Blood flow velocity in donor coronary artery depends on the degree and pattern of collateral vessel development: a study using thrombolysis in myocardial infarction frame count method.

To understand the influence of collateral vessels on the coronary flow, TIMI frame count (TFC) method was applied as a measure of mean coronary blood flow velocity in artery giving collateral blood supply to the other artery in angiograms of 76 patients with single occluded coronary artery: RCA giving collaterals to occluded LAD or LAD giving collaterals to occluded RCA. As a control group, TFC was applied in angiograms of 30 patients with mild or no coronary artery disease. TFC was lower (faster blood flow) in LAD giving collaterals to occluded RCA (43 patients) than in LAD in control group (21.8 +/- 10.5 vs. 33.9 +/- 20.8 frames; P < 0.01). Higher degree of collateral vessels (Rentrop classification) and mixed- and distal-type collaterals (through the interventricular septum and heart apex) was associated with lower TFC. There was no difference in TFC in the RCA giving collaterals to an occluded LAD (33 patients) compared to the TFC in RCA in control group (16.6 +/- 9.0 vs. 18.5 +/- 6.0; P = NS), even in angiograms with higher degree of collateral vessel development. TFC was lower (faster blood flow) only in subgroups with mixed (proximal and distal types together in the same patient) and distal (through the interventricular septum and the apex of the heart) collateral types. A delayed contrast appearance in occluded LAD compared to occluded RCA has been found (35.1 +/- 16.1 vs. 20.2 +/- 7.3 frames; P < 0.001) with earlier contrast appearance in occluded LAD when proximal collateral vessels (through the conal and acute marginal branches of RCA) were presented. The coronary flow in donor arteries depends not only on the degree but also on the pattern of collateral vessels. The simple TFC method may facilitate the study of collateral filling pattern and offer insight into the influence of collaterals on the ventricular function.     

Fractional flow reserve for the assessment of complex multivessel disease in a patient after hybrid coronary revascularization

We present a case of a 43‐year‐old woman with history of hybrid coronary revascularization [endoscopic atraumatic coronary artery bypass (ACAB)] of left internal mammary artery (LIMA) to the left anterior descending artery (LAD) and stent implantation in right coronary artery (RCA), who presented 6 years later with recurrent atypical angina. Coronary angiography revealed patent LIMA to LAD and RCA stent, with a new lesion in an obtuse marginal artery and significant progression of disease in the proximal/mid LAD proximal to LIMA touchdown. To further evaluate the hemodynamic significance of these new disease segments, the patient underwent fractional flow reserve (FFR) assessment of the left coronary system with subsequent stent implantation in the proximal/mid LAD. This case illustrates (1) the critical value of FFR assessment in determining the ischemia provoking lesions in this post ACAB patient with complex multivessel coronary artery disease; and (2) the accelerated progression of atherosclerosis in bypassed segments as compared to segments proximal to stents. © 2012 Wiley Periodicals, Inc.     

Coronary anatomy and left ventricular function in the first 12 hours of acute myocardial infarction: the Western Washington Randomized Intracoronary Streptokinase Trial

The relationships among clinical variables, coronary anatomy, and left ventricular function during the early hours of acute myocardial infarction (AMI) were evaluated from data acquired in the Western Washington Intracoronary Streptokinase Trial. All patients had symptoms and electrocardiographic changes typical of AMI. All data were obtained before treatment with streptokinase. Mean time to catheterization was 4.1 hr after onset of symptoms. Coronary angiograms (n = 245) were analyzed for location of infarct-related occlusion and collateral flow to the infarct bed. Left ventricular ejection fraction and regional left ventricular function were quantitated in 227. Sixty-two percent of occlusions were in the most proximal segment of the involved coronary artery. Collateral circulation was seen in 42% overall, in 31% with left anterior descending artery (LAD) occlusion, and in 52% with right coronary artery (RCA) occlusion (p less than .005). Left ventricular ejection fraction was lowest and regional function was most abnormal in the group with proximal LAD occlusion. Hyperkinesis was present in 32%; in those with hyperkinesis, hyperkinetic segment length was longest in those with RCA or circumflex occlusion. Multivariate analysis identified proximal LAD occlusion as the factor most closely associated with left ventricular ejection fraction and with measures of left ventricular regional hypofunction. We conclude that (1) AMI is usually caused by occlusion or subtotal occlusion in the most proximal portion of the involved coronary artery, (2) collateral circulation is more frequent with RCA than with LAD occlusion, and (3) location of the infarct-related occlusion is the most important determinant of global and regional left ventricular function in the early hours of AMI.     

The sword of Damocles: an illustrative example of the life-saving effect of the collateral circulation

There is an ongoing debate on the effective importance of the collateral network, especially in the current era, where most patients with significant coronary artery disease are revascularized, be it percutaneously or surgically; thus, people may question a significant benefit of the coronary collateral circulation. However, the presented 61-year-old male patient demonstrates an unambiguous situation of a life-saving effect of the collateral circulation. The patient presented without any angina symptoms and with only mild shortness of breath on moderate to severe exertion. A subsequent angiography revealed a complete chronic occlusion of the main coronary artery. The entire left coronary system was provided by well-developed right to left collaterals. Additionally, the patient had an 80-90% stenosis of his mid-right coronary artery (RCA). The entire blood supply to the heart had to pass this lesion to provide the RCA area and also the left anterior descending and left circumflex areas via collaterals. This extreme example illustrates the potentially lifesaving effect of the coronary collateral circulation. Obviously, the entire myocardium can in some cases be perfused entirely via one critically stenosed vessel.     

Physiological impact of CTO recanalization assessed by coronary pressure measurement: A case report

In this case report, physiological changes of myocardial perfusion in the collateral recipient right coronary artery (RCA) and the collateral donor left anterior descending artery (LAD) with an intermediate lesion were assessed using intracoronary pressure measurement, before and after revascularization of chronic total occlusion (CTO). A 44‐year‐old male was referred for a catheter examination due to silent myocardial ischemia. An invasive coronary angiogram revealed diffuse narrowing of the RCA with focal occlusive segments in addition to intermediate stenosis in the LAD. A well developed collateral channel from the LAD to the RCA was also confirmed. Fractional flow reserve (FFRmyo) of the LAD before opening the RCA was 0.81. After successful revascularization of the RCA, FFRmyo of the LAD and the RCA were measured with and without an RCA balloon occlusion. Because collateral fractional flow reserve (FFRcoll) of the RCA could be regarded as FFRmyo before revascularization, FFRmyo of the RCA increased from 0.67 to 0.90, meaning a 23% increase of maximum flow by intervention. Interestingly, improvement of FFRmyo of the LAD from 0.81 to 0.93 was also observed, which means a 12% increase of maximum flow. Coronary steal in the LAD was reconfirmed by dramatic worsening of FFRmyo from 0.93 to 0.77 by an RCA balloon occlusion. This phenomenon may be explained by an immediate recruitment of collateral channels. This case clearly demonstrated that CTO opening improves perfusion in not only myocardium supplied by the CTO vessel, but also in that which is supplied by a contralateral collateral donor artery. © 2013 Wiley Periodicals, Inc.     

Relation of coronary arterial occlusion pressure during percutaneous transluminal coronary angioplasty to presence of collaterals

To investigate the relation of the gradient across a coronary artery stenosis and the pressure distal to the stenosis after proximal occlusion during percutaneous transluminal coronary angioplasty to the amount of angiographically estimated collateral circulation, 63 patients (55 men, 8 women) were studied. All patients had 1-vessel disease (54 left anterior descending, 8 right coronary artery and 1 circumflex coronary artery). All patients had documented ischemia, and angioplasty was carried out within 4 weeks after the initial angiogram. The patients were separated into 4 groups: 0 = no collaterals (35 patients), +1 = just visible collaterals (8 patients), +2 = collaterals without reaching the contralateral vessel (10 patients), and +3 = filling of the contralateral vessel (10 patients). There was no difference in age among the 4 groups. There was a significant negative relation of the gradient vs the extent of collateral circulation, although the degree of stenosis increased significantly from group 0 to group +3. There was a significant positive relation of the occlusion pressure (in absolute terms and in percent of the proximal systolic pressure) vs the extent of collateral circulation. There was a significantly smaller change of the occlusion pressure vs the distal pressure before occlusion if good collaterals were present. The occlusion pressure remained constant during 1 occlusion up to 40 seconds and was reproducible in 3 successive occlusions. In conclusion, the pressure distal to a coronary artery stenosis is mainly dependent on the severity of the stenosis and on the collateral flow. If anterograde flow is eliminated by proximal occlusion the distal pressure is only dependent on the extent of collateral circulation.     

The effect of cigarette smoking on the pattern of coronary atherosclerosis. A case-control study

Cigarette smoking is a risk factor for development of coronary atherosclerosis. We examined the relationship between smoking and the anatomic location of coronary artery stenosis in 8,705 patients undergoing cardiac catheterization for suspected coronary artery disease (CAD). The smoking history of patients with CAD (greater than or equal to 70 percent stenosis) was compared with that of control subjects (0 percent stenosis) for each of nine anatomic locations (proximal, middle, and distal segments of right [RCA], anterior descending [LAD], and circumflex arteries [LCX]), using a case-control method. The odds ratio (OR) estimate of relative risk of CAD for smokers relative to nonsmokers was 2.8, with a 95 percent confidence interval (CI) of 2.5 to 3.1. Relative risk was greater for RCA stenosis (OR = 5.8; CI = 4.6-7.2) than for LCX (OR = 3.5; CI = 2.7-4.5) or LAD (OR = 2.1; CI = 1.8-2.4) lesions when comparing smokers with nonsmokers. After control for age, gender, history of diabetes mellitus, and serum cholesterol level, the adjusted relative risk for an RCA lesion (Mantel-Haenszel odds ratio [MOR] = 4.9) was significantly elevated (p less than 0.05) compared with the LAD (MOR = 1.9) but not with the LCX (MOR = 3.1). The relative risks of CAD were the same (p greater than 0.05) for the proximal, middle, and distal coronary segments. Thus, smoking increased the risk of all coronary lesions but did so more for the RCA than for other vessels, suggesting a spatial pattern to the increased risk produced by smoking.     

Dobutamine stress echocardiography as a predictor of coronary lesion severity on coronary angiography.

In order to evaluate the capacity of dobutamine stress echocardiography (stress echo) to predict the severity of atherosclerotic lesions observed on coronary angiography in patients with coronary artery disease, we performed a retrospective study at Instituto Nacional de Cardiologia and Universidade Federal Fluminense, Brazil. The health records of 40 patients who underwent both stress echo and coronary angiography within a period of less than 14 days were assessed. For the stress echo analysis, the heart was divided into 16 segments and the different types of response assessed: biphasic, ischemic, viable or unchanged. The main arteries - left anterior descending artery (LAD), left circumflex coronary artery (LCx) and right coronary artery (RCA) and their branches - were studied by coronary angiography to assess the degree of obstruction (in %), the type of lesion (A, B1, B2 or C), and the presence or absence of collateral circulation. The following results were obtained: patients showing an altered response on stress echo (ischemic) presented a higher degree of coronary obstruction as well as more complex lesions in the anterior descending artery on coronary angiography. A higher degree of obstruction was associated with more complex lesions (in LAD, LCx and RCA) and collateral circulation (in LAD and RCA). The presence of more complex lesions also correlated with collateral circulation in the LAD. Based on these results, we concluded that dobutamine stress echocardiography is a non-invasive test capable of predicting the severity of coronary lesions in patients with chronic ischemic cardiopathy.     

Acute myocardial infarction showing total occlusion of right coronary artery and thrombus formation of left anterior descending artery

A 33-year-old Japanese man had an attack of chest pain associated with ST-segment elevation in the inferolateral leads on his electrocardiogram. Emergency coronary angiography showed total obstruction in the mid right coronary artery (RCA) and a movable thrombus in the proximal left anterior descending artery (LAD). We performed emergency percutaneous transluminal coronary angioplasty (PTCA) for the RCA lesion. The operation was successful and we then conducted intracoronary thrombolysis (ICT) with tisokinase 6,400,000 IU for the LAD thrombus. Its size was reduced by ICT. He had an uneventful hospital course. After 1 month, repeat coronary angiography showed no significant stenosis in the RCA nor thrombus in the LAD. A coronary spasm provocation test was performed using acetylcholine. Coronary spasm in the LAD was induced by an intracoronary injection of 100 microg acetylcholine. In this case, we observed a unique condition suggesting simultaneous double coronary artery occlusion.     

Treatment of a native right coronary artery with the PercuSurge Guardwire protection system during PTCA and stenting

Cardiac catheterization in a patient with recent-onset unstable angina demonstrated a suboccluded dominant right coronary artery (RCA), with angiographic evidence of a large thrombus load and a severe focal stenosis of the left anterior descending (LAD) coronary artery. After abciximab, uneventful PTCA and stenting of the LAD was performed. The thrombus containing lesion of RCA was treated with balloon predilatation and stent deployment, and the whole procedure was accomplished with protection of the distal vessel by means of PercuSurge. This device was planned to avoid distal debris migration during percutaneous interventions of saphenous bypass grafts. The system is designed to allow the placement of a temporary occlusion device, a low-profile balloon, distal to the lesion to be treated during the procedure. The occlusive balloon is kept inflated during the treatment of the lesion. Before deflating the balloon and allowing blood to reach the distal vessel, whenever it is necessary, the material proximal to the balloon is aspirated through a monorail catheter. This aspiration removes blood and thrombi proximal to the occlusive balloon from the treated coronary artery. The case we present first reports the application of the device in a large native coronary artery, with an optimal distal flow restoring and no evidence of thrombus embolization. This type of protection of distal coronary vessels towards micro- and macroembolization of thrombi is a promising system of performing safer percutaneous interventions, even in acute ischemic syndromes.     

An abnormal finding in an angiogram

An 80 year old Chinese gentleman was admitted with NSTEACS characterized by anterior T wave inversion and raised Troponin T. His coronary angiogram showed stenosis of the proximal LAD. He underwent PCI to LAD lesion. The RCA was large and there was large collateral between, RCA and PA (fig 1,2), which was not intervened. He made good recovery and has been asymptomatic for over 2 years. Coronary artery anomalies are found in 1% of the population, RCA is the most commonly involved. Best approach would be to observe the patients, as most of them do not develop any symptoms.     

91例冠心病患者的冠状动脉病变及侧支循环分布特点

目的：探讨冠心病患的冠状动脉病变及侧支循环分布的特点。方法：选择91例冠状动脉造影(CAG)阳性的病人，按CAG结果，分析阳性组总体及单支、双支、三支病变组的冠脉病变血管的分布、侧支循环形成的比例及二的关系。结果：(1)冠心病的冠脉病变以累及左前降支(LAD)最多，且常合并其他血管病变；其次为右冠(RCA)、左回旋支(LCX)，而对角支(Dig)及左主干(LM)累及最少；(2)侧支循环的建立与病变部位有关，其中RCA病变形成侧支循环比例最高，其次为LCX和LAD。此外，虽然随病变冠脉支数增加侧支循环建立的比例有递增趋势，但三组间比较无统计学意义。结论：(1)冠脉病变以左前降支最多见；(2)右冠病变最易形成侧支循环。     

Comparison of coronary collateral circulation in diabetic and nondiabetic patients suffering from coronary artery disease.

BACKGROUND AND HYPOTHESIS: Although it is well established that diabetes mellitus (DM) induces more severe coronary artery disease (CAD), it is not known whether it contributes to the development of coronary collateral circulation. The present study examines coronary collateral circulation in diabetic and nondiabetic patients with angiographically verified CAD. METHODS: The study group consisted of 463 diabetic patients (382 men, 81 women) with a mean age of 60.3 +/- 8.8 years, and 227 nondiabetic subjects (159 men, 68 women) with a mean age of 59.2 +/- 9 years. The extension and functional capacity of coronary collateral circulation was assessed according to the Cohen and Rentrop grading system of 0 to III. RESULTS: We found that diabetic patients had grade III collateral circulation more frequently than nondiabetic subjects (13.2 vs. 8.5%, p < 0.01). This finding was even more pronounced in diabetic men aged < 55 years compared with both nondiabetic men (20 vs. 3.4%, p < 0.001) and diabetic women (20 vs. 2.2%, p < 0.001). Grade III collateral circulation was found to develop mainly at the left anterior descending (LAD) coronary artery and the right coronary artery (RCA), where complete occlusions of coronary arteries usually occur. CONCLUSIONS: Diabetic patients with CAD develop more extensive coronary collateral circulation than nondiabetic subjects, especially men aged < 55 years. The collateral circulation mainly develops at the LAD and RCA.     

A rare coronary anatomy comprising dual (Type IV) left anterior descending arteries and an anomalous left circumflex artery from the right coronary artery

We present the case of a rare coronary anomaly in a 64-year-old male who presented with exertional angina. The right coronary artery (RCA) was dominant, giving origin proximally to an anomalous left circumflex (LCX) artery and a left anterior descending (LAD) artery which supplied the conventional mid and distal LAD territory. The left main artery (LM) arose from the left coronary sinus and branched into a large first septal and an intermediate artery. There was associated non-critical atherosclerotic disease. We report this because of the rare division of the LAD area of supply by arteries from both coronary sinuses (dual LAD) with an anomalous LCX also arising from the proximal RCA. The clinical implications are discussed.     

Relationship between regional ventricular asynergy and the anatomic lesion in coronary artery disease

The percentage of left ventricular (LV) asynergy was measured in patients with isolated narrowing or obstruction of the right coronary artery (RCA), the anterior descending branch of the left coronary artery (LAD), or a combination of these lesions.Incomplete obstruction of a vessel was not associated with important asynergy. Isolated obstruction of the LAD caused asynergy of the distal two-thirds of the anterior wall and apex of the LV and 46 per cent asynergy. Isolated obstruction of the RCA caused asynergy of the middle or basal thirds of the diaphragmatic surface and 15 per cent asynergy. Double-vessel disease produced a combination of the individual lesions, and total obstruction of both arteries caused extensive asynergy.In each patient the extent of asynergy was modified by the underlying coronary artery anatomy and the collateral circulation. Ejection fraction was related to the percentage of LV asynergy.     

体外反搏治疗冠心病前后冠状动脉造影对比

为了估计体外反搏对冠心病的治疗价值,对2例稳定型心绞痛患者(病程分别为10年和3年),在反搏前后进行冠状动脉(以下简称冠脉)造影,观察冠脉侧支循环的变化。例1于1986年5月31日造影示三支病变,狭窄程度:前降支90%,回旋支99%,右冠脉3处狭窄均为75%,伴少量侧支。经每天1h(共87h)反搏后,在同一医院于1986年9月13日进行第二次造影,前后对比三支狭窄程度无改变,但增加许多网状侧支循环。例2第一次冠脉造影示三支病变,狭窄程度前降支为75%,回旋支75%,右冠脉90%。立即进行体外反搏94h后,第二次冠脉造影,前后对比狭窄处无明显改变,侧支增加。     

右冠状动脉病变对左冠状动脉狭窄患者左心室功能的影响

目的　探讨右冠状动脉病变对左冠状动脉狭窄患者左心室功能的影响及其机制。方法　对比分析左冠状动脉狭窄患者在合并与不合并右冠状动脉病变时的左心室射血分数。结果　与相应部位单纯左冠状动脉狭窄患者相比 ,合并右冠状动脉病变患者左心室射血分数均呈不同程度地下降 ,其中在左前降支、左前降支 +左回旋支狭窄基础上合并右冠状动脉病变时左心室射血分数下降有统计学意义 (P <0 .0 5或 0 .0 1) ,左主干合并右冠状动脉狭窄患者下降幅度最大 ,但无统计学意义。结论　右冠状动脉病变可在单纯左冠状动脉狭窄的基础上使左心室收缩功能进一步恶化 ;当左冠状动脉狭窄部位为左前降支、左主干或左前降支 +左回旋支时 ,对左心室收缩功能影响更为严重     

右冠状动脉狭窄程度对左冠状动脉狭窄患者左室射血分数的影响

目的研究右冠状动脉不同程度狭窄对左冠状动脉狭窄患者左室射血分数（LVEF）的影响。方法根据左冠状动脉病变部位不同,将1 000例左冠状动脉狭窄患者分为左前降支（LAD）狭窄,左回旋支（LCX）狭窄,左主干（LM）狭窄,左前降支+左回旋支（LAD+LCX）狭窄4个系列。每个系列再根据右冠状动脉（RCA）病变程度不同分为RCA正常组（直径狭窄<50%）、RCA非闭塞组（99%>直径狭窄≥50%）和RCA闭塞组（直径狭窄≥99%）,比较分析3组间LVEF的差异。结果在LAD,LCX,LM,LAD+LCX狭窄时,与RCA正常组LVEF相比,RCA非闭塞组LVEF分别下降0.9%,0.3%,3.4%和2.8%;RCA闭塞组LVEF分别下降10.9%,3.7%,6.5%和5.2%。LAD狭窄时,RCA非闭塞组和RCA闭塞组之间LVEF有统计学差异（P<0.01）。结论右冠状动脉病变可在左冠状动脉狭窄的基础上使左室射血分数进一步下降;当左冠状动脉狭窄为闭塞性病变时,影响更为明显。     

Successful coronary intervention of chronic total occlusion of the right coronary artery by ipsilateral injection via an isolated conus artery

A conus artery is sometimes a good collateral source for the left anterior descending coronary artery and the right coronary artery (RCA). In some cases, the conus artery arises independently of the RCA from a separate orifice, which is called an isolated conus artery. The conus artery is often missed by angiography for RCA if a catheter is deeply engaged. This case report describes a percutaneous coronary intervention of chronic total occlusion of the proximal RCA with good collateral circulation from an isolated conus artery by super-selective ipsilateral injection via the artery.     

An abnormal finding in an angiogram

An 80 year old Chinese gentleman was admitted with NSTEACS characterized by anterior T wave inversion and raised Troponin T. His coronary angiogram showed stenosis of the proximal LAD. He underwent PCI to LAD lesion. The RCA was large and there was large collateral between, RCA and PA (fig ), which was not intervened. He made good recovery and has been asymptomatic for over 2 years. Coronary artery anomalies are found in 1% of the population, RCA is the most commonly involved. Best approach would be to observe the patients, as most of them do not develop any symptoms.