Acute myocardial infarction with angiographically normal coronary arteries

The exact etiology of myocardial infarction remains unknown in a majority of the patients with normal coronary arteries. Those who smoke cigarettes and use cocaine are more prone to have this condition. The possible mechanisms underlying myocardial infarction with normal coronary arteries are hypercoagulable states, coronary embolism, an imbalance between oxygen demand and supply, nonatherosclerotic coronary diseases, coronary trauma, coronary vasospasm, and coronary thrombosis. Myocardial infarction with normal coronary arteries primarily affects younger persons and is distinctly rare in patients older than 50 years. We describe a case of acute myocardial infarction with normal coronary arteries in a 61-year-old woman who smoked cigarettes. The clinical perspectives and management of the myocardial infarction with normal coronary arteries are discussed.     

Acute myocardial infarction with angiographically normal coronary arteries.

The authors present the case of a 51-year-old woman, with no known cardiovascular risk factors, admitted with anterior acute myocardial infarction complicated by primary ventricular fibrillation, who underwent reperfusion therapy with tenecteplase. Left heart catheterization on the sixth day showed left ventricular anteroapical akinesia and normal coronary arteries. The causes of acute myocardial infarction with normal coronary arteries and its differential diagnosis are discussed.     

Characteristics and outcomes of patients with acute myocardial infarction and angiographically normal coronary arteries

This study on patients undergoing coronary angiography for acute myocardial infarction demonstrated that 2.8% of patients had angiographically normal coronary arteries and that these patients have a better prognosis than patients with angiographically verified coronary artery disease. The trend toward a higher prevalence of malignancy in this unique patient group raises the possibility of malignancy-induced hypercoagulability or inflammation as an underlying etiologic factor.     

Tissue plasminogen activator activity and inhibition in acute myocardial infarction and angiographically normal coronary arteries

Parameters of blood coagulation, blood platelet reactivity and fibrinolysis were analyzed in 18 patients with acute myocardial infarction (AMI) and angiographically normal coronary arteries. This study group was compared with a patient control group of 18 AMI patients with 1-vessel obstructive coronary artery disease. Patients were matched for sex, age and AMI date. A healthy control group consisted of 18 sex- and age-matched volunteers. Blood coagulation measurements and platelet reactivity were similar in the 3 groups, except for fibrinogen, which was significantly higher in the patient control group. Plasma activity of tissue plasminogen activator (tPA) was detectable in only 2 patients in the study group, 9 in the patient control group (p less than 0.02) and 12 in the healthy control group (p less than 0.0001). Median plasma tPA inhibitory activity was higher in the study group (10.3 IU/ml) and the patient control group (8.1 IU/ml) than in the healthy control group (2.7 IU/ml, p less than 0.0001 and p less than 0.03). Thus, reduced activity and enhanced inhibition of plasma tPA may be important factors in the origin of coronary thrombosis, especially in the absence of coronary artery disease.     

Acute myocardial infarction with normal coronary arteries. In vivo demonstration of coronary thrombosis during the acute episode

Two cases with acute myocardial infarction are presented. Both had thrombotic occlusion of the infarct-related artery. Following successful thrombolysis with streptokinase, coronary angiography was normal. These cases prove that "myocardial infarction with normal coronaries" can be associated with coronary thrombosis in the acute stage.     

Electrocardiographic characteristics of patients with inferior myocardial infarction but angiographically normal coronary arteries

Normal coronary arteries were found in 22 (5.8%) of 379 patients presented with acute inferior myocardial infarction. These patients were significantly younger, had less cardiovascular risk factors, better systolic heart function, and lower cardiac enzymes level. Electrocardiography significantly showed more (1) ratio of ST-segment elevation in II/ III ≥ 1; (2) isoelectric ST-segment in I; (3) ST-segment elevation in I; and less (4) paroxysmal atrial fibrillation; (5) ST-segment depression in I; and (6) ST-segment elevation in V4R. In conclusion, this subset of patients had clinical features suggestive of smaller infarct size compared with those suffering from atherosclerotic disease. They may have more left circumflex artery involvement and distal right coronary artery occlusion, as deduced from electrocardiography.     

Acute ST elevation myocardial infarction with angiographically normal coronary arteries: causes and outcomes

A minority of patients presenting with ST elevation myocardial infarction (STEMI) have angiographically normal coronary arteries. We aimed to assess its incidence, identify possible aetiologies and determine long-term prognosis. We retrospectively analysed 714 consecutive patients presenting with STEMI over a 10-year period (1995 to 2005), and identified 41 patients with angiographically normal coronary arteries. Mean age was 44 ± 15 years; the majority were male. Specific diagnoses were made in 13/41 (32%) patients, including peri-myocarditis (11/41) and Takotsubo cardiomyopathy (2/41). No specific diagnosis was made in the remainder and these were considered cryptogenic AMI's. At a mean follow-up of 44 ± 30 months, 1 patient with cryptogenic AMI had a non-cardiovascular death and 1 patient required pacing. In conclusion, there is a small but definite incidence of angiographically normal coronary arteries in patients presenting with STEMI. While the eventual aetiology remains uncertain in most patients, long-term outcomes appear favourable.     

冠状动脉造影正常的急性心肌梗死患者临床预后的研究

目的　通过对冠状动脉 (冠脉 )造影正常的急性心肌梗死 (MINC)患者的随访 ,探讨其临床预后 ,并分析发病危险因素。方法　 1987至 2 0 0 1年北京大学第一医院 4 0例 (A组 )首次急性心肌梗死后冠脉造影正常 (冠脉造影狭窄程度小于 2 0 % )患者。同时随访了 12 9例 (B组 )年龄、性别、梗死部位与A组相匹配的冠脉造影严重狭窄 (梗死相关血管狭窄程度 >5 0 % )的急性心肌梗死患者 ,比较分析两组患者急性期、远期预后及发病危险因素。结果　高血压史、危险因素个数、梗死后心绞痛发生率A组明显低于B组。住院期间LVEFA组明显高于B组。两组患者平均随访时间相似 (6 7± 4 0比 6 8± 34月 )。复合心血管事件发生率A组明显少于B组。结论　MINC患者急性期、远期预后明显好于MICS患者 ,冠心病危险因素明显少于后者     

Angiographic findings in the coronary arteries after thrombolysis in acute myocardial infarction.

The angiographic appearance of the coronary arteries was examined in 308 patients with acute myocardial infarction (AMI) who received high-dose intravenous thrombolytic therapy. Coronary angiography was performed on day 7 after admission to the hospital. Patients had an average of 2.4 discrete arterial narrowings or obstructions. The narrowings were proximal and related to bifurcations. Four fifths of the culprit arteries were patient; 104 (34%) had a ruptured plaque, 22 (7%) had an ulcerated plaque, and in 190 (62%) the lesions were eccentric. Patients differed from a comparable, previously studied, control series of 302 patients with chronic stable angina pectoris who had more extensive disease. They had 5.7 narrowings/patient, also located proximally and at bifurcations, but more widely distributed in the coronary tree. Patients with AMI who are suitable for thrombolysis have a unique coronary angiographic picture. The data confirm that AMI is caused by sudden rupture of a localized atheromatous plaque that initiates an obstructive thrombotic cascade.     

Acute myocardial infarction with angiographically demonstrated normal coronary arteries in the presence of hypertrophic cardiomyopathy

A 51-year-old black woman with known, echocardiographically-documented hypertrophic cardiomyopathy was admitted to the hospital with an acute myocardial infarction diagnosed by both electrocardiographic and serum enzyme changes. Six weeks following discharge, the patient underwent left-sided heart catheterization, left ventriculography, and coronary arteriography, and she was found to have entirely normal coronary arteries. There are possible pathogenetic mechanisms of myocardial infarction in the presence of normal coronary arteries in patients with hypertrophic cardiomyopathy, and it is also possibly significant that myocardial infarction is seen in patients with hypertropic cardiomyopathy.