Protective role of collaterals in patients with coronary artery occlusion

We reviewed the clinical, hemodynamic and angiographic data of 105 patients with right coronary artery occlusion and of 82 patients with left anterior descending coronary artery occlusion, subdivided into 3 groups by the presence and quality of collaterals to the occluded coronary (absent, poor or good collaterals). We found that patients with right coronary artery occlusion and good collaterals had a lower frequency of diaphragmatic myocardial infarction (60%) than patients with absent collaterals (100%) (P < 0.01). In addition, in patients with old diaphragmatic myocardial infarction, both poor and good collaterals were associated with a lower frequency of severe asynergy of the diaphragmatic left ventricular segments at left ventriculography (54% and 14%, respectively), compared to patients with no collaterals to the right coronary artery (92%, P < 0.02 vs. poor collaterals, P < 0.001 vs. good collaterals). In contrast, in patients with left anterior descending coronary artery occlusion, the presence of either poor or good collaterals to the left anterior descending coronary artery was not associated with a lower frequency of old anterior myocardial infarction, or, in patients with old anterior myocardial infarction, with a less severe asynergy of the anterior left ventricular segments.Our results suggest that collaterals are effective in protecting the diaphragmatic left ventricular wall in patients with right coronary artery occlusion, but not the anterior left ventricular wall in patients with left anterior descending coronary artery occlusion.     

Anterior ST-segment elevation with right coronary artery occlusion: a unique case of isolated right ventricular infarction

Anterior ST-segment elevation is the classic electrocardiographic feature of anterior left ventricular myocardial infarction due to occlusion of the left anterior descending artery. However, anterior ST-segment elevation has also been described in patients with right coronary artery occlusion, in whom concomitant inferior ST-segment elevation is also typically present. A case of proximal right coronary artery occlusion resulting in anterior ST-segment elevation without inferior ST-segment elevation is reported in this article. It is hypothesized that the inferior left ventricular wall was protected by left-to-right collaterals, as seen on coronary angiography, with resultant isolated right ventricular infarction upon proximal right coronary artery occlusion. In conclusion, this report presents a unique case of an isolated right ventricular infarction resulting in an electrocardiographic pattern mimicking anterior-wall left ventricular infarction.     

The power of collateral circulation: a case of asymptomatic chronic total occlusion of the left main coronary artery

Total occlusion of the left main coronary artery predominantly presents with recurrent angina or myocardial infarction. Long-term survival and myocardial function depends on the well-developed right to left collaterals. We report a case of a 46-year-old man who was referred because of incidental finding of low ejection fraction during work-up for syncope 5 months prior. The patient denied any recurrence or any other symptom after that episode and claimed an unchanged exercise capacity. He had hypertension, hyperlipidemia, and history of 15-pack/year smoking. Except for class II morbid obesity, he had completely normal vital signs, physical examination, and lab tests on admission. The echocardiogram was suggestive of previous anterior wall myocardial infarction and demonstrated a low left ventricle ejection fraction with diffuse hypokinesis of the left ventricle. The patient underwent cardiac catheterization, which revealed total occlusion of the left main coronary artery, dominant right coronary artery with a 95% stenosis in the proximal segment, and collaterals from the right to the left coronary arteries. The patient was immediately referred for coronary artery bypass surgery. This case demonstrates the power of collateral circulation in protecting the patient from symptoms and death despite total occlusion of the left main coronary artery and severe stenosis of the proximal right coronary artery.     

A case of acute myocardial infarction due to simultaneous occlusion of the right coronary artery and left anterior descending coronary artery

We reported a rare case of a 53-year-old man who experienced acute myocardial infarction due to simultaneous occlusion in the right coronary artery and the left anterior descending coronary artery. He also experienced thromboembolisms on several occasions. So anticoagulant therapy is necessary for patients with exceedingly poor LV function.     

Coronary collateral circulation

The occurrence and influence of coronary collateral circulation and obstruction of the supplying coronary arteries on left ventricular contractility, prevalence of myocardial infarction, and bicycle exercise ergometer test were studied in a random sample of 286 patients with angiographically documented coronary artery disease. Collaterals appeared increasingly in all three main coronary arteries with grade of obstruction. The highest prevalence of collaterals occurred in stenosis of the right coronary artery (60%), followed by the left descending artery (45%); they occurred least in the left circumflex artery (21%) (p less than 0.001). The frequency of intra-arterial collateral circulation was 42%, 11%, and 12%, respectively (p less than 0.001). With total occlusion of the left anterior descending coronary artery, 22% of the patients had normokinetic anterior and apical left ventricular wall when collaterals were present. More often, the inferior wall showed normal contraction with total occlusion of the right coronary artery and collaterals [52%, p less than 0.001 compared with left anterior descending artery (LAD)]. The prevalence of inferior myocardial infarction was 39%, with collateral circulation to the totally occluded right coronary artery. The respective prevalence of anterior infarction and total occlusion in the left coronary artery was 58% (p less than 0.02). The presence or absence of collaterals had no obvious influence on ST-segment response during bicycle ergometer test. In triple-vessel disease, peak work capacity was better when collaterals to LAD were not jeopardized (427 kpm) than when jeopardized (321 kpm) (p less than 0.02).     

Intravascular echocardiography (ICUS) diagnosis of post-traumatic coronary dissection involving the common trunk. A case report and review of the literature]

A case is reported in which a 31-years-old man experienced coronary artery dissection with an acute anterior myocardial infarction following blunt chest trauma in a car accident. Due to ECG signs of acute myocardial infarction a coronary angiography was performed showing an abrupt occlusion of the mid part of the left anterior descending artery and a linear filling defect in the proximal portion of the vessel. Additional detailed intravascular ultrasound was performed, revealing a long intimal tear involving the left anterior descending artery and the left main. The patient underwent immediate coronary artery bypass surgery. Two vein grafts were made from aorta to the left anterior descending artery and the circumflex artery, respectively. Repeat angiography was performed early after the operation; dissection of the left main and the left anterior descending artery was still visible and the grafts to the left descending artery and the circumflex were patent.     

Evaluation of electrocardiographic algorithms in the assessment of the infarct-related artery in acute myocardial infarction

OBJECTIVES: In acute myocardial infarction, it is of great value to identify the infarct-related artery and the site of occlusion in a coronary artery (proximal versus distal).This study assessed the diagnostic value of two previously published electrocardiographic algorithms to identify the infarct-related artery and the site of occlusion in anterior and inferior acute myocardial infarction. METHODS AND RESULTS: We studied retrospectively a group of 88 patients with a first myocardial infarction. We determined the infarct-related artery using the electrocardiographic algorithms on the electrocardiogram at the time of admission and compared these results with the angiographically determined infarct-related artery. The best electrocardiographic algorithm could determine the infarct-related artery in an inferior myocardial infarction as the left circumflex coronary artery and as the proximal and distal right coronary artery with a sensitivity of 63%, 67% and 80%, respectively, and a specificity of 100%, 82% and 69%, respectively. One algorithm was unable to diagnose a left circumflex coronary artery occlusion. In an anterior myocardial infarction the best electrocardiographic algorithm could determine the infarct-related artery as the proximal and distal left anterior descending coronary artery with a sensitivity of 85% and 80%, respectively, and with a specificity of 77% and 82%, respectively. CONCLUSION: In acute myocardial infarction the use of electrocardiographic algorithms is helpful to predict the site of occlusion and can play a crucial role in the care of patients.     

Exercise-induced plaque rupture producing myocardial infarction

A 37-year-old man with unstable angina was subjected to coronary angiography. The right coronary artery showed a minor proximal stenosis, but there were no obstructive lesions in the left coronary artery. He developed a small inferior infarction. He was asymptomatic until re-admission 1 month later, 1 hour after a normal exercise test, with anterior myocardial infarction. Acute coronary angiography showed sub-total occlusion of the left anterior descending artery. The occlusion was partially relieved after intracoronary injection of nitroglycerin. Intracoronary infusion of streptokinase had no further effect. Balloon angioplasty was then successfully performed. It is suggested that stress-induced plaque rupture with intimal hemorrhage and secondary spasm resulted in sub-total occlusion of the left anterior descending artery producing the second myocardial infarction.     

Thrombolysis of acute total occlusion of the left main coronary artery and long-term survival

A young woman was admitted with acute anterior myocardial infarction. Emergency coronary angiography showed a total occlusion of the LMCA. Selective infusion of streptokinase recanalized the left main coronary artery (LMCA), the circumflex artery, and the first diagonal, but not the entire left anterior descending artery (LAD). The right coronary artery was dominant and normal. The left-sided congestive heart failure was severe; treatment improved the heart failure and the patient was discharged on Day 25. She was readmitted for control 28 months later: she was only moderately disabled and coronary angiography showed the same occlusion of the LAD; result on ejection fraction (right anterior oblique view 30 degrees) was not significant, but circumflex artery recanalization probably preserved lateral wall contraction. The presence of a normal dominant right coronary artery seems to be a very important factor in contributing to initial survival.     

Quantitation of variations in regional left ventricular function in isolated disease of the left anterior descending coronary artery

The pattern of contraction of the endocardial wall of the left ventricle in the right anterior oblique cineangiogram was studied by using a frame by frame radial technique and a fixed centroid without correction for rotation and translation motion during the cardiac cycle. Spatial defects of contraction were quantitated by measuring the shortening fraction of each radius and temporospatial defects by using a time-contraction integral. Twelve normal subjects were used as a basis for comparison. Thirty-two patients with isolated disease of the left anterior descending (LAD) coronary artery were divided into seven arbitrary clinicopathological subsets. Five subsets showed significant quantitative differences in contraction from the normal subjects but there was no significant difference between the subsets. They had a typical defect of contraction in the distal two thirds of the anterior wall, the apex and distal quarter of the inferior wall of the left ventricle. The subsets included: (1) patients who had undergone an anterior myocardial infarction and who had total occlusion of the LAD artery and a large anterior infarction on ECG; (2) patients with a previous classical myocardial infarction but with only 95% residual narrowing of the LAD; (3) patients with an anterior infarction and total occlusion of the LAD with return of the R waves in the anterior precordial leads; (4) patients with anterior infarction, LAD obstruction and left bundle branch block and (5) patients with anterior infarction but with early successful reperfusion with intracoronary streptokinase. Two other subsets, (1) patients with total obstruction of the LAD without a clinical myocardial infarction or (2) subtotal occlusion of the LAD without infarction, had mild left ventricular dysfunction at rest and did not differ significantly from normal.     

Anterior ST-segment deviation during inferior myocardial infarction: arteriographic correlations during the acute phase

Electrocardiographic changes in the anterior wall lead in inferior myocardial infarction were studied in coronary angiographic findings in the acute stage. The subjects were 40 patients with initial inferior myocardial infarction due to right coronary lesions. ST segments were elevated in 7 patients, remained unchanged in 11 and were depressed in 22. Two patients predominantly perfused in the left coronary artery showed ST elevation. All seven patients who showed elevation of the ST segments had occlusion of the ventricular branch proximal to right. However, another 15 (68%) of the patients with occlusion of the same lesion did not show elevation of any ST segment. There was no difference in left ventricular ejection fraction between the groups. The regional ejection fraction at the left ventricular inferior wall was significantly (p less than 0.01) higher in the ST elevated group than in the ST depressed group. Elevation of the ST segments in the anterior wall lead was observed only when the right ventricular free wall sustained injury, and no elevation of any ST segment was observed when the range of injury in the inferoposterior wall was wide, even in the presence of injury to the right ventricular free wall.     

Myocardial infarction due to congenital coronary arterial aneurysm (with successful saphenous vein bypass graft)

A 32 year old white woman with congenital saccular aneurysm of the left coronary artery is described. The patient presented with acute myocardial infarction. Calcification in the wall of the aneurysm could be seen on the chest roentgenogram. Selective coronary cineangiograms demonstrated a calcified aneurysm at the origin of the left anterior descending coronary artery which caused complete occlusion of this vessel and partial compression of the circumflex coronary artery. Left ventricular cineangiograms disclosed an akinetic area in the anterior wall and mild mitral regurgitation. The patient successfully underwent saphenous vein bypass graft from aorta to left anterior descending coronary artery. Postoperative studies demonstrated patency of the vein graft with excellent antegrade filling of a normal vessel and nonfunctioning of the previously demonstrated collateral channels.     

Early occlusion and late stricture of normal coronary arteries following blunt chest trauma

A 27-year-old man had inferior myocardial infarction following superficial chest trauma. Coronary arteriography documented an isolated total occlusion of the right coronary artery, probably caused by localized extra-coronary compression, and no other evidence of intrinsic coronary disease. The left anterior descending artery later developed a localized proximal stenosis, most likely due to mural thrombus, which progressed rapidly to cause anterior myocardial infarction despite coronary artery surgery. The etiology of this lesion is discussed and support given to the "encrustation" hypothesis of human atherosclerosis. Exercise thallium scintigraphy proved helpful in the management of this case.     

Ischémie subaiguë bilatérale des membres inférieurs,une présentation rare de périartérite noueuse

Study's goalAs there are no guidelines. This short report shows our experience in management of sub-acute limb ischemia with polyarteritisnodosa.IntroductionAcute limb ischemia is rarely seen in periarteritisnodosa.Case ReportHere, we present a case with peripheral vascular disease of both lower limbs leading to foot claudication and then a subacute limb ischemia with large necrotic plaques on the lower limb. Angioscan showed occlusion of both superficial femoral arteries. Angiographic imaging showed abnormalities in medium-sized arteries. Pathological study of biopsy from the artery, vein, nerve and skin of the amputated leg confirm the diagnosis of periarteritisnodosa. She benefited from femoral popliteal bypass in both legs, anticoagulant drug and steroids. The non-amelioration of the left leg led to his amputation. The right leg was healed.     

Clinical significance of inferior ST elevation during acute anterior myocardial infarction.

OBJECTIVES--To clarify the genesis and clinical significance of inferior ST elevation during acute anterior myocardial infarction. PATIENTS AND DESIGN--A total of 106 patients with first acute anterior myocardial infarction (< or = 6 h) were divided into two groups according to the presence (group A, n = 12) or absence (group B, n = 94) of ST elevation of > or = 1 mm in at least two of the inferior leads on the admission electrocardiogram. RESULTS--On admission electrocardiograms, group A had a smaller summed ST deviation in the lateral limb leads than group B. On emergency coronary arteriograms, the incidence of a wrapped left anterior descending artery was higher in group A than in group B (100% v 27%, P < 0.01). The incidence of occlusion of a left anterior descending artery distal to its first diagonal branch was higher in group A than in group B (100% v 46%, P < 0.01). Peak serum creatine kinase activity and in-hospital mortality tended to be lower in group A than in group B. Group A had better left ventricular ejection fraction and regional wall motion in the anterobasal and anterolateral regions in the chronic phase than group B. In contrast, regional wall motion in the diaphragmatic region was reduced to a greater extent in group A than in group B. CONCLUSIONS--Inferior ST elevation during acute anterior myocardial infarction appears only in the presence of a combination of a lesser degree of transmural ischaemic myocardium in the anterobasal and anterolateral wall together with transmural ischaemic myocardium in the inferior wall; in all cases there was occlusion of a wrapped left anterior descending artery distal to its first diagonal branch. Patients with such an ST elevation appear to have a better in-hospital prognosis than those without it.     

Pure right ventricular infarction.

A 76-year-old man with chest pain was admitted to hospital where electrocardiography (ECG) showed ST-segment elevation in leads V1-4, indicative of acute anterior myocardial infarction. ST-segment elevation was also present in the right precordial leads V4R-6R. Emergency coronary angiography revealed that the left coronary artery was dominant and did not have significant stenosis. Aortography showed ostial occlusion of the right coronary artery (RCA). Left ventriculography showed normal function and right ventriculography showed a dilated right ventricle and severe hypokinesis of the right ventricular free wall. Conservative treatment was selected because the patient's symptoms soon ameliorated and his hemodynamics was stable. 99mTc-pyrophosphate and 201Tl dual single-photon emission computed tomography showed uptake of 99mTc-pyrophosphate in only the right ventricular free wall, but no uptake of 99mTc-pyrophosphate and no perfusion defect of 201Tl in the left ventricle. The peak creatine kinase (CK) and CK-MB were 1,381 IU/L and 127 IU/L, respectively. His natural course was favorable and the chest pain disappeared under medication. Two months after the onset, the ECG showed poor R progression in leads V1-4 indicating an old anterior infarction. Coronary angiography confirmed the ostial stenosis of the hypoplastic RCA. This was a case of pure right ventricular free wall infarction because of the occlusion of the ostium of the hypoplastic RCA, but not of the right ventricular branch. Because the electrocardiographic findings resemble those of an acute anterior infarction, it is important to consider pure right ventricular infarction in the differential diagnosis.     

Multiple coronary thrombosis in a patient with thrombocytosis

A 59-year-old woman was admitted with acute inferior myocardial infarction. Cardiac catheterization revealed total occlusion in the right coronary artery and thrombus-like filling defect in the left anterior descending coronary artery. With simultaneous intracoronary urokinase infusion to the right and left coronary arteries, the right coronary artery became patent and the thrombus in the left anterior descending coronary artery was released to the distal coronary artery. Thrombocytosis was disclosed by laboratory examination. The relationship between myocardial infarction and thrombocytosis is discussed.     

Noninvasive assessment of left and right ventricular filling in myocardial infarction with a two-dimensional Doppler echocardiographic method

Inflow characteristics of left and right ventricular filling were assessed in 40 patients with myocardial infarction and in 10 normal subjects by pulsed Doppler echocardiography. Patients with myocardial infarction were subdivided into four groups, focusing on the involvement of right ventricular and septal branches of the coronary arteries. Group I consisted of 11 patients with anterior infarction who showed an obstructive lesion of the proximal left anterior descending branch involving the first septal perforator with a patent right coronary artery. Group II consisted of 10 patients with inferior infarction who showed an obstructive lesion of the proximal right coronary artery involving the right ventricular branch. Group III consisted of 12 patients with both anterior and inferior infarction who showed obstructive lesions of both the proximal left anterior descending branch and the right coronary artery involving the right ventricular branch. Group IV consisted of seven patients with lateral infarction who showed an obstructive lesion of the diagonal branch or branches of the circumflex coronary artery with a patent left anterior descending branch and right coronary artery. Three measurements were performed from the transmitral and transtricuspidal inflow velocity patterns to assess the left and right ventricular diastolic behaviors. These measurements were: acceleration half-time, deceleration half-time of early diastolic rapid inflow, and the ratio of the peak velocity of early diastolic rapid inflow to that of the late diastolic inflow due to the atrial contraction. Impaired diastolic filling of the left ventricle compensated by enhanced left atrial contraction was observed in patients with myocardial infarction from groups I, II, III and IV.(ABSTRACT TRUNCATED AT 250 WORDS)