Acute occlusion of left main coronary artery without ventricular damage

Abstract

Summary:We report a patient with acute occlusion of left main coronary artery with only a small increase of cardiac enzymes but without electrocardiographic signs of acute myocardial infarction. Normal global and regional left ventricular function could be documented angiographically. Damage of myocardium was prevented by extensive collateral circulation from a large dominant right comnary artery. Key words: acute occlusion of left main coronary artery Case ReportA 42-year-old female was admitted because of sudden onset of thoracic pain. Risk factors for coronary heart disease were hypertension and elevated serum cholesterol. Admission electrocardiogram (ECG) showed 2 mm STsegment depression in precordial leads V3-V5. Maximal documented rise of creatine kinase MB (CKMB) fraction was 38 U/L (normal range up to 10 U/L). Because of the small infarct size and the minor ECG changes the patient was recommended to conservative therapy and thrombolysis was not done. Postinfarct angina and a pathologic exercise stress test required coronary angiography 10 days after admission. The ostium of the left main coronary artery was cannulated using a 8 Fr Judkins coronary catheter and revealed a short, totally occluded left main stem. Only few millimeters of the occluded left main stem were opacified by contrast material. The right coronary artery was a smooth dominant large vessel. Collateral circulation to the left anterior descending artery could be documented via septa1 collaterals from the posterior descending artery and via ventricular branches of the right coronary artery. Additional filling of the left anterior descending artery was seen by a conus artery from the proximal right coronary artery. Circumflex artery was filled antegrade from the origin of the left anterior descending artery (Figs. I , 2). No additional stenoses were visible in the remaining coronary artery system. Surprisingly, biplane left ventriculography (RAO 30" and LAO 60") showed normal left ventricular volumes and normal global ejection fraction (72%). Also, regional left ventricular function was completely normal (Figs. 3 , 4). Although no vascular filling defect of left ventricular myocardium was present, additional contrast injection in the aorta ascending was done to rule out protection of left myocardium by aberrant vessels. The patient underwent elective bypass operation and was diagnosed in good condition. DiscussionSurvival of acute total occlusion of the left main core)-nary artery is extremely rare. 1 . 3 . 9 . 1 1 The majority of these patients suffer extensive myocardial infarction followed by rapid onset of cardiogenic shock or other lethal complications. In a few cases, myocardium is protected by well-developed collaterals and patients have survivcd. However, in most such cases, extensive myocardial infarction followed by a decrease of global and regional left ventricular function is seen. A recent article summarized the literature on acute occlusion of left main coronary artery,' where only four cases were cited showing normal global b...

Electrocardiographic changes of ST-elevation myocardial infarction in patients with complete occlusion of the left main trunk without collateral circulation: Differential diagnosis and clinical considerations

“…The few patients with complete occlusion of the LMT and a NSTEMI pattern usually present with well-developed CC. [11][12][13][14][15] To our knowledge, no series describing LMT occlusion (TIMI flow = 0) with a STEMI pattern has been published in the literature. We found that the most typical ECG pattern in our small series was the one described in proximal occlusion of a long LAD, consisting of ST elevation in the precordial leads from V 2 to V 4 through V 6 and in leads I and aVL, as well as ST depression in the inferior leads 16 and often with RBBB and LAH.…”

Effect of Primary Angioplasty on Total or Subtotal Left Main Occlusion

“…From an anatomic point of view, the left ventricular myocardium is mainly supplied by the left coronary artery, and, theoretically, acute LMCA occlusion usually results in severe left ventricular dysfunction and clinical deterioration occurred within minutes, leaving no chance to take the patient to the cardiac catheterization laboratory. However, LMCA occlusion does not always lead to a fatal outcome, 2,4,15,16 and, actually, there are always some patients managed with conventional therapy who can survive several years. Thus, it is not surprising that the clinical outcomes of the patients with acute LMCA occlusion must depend on some distinguishing features that will substantially alter an otherwise unfavorable prognosis in this clinical setting.…”

“…Thus, it is not surprising that the clinical outcomes of the patients with acute LMCA occlusion must depend on some distinguishing features that will substantially alter an otherwise unfavorable prognosis in this clinical setting. Previous studies [2][3][4]16 have suggested that the presence of collateralization is crucial for the prognosis, and only patients with a dominant RCA will survive to receive a diagnosis and invasive treatment. 2 However, this observation may not convince everyone, because a statistical method has never been performed to supported this observation.…”

“…A cute left main coronary artery (LMCA) occlusion is a rare angiographic finding. 1,2 When it takes place, the prognosis is usually extremely poor unless there are substantial preexisting intercollaterals [2][3][4] and complete reperfusion is rapidly established. Pump failure or refractory ventricular dysrhythmias 3,5 are the leading causes of death in patients in this clinical condition.…”

Reciprocal Changes in 12-Lead Electrocardiography Can Predict Left Main Coronary Artery Lesion in Patients With Acute Myocardial Infarction

“…A total of 34 patients with acute LMCA occlusion have been described in 11 reports. 6,7,[11][12][13][14][15][16][17][18][19] ST segment depression in the precordial leads was reported in 12 patients. According to Sclarovsky, et al manifestation of LMCA stenosis is diffuse ST segment depression over the inferior leads and the precordial leads except V 2 and V 3 on ECG, as in this series.…”