Detection of patency of internal mammary artery grafts to the left anterior descending artery by transthoracic Doppler echocardiography

BACKGROUND: To determine whether a coronary artery bypass graft (CABG) is patent, we examined the flow of the left internal mammary artery (LIMA) to the left anterior descending artery (LAD) by transthoracic Doppler echocardiography (TTDE). PATIENTS AND METHODS: Eighty-seven patients with CABG (LIMA to distal LAD) were enrolled in the study. The flows from each subject were analyzed by three criteria: mosaic flow at the anastomosis site, distal anterograde flow (ante flow), and proximal retrograde flow (retro flow). RESULTS: On angiography, 79 grafts were patent and eight were not. TTDE study of 79 patent grafts demonstrated mosaic, ante, and retro flow in 63 (79.7%), 74 (93.7%), and 35 grafts (49.4%), respectively. The averaged diastolic peak velocity of ante flow was 26.3 +/- 11.0 cm/sec, significantly higher than that (4.8 +/- 7.1 cm/sec, P < or = 0.0001) in eight patients without patent grafts. These eight patients had no mosaic or retro flow and only three had ante flow. The accuracies to predict patency were 81.6%, 90.8%, and 49.4% for mosaic, ante, and retro flows, respectively. CONCLUSIONS: The existence of mosaic, retro, or sufficient ante flows strongly indicated the patency of LIMA to the LAD. When symptoms are possible to be derived from the occlusion of CABG to LAD, TTDE is a promising method to examine whether a LIMA to LAD bypass is patent.     

Short- and medium-term study of arterial grafts and native coronary circulation after in situ implant of the internal mammary artery

The internal mammary artery (IMA) is being increasingly utilized as a conduit for myocardial revascularization, based on its higher long-term patency. The aim of this study is the serial assessment of the changes of native coronary vessels after IMA coronary anastomosis. Twenty-six consecutive patients (24 males and 2 females, mean age 56.4 years) received an IMA graft on the left anterior descending (LAD) artery. IMA coronary anastomosis was single in 11 patients and double (LAD and diagonal branch) in the remaining 15 cases. In 23 patients (88.5%) at least one associated saphenous vein graft was inserted. Post-operatively, no new Q waves or low-output syndromes were observed. Follow-up angiographic study, including selective opacification of the IMA graft, was carried out after 1 month and after 1 year. The cumulative patency rate of IMA grafts was 97.7% after 1 month. The LAD stenosis proximal to the IMA anastomosis progressed to total occlusion in 6 patients (28.5%), all of them with a preoperative stenosis ranging from 90 to 99%; its diameter remained unchanged in 6 patients (28.5%), while a reduction of the coronary narrowing greater than or equal to 20% was observed in 9 patients (43%). Preoperatively, the LAD stenosis of the latter groups ranged from 70 to 90%. Severity of residual stenosis and relative diameters of LAD artery and IMA graft influenced the competitive flow distribution through these vessels.(ABSTRACT TRUNCATED AT 250 WORDS)     

Noninvasive detection of total occlusion of the left anterior descending coronary artery with transthoracic Doppler echocardiography.

OBJECTIVES: The purpose of this study was to evaluate the value of transthoracic Doppler echocardiography (TTDE) for the noninvasive detection of total left anterior descending coronary artery (LAD) occlusion. BACKGROUND: Total coronary occlusion is associated with an adverse long-term prognosis, and mechanical revascularization may be required for the patient with total coronary occlusion. However, a noninvasive diagnosis of total coronary occlusion before coronary angiography (CAG) has been difficult, especially in patients without clinical signs. METHODS: We studied 103 consecutive patients who underwent CAG for the evaluation of coronary artery disease. The study group consisted of 16 patients with total LAD occlusion (group A) and 87 patients without total LAD occlusion (group B). Coronary flow velocity in the mid-portion of the LAD was recorded by TTDE. RESULTS: Adequate spectral Doppler recordings of diastolic flow in the LAD were obtained in 98 study patients (95%; 15 patients in group A and 83 patients in group B). In group A, retrograde LAD flow was obtained in 14 (93%) of 15 patients. The mean diastolic velocity of the retrograde flow was 21.0 +/- 6.1 cm/s. In group B, antegrade LAD flow was obtained in all 83 patients (100%). The mean diastolic velocity of the antegrade flow was 21.5 +/- 7.1 cm/s. Retrograde LAD flow by TTDE had a sensitivity of 93% and a specificity of 100% for the detection of total LAD occlusion. CONCLUSIONS: Retrograde flow in the LAD by TTDE is a highly sensitive and specific finding that can be used to noninvasively diagnose total LAD occlusion.     

Strategy for post coronary artery bypass grafting in patients with bypass graft stenosis: comparison of percutaneous transluminal coronary angioplasty for the native coronary artery, internal mammary artery and saphenous vein graft]

OBJECTIVES: The strategy for post coronary artery bypass grafting (CABG) was investigated in patients with graft stenosis. METHODS: The study included 123 post-CABG patients with graft stenosis. The patients were divided into three groups according to target vessels; saphenous vein graft (SVG; n = 72), internal mammary artery (IMA; n = 21) and native coronary artery (n = 30). Furthermore, SVG lesions were divided into proximal anastomosis (n = 23), body (n = 40) and distal anastomosis (n = 9). The procedural success rate and late patency rate were compared between the three groups. Furthermore, the relationships between pre percutaneous transluminal coronary angioplasty (PTCA) percentage diameter stenosis, procedural success rate and late patency rate were evaluated. RESULTS: Procedural success rate was similar in the three groups, but late patency rate was higher in the IMA group. Procedural success rate and late patency rate were significantly lower in proximal anastomoses compared to other sites of SVG stenoses, IMA group and native coronary artery group (p < 0.05). Totally occluded native coronary artery lesions had a high procedural success rate compared with occluded IMA and SVG lesions, but the late patency rate was not higher. Procedural success rate showed no significant difference for 75-99% stenotic lesions, but the late patency rate was significantly higher in the IMA group (p < 0.05). Patients in the stenting group had a greater late patency rate compared with the balloon angioplasty group. There was no significant difference in late patency rate between the IMA group and SVG group. CONCLUSIONS: Late patency rate of the IMA is higher than that of the native coronary artery. SVG with proximal anastomosis and severe stenosis shows a significantly lower late patency rate than the native coronary artery. Therefore, PTCA should be considered for the native coronary artery in the absence of chronic total occlusion.     

Enhanced coronary flow velocity during intra-aortic balloon pumping assessed by transthoracic Doppler echocardiography

OBJECTIVES: The study was done to determine potential utility of measuring coronary flow velocity (CFV) by transthoracic Doppler echocardiography (TTDE) during intra-aortic balloon pumping (IABP). BACKGROUND: Use of IABP has been shown to increase CFV assessed by an invasive technique. The CFV in the left anterior descending coronary artery (LAD) can be measured by TTDE. METHODS: Coronary flow velocity in the distal LAD by TTDE was measured in 40 critically ill patients requiring IABP. All patients received emergency coronary angiography. Both CFV and pressure data were obtained during 1:2 balloon pumping. RESULTS: Adequate diastolic CFV recording was obtained in all patients. The IABP decreased systolic pressure and increased diastolic pressure. Average peak diastolic flow velocity and diastolic velocity time integral was 19 +/- 11 cm/s and 7.7 +/- 4.4 cm with non-augmented beat. These values were increased significantly (61 +/- 38%, 59 +/- 35%, p < 0.001) with augmented beat. Significant correlation was noted between % diastolic pressure augmentation and % increase in diastolic CFV (r = 0.62 to 0.69, p < 0.001). There was no significant difference in flow enhancement during IABP, irrespective to the proximal LAD stenosis severity (severe stenosis: 73 +/- 70%; intermediate stenosis: 61 +/- 29%; no significant stenosis: 58 +/- 29%; p = NS, analysis of variance). By continuous recording of CFV, the optimal timing of balloon control could be adjusted to maximize flow velocity during augmentation. CONCLUSIONS: Use of TTDE can be employed in monitoring CFV augmentation during IABP. The IABP produced significant distal flow enhancement even in patients with critical proximal stenosis. This totally noninvasive approach may help to optimize the benefits of IABP for coronary flow augmentation.     

Noninvasive coronary flow velocity reserve measurement in the posterior descending coronary artery for detecting coronary stenosis in the right coronary artery using contrast-enhanced transthoracic Doppler echocardiography

BACKGROUND: Coronary flow velocity reserve (CFVR) measurement by transthoracic Doppler echocardiography (TTDE) has been found to be useful for assessing left anterior descending coronary artery (LAD) stenosis. However, this method has been restricted only for the LAD. The purpose of this study was to detect severe right coronary artery (RCA) stenosis by CFVR measurement using contrast-enhanced TTDE. METHODS: In 60 consecutive patients with angina pectoris (mean (SD) age: 60 (11), 18 women), coronary flow velocities in the RCA were recorded in the postero-descending coronary artery by contrast-enhanced TTDE at rest and during hyperemia induced by intravenous infusion of adenosine triphosphate (140 mcg/ml/kg). CFVR was calculated as the ratio of hyperemic to basal peak and mean diastolic flow velocity. CFVR measurements by TTDE were compared with the results of coronary angiography performed within 1 week. RESULTS: Coronary flow velocity was successfully recorded in 49 (82%) of the 60 patients with contrast agent. CFVR (mean (SD)) was 1.4 (0.4) in patients with, and 2.6 (0.6) in patients without significant stenosis in the RCA (%diameter stenosis > 75%, P < 0.001). Using the cutoff value 2.0 for CFVR in the RCA, its sensitivity and specificity in detecting significant stenosis in the RCA were 88% and 91%, respectively. CONCLUSION: CFVR measurement in the postero-descending coronary artery by contrast enhanced TTDE is a new, noninvasive method to detect significant stenosis in the RCA.     

Follow-up angiography of 100 revascularizations of the anterior interventricular artery by the left internal mammary artery

One hundred and fifty patients who underwent revascularisation of the left anterior descending artery (LAD) by the left internal mammary artery (LIMA) between 1981 and 1983 were recalled for control coronary angiography one year after surgery. One hundred patients gave consent. The patency rate in these 100 patients was 90 per cent. The presumed causes of the 10 thromboses observed were: for LAD (5 cases), technical problems (3 cases), competitive flow (2 cases). Ten per cent of the patent LIMA grafts were abnormal: moderate stenosis of the anastomosis (5 cases), small LIMA (3 cases), stenosis of the middle segment of the LIMA (1 case). In addition, we observed 7 cases of competitive flows: 3 cases with a LAD which was not sufficiently stenotic, 4 cases with a large saphenous diagonal bypass graft. If a diagonal artery bypass is necessary, it is better to revascularize by either a latero-lateral anastomosis with the LIMA or by using the right IMA. Ninety per cent of the patent grafts were quite satisfactory ar 1 year: regular, supple, and perfectly congruent with the bypassed artery which was injected massively. As a number of North American teams have shown, this good patency rate seems to be maintained at long term, which is not the case with saphenous vein bypass grafts.     

Detection of Severe Stenosis and Total Occlusion in the Left Anterior Descending Coronary Artery with Transthoracic Doppler Echocardiography in the Emergency Room

Background: The noninvasive measurement of coronary flow velocity in the left anterior descending artery (LAD) has recently been realized by using the transthoracic Doppler echocardiography (TTDE). A couple of investigations demonstrated that the diastolic-to-systolic peak velocity ratio (DSVR) by TTDE is a simple and noninvasive method for the detection of severe stenosis in the elective settings. However, the usefulness of DSVR by TTDE in the emergency settings has not been evaluated. Objective: The purpose of this study was to assess the clinical feasibility to document the LAD flow by TTDE in emergency patients who complained of chest pain. Methods: We studied 49 consecutive patients with acute coronary syndrome who were going to undergo emergency coronary angiography (CAG) for the anatomical diagnosis and the facilitated percutaneous coronary intervention (PCI). Prior to CAG, we recorded the LAD flow by TTDE and measured the diastolic peak velocity (DVp), systolic peak velocity (SVp), and their ratio, DSVR (DVp/SVp) of LAD flow. Results: By CAG, the culprit lesions actually resided in the proximal LAD in 36 patients. Among the 36 patients, we detected the Doppler LAD flow in 29. Five out of 7 patients who were unable to detect the LAD flow revealed total occlusions by CAG. DSVR of the LAD is significantly lower in 17 patients who showed severe stenoses ( > 90%) than those in the rest of 12 patients who did not show such critical stenoses (1.44 ± 0.16 vs 2.10 ± 0.26, P < 0.0001). Conclusion: In the emergency settings, a noninvasive assessment of the LAD flow by TTDE accurately estimates the critical stenotic lesions of the LAD.     

Correlation between distal left anterior descending artery flow velocity by transthoracic Doppler echocardiography and corrected TIMI frame count before mechanical reperfusion in patients with anterior acute myocardial infarction.

BACKGROUND: This study was designed to determine the utility of transthoracic Doppler echocardiography (TTDE) in evaluating angiographic Thrombolysis in Myocardial Infarction (TIMI) frame count as a quantitative index of coronary reperfusion in patients with anterior acute myocardial infarction (AMI) before mechanical reperfusion. METHODS AND RESULTS: Color and pulsed TTDE was performed to evaluate distal left anterior descending coronary artery (LAD) reperfusion in 56 consecutive patients with a first anterior AMI before coronary intervention, and these findings were compared with the corrected TIMI frame count (cTFC) by subsequent angiography. Twenty-four of the 56 patients had LAD reperfusion (TIMI 2 or 3) by angiography. Visual antegrade distal LAD flow by color TTDE was detected in 21 of these 24 patients. In the 21 patients, diastolic peak velocity of the distal LAD flow by pulsed TTDE showed a significant correlation with cTFC by angiography (r = -0.74, p < 0.001). The diagnosis of high risk with angiographic cTFC >40 by distal LAD peak velocity <21 cm/s using TTDE had a sensitivity, specificity, and accuracy of 82%, 93%, and 91%, respectively. CONCLUSION: TTDE enables noninvasive and quantitative evaluation of distal LAD reperfusion in patients with anterior AMI in the acute phase before mechanical reperfusion.     

应用多普勒导丝技术研究内乳动脉与冠状动脉前降支血流动力学

目的 比较内乳动脉(IMA)与冠状动脉前降支(LAD)相关血流动力学参数。方法应用血管内多普勒导丝记录22例患者IMA和LAD的平均峰值流速(APV)、舒张收缩流速比(DSVR),造影测量血管直径(D),计算血流量(F)。结果IMA的APV和DSVR与LAD相比有明显差别[分别为(38±12)cm/s VS(23±7)cm/s,P<0.001;0.6±0.3VS 2.4±1.1,P<0.001)];IMA的D和F明显低于LAD[分别为(2.3±0.4)cm vs(3.2±1.1)cm,P<0.05;(90±12)ml/min vs(260±12)ml/min,P<0.001]。结论IMA收缩期供血为主,血流量小;而LAD舒张期供血为主,血流量大。     

Noninvasive assessment of coronary flow reserve in the left anterior descending artery by transthoracic echocardiography before and after stenting

BACKGROUND: Noninvasive assessment of coronary flow reserve in the left anterior descending artery (LAD) by transthoracic Doppler echocardiography (TTDE) has been already validated as a new method for determining the degree of stenosis over the proximal flow. OBJECTIVES: The aim of the study is to determine, by TTDE, the feasibility and the value of the coronary flow reserve (CFR) (defined as the maximal increase in coronary blood flow above its basal pressure for a given perfusion pressure when coronary circulation is maximally dilated) in the mid-to-distal LAD before and after percutaneous angioplasty and to demonstrate the early recovery of microvascular tone immediately after stenting. METHODS: The study population consisted of 36 patients with significant isolated LAD stenosis (70-90%) identified by coronary angiography. CFR was recorded in the mid-to-distal LAD at rest and during hyperemia obtained after adenosine intravenous infusion before and after stenting. RESULTS: Adequate visualization of the LAD was obtained in 25 out of 36 patients (70%). At rest the mean CFR was 1.5132 +/- 0.33 (1.1-2.58). However, after stenting the mean CFR was significantly higher: 2.18 +/- 0.55 (1.3-3.8), with P <0.01. CONCLUSIONS: CFR can be easily determined by TTE in approximately 70% of patients. Noninvasive Doppler echocardiography shows impaired CFR in patients with LAD disease. After stenting CFR is restored, demonstrating early recovery of microvascular tone. These results are comparable to those published in the same conditions. Larger series with a long-term follow-up may allow identifying patients at high risk for restenosis after stenting.     

Physiologic assessment of coronary artery stenosis by coronary flow reserve measurements with transthoracic Doppler echocardiography: comparison with exercise thallium-201 single piston emission computed tomography

OBJECTIVES: We evaluated the value of coronary flow reserve (CFR), as determined by transthoracic Doppler echocardiography (TTDE), for physiologic assessment of coronary artery stenosis severity, and we compared TTDE measurements with those obtained by exercise thallium-201 (Tl-201) single-photon emission computed tomography (SPECT). BACKGROUND: Coronary flow reserve measurements by TTDE have been reported to be useful for assessing angiographic left anterior descending coronary artery (LAD) stenosis. However, discrepancies exist between angiographic and physiologic estimates of coronary lesion severity. METHODS: We studied 36 patients suspected of having coronary artery disease. The flow velocity in the distal LAD was measured by TTDE both at rest and during intravenous infusion of adenosine. Coronary flow reserve was calculated as the ratio of hyperemic to basal peak (peak CFR) and mean (mean CFR) diastolic flow velocities. The CFR measurements by TTDE were compared with the results of Tl-201-SPECT. RESULTS: Complete TTDE data were acquired for 33 of 36 study patients. Of these 33 patients, Tl-201-SPECT confirmed reversible perfusion defects in the LAD territories in 12 patients (group A). Twenty-one patients had normal perfusion in the LAD territories (group B). Peak CFR and mean CFR (mean value +/- SD) were 1.5 +/- 0.6 and 1.5 +/- 0.7 in group A and 2.8 +/- 0.8 and 2.7 +/- 0.7 in group B, respectively. Both peak and mean CFR < or = 2.0 predicted reversible perfusion defects, with a sensitivity and specificity of 92% and 90%, respectively. CONCLUSIONS: Noninvasive measurement of CFR by TTDE provides data equivalent to those obtained by Tl-201-SPECT for physiologic estimation of the severity of LAD stenosis.     

Usefulness of coronary flow velocity measurement by transthoracic Doppler echocardiography in patients with acute coronary syndrome

OBJECTIVES: To evaluate the usefulness of left anterior descending coronary artery (LAD) flow measured by transthoracic Doppler echocardiography (TTDE) in patients with acute coronary syndrome. METHODS: Thirty consecutive patients with acute coronary syndrome in the LAD territory and unstable angina or non-ST-segment elevation myocardial infarction required decisions on the need for emergency coronary angiography. The diastolic peak flow velocity was measured in the distal segment of the LAD under guidance of color Doppler echocardiography in the emergency room. If LAD flow was not detected within 10 min, the coronary flow was judged as under the detection limit. The results of TTDE were compared with the Thrombolysis in Myocardial Infarction (TIMI) grade of LAD determined by coronary angiography, which was performed within 1 week (mean 2.5 +/- 1.5 days) in all patients. RESULTS: Coronary flow was not detected by TTDE in six patients who had TIMI grade 1 or 0. The diastolic peak flow velocity in 19 patients with TIMI 3 was higher than that in 5 patients with TIMI 2 (20.1 +/- 4.1 vs 10.9 +/- 2.3 cm/sec, p = 0.0001). A diastolic peak flow velocity of 14 cm/sec was the optimal cut-off value for the prediction of TIMI 3, with a sensitivity of 95% and a specificity of 100%. CONCLUSIONS: Coronary flow velocity measured by TTDE closely reflected the TIMI grade. Coronary flow measurement by TTDE is useful to decide the treatment strategy for patients with acute coronary syndrome in the emergency room.     

Sequential internal mammary artery (IMA) grafts in coronary artery bypass surgery

Since 1972, double or triple left IMA bypasses have been made on 61 consecutive patients with a total of 123 distal anastomoses to the LAD or to the LD branches of the LAD. There were 54 additional vein grafts with 102 distal anastomoses. The number of single IMA grafts in the same period of time was 400. Hospital mortality was 2 patients (3.3%), with a late mortality of 7 patients (11.3%), 2 of them being heart-related, one of hypernephroma, one suicide, and of unknown cause in the remaining 3 patients. Five patients refused postoperative angiography. There were 50 patients with one or more postoperative angiograms available for the analysis after a mean follow-up time of 35.1 (0.5 to 128) months. The late patency of the left IMA anastomoses was 97% (98/101) and 82.4% (84/102) of the vein anastomoses. There were 2 anastomotic left IMA occlusions to the LD at 2 weeks and 10 months, respectively, and to LAD at 13 months. No left IMA graft had become completely occluded. According to the trend analysis, there was a 97.5% patency at 5 years, and 95.7% at 10 years with left IMA grafts compared to 78.4 and 67.9, respectively, with vein grafts. Ten left IMA grafts were dilated, 2 narrowed and 36 unchanged at the late angiography. Sequential left IMA graft, in appropriate cases seems to result in the most superior patency rate of all types of grafts.     

Usefulness of high-frequency transthoracic Doppler echocardiography in noninvasive diagnosis of the left internal thoracic artery graft stenosis at the anastomosis.

BACKGROUND: Stenosis of the left internal thoracic artery (LITA) graft, which usually occurs at the site of the anastomosis, can be noninvasively evaluated by the flow pattern in the proximal graft, but the flow pattern is influenced by several other factors. METHODS AND RESULTS: In the present study, LITA graft flow was investigated by high-frequency transthoracic Doppler echocardiography in 75 consecutive patients who underwent postoperative angiography of the LITA graft. The flow velocity was measured at both the anastomosis and proximal to it, and compared with the quantitative angiographic results. Flow at both sites was detected in 61 (81%) of the 75 patients. The diastolic velocity ratio of the anastomosis to the proximal site correlated with the percent diameter stenosis at the anastomosis. A diastolic velocity ratio >2.0 had a high sensitivity, specificity, positive predictive value and negative predictive value for the presence of significant stenosis at the anastomosis of a LITA graft. CONCLUSIONS: High-frequency transthoracic Doppler echocardiography can be used for the noninvasive diagnosis of LITA graft stenosis.     

Comparison of the postoperative blood flow waveforms of the bypassing grafts in patients following minimally invasive direct coronary artery bypass

PURPOSE: To use Doppler ultrasound velocimetry to detect and compare the postoperative flow characteristics of the bypassing grafts in patients following minimally invasive direct coronary artery bypass surgery (MIDCAB). MATERIALS AND METHODS: From January 1997 to June 1999, 34 patients underwent MIDCAB with the left internal thoracic artery (LITA) to the left anterior descending coronary artery (LAD) [n = 23], with the right gastroepiploic artery (RGEA) to the right posterior descending artery (RPD) [n = 3], or with the LITA with a saphenous vein graft extension to the LAD (n = 6), the diagonal coronary artery (n = 1), or the right acute coronary artery (n = 1). There were two patients with LITA to the LAD and RGEA to the RPD. Patients underwent MIDCAB due to coronary artery stenosis (100% occlusion, n = 10; 90 to 99% stenosis, n = 18; < 90% stenosis, n = 5) or unsuccessful percutaneous transcoronary angioplasty with dissection (n = 1). All patients underwent flow velocity measurement by Doppler ultrasound velocimetry in the immediate postoperative period, and at 6-month and 12-month intervals; graft flows were quantified based on Doppler velocimetric data. RESULTS: The results showed that in a patient with a totally occluded LAD or RPD, typical biphasic velocity waveforms were consistently observed. However, a delayed diastolic wave was noted in RGEA grafts. In patients with less-occluded stenotic lesions or with strong back flows, the flow velocity patterns showed biphasic waveforms but systolic reversal was observed in the area closest to the anastomotic site. CONCLUSION: The presence of an LAD or RPD stenosis proximal to the anastomotic site significantly affects the LITA or RGEA graft flow volume. The biphasic flow pattern proves that an LITA or RGEA graft transports the blood primarily to coronary arteries during the diastolic phase.     

经胸彩色多普勒检测冠心病患者冠状动脉左前降支和右冠状动脉远端血流储备

目的评价经胸彩色多普勒超声心动图(TTDE)检测冠状动脉前降支(LAD)和右冠状动脉后降支(PDA)血流储备和开放程度的可行性。方法65例(男48例,女17例)连续临床诊断或疑似冠心病患者,平均年龄(58±14)岁,左室射血分数(49±8)%,用TTDE冠状动脉显像方式于心尖两腔切面显示LAD和PDA远端的血流,在基础状态和持续静脉注射腺苷(140μg·kg-1·min-1)情况下分别测定其冠状动脉血流储备(CFR),结果与冠状动脉造影对比。结果所有患者基础和充血状态LAD血流均得到显示(其中4例应用造影剂),55例患者PDA得到显示(5例应用造影剂),有2例患者PDA闭塞,因此LAD的检测成功率为100%(65/65),PDA的CFR检测成功率为87%(55/63),所有患者腺苷静脉注射时间均少于4min,CFR检测平均时间为(7.3±1.6)min。以CFR≤2.0和CFR≤1.8分别作为判断冠状动脉狭窄(≥50%)和显著狭窄(≥70%)的标准,准确性相近,诊断LAD和RCA狭窄的灵敏度、特异度和ROC曲线下面积分别为89%/93%,86%/84%,0.89/0.92,诊断显著狭窄的灵敏度、特异度和ROC曲线下面积分别为88%/89%,90%/83%,0.94/0.95。结论经胸多普勒超声心动图检测LAD和PDA成功率和诊断冠状动脉狭窄的准确性均较高,有重要临床价值。     

Coronary artery size as a predictor of Y-graft patency following coronary artery bypass surgery

This study aims to evaluate the association between target vessel size and graft patency in the right IMA–right coronary territory anastomosis.A total of 402 patients who underwent CABG between 2005 and 2016 using the right IMA Y-graft to the posterolateral branch or posterior descending artery were enrolled. Preoperative coronary angiography was utilized to measure the size of the target coronary arteries in the right territory. Follow-up angiography and computed tomography at 6 to 12 months were used to determine graft patency.Thirty patients (7.5%) were found to have occluded graft. Larger target vessel size was associated with lower risk of graft occlusion (OR: 0.18, 95% CI:0.05–0.62, P = .007). The receiver operating characteristic (ROC) curve showed that the cutoff-value of 1.93 mm was found to have the maximum sum of sensitivity and specificity for graft patency (Area under the curve (AUC): 0.65, P = .01). Excluding patients with right coronary artery total occlusion, the discriminative performance of target vessel size became more prominent (AUC: 0.76, P < .01), with same cutoff value.In the setting of bilateral IMA composite grafting, the patency of right IMA to right coronary territory was influenced by the size of the target coronary artery. The influence of target coronary artery size was prominent in non-total occlusion patients. Careful selection of a target anastomosis site is recommended.     

Transthoracic Doppler assessment of coronary flow velocity reserve in children with Kawasaki disease: comparison with coronary angiography and thallium-201 imaging

OBJECTIVES: The purpose of this study was to determine the feasibility of coronary flow velocity reserve (CFVR) measurement by transthoracic Doppler echocardiography (TTDE) in children with Kawasaki disease (KD). BACKGROUND: Doppler-derived CFVR is a reliable marker predicting the presence of myocardial ischemia. METHODS: We studied 49 patients (median age 11 years) with KD. The CFVR was calculated as the ratio of hyperemic to basal peak (peak CFVR) and mean (mean CFVR) diastolic flow velocities in the posterior descending coronary artery (PD) and left anterior descending coronary artery (LAD). The CFVR measurements by TTDE were compared with the results of coronary angiography, thallium-201 (Tl-201) single-photon emission computed tomography (SPECT), and intracoronary Doppler study. RESULTS: The CFVR measurements by TTDE were obtained in 92 (94%) of 98 vessels of the PD and LAD in 49 study patients. Both peak and mean CFVRs for 21 stenotic vessels were significantly smaller than those for 35 normal vessels and for 20 vessels with aneurysmal lesions (p < 0.0001). Peak and mean CFVR <2.0 predicted significant coronary stenosis, as determined by coronary angiography, with sensitivities and specificities of 89% and 96% and 89% and 97%, respectively. Also, both peak and mean CFVRs were correlated with reversible perfusion defects on Tl-201 SPECT (agreement 80%; kappa 0.4). The correlation between peak and mean CFVRs determined by the TTDE and intracoronary Doppler studies in 36 vessels of 23 patients were 0.76 and 0.80, respectively. CONCLUSIONS: The CFVR measured by TTDE predicts the presence of significant coronary stenosis of either the right coronary artery or LAD, as well as myocardial ischemia of these territories in children with KD.     

Noninvasive assessment of coronary flow velocity and coronary flow velocity reserve in the left anterior descending coronary artery by Doppler echocardiography: Comparison with invasive technique

Objectives. The purpose of this study was to evaluate whether transthoracic Doppler echocardiography (TTDE) can reliably measure coronary flow velocity (CFV) and coronary flow velocity reserve (CFVR) in the left anterior descending coronary artery (LAD) in the clinical setting.Background. Coronary flow velocity measurement has provided useful clinical and physiologic information. Advancement in TTDE provides noninvasive measurement of CFV and CFVR in the distal LAD.Methods. In 23 patients, CFV in the distal LAD was measured by TTDE (5 or 3.5 MHz) under the guidance of color Doppler flow mapping at the time of Doppler guide wire (DGW) examination. Coronary flow velocity in the distal LAD were measured at baseline and hyperemic conditions (intravenous administration of adenosine 0.14 mg/kg/min) by both TTDE and DGW techniques. Coronary flow velocity reserve was defined as the ratio of peak hyperemic to basal averaged peak velocity in the distal LAD.Results. Clear envelopes of basal and hyperemic CFV in the distal LAD were obtained in 18 (78%) of 23 study patients by TTDE. There were excellent correlations between TTDE and DGW methods for the measurements of CFV (averaged peak velocity: r = 0.97, y = 0.94x + 0.40; averaged diastolic peak velocity: r = 0.97, y = 0.94x + 0.69; systolic peak velocities: r = 0.97, y = 0.91x + 0.87; diastolic peak velocity: r = 0.98, y = 0.95x + 1.10). Coronary flow velocity reserve from TTDE correlated highly with those from DGW examinations (r = 0.94, y = 0.95x + 0.21).Conclusions. Noninvasive measurement of CFV and CFVR in the distal LAD using TTDE accurately reflects invasive measurement of CFV and CFVR by DGW method.