经胸多普勒超声无创检测冠心病患者冠状动脉各主要分支血流储备

目的 评价经胸多普勒超声心动图(TTDE)检测冠状动脉各主要分支血流储备的可行性和准确性.方法 临床疑诊冠心病拟行冠状动脉造影的439例患者,在进行冠状动脉造影前1周内进行TTDE检查,检测左前降支(LAD)、左旋支(LCx)和右冠状动脉后降支(PDA)远端的血流储备.在基础状态和持续静脉注射腺苷(140μg·kg-1·min-1)情况下分别测定其血流速度,计算血流储备(CFR)及其诊断冠状动脉狭窄的准确性.结果 439例患者中28支LAD、12支LCx和21支PDA闭塞.LAD的CFR检测成功率为96.8%(395/411),LCx的CFR检测成功率为74.9%(320/427),PDA的CFR检测成功率为83.0%(347/418).以CFR≤2.0和CFR≤1.7分别作为判断冠状动脉狭窄(≥50%)和显著狭窄(≥75%)的标准,诊断LAD、LCx和PDA狭窄的灵敏度和特异度分别为81%和87%,64%和82%,79%和85%,诊断显著狭窄的灵敏度、特异度分别为86%和81%,70%和85%,81%和82%.结论 经胸多普勒超声心动图检测冠状动脉各主要分支血流储备的成功率和判断冠状动脉狭窄的准确性均较高,具有一定临床应用价值.     

经胸超声心动图诊断小儿左冠状动脉起源于肺动脉

部分小儿病例存在婴儿型与成人型的交叉重叠,难以截然分型.     

Doppler echocardiographic approach to the blood flow of the left anterior descending coronary artery

Assessment of flow in the left anterior descending coronary artery by Doppler echocardiography appeared to be possible in some patients in which the coronary artery system might be wide and/or the displacement of the coronary artery might be reduced because of cardiac enlargement or of impaired cardiac function. A study of this possibility was carried out in 78 patients, 20 cases with hypertrophic cardiomyopathy, 10 with dilated cardiomyopathy, 20 with aortic valve disease, and 28 following valve replacement for aortic valve disease. The anterior interventricular sulcus was a helpful landmark to search for the left anterior descending artery. The characteristic feature of the coronary flow pattern, that the flow ran mainly during diastole, was also helpful in finding the coronary artery. Complementary roles of ultrasonic imaging and Doppler ultrasound evaluation should be emphasized for identifying a thin echo-free space in the sulcus as the coronary artery. The left anterior descending coronary artery was imaged in 26 of the 78 patients. The peak velocity ranged 24 cm/s to 75 cm/s in different patients. Because the present study was carried out in patients with some particular diseases, these results do not indicate that current techniques can be routinely used for assessing the coronary flow. The detection rate will be increased with improvements in image resolution and the Doppler sensitivity. Although the detection rate of the coronary artery was not satisfactory in the present stage, the effect of sublingual administration of nitroglycerin on coronary circulation was noninvasively assessed in some patients, where reduction of the flow velocity by about 27% was observed in real time.     

Digital subtraction angiographic assessment of the coronary arteries and coronary flow reserve

Although intravenous digital subtraction angiography was originally intended as a means of performing lessinvasive peripheral angiography, this less invasive approach has not proven feasible for coronary artery studies. Digital imaging has, however, proven helpful for the immediate replay, enhancement and quantification of coronary arteriography and enables the performance of regional blood flow (coronary flow reserve) analysis. Flow analysis is clinically helpful in determining the hemodynamic significance of individual coronary stenoses, which cannot always be assessed even using quantitative stenosis measurements. One method of assessing flow reserve by digital means uses parametric images to display the timing (color coded) and density (intensity coded) of the contrast bolus as it transverses the regional myocardial circulation. Analysis of baseline and hyperemic condition parametric images provides quantitative regional flow reserve information.     

冠脉血流显像技术无创性评价轻度高血压患者冠脉血流储备

目的　了解轻度高血压是否存在冠脉循环的功能性损害。方法　应用经胸超声心动图冠脉血流显像技术测量 2 3例无症状轻度高血压患者在静脉输注潘生丁溶液结合等长握力负荷状态下前降支冠脉血流的速度变化 ,并与 2 1例正常健康者对照。结果　轻度高血压组最大冠脉血流与基础冠脉血流速度比值较对照组降低 (峰值速度比为 3 .0 2± 0 .64vs 3 .77± 0 .5 8,P <0 .0 5 ) ,最小冠脉血管阻力指数较对照组增大 ( 0 .3 4± 0 .0 6vs 0 .2 6± 0 .0 8,P <0 .0 5 ) ,舒张功能出现轻度异常。两组左室腔径、左室重量和左室收缩功能无明显改变。结论　无症状的轻度高血压患者可出现冠脉储备降低和舒张功能异常。冠脉血流显像技术为评估冠脉循环功能提供了无创、简便、实用的冠脉血流储备检测手段。     

Serial Doppler echocardiographic assessment of left and right ventricular performance after a first myocardial infarction.

We sought to investigate the relation between left ventricular (LV) and right ventricular (RV) function assessed with the Doppler-derived myocardial performance index (MPI), to assess serial changes, and to investigate the prognostic value of biventricular assessment of cardiac function after a first myocardial infarction (MI). To do so, serial Doppler echocardiography was performed in 77 consecutive patients with a first MI. Right ventricular MPI correlated significantly with LV MPI (r = 0.51, P <.0001). In patients with echocardiographic signs of RV MI, the RV MPI was significantly higher (0.59 +/- 0.18 versus 0.44 +/- 0.19, P =.001), whereas no difference in LV MPI was seen (0.55 +/- 0.19 versus 0.56 +/- 0.13, P = not significant). Right ventricular MPI showed a rapid normalization during follow-up, whereas LV MPI did not decrease. During follow-up, 23 patients died of cardiac causes or were readmitted because of worsening heart failure. Multivariate Cox analysis indicated LV MPI (relative risk 4.9 [95% CI 1.8-13.5], P =.002) and RV MPI (relative risk 3.8 [1.3-17.0], P =.01) to be predictors of cardiac events. Thus the RV MPI is frequently abnormal after a first MI but normalizes rapidly on follow-up, and biventricular assessment of cardiac function may improve the prognostic accuracy compared with LV assessment alone.     

Coronary blood flow reserve response to left anterior descending coronary artery stenting and its value in predicting coronary restenosis.

BACKGROUND: Heterogeneous results of coronary flow velocity reserve (CFVR) to percutaneous procedures have been reported and the impact of transesophageal echocardiographic evaluation of CFVR in predicting restenosis has not been completely established. Methods and results: We studied 20 control volunteers and 51 patients with left anterior descending coronary artery stenosis to determine the CFVR response to left anterior descending coronary artery stenting, the clinical markers of persistent CFVR impairment, and its value in predicting restenosis. Prestent CFVR was lower in the stenosis group than in control volunteers (1.89 +/- 0.66 vs 3.82 +/- 1.15; P <.001). Although there was a significant increase of CFVR after stenting (2.58 +/- 0.76; P <.001 vs prestent), it remained depressed in 53% of patients and was independently related to multivessel disease (odds ratio, 0.14; 95% confidence interval 0.03-0.55; P =.005), age (odds ratio, 1.07; 95% confidence interval 0.99-1.15; P =.056), and prestent CFVR (odds ratio, 3.78; 95% confidence interval 0.99-14.42; P =.051). CFVR measured both before and early after stenting did not differ between patients with and without restenosis. CONCLUSIONS: CFVR impairment occurs in a large proportion of patients despite successful stenting and appears to be consequent of the extent of atherosclerotic coronary disease. Periprocedural CFVR conferred no predictive value for subsequent intrastent restenosis.     

Potential use of transthoracic echocardiography in the assessment of coronary flow reserve.

Coronary flow reserve provides a gold standard assessment of the epicardial and microvascular coronary circulation. However, measurement of coronary flow reserve is limited by the invasiveness or complexity of the methods hitherto available. We investigated whether transthoracic echocardiography could be used to assess coronary flow reserve. We imaged distal left anterior descending coronary artery diameter and flow in 14 healthy volunteers, both at rest and during intravenous infusion of adenosine (140 microg/kg per minute). Volunteers were men, with an average (+/-SD) age of 28.4 +/- 6.3 years. Complete data were acquired in 11 cases. Average distal left anterior descending coronary artery diameter was 0.213 +/- 0.03 cm. Velocity time integral rose from 8.6 +/- 2.1 cm to 27.7 +/- 5.6 cm with adenosine infusion. Heart rate rose from 64.7 +/- 9. 8 to 75.3 +/- 11.7 bpm. The Doppler angle of incidence to flow was 42.4 +/- 8.7 degrees. Resting distal left anterior descending coronary artery flow was therefore calculated as 13.4 +/- 3.2 mL/min and hyperemic flow as 51.2 +/- 16.2 mL/min, yielding a coronary flow reserve of 3.81 +/- 0.6. We conclude that coronary flow reserve can be assessed in a selected population with the use of transthoracic echocardiography and an intravenous infusion of adenosine. The simplicity of this noninvasive technique suggests that it could become a useful tool for measurement of coronary flow reserve if imaging success rates can be optimized.     

Noninvasive assessment of flow velocity and flow velocity reserve in the right gastroepiploic artery graft by transcutaneous Doppler echocardiography: comparison with an invasive technique.

BACKGROUND: The measurement of flow velocity (FV) in coronary artery bypass grafts using a Doppler guidewire has provided useful clinical and physiologic information. The recently developed transcutaneous Doppler echocardiography is a noninvasive technique to measure FV and FV reserve (FVR) in the right gastroepiploic artery (GEA) graft. The purpose of this study was to evaluate whether transcutaneous Doppler echocardiography accurately measures FV and FVR in the right GEA graft in a clinical setting. METHODS: In 33 patients who underwent graft angiography for the assessment of the right GEA graft, FV in the right GEA graft was measured by transcutaneous Doppler echocardiography under the guidance of color flow Doppler imaging at the time of examination using a Doppler guidewire. FV in the midportion of the right GEA graft was measured at baseline and during hyperemic conditions using both transcutaneous Doppler echocardiography and a Doppler guidewire. RESULTS: There were excellent correlations between the value of FV obtained by transcutaneous Doppler echocardiography and those obtained with the Doppler guidewire (averaged peak velocity: y = 0.95 x + 1.46, r = 0.98, standard error of the estimate [SEE] = 2.94 cm/s; averaged systolic peak velocity: y = 0.94 x + 1.18, r = 0.97, SEE = 3.15 cm/s; diastolic peak velocity: y = 0.97 x + 1.62, r = 0.98, SEE = 4.40 cm/s; averaged diastolic peak velocity: y = 0.95 x + 1.75, r = 0.98, SEE = 3.60 cm/s). The FVR as determined by transcutaneous Doppler echocardiography showed a good correlation with that determined using the Doppler guidewire method (y = 0.90 x + 0.21, r = 0.92, SEE = 0.31). CONCLUSIONS: Transcutaneous Doppler echocardiography proved to be an accurate noninvasive method to measure FV and FVR in the right GEA graft.     

Prenatal diagnosis of a right coronary artery to right atrial fistula with a giant coronary artery aneurysm: A case report

Coronary artery fistula (CAF) is a rare cardiac anomaly. Here, we diagnosed a right coronary artery-right atrium fistula with giant coronary artery aneurysm (CAA) via fetal echocardiography at 35 weeks' gestation. An urgent caesarean delivery was performed at 36 weeks' gestation because CAA caused mitral obstruction, and fetal atrial flutter was present. Following delivery, we performed aneurysm ligation because the new-born developed atrial tachycardia. The intraoperative findings confirmed the sonographic findings. To the best of our knowledge, prenatal ultrasound diagnosis of CAF and giant CAA has not been reported in the literature. We focus on the ultrasonic characteristics and differential diagnosis in this literature.     

Regional atrial blood flow in dogs. Effect of hypertrophy on coronary flow reserve.

Little is known regarding regional atrial blood flow responses during varying hemodynamic states in both the normal and hypertrophied atria. This study was undertaken to develop a canine model of chronic atrial hypertrophy and to define in both this group and in normal dogs the regional blood flow response to acute atrial fibrillation and to measure coronary flow reserve. In the 12 dogs with atrial but not ventricular hypertrophy the mean left and right atrial weights were 75 and 47% respectively greater than in the normal group. Blood flow in the normal dogs was less in the appendage than in the non-appendage region for both atria and increased significantly during atrial fibrillation. Similar findings were noted in the hypertrophy group except that during control conditions the left atrial appendage flow was similar to the nonappendage flow. Minimal vascular resistance for the hypertrophy group, 39 +/- 3 was significantly (P less than 0.05) greater when compared to the normal group 28 +/- 2 mmHg/cm3 per min per g. Thus, significant regional blood flow differences occur in both the normal and hypertrophied atria. In addition, atrial hypertrophy does not alter the autoregulatory capacity to the hemodynamic stress of atrial fibrillation but does reduce coronary flow reserve.     

Intravascular ultrasound study and evidence of pathological coronary flow reserve in patients with isolated coronary artery aneurysms

Objectives  

Isolated coronary artery aneurysms (CA) are defined as non-obstructive lesions with luminal dilation ≥2-fold of normal coronary diameters.