Clinical and hemodynamic aspects of single vessel coronary artery disease

Two-hundred consecutive patients with arteriosclerotic heart disease underwent complete clinical and hemodynamic evaluation. Fifty-two patients (26 per cent) had significant single vessel coronary artery disease and were compared to 148 patients with more extensive coronary artery disease and to a group of 14 normal patients. The single vessel disease group, when compared to the diffuse disease group, was characterized by a shorter duration of angina pectoris, lower frequency of a history of congestive heart failure or cardiomegaly, and a lower frequency of electrocardiographic (ECG) evidence of a transmural myocardial infarction. The combination of angina pectoris for three or more years with cardiomegaly was the only factor which completely separated the two coronary disease groups. Cardiomegaly, when present in single vessel involvement, was always due to left anterior descending (LAD) disease, together with an anterior infarction on ECG and left ventricular asynergy. The single vessel disease group included 32 patients with LAD disease, 17 with RCA, and 3 with circumflex artery involvement. Resting hemodynamics in these 52 patients (other than a higher left ventricular end-diastolic pressure and wall stress) were not significantly different from hemodynamics in a normal group. Patients with diffuse disease were characterized by many hemodynamic alterations and by left ventricular (LV) asynergy, when compared to the single vessel disease or normal groups. The diffuse disease group had a lower ejection fraction (EF) and an increased frequency of LV asynergy and coronary collateral circulation than did the LAD group. In the single vessel disease group LV asynergy did not correlate with the ECG. LV synergy, however, was not found in any patient in the LAD group with abnormal Q waves on ECG. The single vessel disease group included only five patients with increased end-diastolic volume (EDV) and all had LAD involvement, increased LV end-diastolic pressure, and decreased EF. The remaining 47 patients with normal LV-EDV revealed that the LAD group had abnormal pressure-volume relationships, indicating a decreased compliance of the left ventricle.     

Left anterior descending coronary artery obstruction. Clinical, electrocardiographic, and angiographic correlates.

Seventy-six patients with severe (greater than 80%) occlusive left anterior descending coronary artery disease by coronary angiography were examined for the electrocardiographic characteristics of this disease in the presence (group A 59 patients) or the absence (group B 17 patients) of anterior wall asynergy (akinesis or dyskinesis). The incidence of clinically documented anterior myocardial infarction in these two groups of patients was examined. The collateral circulation to the left anterior descending coronary artery was also examined in the groups of patients with and without anterior wall asynergy. Thirty-eight of 59 (64%) patients with anterior wall asynergy (group A) showed electrocardiographic signs of anterior myocardial infarction, 17 per cent showed probable electrocardiographic signs of anterior myocardial infarction and 19 per cent showed no electrocardiographic signs. None of the 17 patients without anterior wall asynergy (group B) showed electrocardiographic signs of anterior myocardial infarction. In group A 74.6 per cent had documented clinical evidence of previous anterior myocardial infarction. Collateral filling of the distal left anterior descending coronary artery was seen in 71 per cent of group A and 100 per cent of group B patients. There was a significantly higher incidence (P = 0.02) of collateral filling in the patients without electrocardiographic evidence of definite anterior myocardial infarction (93% of 28 patients), than in those who showed definite electrocardiographic evidence of anterior myocardial infarction (66% of 38 patients).it is concluded that severe occlusive left anterior descending coronary artery disease with anterior wall myocardial asynergy is usually associated with electrocardiographic signs of anterior myocardial infarction, whereas equally severe left anterior descending coronary artery disease without anterior wall asynergy is rarely associated with electrocardiographic abnormalities of anterior myocardial infarction. Severe left anterior descending coronary artery obstruction without electrocardiographic and angiographic evidence of anterior myocardial infarction is usually associated with collateral circulation to the left anterior descending coronary artery and collateral circulation to the left anterior descending coronary artery is present less frequently when obstruction is associated with anterior myocardial infarction.     

Left anterior descending coronary artery obstruction. Clinical, electrocardiographic, and angiographic correlates.

Seventy-six patients with severe (greater than 80%) occlusive left anterior descending coronary artery disease by coronary angiography were examined for the electrocardiographic characteristics of this disease in the presence (group A 59 patients) or the absence (group B 17 patients) of anterior wall asynergy (akinesis or dyskinesis). The incidence of clinically documented anterior myocardial infarction in these two groups of patients was examined. The collateral circulation to the left anterior descending coronary artery was also examined in the groups of patients with and without anterior wall asynergy. Thirty-eight of 59 (64%) patients with anterior wall asynergy (group A) showed electrocardiographic signs of anterior myocardial infarction, 17 per cent showed probable electrocardiographic signs of anterior myocardial infarction and 19 per cent showed no electrocardiographic signs. None of the 17 patients without anterior wall asynergy (group B) showed electrocardiographic signs of anterior myocardial infarction. In group A 74.6 per cent had documented clinical evidence of previous anterior myocardial infarction. Collateral filling of the distal left anterior descending coronary artery was seen in 71 per cent of group A and 100 per cent of group B patients. There was a significantly higher incidence (P = 0.02) of collateral filling in the patients without electrocardiographic evidence of definite anterior myocardial infarction (93% of 28 patients), than in those who showed definite electrocardiographic evidence of anterior myocardial infarction (66% of 38 patients).it is concluded that severe occlusive left anterior descending coronary artery disease with anterior wall myocardial asynergy is usually associated with electrocardiographic signs of anterior myocardial infarction, whereas equally severe left anterior descending coronary artery disease without anterior wall asynergy is rarely associated with electrocardiographic abnormalities of anterior myocardial infarction. Severe left anterior descending coronary artery obstruction without electrocardiographic and angiographic evidence of anterior myocardial infarction is usually associated with collateral circulation to the left anterior descending coronary artery and collateral circulation to the left anterior descending coronary artery is present less frequently when obstruction is associated with anterior myocardial infarction.     

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.     

The effect of cardiac sympathetic nerve stimulation on the right ventricle in canine heart

The change in coronary hemodynamics during right or left cardiac sympathetic nerve stimulation was studied in anesthetized open chest dogs. No difference in the increasing rate of mean coronary blood flow between right coronary artery (RCA) and left anterior descending coronary artery (LAD) was observed. However the increasing rate of right ventricular systolic pressure X heart rate (RVSP X HR) was greater than that of left ventricle (LV). With phentolamine injection, cardiac sympathetic nerve stimulation showed similar changes as the controls. Beta-stimulation by isoproterenol infusion did not cause different effects on the increasing rate of coronary blood flow between RCA and LAD. These results showed that cardiac sympathetic nerve stimulation increased the double product of the right ventricle (RV) more than that of the LV and the increase was not affected by phentolamine. Moreover, cardiac sympathetic nerve stimulation, either the right or the left, caused the greater effects on the RV compared to the LV mainly through beta-adrenoceptors, and that the response of the RV to increase in oxygen demand was possibly, in part, different from that of the LV.     

The possibility of non-invasive identification of occluded coronary artery in acute myocardial infarction. A comparison of ECG and echocardiography with coronary arteriography or autopsy

In 73 patients with acute occlusion of single coronary artery, the authors assessed the possibilities of ECG and echocardiography in determining non-invasively which of the 3 main arteries had been occluded. The sensitivity of ECG for the individual arteries and particular ECG signs ranged between 30-98%, the specificity was between 86-100%. While it was always possible to determine occlusion of the left anterior descending coronary artery (LAD), in several cases it was difficult to distinguish between occlusion of the left circumflex (LCX) and the right coronary artery (RCA). The LCX occlusion is a frequent source of error in interpreting electrocardiograms of patients with fresh myocardial infarction. The sensitivity of echocardiography in identifying the occluded coronary artery ranged between 77-100%, specificity 97-100%. The following ECG and echocardiographic signs of coronary occlusion were determined. The LAD occlusion is indicated by ECG changes in V1-4, and anteroseptal and apica asynergy on echocardiography. LCX occlusion: increased R wave amplitude in V1, and lateral and posterior wall asynergy. The RCA occlusion: ECG changes in II, III, aVF, asynergy of the posterior wall and part of the septum and right ventricle. These combined signs make possible the identification the occluded coronary artery in 95% of patients with myocardial infarction.     

Myocardial bridging of the left anterior descending coronary artery and right coronary artery in a patient with mitral valve stenosis

Myocardial bridging is defined as the intramural course of a major epicardial coronary artery, and is mostly confined to the left ventricle and the left anterior descending coronary artery (LAD). Although it is considered to be a benign anomaly, it can lead to such complications as acute myocardial infarction, ventricular tachycardia, syncope, atrioventricular block and sudden cardiac death. Isolated myocardial bridging of the right coronary artery (RCA) and left circumflex artery have been reported in the literature In our case, myocardial bridging was observed in both the LAD and the RCA in a patient with mitral valve stenosis.     

冠心病伴束支传导阻滞患者冠状动脉病变特点研究

目的 :探讨冠心病伴束支传导阻滞患者冠状动脉血管病变特点。方法 :回顾性分析冠心病伴束支传导阻滞患者 (束支阻滞组 ,39例 )及无束支阻滞的冠心病患者 (对照组 ,35 1例 )心电图束支阻滞有无与冠状动脉病变的对应关系。结果 :与对照组比较 ,束支阻滞组左主干、左回旋支 (LCX)及三支血管 [左前降支 (LAD)、LCX、右冠状动脉 (RCA)同时存在病变 ]发生病变比率增加 (P <0 .0 1,P <0 .0 5 ,P <0 .0 5 )。右束支传导阻滞(RBBB)者LAD及RCA发病率高 ,RBBB并发左前分支阻滞 (LAFB)者三支血管病变发生率增高 ,左束支传导阻滞 (LBBB)者LAD、LCX病变发生率高 ,LAFB者LAD病变发生率高 ,房室传导阻滞伴束支阻滞患者多为三支血管病变。结论 :冠心病伴束支阻滞预示冠状动脉病变广泛而严重 ,LBBB提示冠状动脉血管病变以左冠状动脉为主 ,RBBB提示冠状动脉血管病变多累及RCA及LAD ,如存在 2种以上阻滞 ,特别是并发有左前分支或房室阻滞时 ,多提示存在三支血管病变及左主干病变     

Predictive value of electrocardiographic patterns in localizing left ventricular asynergy in coronary artery disease.

Transmural myocardial infarction by ECG (ECG-MI) was correlated with left ventricular asynergy by biplane left cineventriculography in 200 patients with coronary artery disease. The ability of individual ECG-MI patterns to predict and correctly localize asynergy was: anterior--98 per cent (43 of 44), inferior--82 per cent (36 of 44), true posterior--73 per cent (11 of 15). Of various combinations of criteria for true posterior ECG-MI, the pattern of an R wave and upright T wave in Lead V1 was most predictive of posterior asynergy--80 per cent (8 of 10). The LAO projection demonstrated a wall motion abnormality not appreciated in the RAO in 8 per cent (10 of 122) of cases of inferoposterior asynergy and enhanced assessment of asynergy in 30 per cent (36 of 122) of cases. It is concluded that: (1) ECG-MI has a high predictive accuracy for left ventricular asynergy, (2) an R-wave and upright T wave in Lead V1 is the best ECG predictor of posterior asynergy, and (3) the LAO projection makes an important contribution to the assessment of regional asynergy in coronary artery dieseas.     

Single coronary artery Left (SCA L)-Right coronary artery arising from mid-left anterior descending coronary artery: New variant of Lipton classification (SCA L-II) diagnosed by computed tomographic angiography

Isolated single coronary artery (SCA) is a rare anomaly. Current classification of left and right is further classified based on the course of the anomalous vessel. We report two SCA L cases where right coronary artery (RCA) arose from mid-left anterior descending coronary artery (LAD). Our observation is a variation from the current Lipton classification SCA L Type II where RCA arose from left coronary artery before the LAD, in our cases the RCA arose from mid LAD after the first septal perforator. We believe that this variant should be described as SCA L Type II variant 2 (V2) while the original Lipton classification should be described as SCA L Type II variant 1 (V1).     

Asymmetric distribution of left ventricular asynergy in coronary artery disease and its relation to coronary stenoses

In 100 patients with coronary artery disease (CAD), the prevalence and severity of asynergy was determined for 9 left ventricular (LV) segments by both radionuclide and contrast angiography. The anterior, septal and lateral LV walls had significantly more prevalent and more severe asynergy in the medial segments than in the basal segments. In contrast, the inferior LV wall exhibited equally severe asynergy in both the medial and basal segments. In general, asynergy was most severe in the apical, medial septal, medial inferior and basal inferior LV segments. This asymmetric distribution of LV asynergy could not be explained by the distribution of occlusions or significant stenoses in the arterial tree, which were relatively uniformly distributed among the left anterior descending (32%), left circumflex (29%) and right (26%) coronary arteries. It is postulated instead that the asymmetric distribution of LV asynergy results from asymmetry of the coronary arterial tree supplying the left ventricle and that the prevalence of asynergy in an LV segment is directly related to its vascular distance from the coronary ostia. Unlike the relatively direct supply of the left anterior descending and circumflex arteries to the basal segments of the anterior, septal and lateral LV walls, the arterial supply to the basal inferior wall begins only after the right or dominant circumflex artery has traversed the length of the atrioventricular groove, significantly increasing its susceptibility to the pressure attenuation and occlusive jeopardy of more proximal stenoses.     

Anomalous left anterior descending, absent circumflex and unusual dominant course of right coronary artery: a case report--R1

A 40-years-old female presented with atypical chest pain. Selective coronary angiography revealed separate osteal origin of anomalous left anterior descending (LAD) and normal origin of right coronary artery (RCA) from right anterior coronary sinus. LAD had a septal course. Left circumflex (LCx) was absent. RCA, a dominant vessel, continued beyond the crux, along the entire length of atrioventricular groove as circumflex artery. There was no myocardial ischemia on stress thallium. As per our knowledge, this type of combination of anatomical variation of coronary circulation has not been described in the literature.     

Combination therapy for adult coronary artery aneurysm with off-pump coronary artery bypass grafting and vein graft-coated stent

We report on a 51-year-old Japanese female with bilateral coronary artery aneurysms. Severe calcified aneurysms were detected in the proximal right coronary artery (RCA) and left anterior descending branch (LAD). The RCA was totally occluded and supplied by the blood flow via septal branches of the LAD. A two-stage management plan, including an off-pump coronary artery bypass grafting for the RCA with a right gastroepiploic artery and catheter angioplasty with an autologous vein graft-coated stent for the LAD, was successfully completed. Prophylactic treatments for coronary artery aneurysm are still controversial, therefore, minimal invasive procedures should be favored to prevent acute cardiac shock or sudden death related to aneurysmal obstruction.     

Relationship between ventricular gradient and the impairment of wall motion of the left ventricle in coronary artery disease

Fifty patients with or without coronary artery disease were studied. Twelve of them showed no coronary artery obstruction, while 38 demonstrated obstruction of the left anterior descending artery (LAD). Of the latter 38, 16 had obstruction at LAD alone, 6 at LAD and right coronary artery (RCA), 8 at LAD and left circumflex artery (LCx) and 8 at LAD, RCA and LCx. Vectorcardiography, selective coronary cineangiography and left ventricular cineangiography were undertaken in all subjects. The vectorcardiogram (VCG) was recorded on a magnetic tape and QRS area vector (Aqrs), T area vector (At) and ventricular gradient (G) were calculated by micro-computer. From left ventriculogram (LVG) "score" was computed to express the grade of impairment of the wall motion. Correlations between various vector-cardiographic parameters and this score were examined. The score correlated significantly (p less than 0.001) with azimuth of Aqrs (r = -0.545), azimuth of At (r = 0.661), magnitude of G (r = -0.705), azimuth of G (r = 0.533), G/Aqrs (r = -0.645), spatial angles between Aqrs and At (r = 0.591) and between max R and max T (r = 0.595) and X component of G (r = -0.758). These results suggested the usefulness of ventricular gradient to grasp the grade of coronary artery disease.     

Correspondence between left ventricular 17 myocardial segments and coronary arteries.

AIMS: The last guidelines recommend a standardized 17-segment model for tomographic imaging of the left ventricle. The aim of this study is to analyse the correspondence of the 17 left ventricular segments with each coronary artery by myocardial perfusion SPECT studies. METHODS AND RESULTS: Fifty patients selected for percutaneous revascularization of one coronary artery [24 left anterior descending (LAD), 15 right coronary artery (RCA), and 11 left circumflex (LCX)] were included. The (99m)Tc-labelled compound was injected immediately after the inflation of the balloon during percutaneous coronary angioplasty. At least 90 s of complete occlusion time was required. Maximal contour of regions of hypoperfusion corresponding to each coronary artery occlusion were delineated over the polar map of 17 segments. Nine segments corresponded to only one coronary artery: eight to LAD (basal anterior, basal anteroseptal, mid-anterior, mid-anteroseptal, apical anterior, apical septal, apical lateral, and apex) and one to LCX (basal anterolateral). Basal inferoseptal, mid-inferoseptal, and apical inferior segments could correspond to LAD or RCA. Basal inferior, basal inferolateral, mid-inferior, and mid-inferolateral segments could correspond to RCA or LCX, whereas the mid-anterolateral segment could correspond to LAD or LCX. CONCLUSION: The most specific segments (anterior, anteroseptal, and all apical segments except the infero-apical) correspond to LAD but no segment can be exclusively attributed to the RCA. Inferoseptal segments can be attributed to LAD or RCA, inferior and inferolateral segments to RCA or LCX, and mid-anterolateral segment to LAD or LCX.     

Coronary Angioscopy Revealing Ruptured Plaque and Thrombus Causing Acute Anterior Myocardial Infarction With a Subsequent Acute Inferior Myocardial Infarction — A Case Report

We report a unique case that suggests that a thrombotic coronary occlusion was caused by local plaque rupture in the left anterior descending coronary artery (LAD), with subsequent thrombotic occlusion in the right coronary artery (RCA), and presented with simultaneous double coronary artery occlusions. ST-segment elevations in the precordial leads and cardiac tamponade were observed first, followed by ST-segment elevations in the inferior leads. Emergency coronary intervention for the RCA lesion resulted in further ST-segment elevation, suggesting an acute inferior infarction. A left ventricular rupture was found in the anterolateral wall, consistent with acute anterior infarction. Angioscopy one month later revealed the presence of ruptured plaque with thrombus, in both the LAD and the RCA. Yuji Okuyama and Masaya Usami, contributed equally to this report     

Reappraisal of the functional significance of the coronary collateral circulation.

A review of data in 465 patients with complete obstruction of either the left anterior descending or right coronary artery was undertaken to evaluate the functional role of the collateral circulation. Complete obstruction of a dominant right coronary artery was observed in 288 patients, 83 percent with distal filling and visualization of the posterior descending artery by way of collateral vessels. Complete obstruction of the left anterior descending artery was noted in 177 patients, 71 percent with filling and visualization distal to the obstruction by way of collateral vessels. Among patients with obstruction of the left anterior descending artery, there was a significantly greater frequency of congestive heart failure and cardiomegaly in those without collateral vessels than in those with collateral vessels. The former also had a significantly greater frequency of both electrocardiographic evidence of an anterior wall myocardial infarction and angiographic findings of anterior wall asynergy. The frequency of inferior myocardial infarction and inferior wall asynergy was not influenced by the presence of collateral vessels. These observations indicate that the collateral circulation plays a significant protective role in the presence of obstruction of the left anterior descending artery, which is not apparent with obstruction of the right coronary artery.     

Intercoronary connection and apical left ventricular hypertrophy: case report and review of the literature.

Cardiac catheterization in a 55-year-old man, presenting with chronic chest pain and new T wave inversion, showed apical left ventricular (LV) hypertrophy and a large intercoronary connection between the posterior descending artery (PDA) and left anterior descending (LAD). Although the LAD was normal, selective angiography of the right coronary artery (RCA) filled the LAD retrogradely. Possible mechanisms and the literature are reviewed.     

Intercoronary connection and apical left ventricular hypertrophy: Case report and review of the literature

Cardiac Catheterization in a 55-year-old man, presenting with chronic chest pain and new T wave Inversion, showed apical left ventricular (LV) hypertrophy and a large intercoronary connection between the posterior descending artery (PDA) and left anterior descending (LAD). Although the LAD was normal, selective angiography of the right coronary artery (RCA) filled the LAD retrogradely. Possible mechanisms and the literature are reviewed.     

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.