冠脉血流显像技术及hsCRP检测无创评价X综合征患者心肌微血管功能

目的利用经胸冠脉血流显像技术(CFI)观测X综合征患者及正常对照组的左前降支血流,同时测定两组入选者血清炎症标志物高敏C反应蛋白(hsCRP)浓度,评价X综合征患者冠脉血流储备(CFR)及与炎症反应的关系。方法利用经胸CFI结合腺苷药物负荷分别测量20例X综合征患者和22例正常对照组的前降支中段静息及最大充血状态时的冠脉舒张期峰值血流速度,计算注射腺苷后的最大平均血流速度与静息状态下平均血流速度的比值,即CFR,采用乳胶增强透射免疫比浊法检测血清hsCRP浓度。结果 X综合征组CFR值低于正常对照组,差异有统计学意义(P0.01),X综合征患者血清hsCRP浓度高于正常对照组,差异有统计学意义(P0.01)。结论 CFI是一种能够准确有效测量CFR的无创性检测方法,X综合征患者CFR功能减退,且X综合征患者CFR减退与炎症反应有关。     

胸痛患者冠状动脉血流储备的超声研究

目的 :应用多平面经食管多普勒超声心动图 (TEE)潘生丁负荷试验 ,探讨胸痛患者的冠状动脉 (冠脉 )循环特点及血流储备 (CFR)功能。方法 :将受试者分为 4组 :冠脉前降支重度狭窄 (A组 ) 10例 ,轻度狭窄 (B组 ) 6例 ,X综合征 (C组 ) 7例 ,冠脉造影正常 (对照组 ) 15例。应用TEE测定冠脉前降支血流频谱 ,以基础状态下(R)和潘生丁负荷后 (D)冠脉舒张期最大流速比值 (D/RPDV)为CFR的指标。结果 :与对照组比较 ,其他 3组基础状态时冠脉血流速度差异无显著性意义 ;CFR明显减低 ,以A组最为明显〔(1.5 5± 4 3)∶(3.4 3± 0 .6 2 )cm/s,P<0 .0 0 1〕 ,狭窄程度与D/RPDV高度相关 (r =0 .83,P <0 .0 0 1) ;B组与C组比较 ,CFR减低程度一致〔(2 .6 2± 0 .71)∶(2 .19± 0 .36 )cm/s,P >0 .0 5 )〕。结论 :CFR反映了冠脉狭窄时冠脉的血流动力学改变 ,可用于判断冠脉狭窄的程度 ;CFR减低是冠脉造影正常患者胸痛的原因     

冠状动脉血流储备和PCI术相关性探讨

目的采用经胸冠状静脉窦多普勒超声心动图冠状动脉血流显像技术观察经皮冠状动脉介入(PCI)术前、术后冠状动脉血流储备(CFR)的变化,评价其对CFR的影响。方法病例组选88例冠心病病人行PCI术后各植入1枚支架。分别于术前、术后24h、术后3个月、术后6个月采用经胸冠状静脉窦二次谐波多普勒超声心动图(TTDE)技术记录冠状静脉窦静息舒张期血流峰速、注射双嘧达莫(潘生丁)后最大舒张期血流峰速。正常对照组为门诊体检正常者30名行TTDE,记录冠状静脉窦静息舒张期血流峰速、注射潘生丁后最大舒张期血流峰速。结果病例组术前CFR与正常对照组比较差异有统计学意义。病例组PCI术后24h和术前CFR值无明显差异,术后3个月CFR较术前增加,术后6个月6例出现支架内再狭窄,与无再狭窄病人比较CFR有统计学意义(P<0.05)。82例无再狭窄病人术后6个月CFR与正常对照组比较无统计学意义。结论PCI术能明显增加冠状动脉血流储备,PCI术后6个月CFR降低可能预示出现再狭窄。采用经胸多普勒冠状动脉血流显像技术是一可行的无创性评价冠心病病人CFR及介入治疗疗效的新方法。     

应用经胸冠状动脉血流显像技术评价支架术前后冠脉血流储备

目的采用经胸多普勒超声心动图冠状动脉血流显像技术观察支架术前后冠状动脉血流速度的变化,评价其对冠状动脉血流储备（CFR）的影响。方法22例冠心病患者(男18例,女4例),平均年龄（53.2±6.7）岁。对狭窄的冠状动脉行经皮冠状动脉腔内成形术（PTCA）后各置入一枚支架。分别于木前、术后72h内采用经胸多普勒冠状动脉血流显像技术记录狭窄远端静息舒张期血流峰速(r-Vd)、注射潘生丁及等长握力实验时最大舒张期血流峰速(d-Vd)及CFR。结果22例患者行支架术均获成功,狭窄率由术前(83.5±8.9)%,降至术后(5.2±9)%(P<0.05)。20支冠脉获得理想多普勒频谱（检出率90.9％）;支架术后r-Vd较术前r-Vd有增加趋势,但无统计学意义;术后静脉注射潘生丁后最大d-Vd及CFR均较术前明显增加［（0.92±0.22)m/svs(0.52±0.18)m/s,2.94±1.16vs1.88±0.40,P均<0.01］。30％患者术后CFR仍<2.0,此组与CFR≥2.0患者组比较,支架术后r-Vd明显增高［(0.45±0.19)m/svs(0.27±0.12)m/s,P<0.05］。少数患者(约18%,4／22)术前出现心绞痛,头昏等不适,静注氨茶碱或(和)含化硝酸甘油可迅速缓解。结论支架术能明显增加冠状动脉血流储备。采用经胸多普勒冠脉血流显像技术结合潘生丁、握力试验是一可行的无创性评价冠心病患者冠脉血流储备及介入治疗疗效的新方法。     

冠状动脉内支架术对冠状动脉血流储备的远期影响

目的　采用经胸多普勒超声心动图冠状动脉 (冠脉 )血流显像技术观察冠脉支架置入术对冠脉血流储备 (CFR)的远期影响。方法　对 34例冠心病患者分别于支架术术前、术后 72h内及随访期 [( 6 .7± 1.5 )个月 ]记录病变血管远端静息舒张期血流峰速 (r Vd)、注射潘生丁及等长握力实验时最大舒张期血流峰速 (d Vd)及CFR。每例患者于随访期复查冠脉造影。结果　随访期造影无再狭窄 2 8例。据术后 72h内CFR分为CFR受损组 ( 10例 ,CFR≤ 2 .5 )及CFR未受损组( 18例 ,CFR >2 .5 )。术后近期CFR受损组r Vd较CFR未受损组明显增高 (P <0 .0 1) ;随访期时CFR受损组CFR升高至CFR未受损组水平 (P >0 .0 5 )。随访期出现再狭窄 6例 ,CFR均 <2 .0 ,降至术前水平。结论　 ( 1)成功的支架术后部分患者存在暂时性CFR降低 ,CFR的降低及其恢复与r Vd的一过性增高及恢复有关 ;( 2 )再狭窄患者冠脉血流储备于随访期显著降低 ,达到术前水平。经胸冠脉血流显像技术可作为冠脉介入治疗后一种简便、安全、无创的随访方法。     

经胸多普勒超声心动图对冠状动脉狭窄的研究

目的探讨经胸多普勒超声心动图(TTDE)对冠状动脉的显示能力及不同程度冠状动脉狭窄的血流动力学的变化。方法选择疑诊为冠脉疾病拟行冠状动脉造影的患者120例,行TTDE检查,观察冠状动脉左前降支和右冠状动脉,计算其检出率。并以冠脉造影结果为标准,回顾性分析不同狭窄组间血流动力学参数有无差异。结果左前降支、右冠状动脉未完全闭塞者红色前向血流的检出率分别为98.00%和66.04%,完全闭塞者蓝色逆向血流检出率分别为70.00%和71.43%。左前降支、右冠状动脉不同狭窄组间舒张期峰值流速、舒张期平均血流速度、舒张期速度时间积分、舒张期的加速度与减速度、舒张期与收缩期峰值血流速度比值差异有统计学意义(P0.05)。而收缩期峰值血流速度,三组之间比较差异无统计学意义(P0.05)。结论 TTDE可评价冠状动脉左前降支和右冠状动脉血流。静息状态下冠状动脉狭窄处舒张期血流参数有显著变化,对诊断冠脉狭窄有重要意义。     

冠状动脉造影正常的胸痛患者冠状动脉血流储备功能研究

目的 :评价冠状动脉血流储备 (CFR)功能的测定对阐明冠状动脉造影正常患者的胸痛机制的临床作用。方法 :4 0例冠状动脉造影正常的胸痛患者分为非心脏病组、X综合征组及高血压组 ,采用TIMI计帧法测定注射罂粟碱前后相关冠状动脉血流帧数的变化 ,并计算CFR。结果 :X综合征组用药前后血流速度均慢于非心脏病组 (P <0 .0 5 ,P <0 .0 1) ,高血压组静息血流速度快于非心脏病组 (P <0 .0 5 )。非心脏病组的CFR范围为2 .0～ 2 .8,X综合征组及高血压组的CFR低于非心脏病组 (P <0 .0 1)。结论 :TIMI计帧法可用于CFR的测定 ,X综合征及高血压患者CFR降低 ,原因可能与冠状动脉小血管的充血反应能力下降和 (或 )基础冠状动脉血流的增加有关     

冠状动脉内多普勒技术评价短期冬眠心肌相关冠状动脉微循环功能

目的观察短期冬眠心肌动物模型相关冠状动脉(冠脉)微循环功能的变化. 方法将6只小型中国家猪采用闭胸法建立短期冬眠心肌(SHM)动物模型,应用冠脉内多普勒技术观察模型制备前后相关冠脉平均峰值流速(APV)、舒张期及收缩期流速比值(DSVR)、冠脉血流储备(CFR)等功能学指示的变化.     

经胸多普勒超声冠状动脉血流储备检查诊断左前降支显著狭窄

目的比较经胸多普勒超声冠状动脉血流储备（CFR）指标诊断左前降支（LAD）显著狭窄的临床价值。方法连续120例怀疑冠心病的患者于冠状动脉造影（CAG）前一天进行双嘧达莫（0．56mg／kg）负荷试验，测定LAD的CFR指标，包括收缩期最大冠状动脉血流储备（SCFRpeak）、收缩期平均冠状动脉血流储备（SCF Rmean）、收缩期流速时间积分储备（SCFRVTI）、舒张期最大冠状动脉血流储备（DCFRpeak）、舒张期平均冠状动脉血流储备（DCFRmean）和舒张期流速时间积分储备（DCFRVTI）。结果82例获得LAD血流频谱，按照CAG结果分为LAD显著狭窄组（A组，≥70％狭窄，n=16）和LAD非显著狭窄组（B组，〈70％狭窄，n=66）。A组患者各项CFR指标均显著低于B组。ROC曲线法分析显示，DCFRmean〈1．825诊断LAD显著狭窄的敏感性和特异性相对较高。结论经胸多普勒超声评价CFR有助于检出LAD显著狭窄，DCFRmean〈1．825是较好的判别指标。     

冠状动脉内多普勒技术评价腺苷预处理保护冠状动脉微循环功能的实验研究

目的观察腺苷预处理(APC)对缺血心肌相关冠状动脉(冠脉)微循环功能的保护作用. 方法将建立心肌缺血模型的12只中国小型家猪随机分为二组:(1)对照组(CON组,n=6),只制备心肌缺血模型;(2)腺苷预处理组(APC组,n=6),制备模型前经冠脉注入6mg腺苷.应用冠脉内多普勒导丝观察模型相关冠脉平均峰值流速(APV)、舒张期与收缩期流速比值(DSVR)、冠脉血流储备(CFR)的变化情况.     

Coronary flow reserve in patients with chest pain and normal coronary arteries.

BACKGROUND--Many studies have shown that coronary flow reserve is reduced in patients with chest pain and angiographically normal coronary arteries. The methods used to assess coronary blood flow have varied, but in nearly all reports dipyridamole has been used to bring about vasodilatation. This study was designed to assess whether the apparent impairment of coronary flow reserve seen with dipyridamole could be reproduced with either papaverine or adenosine, which induce maximum coronary blood flow by different mechanisms. METHODS--25 patients with chest pain and angiographically normal coronary arteries were studied with an intracoronary Doppler flow probe and quantitative angiography to determine epicardial coronary artery area, coronary blood flow velocity, coronary flow reserve, and coronary vascular resistance index (CVRI, the ratio of resistance after intervention to basal resistance). All patients received papaverine 8 mg. Eight patients with positive exercise tests received intracoronary papaverine (8 and 10 mg), intracoronary adenosine (6, 20, 60 micrograms), and high-dose intravenous dipyridamole (0.84 mg/kg). RESULTS--The velocity ratio (peak after intervention: baseline) (mean (SEM)) after 8 mg papaverine was 3.3 (0.2) (n = 25) and the coronary flow reserve was 4.1 (0.3) (n = 25). There were no differences between patients with a positive (n = 16) or negative (n = 9) exercise test. In eight patients coronary flow reserve was measured after increasing doses of papaverine, adenosine, and dipyridamole. Coronary flow reserve was 4.5 (0.3) with papaverine, 4.8 (0.3) with adenosine, and 3.5 (0.4) with dipyridamole (p = 0.08 v papaverine and adenosine). CVRI was 0.22 (0.01) with papaverine, 0.21 (0.02) with adenosine, and 0.29 (0.03) with dipyridamole (p < 0.05 v papaverine, p = 0.09 v adenosine). CONCLUSIONS--These results indicate that measurement of coronary flow reserve and CVRI in patients with chest pain and normal coronary arteries depends on the pharmacological stimulus. Normal values were obtained with papaverine in all patients, irrespective of the exercise test response. In patients with a positive exercise test significantly lower values were obtained with dipyridamole than with papaverine, or adenosine. The reported impairment of coronary flow reserve in patients with angina and normal coronary arteries may reflect the variability in response to different pharmacological agents. The mechanism underlying this variability is unknown, but may involve an abnormality of adenosine metabolism in the myocardium.     

Does coronary flow reserve assessed by blood flow velocity analysis reflect absolute coronary flow reserve?

Doppler guidewire enables us to measure phasic coronary velocity and has been used for the measurement of coronary flow reserve (CFR). Although CFR is usually calculated by the quotient of peak flow velocity during papaverine infusion and flow velocity at rest, this assumption is true only if conduit vessel size is constant. To determine the accuracy of measurement of CFR using average peak velocity (APV) with Doppler guidewire, we investigated the influence of intracoronary papaverine on coronary flow velocity and coronary arterial diameter (CAD) and examined the correlation between CFR derived using APV and that derived using coronary blood flow (CBF) in 26 patients with normal coronary arteries. We measured phasic coronary flow velocity, and performed quantitative coronary angiography in the proximal left coronary artery at control and during 10 mg of intracoronary papaverine. Compared to control value, papaverine induced a significant increase in APV (% increase: 182 ± 101%; P<0.001). Papaverine also significantly increased CAD (16 ± 10%; P<0.001). Thus, CFR derived from APV was significantly lower than that derived from CBF (2.8 ± 1.0 vs. 4.0 ± 1.5, P<0.001). Although there was a significantly strong positive correlation between these two methods (R² = 0.83, P<0.001), there was also considerable variability with regard to predicting one variable from the other. These results suggest the importance of standardizing the conditions in which coronary flow velocity is measured with regard to either controlling or measuring changes in epicardial coronary arterial diameter during changes in distal resistance vessel tone. © 1996 Wiley-Liss, Inc.     

Coronary endothelium-dependent and independent vasomotor responses in patients with hypertrophic cardiomyopathy.

It is well known that coronary flow reserve (CFR) is decreased in patients with hypertrophic cardiomyopathy (HCM), but it is unclear whether coronary endothelial function is impaired. Coronary endothelial function and CFR in the coronary macro- and microcirculation was evaluated in 14 patients with HCM and 11 control subjects. Acetylcholine (ACh), bradykinin (BK) and papaverine were infused into the left coronary artery. Coronary cross-sectional area was determined by quantitative coronary angiography and coronary blood flow (CBF) was determined by the product of the coronary cross-sectional area and CBF velocity measured by an intracoronary Doppler guidewire. Acetylcholine at 100 microg induced diffuse coronary spasms of the left anterior descending coronary arteries in 3 of the patients with HCM. The changes in the diameter of the left anterior descending coronary artery and the increases in CBF induced by BK (0.2, 0.6, and 2.0 microg/min) did not differ between the 2 groups. CFR was lower in the HCM group than in the control group (p<0.01). Moreover, the ratio of BK-induced CBF increase to papaverine-induced CBF increase was comparable between the 2 groups. Endothelium-dependent vasodilation of the epicardial and resistance coronary arteries induced by BK was preserved despite the decreased CFR in patients with HCM.     

Relation of impaired coronary microcirculation to increased urine albumin excretion in patients with systemic hypertension and no epicardial coronary arterial narrowing

Coronary flow reserve (CFR) is impaired and urinary albumin excretion is increased in patients with essential hypertension. Our aim was to investigate the associations between CFR and cardiac and renal damage in hypertensives. For this purpose we studied 37 never-treated hypertensives (57.9 years old, 16 men) without chest pain but with a positive ischemia stress test result and normal coronary arteries on coronary angiogram. CFR was calculated by a 0.014-inch Doppler guidewire (Flowire, Volcano, San Diego) in the left anterior descending artery in response to bolus intracoronary administration of adenosine (60 μg) as the ratio of hyperemic to basal average peak velocity of the distal vessel. All participants underwent complete echocardiographic study including left ventricular diastolic function evaluation by tissue Doppler imaging (peak early diastolic velocity/peak atrial systolic velocity) and determination of the albumin-to-creatinine ratio (ACR). Hypertensives with low CFR (<2.5, n = 22) compared to those with high CFR (n = 15) exhibited a larger left ventricular mass index by 10.9 g/m(2) (p = 0.045) and ACR values by 10 mg/g (p <0.001). CFR was negatively correlated with logACR (r = -0.511, p = 0.001). LogACR (beta -0.792, p <0.001), male gender (beta 0.313, p = 0.005), left ventricular mass index (beta -0.329, p = 0.007), and peak early diastolic velocity/peak atrial systolic velocity (beta 0.443, p <0.001) were the only independent predictors of CFR in linear regression analysis (adjusted R(2) = 0.672). In conclusion, never-treated asymptomatic hypertensives who exhibit impaired CFR and angiographically normal epicardial arteries are characterized by intrarenal vascular damage as reflected by increased ACR. These findings suggest a plausible role of ACR estimation in the identification of hypertensive subjects with early coronary microvascular dysfunction.     

Noninvasive Measurement of Left Coronary Blood Flow Reserve by Transthoracic Doppler Echocardiography: Comparison with Doppler Guidewire Ultrasonography

The development of new ultrasound instrumentation has made epicardial coronary artery blood flow imaging easier with the use of transthoracic coronary Doppler echocardiography (TCDE). This study was performed to investigate the accuracy of coronary blood flow reserve (CFR) measurement by TCDE. In 15 patients with ischemic heart disease in the absence of valvular disease or atrial fibrillation, coronary flow at rest and flow with hyperemia induced by intravenous dipyridamole infusion were recorded by TCDE and Doppler guidewire ultrasonography. The CFR was determined as the ratio of the maximum hyperemic diastolic time-averaged peak velocity to the velocity at rest in the proximal or distal left anterior descending coronary artery. It was found that the CFR of the left anterior descending coronary artery measured by TCDE was comparable in accuracy with CFR measured by invasive methods (r = 0.87, P < 0.0001, n = 15).     

Assessment of flow velocity reserve by transthoracic Doppler echocardiography and venous adenosine infusion before and after left anterior descending coronary artery stenting.

OBJECTIVES: We sought to evaluate whether coronary flow velocity reserve (CFR) (the ratio between hyperemic and baseline peak flow velocity), as measured by transthoracic Doppler echocardiography during adenosine infusion, allows detection of flow changes in the left anterior descending coronary artery (LAD) before and after stenting. BACKGROUND: The immediate post-stenting evaluation of CFR by intracoronary Doppler has shown mixed results, due to reactive hyperemia and microvascular stunning. Noninvasive coronary Doppler echocardiography may be a more reliable measure than intracoronary Doppler. METHODS: Transthoracic Doppler echocardiography during 90-s venous adenosine infusion (140 microg/kg body weight per min) was used to measure CFR of the LAD in 45 patients before and 3.7 +/- 2 days after successful stenting, as well as in 25 subjects with an angiographically normal LAD (control group). RESULTS: Adequate Doppler spectra were obtained in 96% of the patients. Pre-stent CFR was significantly lower in patients than in control subjects (diastolic CFR: 1.45 +/- 0.5 vs. 2.72 +/- 0.71, p < 0.01; systolic CFR: 1.61 +/- 1.02 vs. 2.41 +/- 0.68, p < 0.01) and increased toward the normal range after stenting (diastolic CFR: 2.58 +/- 0.7 vs. 2.72 +/- 0.75, p = NS; systolic CFR: 2.43 +/- 1.01 vs. 2.41 +/- 0.52, p = NS). Diastolic CFR was often damped, suggesting coronary steal in patients with > or =90% versus <90% LAD stenosis (0.86 +/- 0.23 vs. 1.69 +/- 0.43, p < 0.01). Coronary stenting normalized diastolic CFR in these two groups (2.45 +/- 0.77 and 2.64 +/- 0.69, respectively, p = NS), even though impaired diastolic CFR persisted in three of four patients with > or =90% stenosis. Stenosis of the LAD was better discriminated by diastolic (F = 49.30) than systolic (F = 12.20) CFR (both p < 0.01). CONCLUSIONS: Coronary flow reserve, as measured by transthoracic Doppler echocardiography, is impaired in LAD disease; it may identify patients with > or =90% stenosis; and it normalizes early after stenting, even in patients with > or =90% stenosis.     

Coronary flow reserve in patients with vasospastic angina: correlation between coronary flow reserve and age or duration of angina

OBJECTIVES: This study sought to assess the coronary flow reserve (CFR) in patients with pure vasospastic angina (VSA). METHODS AND RESULTS: The phasic flow velocities of both spasm-positive and spasm-negative coronary arteries of the left anterior descending artery (LAD) were recorded at rest and during hyperaemia (50 microg of adenosine triphosphate infusion intracoronary) using a 0.014 inch, 15 MHz Doppler guide wire in 42 patients with pure VSA and acetylcholine (ACh)-induced coronary artery spasms (20-100 microg), and 23 controls with normal coronary arteries without ACh-induced vasospasm. These 42 patients had 16 vessels with focal spasms (>99%), 17 vessels with diffuse spasms (>90%) in the LAD, and nine vessels with ACh-induced spasms in the right coronary artery, but not the LAD. Coronary flow reserve was obtained from the ratio of the hyperaemic/baseline time-averaged peak velocity. Coronary flow reserve did not differ between patients with VSA and the controls (2.9+/-0.8 versus 3.2+/-0.7, NS). Moreover, CFR did not differ among the four cases (focal: 2.8+/-0.7; diffuse: 3.0+/-0.9; non spasm: 2.9+/-0.7 versus controls: 3.2+/-0.7, respectively, NS). Coronary flow reserve in vessels with proximal spasms was significantly higher than that in vessels with mid or distal spasms (3.4+/-0.8 versus 2.6+/-0.6, 2.6+/-0.9, p<0.05). The only significant correlation was between CFR and age (p=0.0275) or the duration of angina before admission (p=0.0405). CONCLUSIONS: There was no difference in CFR in patients with ACh-induced spasms between the spasm-positive and spasm-negative vessels. Moreover, CFR was maintained normally in vessels with diffuse spasms, as in those with focal spasms. The most important determinant factors for CFR in patients with VSA were age and the duration of angina before admission.     

A simplified method to measure coronary blood flow velocity in patients: validation and application of a Judkins-style Doppler-tipped angiographic catheter

To facilitate more rapid and safe measurement of coronary flow velocity reserve in patients, we developed a Judkins-style angiographic catheter tipped with a 20 MHz Doppler crystal. In 19 patients without coronary artery disease, resting and hyperemic (10 mg intracoronary papaverine) mean and phasic coronary flow velocity signals were measured with the Judkins-style and 2.5F intracoronary Doppler catheters at identical coronary loci. Mean coronary flow velocity at rest was similar (14 +/- 8, 10 +/- 7 cm/sec, p = ns), but was higher during hyperemia for the Judkins-Doppler (41 +/- 8 versus 32 +/- 14 cm/sec, p less than 0.05). Coronary flow velocity reserve, calculated as the ratio of mean velocity at rest to mean velocity following papaverine, was 3.3 +/- 1.4 and 3.7 +/- 1.2 units (p = ns) for the Judkins and intracoronary Doppler techniques, respectively (r = 0.801, p less than 0.001). The Judkins-style Doppler catheter technique permits flow velocity and coronary flow velocity reserve measurements that correlate strongly with those of the intracoronary catheter technique, facilitating safe, quick, and accurate assessment of coronary physiology.     

Prediction of the physiologic significance of coronary arterial lesions by quantitative lesion geometry in patients with limited coronary artery disease

Studies in animals with normal coronary arteries have shown that coronary flow reserve can be predicted by angiographic measurements of arterial stenosis. Studies in man, however, suggest that even quantitative analysis of coronary angiograms cannot predict the physiologic significance of individual coronary lesions. These studies, however, were carried out in patients with either widespread, diffuse coronary artery disease or by measurement techniques that tend to underestimate maximal coronary flow reserve. To determine the relationship between coronary arterial stenosis and coronary flow reserve (CFR) in patients with discrete limited coronary atherosclerosis, we studied 50 patients with a single discrete coronary stenosis in only one or two vessels. The minimum coronary arterial cross-sectional area (mCSA), percent area stenosis (%AS), and percent diameter stenosis in the left and right anterior oblique projections were determined by the Brown/Dodge method of quantitative coronary angiography. A No. 3F coronary Doppler catheter was placed immediately proximal to the lesion. Measurements of CFR were obtained by intracoronary administration of papaverine in doses sufficient to provide maximal arteriolar vasodilation. In 25 patients, a translesional pressure gradient was obtained with an angioplasty catheter. CFR measured in patients with coronary artery disease was compared with that in 13 patients with normal coronary vessels. In normal patients, CFR averaged 5.0 +/- 0.6 (peak/resting velocity ratio; mean +/- SEM, range 3.7 to 8.2). In patients with limited coronary artery disease, CFR was closely correlated with %AS (r = .85), mCSA (r = .79), and the translesional pressure gradient (r = .83). Additionally, the most severe percent diameter stenosis in either the left or right anterior oblique view was also highly correlated with CFR (r = .82). Importantly, all arteries with lesions producing less than 70% area stenosis and less than 50% diameter stenosis, or with greater than 2.5 mm2 mCSA had CFR of over 3.5. These results suggest that, in contrast to the poor correlation of percent area and percent diameter stenosis to CFR measured in patients with multivessel coronary artery disease, CFR measured at angiography in patients with discrete, limited coronary artery disease correlates closely with luminal stenosis determined precisely with quantitative coronary angiography. Differences in the extent of diffuse arterial narrowing may account for these discrepancies.     

Evaluation of Coronary Flow Velocity Dynamics and Flow Reserve in Patients With Kawasaki Disease by Means of a Doppler Guide Wire

Objectives. To assess the pathophysiologic effects of the coronary sequelae of Kawasaki disease on coronary hemodynamic variables, we regionally evaluated the flow velocity dynamics and flow reserve in coronary vessels with lesions using an intracoronary Doppler flow guide wire.Background. The pathophysiologic effects of the coronary sequelae of Kawasaki disease on coronary hemodynamic variables have not been completely clarified, and we previously reported some discrepancies between coronary angiographic findings and exercise stress tests in Kawasaki disease.Methods. Doppler phasic coronary flow velocity was determined using an 0.018-in. (0.046-cm) intracoronary Doppler flow guide wire at rest and during the adenosine triphosphate–induced hyperemic response in 95 patients (75 male, 20 female, mean age 9.8 ± 6.2 years) with Kawasaki disease.Results. In 25 patients with coronary aneurysms in 29 vessels, the average peak velocity and diastolic to systolic velocity ratio were significantly (p < 0.05) decreased in the moderate-sized and large-sized aneurysms. Significantly lower values in coronary flow reserve (CFR) were noted in 3 of 10 vessels with moderate aneurysms and in 4 of 7 vessels with large aneurysms. A significant positive correlation (y = 0.53x + 14.6, r²= 0.91) was observed between the percent diameter stenosis evaluated by angiography and that calculated from the flow velocity measurement. However, the percent diameter stenosis calculated from the flow velocity measurement was underestimated compared with that determined by angiography in the stenotic lesions of intermediate severity. A reduced CFR was noted in five of seven vessels with intermediate stenosis ranging from 50% to 75%, and also in three vessels with mild stenosis ranging from 30% to 40%. A reduced CFR was also observed in six of the eight angiographically normal vessels associated with the area of reduced perfusion on exercise thallium-201 myocardial scintigraphy.Conclusions. Abnormalities in flow dynamics and a reduction in flow reserve were revealed in coronary aneurysms of intermediate to large size and in stenotic lesions, even of mild to intermediate severity, in patients with Kawasaki disease. Abnormalities in the coronary microcirculation, as well as epicardial lesions, contribute to the pathophysiologic responses in Kawasaki disease.