Effects of acidic fibroblast growth factor on normal and ischemic myocardium.

We sought to determine the effects of acidic fibroblast growth factor (FGF) on ischemic and normal myocardium and to determine whether direct application of acidic FGF to the heart could promote angiogenesis. Eighteen dogs underwent placement of an ameroid constrictor on the left anterior descending coronary artery (LAD). Three weeks later, a left internal mammary artery (IMA) pedicle was positioned over the LAD territory, with a sponge saturated with acidic FGF (n = 12) or saline (n = 4) interposed between the pedicle and the heart. Polytetrafluoroethylene fiber or collagen I sponges were used to deliver the acidic FGF. Weekly angiography of the IMA was performed in all dogs, but significant IMA to coronary collaterals were not demonstrable in any dog. Eight dogs had histological evidence of subendocardial infarction in the LAD territory (five acidic FGF, three control, p = NS). Striking smooth muscle cell hyperplasia was present in arterioles and small arteries exclusively in areas of subendocardial infarction in all of the acidic FGF-treated dogs but in none of the control dogs (p less than 0.05). Noninfarcted myocardium appeared normal in all dogs. In two additional dogs, ameroid constrictors were not placed on the LAD, such that acidic FGF-treated sponges were placed on normally perfused myocardium of the LAD territory. Histological evaluation of those hearts revealed normal myocardium, without evidence of myocardial infarction or smooth muscle cell hyperplasia. Thus, when acidic FGF is delivered to the myocardium via an epicardial sponge in dogs whose coronary flow is compromised, acidic FGF does not cause an angiogenic response in viable myocardium but causes vascular smooth muscle cell hyperplasia in areas subjected to ischemic injury.     

Internal elastic membrane in the internal mammary and left anterior descending coronary arteries and its relationship to intimal thickening

The internal mammary artery (IMA) is less prone to intimal thickening than coronary arteries and is routinely used in coronary bypass surgery. To resolve whether morphologic differences can explain why IMA develops less intimal thickening, morphometric measurement of the left anterior descending coronary artery (LAD) and IMA was carried out in 62 autopsies from individuals of various age groups. The amount of intimal thickening, the degree of folding of the internal elastic membrane, and media thickness were estimated by appropriate indices. Intimal thickening of LAD was more marked, occurred earlier and could be demonstrated even below one year of age, but was not found before 21 years of age in the IMA. A fold-index of the internal elastic membrane was significantly higher in the IMA than in the LAD and correlated negatively with an intimal thickening index in both arteries (P less than 0.0001 for both). The fold-index decreased with age, most markedly in LAD. Negative correlation was also found between a media thickness index and the intimal thickening index in LAD (P less than 0.02). The fold-index may indicate the magnitude of tangential intimal tension during life and may be of significance for development of intimal thickening and atherosclerosis. Lower fold-index may in part explain the propensity of atherosclerosis in LAD compared with IMA. Also, reduced fold-index with age accompanied the occurrence of atherosclerosis with age.     

Subclavian coronary steal syndrome: an obligatory common fate between subclavian artery,internal mammary graft and coronary circulation

The long-term patency of the left internal mammary artery (IMA) has made it the preferred conduit for myocardial revascularization. The proximal segment of the subclavian artery becomes functionally connected to the coronary circulation as a result of IMA implantation during coronary artery bypass surgery. The subclavian coronary steal syndrome results from stenosis in the left subclavian artery proximal to the IMA, compromising blood flow to the myocardium. We describe 7 patients, aged 55-75 years, 1.7-10.5 years after coronary bypass who presented with recurrent angina due to subclavian artery stenosis. The IMA graft was found open in each patient. A true steal mechanism was not demonstrated, casting doubt on the syndrome's traditional name. Angioplasty and stenting of the subclavian artery resulted in the immediate disappearance of angina and continuous benefit at a follow-up of 3-32 months. The subclavian coronary steal syndrome, although rare, is a severe condition readily treated by angioplasty and stenting.     

Left internal mammary artery grafting to left anterior descending coronary artery by minimally invasive direct coronary artery bypass approach

New surgical techniques for the treatment of the isolated lesion of the left anterior descending coronary artery (LAD) include off-pump surgery, minimal access to the heart, and endoscopic or computer enhanced coronary artery bypass surgery. The term minimally invasive direct coronary artery bypass surgery (MIDCAB) is related to a leftside minithoracotomy, the harvest of the left internal mammary artery (IMA) under direct vision, and an anastomosis performed between IMA and LAD under direct vision, using the technique of mechanical local immobilization by a special device. Alternative techniques include endoscopic harvesting of the IMA, or as a new and still experimental approach, the closed-chest total endoscopic coronary artery bypass grafting (TECAB) with the use of a high tech telemanipulator system. The currently reported results demonstrate the safety of MIDCAB surgery (30-day mortality < 0.5%, perioperative myocardial infarction < 2%, early patency rate between 95% and 98%). Mid-term results after 6 months have shown a patency rate between 94% and 97%, and more than 90% of the patients are without any angina symptoms. Due to this promising results MIDCAB is an alternative treatment for high-grade LAD lesions.     

Induction of myocardial neoangiogenesis by human growth factors. A new therapeutic approach in coronary heart disease

Currently available approaches for treating human coronary heart disease aim to relieve symptoms and the risk of myocardial infarction either by reducing myocardial oxygen demand, preventing further disease progression, restoring coronary blood flow pharmacologically or mechanically, or bypassing the stenotic lesions and obstructed coronary artery segments. Gene therapy, especially using angiogenic growth factors, has emerged recently as a potential new treatment for cardiovascular disease. Following extensive experimental research on angiogenic growth factors, the first clinical studies on patients with coronary heart disease and peripheral vascular lesions have been performed. The polypeptides fibroblast growth factor (FGF) and vascular endothelial growth factor (VEGF) appear to be particularly effective in initiating neovascularization (neoangiogenesis) in hypoxic or ischemic tissues. The first clinical study on patients with coronary heart disease treated by local intramyocardial injection of FGF-1 showed a 3-fold increase of capillary density mediated by the growth factor. Also, angiogenic growth factor injection intramyocardially as sole therapy for end-stage coronary disease showed an improvement of myocardial perfusion in the target areas as well as a reduction of symptoms and an increase in working capacity. Angiogenic therapy of the human myocardium introduces a new modality of treatment for coronary heart disease in terms of regulation of blood vessel growth. Beyond drug therapy, angioplasty and bypass surgery, this new approach may evolve into a fourth principle of treatment of atherosclerotic cardiovascular disease.     

Long-term patency of saphenous vein and left internal mammary artery grafts after coronary artery bypass surgery: results from a Department of Veterans Affairs Cooperative Study

OBJECTIVES: This study defined long-term patency of saphenous vein grafts (SVG) and internal mammary artery (IMA) grafts. BACKGROUND: This VA Cooperative Studies Trial defined 10-year SVG patency in 1,074 patients and left IMA patency in 457 patients undergoing coronary artery bypass grafting (CABG). METHODS: Patients underwent cardiac catheterizations at 1 week and 1, 3, 6, and 10 years after CABG. RESULTS: Patency at 10 years was 61% for SVGs compared with 85% for IMA grafts (p < 0.001). If a SVG or IMA graft was patent at 1 week, that graft had a 68% and 88% chance, respectively, of being patent at 10 years. The SVG patency to the left anterior descending artery (LAD) (69%) was better (p < 0.001) than to the right coronary artery (56%), or circumflex (58%). Recipient vessel size was a significant predictor of graft patency, in vessels >2.0 mm in diameter SVG patency was 88% versus 55% in vessels 2.0 mm in diameter.     

Delayed pleuropulmonary complications following coronary artery revascularization with the internal mammary artery

We have seen four cases of delayed postoperative pleuro-pulmonary complications associated with use of the internal mammary artery (IMA) conduit. In each case the left IMA was used as a bypass conduit to the left anterior descending (LAD) coronary artery. In two of the instances the complications were life-threatening to the patients. Each patient was left with symptomatic residual roentgenographic changes. The IMA is becoming the graft of choice for coronary artery revascularization. The potential for delayed pleuropulmonary complications associated with use of this graft is not well recognized.     

不同部位的人体冠状动脉搭桥材料血管释放一氧化氮和内皮超极化因子差异的实验研究

目的:本研究通过直接检测人体乳内动脉(IMA)、大隐静脉(SV)与桡动脉(RA)内皮细胞释放的一氧化氮(NO)浓度以及平滑肌细胞膜电位信号,对比不同部位的人体冠状动脉搭桥材料血管释放一氧化氮和内皮超极化因子(EDHF)的差异.方法:将冠状动脉搭桥手术(CABG)常用的不同部位搭桥材料血管分为4组:乳内动脉组(n=15)、桡动脉组(n=6)、大隐静脉组(n=23),以及压力扩张后的大隐静脉组[简称PV组,n=9,将肝素生理盐水注入大隐静脉管腔,压力维持在100～600 mmHg(1 mmHg=0.133 kPa)].分别将长度为5 mm的血管片放置于37℃血管灌流室中,加入乙酰胆碱(log M-8~log M-5)和缓激肽(log M-10~log M-7),以激发内皮细胞释放一氧化氮与EDHF.应用一氧化氮测定仪与膜电位记录仪,直接检测桥血管释放的一氧化氮与平滑肌细胞膜电位信号,研究其一氧化氮释放动力学与EDHF介导的超极化反应.结果:①一氧化氮基础释放浓度:乳内动脉组显著高于大隐静脉组与桡动脉组;而桡动脉组的一氧化氮基础释放水平明显高于大隐静脉组.②在乙酰胆碱的激发下,乳内动脉组释放的一氧化氮总量明显超过桡动脉组和大隐静脉组;在缓激肽(log M-8、log M-7)的激发下,乳内动脉组和大隐静脉组均较桡动脉组升高.③PV组一氧化氮的基础释放与刺激性释放均显著减少.④乳内动脉组由EDHF调节的平滑肌细胞超极化幅度明显高于大隐静脉组与桡动脉组.桡动脉组与大隐静脉组相比,由乙酰胆碱激发、EDHF介导的平滑肌细胞超极化幅值亦明显增高,差异均有统计学意义(P<0.05~0.01).结论:①从内皮细胞一氧化氮与EDRF介导的内皮细胞功能角度评价,乳内动脉最佳,而桡动脉明显优于大隐静脉;②压力扩张会损害大隐静脉一氧化氮介导内皮细胞功能,导致大隐静脉桥远期通畅率低下.     

Coronary artery bypass grafting by utilizing the internal mammary artery graft in 100 Japanese patients

The internal mammary artery (IMA) grafting for myocardial revascularization was performed in 100 Japanese patients during a three-year period. There were 86 males and 14 females with the mean age of 58 +/- 9 (37 approximately 75 year-old). Unilateral IMA was used in 88 patients and bilateral IMA was used in 12 patients. Sequential IMA grafting was performed in 5 patients. The sites of IMA grafting were 91 left anterior descending arteries (LAD), 16 diagonal branches, 8 circumflex arteries and 2 right coronary arteries. Saphenous vein or gastroepiploic artery was concomitantly used to bypass the other coronary arteries in 90 patients. The number of distal anastomosis ranged from 1 to 6 and the mean was 2.8 per patient. Two patients died within 30 days and one patient died at 3 months after surgery. Perioperative myocardial infarction was noted in 3 patients. Symptomatic relief was obtained in 94 (97%) of 97 survivors. The patency of the IMA graft at mean 2.2 postoperative months was 97% (58/60) in LAD, 100% (14/14) in the diagonal branch, 100% (5/5) in the circumflex artery, 100% (1/1) in the right coronary artery, and 98% (78/80) in over-all grafted coronary arteries. Pre- and postoperative exercise thallium scintigraphy in 13 patients, who received the IMA graft to severely stenosed LAD, showed significant improvement of the washout ratio (from 33.1 +/- 16.9% to 47.4 +/- 14.8%) which was nearly equivalent to that of the saphenous vein graft to LAD (from 24.8 +/- 6.2% to 48.1 +/- 6.6%, n = 7).(ABSTRACT TRUNCATED AT 250 WORDS)     

Coronary artery bypass surgery: Assessment of revascularization by determination of blood flow and myocardial mass

Evaluation of 70 bypass grafts in 43 patients by determinations of graft and myocardial blood flow and myocardial mass demonstrated the potential of coronary artery bypass grafts to increase significantly blood flow to sizable masses of myocardium. The amount of myocardial mass perfused had a wide range but was similar whether bypasses were placed on the right or on the left anterior descending coronary artery (107 ± 13 g, respectively). Mean myocardial blood flow was 76 percent higher with the graft open. Flow levels in bypass grafts ranged widely but were similar in bypasses to the right and to the left anterior descending coronary arteries (47 ± 7 ml/min and 49 ± 6 ml/min, respectively). Flow levels in grafts to the circumflex artery and in Internal mammary artery to left anterior descending coronary bypasses were lower (11 ± 4 ml/min and 23 ± 6 ml/min, respectively). There was no relation between blood flow in the bypass graft and the degree of change induced in myocardial blood flow. The measurement of graft flow alone was an Insufficient indicator of revascularization since it did not take into account changes in rate and extent of distribution of myocardial perfusion brought about by the new blood flow.     

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.     

Internal mammary artery steal syndrome secondary to a para-IMA after coronary artery bypass graft： a case report

Introduction
The use of the intemal mammary artery （IMA） in coronary artery bypass graft（CABG） for myocardial revascularization is gaining popularity in routine practice, especially when the target vessel is the left anterior descending artery （LAD）. Occasionally, IMA hypoperfusion occurs when there is inadequate flow through the IMA graft to the LAD artery due to the exist of lateral branches.     

重组腺相关病毒载体介导成纤维细胞生长因子2基因诱导缺血心肌血管新生

探讨重组 2型腺相关病毒载体介导 2型成纤维细胞生长因子基因诱导家兔缺血心肌血管生成的作用。实验对象为 2 0只新西兰兔 ,手术建立心肌缺血模型后随机分为成纤维细胞生长因子基因治疗组和对照组 ,分别向缺血区域心肌注射成纤维细胞生长因子腺相关病毒或磷酸盐缓冲液。 4周后取心肌及肝、肾等器官组织标本 ,采用逆转录聚合酶链反应检测目的基因mRNA的表达 ;制作组织学切片以观察组织病理改变 ,于高倍镜下计数缺血区域微血管数目。结果发现转染的 2型成纤维细胞生长因子基因在缺血心肌中有表达 ,成纤维细胞生长因子基因治疗组缺血区域单个高倍视野内的微血管数为 12 .0± 1.4条 ,对照组为 4 .5± 1.5条 ,二者差异具有显著性 (P <0 .0 1)。 2型成纤维细胞生长因子基因治疗组的肝脏、肾脏、脾脏、角膜和睾丸标本中均未发现 2型成纤维细胞生长因子基因的表达 ,病理检查也未发现组织结构异常。说明腺相关病毒载体介导的 2型成纤维细胞生长因子基因可以有效地转染入家兔缺血心肌 ,并具有明显的诱导缺血心肌血管生成的作用 ,且基因表达仅限于心肌。     

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.     

Evaluation of high-pressure retrograde coronary venous delivery of FGF-2 protein.

Delivery of angiogenic factors to ischemic myocardium remains a practical challenge. We evaluated the efficiency and efficacy of delivery of fibroblast growth factor-2 (FGF-2) protein via high-pressure retrograde injection into the anterior interventricular vein (AIV) in a porcine model of chronic myocardial ischemia. Labeled FGF-2 protein was delivered to the myocardium of three pigs via the AIV and the left anterior descending (LAD) coronary artery in three others. At 1 hr, the amount of protein in the left ventricle and the LAD region was quantified. Copper stents were implanted in the LAD of 25 pigs, resulting in chronic myocardial ischemia. At 4 weeks, microsphere-derived myocardial blood flow was assessed at rest and during pacing. In eight pigs (AIV FGF), FGF-2 protein (6 microg/kg) was delivered via high-pressure retrograde injection into the AIV. Six pigs (intracoronary FGF) received the same amount of FGF-2 by intracoronary delivery. Five pigs (AIV saline) received a placebo injection into the AIV and six pigs (control) served as controls. Four weeks later, myocardial blood flow was reassessed. At 1 hr, significantly more FGF remained in the left ventricle (1.3 vs. 0.82 microg; P < 0.04) and in the LAD region (1.2 vs. 0.64 microg; P = 0.03) after AIV compared to intracoronary delivery. Four weeks after treatment, resting LAD blood flow (normalized to right ventricular flow) improved slightly in the AIV FGF and intracoronary FGF arms (1.32-1.37 for both; P = 0.11), while it decreased significantly in the AIV saline (1.32-1.23; P = 0.02) and the control arms (1.32-1.19; P = 0.0004). Pacing LAD blood flow decreased significantly in the control arm (1.30-1.23; P < 0.05), but did not change significantly in the other three arms. High-pressure retrograde injection into the AIV may represent an efficient and effective means for delivering angiogenic factors to ischemic myocardium.     

The influence of combined intra-aortic balloon counterpulsation and hyperosomotic mannitol on regional myocardial blood flow in ischemic myocardium in the dog.

We investigated the combined effectiveness of intra-aortic balloon counterpulsation and hyperosmotic mannitol (25%) on regional myocardial blood flow during acute coronary insufficiency. Cardiac output and paced heart rate were held constant in chloralose-anesthetized dogs during right heart bypass. Acute coronary insufficiency was produced by ligation of the proximal left anterior descending coronary artery (LAD). Regional myocardial blood flow was measured using radioactive microspheres. Left ventricular end-diastolic pressure, mean aortic pressure, maximum left ventricular dp/dt, and hematocrit were unchanged by combined mannitol infusion and balloon pumping. Studies of combined treatment with balloon pumping and mannitol immediately after the second of two 13-minute consecutive reversible ligations of the LAD demonstrated that (1) collateral coronary blood flow increased 46% (P less than 0.02) in ischemic myocardium compared with mannitol infusion along during the first LAD ligation, and (2) collateral coronary blood flow increased 27% (P less than 0.05) in ischemic myocardium compared with balloon pumping along during the first LAD ligation. Studies in which combined treatment was delayed until 20 minutes after LAD ligation demonstrated that collateral coronary blood flow was elevated by 33% (P les than 0.05) in ischemic myocardium compared to control studies in which balloon pumping alone had no effect. The results suggest that the increase in collateral coronary blood flow was in part a result of an increased transmural pressure gradient produced by balloon diastolic augmentation and the ability of mannitol to reduce coronary vascular resistance in ischemic myocardium.     

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)     

Coronary artery revascularization without cardiopulmonary bypass

At the Texas Heart Institute between October 1969 and August 1983, there were 191 single bypass procedures performed without pump oxygenator support. These cases have been divided into two groups: Group I (160 patients) represents the time period from October 1969 through December 1981 and includes our experience with single vessel left anterior descending (LAD) coronary artery bypass without pump oxygenator support; Group II (31 patients) represents the period between January 1982 and August 1983 and includes our initial operative experience in patients with failed percutaneous transluminal coronary angioplasty (PTCA). Of 145 primary operations in Group I patients, 113 were single bypasses to the right coronary artery with a postoperative infarction rate of 3.5% (4/113). Single bypass to the left anterior descending (LAD) coronary artery in 32 patients who underwent operation early in the series was associated with a postoperative infarction rate of 18.7% (6/32) and is no longer performed without pump oxygenator support. Fifteen patients had previous coronary bypass operations and underwent single bypass without pump as a second procedure. Postoperative infarction rate in this redo group was 6.6% (1/15). Long-term follow-up data was obtained on all patients from 1 to 11 years after surgery (mean follow-up, 4 years). Four late cardiac deaths occurred at 2,3,4 and 7 years in the primary operation group (3.5%) 4/113. One late death occurred at 7 years in the redo group (6.6%) 1/15. In Group II, failed PTCA accounted for 39% of the 31 patients who underwent single right bypass without pump support; there were no perioperative infarctions and one death. Coronary bypass can be safely and effectively employed without pump oxygenator support if performed expeditiously and limited to right coronary lesions which have an adequate distal vessel. This technique has become more useful with the advent of attempted PTCA for single coronary lesions.     

Hemodynamics and coronary blood flow during exercise after coronary artery bypass grafting with internal mammary arteries in children with Kawasaki disease

BACKGROUND. Saphenous vein grafts (SVG) and internal mammary artery (IMA) grafts have been used for coronary artery bypass grafting. In adult patients with bypass grafting for atherosclerotic coronary artery disease, IMA grafts have been reported to have long-term patency; however, results are conflicting on whether the graft is sufficient to meet increased myocardial oxygen demand during exercise. There have been no studies on hemodynamics and blood flow during exercise after bypass grafting with IMA in pediatric patients with Kawasaki disease. METHODS AND RESULTS. We studied 17 pediatric patients with Kawasaki disease (average age, 7.5 +/- 3.1 years), who underwent coronary artery bypass grafting with the IMA. The average number of coronary artery bypass grafts was 2.1 +/- 0.7/patient. For all patients, the left IMA was anastomosed to the left anterior descending coronary artery; for eight patients, the right IMA was also anastomosed to the right coronary artery. In addition, 11 SVGs were used. The postoperative patency rates after 1 month were 100% with the IMA graft and 91% with SVG. One year after the operation, the patency rates were 100% with IMA and 50% with SVG. Hemodynamics during exercise were measured with a bicycle ergometer, and coronary sinus blood flow was measured by the continuous thermodilution method in six patients. The relation between delta LVEDP (the difference between left ventricular end-diastolic pressure at rest and during exercise) and delta SVI (the difference between the stroke volume index at rest and during exercise) was analyzed. Four of six patients had reduced cardiac function before operation (delta LVEDP, positive; delta SVI, negative). However, after the operation, all patients demonstrated improvements in cardiac function during exercise (delta LVEDP, positive; delta SVI, positive). Coronary sinus flow per left ventricular mass increased after operation from 70 +/- 46 to 87 +/- 56 ml/min at rest (p less than 0.05) and from 139 +/- 118 to 183 +/- 150 ml/min during exercise (p less than 0.05). CONCLUSIONS. In conclusion, this study reveals improvements in both hemodynamics and coronary blood flow during exercise after coronary artery bypass grafting with IMA grafts in pediatric patients with Kawasaki disease.     

Contrast-echocardiography: confirmation of patency of laser channels after transmyocardial laser revascularization.

AIMS: Apart from casuistic autopsy results there is no long-term evidence for channel perfusion after transmyocardial laser revascularization in humans. METHODS AND RESULTS: Fifteen consecutive patients aged 63+/-17 years were investigated 71+/-15 days after coronary artery bypass surgery and/or transmyocardial revascularization with 13-37 (20+/-5) channels (CO(2) laser, 40 J/pulse). Echocardiography was performed after injection of 6 ml echo contrast medium into left ventricular cavity and after injection of 3 ml contrast medium into the left main coronary artery. In five patients with additional bypass surgery to the same region, we also injected 3 ml contrast medium into bypass graft. We could prove in 10 of 15 patients (67%) one or two laser channels in the apical left ventricular myocardium. Channels were perfused exclusively during systole. During following heart cycles myocardium was opacified up to a mean width of 1.4+/-0.4 cm, a mean depth of 0.71+/-0.1cm, and a mean area of 1.0+/-0.6 cm(2). Contrast medium was washed out via coronary venous system in 9+/-8 systoles. CONCLUSION: This is the first clinical evidence of long-term laser-channel patency in humans showing perfused myocardium via left ventricular cavity.