用校正的TIMI血流分级(CTFC)方法评价冠状动脉血流速度,2组均行心电图及腺苷负荷SPECT检查。结果:CSF者发生心电图及腺苷负荷SPECT异常的例数比对照组明显增多,同时心肌缺血的范围与缺血程度也均大于血流正常者(P<0.01)。结论:腺苷负荷SPECT发现CSF存在可逆性心肌缺血,可能CSF与心肌缺血关系密切。     

心肌血流储备分数指导下药物治疗冠状动脉临界病变患者的远期疗效

目的研究心肌血流储备分数(FFR)指导下药物治疗冠状动脉临界病变患者的安全性。方法 2010年4月至2011年9月武汉亚洲心脏病医院介入中心行冠状动脉造影提示临界病变同时行冠状动脉内压力导丝测定FFR≥0.8的连续15例患者,规范冠心病二级预防药物治疗。随访≥1年,包括主要不良事件(包括死亡、心肌梗死、再次靶病变血运重建术、卒中)及再发心绞痛、再次住院、出血发生情况。结果 15例患者平均(61±7.49)岁。其中男性7例(46.7%),冠状动脉造影病变平均(1.2±0.5)支。15例患者冠状动脉造影提示19处临界病变:左前降支15处、回旋支3处,右冠状动脉1处;其中单支病变者11例(73.3%),双支病变者4例(26.7%),均合并前降支病变;FFRmyo均值(0.88±0.06)。15例患者平均随访(23.6±5.67)个月,其中1例(6.7%)失访。2例(13.3%)不稳定型心绞痛患者随访期间出现心绞痛,症状较前无明显加重,含服硝酸甘油可缓解,余心肌梗死、再次靶病变血运重建术、卒中、全因死亡、再次住院率、出血等不良事件无发生。对入选患者心绞痛发生情况采用Kaplan-Meier法做生存分析,FFR术后平均再发心绞痛时间为术后(29.12±0.67)个月。结论初步验证了FFR指导下药物治疗冠状动脉临界病变患者是可行的。     

Effects of dobutamine on left ventricular performance and myocardial metabolic demands in patients with ischemic heart disease

Sixteen patients with coronary artery disease undergoing cardiac catheterization were studied. Eleven had previous infarcts and the patients were divided into two groups: In group I were 7 patients with no left ventricular dysfunction, no increase in ventricular size, or symptoms of congestive failure; group II included 9 patients with ventricular dysfunction, increased ventricular size, and 7 of the 9 had congestive failure. Each patient underwent a continuous infusion of dobutamine from 2.5 to 10 μUg/kg min^-1 with dosage increments of 2.5 μUg/kg at 15-minute intervals. Systemic and coronary hemodynamic measurements were obtained at the end of the 5 and 10 μUg/kg min^-1 infusion doses. Left ventricular performance improved (higher cardiac index, left ventricular stroke work index and mean systolic ejection rate, and lower left ventricular end-diastolic pressure), while heart rate, mean arterial pressure, and coronary sinus blood flow increased after dobutamine in the 16 patients. While patients in both groups had a rise in cardiac index, a reduction in left ventricular end-diastolic pressure, an unchanged mean arterial pressure and a rise in coronary blood flow, only patients in group I had a significant increase in heart rate, and only patients in group II had significant increases in left ventricular stroke work index and mean systolic ejection rate, and a significant reduction in systemic vascular resistance. Left ventricular oxygen consumption did not increase significantly in either group. However, 5 patients showed a decreased myocardial lactate extraction after 10 μUg/kg min^-1 of intravenous dobutamine, 3 from group I and 2 from group II. These 5 patients had less ventricular dysfunction than patients with a normal lactate response to intravenous dobutamine. We conclude that the improvement in left ventricular performance observed after dobutamine administration in patients with ischemic heart disease is not usually associated with a major increase in left ventricular oxygen consumption or with marked aggravation of myocardial ischemia. This appears to be particularly true in patients with relatively severe left ventricular dysfunction.     

Detection of impaired coronary flow reserve in coronary artery disease using transthoracic echocardiographic assessment of coronary sinus blood flow

In order to establish whether coronary flow reserve (CFR) can be measured by transthoracic echocardiography (TTE) with pulse wave Doppler echocardiography, 14 patients with coronary artery disease (CAD) and 12 normal subjects were studied. Coronary sinus blood flow was measured at rest and 2 minutes after intravenous injection of 0.56 mg/kg dipyridamole (DP). CFR was calculated as the DP to rest flow ratio. Patients with CAD were found to have significantly decreased CFR when compared to normal subjects. These findings suggest that TTE may be useful in diagnosing CAD.     

左主干开口于无冠窦急性前壁心肌梗死经皮冠状动脉支架术致左主干回旋支夹层一例

1 病例资料 患者男性,54岁,因持续性心前区疼痛5h入院。既往史：吸烟。查体：BP120／80mmHg（1nllnHg=0．133kPa）,神清,自动体位,查体合作。口唇无发绀,颈静脉无怒张;肺呼吸音清,未闻及干湿哕音,心界无扩大,心率100次／min,节律规整,未闻及杂音,肝脾正常,双下肢无水肿。     

心肌灌注显像对非ST段抬高的急性冠脉综合征介入治疗心肌再灌注的研究

目的通过心肌灌注断层显像研究急性冠脉综合征(ACS)冠脉介入治疗(PCI)前后心肌再灌注的变化。方法2000-012005-01对中山大学附属第五医院的106例ACS患者用99m锝甲氧基异丁基异腈心肌灌注断层显像测定心肌再灌注后的心肌复活面积情况。结果PCI后心肌显像心肌缺损面积较PCI前缩小,两者相比差异具有显著性[(12·8±4·6)%对(26·7±4·9)%,P<0·05];PCI后冠状动脉造影TIMI血流Ⅲ级者再灌注后心肌缺损面积缩小率明显大于冠状动脉造影TIMI血流≤Ⅱ级者(43·4%对14·6%,P<0·05);PCI后预后不良组心肌缺损面积明显高于预后较好组[(25·81±5·7)%,n=19对(13·6±4·2)%,n=87,P<0·05]。PCI后开通二级以上冠状动脉2支以上血管的心肌缺损面积缩小率明显高于开通1支血管的患者(39·1%,n=31对23·7%,n=71,P<0·05)。结论心肌灌注断层显像可作为ACS无创性心肌再灌注疗效评价较准确的手段。     

腺苷负荷心肌灌注显像141例临床分析

目的:腺苷负荷心肌灌注显像(MPI)与冠状动脉造影(CAG)2种检查方法的结果对比分析。方法:对141例患者分别行腺苷负荷MPI及CAG检查,并使用校正的TIMI血流分级(CTFC)方法评价冠状动脉血流速度。对2种方法的检查结果进行比较分析。结果:腺苷负荷MPI阳性的99例患者中,经CAG检查确诊冠心病者52例,冠状动脉慢血流(CSF)者37例,冠状动脉正常者10例。腺苷负荷MPI对冠心病诊断的灵敏度和特异度为92.9%和44.7%;对CSF诊断的灵敏度和特异度为82.2%和75.0%。结论:腺苷负荷MPI阳性者中一部分为冠心病患者,一部分为CSF者,对于腺苷负荷MPI异常的患者需进一步行CAG检查以明确病情。     

血栓抽吸导管(DIVERTM)在急性心肌梗死急诊冠状动脉介入治疗中的应用

目的评价急性心肌梗死急诊冠状动脉介入治疗(PCI)中应用血栓抽吸导管(DIVERTM)的临床疗效与安全性。方法选择2005年3月至2006年4月符合急诊PCI治疗条件的急性心肌梗死患者共74例,入选患者梗死相关血管(IRA)100%闭塞伴冠状动脉内血栓,开通IRA后均置入西罗莫司药物涂层支架。其中36例(A组)将0.36mm(0.014in)BMW冠状动脉导丝送至闭塞血管远端,沿该导丝送入血栓抽吸导管(DIVERTM),持续负压下从血管近端至远端缓慢推抽2~3次,造影提示血栓影消失后直接置入支架;另外38例(B组)按常规方法完成PCI术。比较两组间血管开通率、无复流发生率、住院期间及出院后半年内心血管事件发生率。结果两组冠状动脉造影显示的血管开通率均为100%,A组无复流发生率及住院期间主要不良心脏事件发生率明显低于B组(2.78%比21.05%,2.78%比10.53%,P均<0.05)。平均随访3.2±1.4个月,随访率93.5%,两组半年内心血管事件发生率均为0。结论在急性心肌梗死急诊PCI中应用血栓抽吸导管(DIVERTM)安全可行,操作简单,能够明显减少冠状动脉内血栓,降低无复流和住院期间心血管事件发生率,其临床效果优于普通治疗组。     

Differences in use of coronary angiography and outcome of myocardial infarction in Toulouse (France) and Gerona (Spain). The MONICA-Toulouse and REGICOR investigators.

AIMS: Differences in the management and organization of health services may account for some of the variability in myocardial infarction case fa tality in different geographic areas. The 28-day outcome was compared i n two regions with similar myocardial infarction incidence and mortality rates that had opposing patients in the use of coronary angiography an d coronary revascularization. METHODS AND RESULTS: The 28-day case fatality of patients aged 35 to 64 years with myocardial infarction, surviving the first hour post-admission to hospitals with coronary care units, was compared in the population of myocardial infarction registries of Toulouse, France and Gerona, Spain. Patient characteristics were similar. In Toulouse, 93% of the 819 registered patients underwent coronary angiography compared with only 6% of the 454 in Gerona. Among hospitalized patients 28-day case fatality was 4.3% and 9.3% in Toulouse and Gerona, respectively (P=0.0003). Rates of thrombolysis and beta-blocker use were higher in Toulouse, although severity indicators were similar to those of Gerona. A model adjusted for these variables showed that the risk of death was 1.90 (95% confidence interval: 1.17-3.07) in Gerona patients compared with those of Toulouse. CONCLUSIONS: Routine angiography use is associated with better 28-day myocardial infarction prognosis than restrictive use. However, the optimum proportion of myocardial infarction patients who have to receive angiography procedures remains unclear.     

心肌声学造影定量心肌血流判断存活心肌的实验研究

目的　评价经静脉心肌声学造影 (MCE)判断存活心肌的可行性。方法　建立急性心肌梗死犬模型 ,经外周静脉持续滴注微泡造影剂 ,通过计算A·β值测定心肌相对血流量。以放射性微球法测定的心肌血流量 (MBF)为标准 ,了解A·β值测定MBF的准确性。通过A·β值估测心肌存活与否 ,病理检查验证其可靠性。结果　放射性微球法所测的正常区、缺血区、坏死区的MBF分别为 ( 1 5± 0 3)、( 0 7± 0 3)、( 0 3± 0 2 )ml·min-1·g-1;MCE测得的A·β值分别为 5 2 46± 15 0 9、2 4 36±3 89、3 74± 3 80 ;正常区、缺血区、坏死区的MBF和A·β值“标化”后分别为 1 0± 0 0、0 44± 0 17、0 17± 0 11和 1 0± 0 0、0 48± 0 0 9、0 0 7± 0 0 8,二者的相关性良好 (r=0 81,P =0 0 0 1)。MCE对坏死心肌的判定结果与病理结果吻合。结论　心肌声学造影可用于活体状态下评价存活心肌 ,“标化”后的A·β值 <0 2 3提示心肌坏死。     

远程缺血预适应对心肌保护作用的研究综述

对于急性冠脉综合征患者经皮冠状动脉介入成为其最有效的治疗方式,为预防其产生的缺血再灌注损伤,远程缺血预适应是目前最有前景的治疗方式。该方案能够有效地缩减心肌梗死面积,减轻心肌细胞水肿,缓解炎症反应,降低血清心肌坏死物以及恶性心律失常的发生率。目前的研究表明,其保护作用与体液机制、神经机制以及二者的相互作用有关。最新的观点认为囊泡机制也参与其中。相关的临床研究也证明了其心脏保护作用。因此完善远程缺血预适应的具体机制以及寻找最优化的治疗方式可能对急性冠脉综合征患者的治疗以及预后带来新的希望。     

Evaluation of potential adverse effects of sodium nitroprusside during pacing-induced myocardial ischaemia in man

To elucidate the potential harmful effects of sodium nitroprusside(NP) on myocardial ischaemia, eleven patients with coronaryartery disease were studied before and during two doses NP infusion.The infusion rates were adjusted to reduce systolic aortic pressureby 10–20 mmHg and to between 100 and 110 mmHg. Myocardialhaemodynamic and metabolic measurements were undertaken in sinusrhythm and during pacing-induced angina pectoris. The procedurewas repeated at the low and high dose NP using the same pacingrate. One patient did not develop ischaemia and was excluded.Low dose NP reduced ischaemia slightly, whereas the higher dosehad no effect despite falling indices of cardiac work. The oxygenuptake was maintained except at high dose treatment during pacingdue to an increased catecholamine stimulation. The transmuralperfusion gradient was unchanged at low dose NP, but fell atthe higher dose suggesting reduced perfusion of ischaemic tissue.High dose NP also decreased coronary arteriolar resistance considerablywhich may have induced a coronary ‘steal’ effect.Thus, NP may induce adverse haemodynamic and metabolic changeswhich counteract the beneficial actions of the drug on ischaemiawhen used in high doses and in patients without heart failure.     

东菱克栓酶冠状动脉溶栓治疗急性心肌梗塞的临床研究

报告6例发病时间在4～10小时内的急性心肌梗塞患者，采用冠状动脉狭窄口堵塞近端注入东菱克栓酶（DF－521）20～30BU（Batroxobinunit简称BU，是Batroxobin的酶活性量的表示单位。37℃以下，标准人～枸椽酸血浆0．3ml中加入Batroxobin溶液0．1ml，19．0±0．2秒发生凝固时其酶活性为2BU）。进行溶栓治疗，60～90分钟后重复冠状动脉造影。结果全部有效，4例闭塞管腔再通（TIMI达Ⅲ级）2例大部分再通（TIMI达Ⅱ级），从而限制了梗塞发展且无出血及其它并发症，效果显著，值得进一步研究推广。     

多巴酚丁胺对心肌桥-壁冠状动脉血流动力学的作用

目的探讨运动对心肌桥患者血流动力学的影响。方法观察8例心肌桥患者在静脉滴注多巴酚丁胺前后壁冠状动脉受压程度的变化,并运用腔内多普勒技术观察壁冠状动脉的基础峰值血流速率(bAPV)、最大峰值血流速率(hAPV)、冠状动脉血流储备(CFR)的变化。结果多巴酚丁胺使壁冠状动脉受压程度由用药前的平均(51.7±21.4)%增加至(90.0±12.7)%,P<0.01;壁冠状动脉近段和远段的 hAPV 分别由(19.83±5.84)cm/s 和(20.75±4.91)cm/s 增加至(31.52±10.93)cm/s 和(30.46±9.01)cm/s;壁冠状动脉近段和远段的 CFR 分别由(2.91±0.62和2.46±0.82,P<0.05)下降至(2.17±0.66和1.83±0.51,P 均<0.01)。结论运动可能使壁冠状动脉受压程度增加,CFR 显著下降。