Masao Yasuno

Importance of coronary collaterals for restoration of left ventricular function after intracoronary thrombolysis

In an evaluation of the role of coronary collaterals in the early period of acute myocardial infarction (AMI), 30 patients with acute total coronary occlusion treated with intracoronary thrombolysis 2 to 8 hours after the onset of symptoms were studied. Only 13 patients with well-developed collaterals in the early period of AMI and successful thrombolysis showed improvement of global and regional ejection fraction (EF) from the acute phase to the chronic phase (global EF from 50% to 71%, p less than 0.001; regional EF from 25.4% to 49.2%, p less than 0.001). In patients with no or less well-developed collaterals and successful thrombolysis, global and regional EF were similar to those in patients in whom thrombolysis was unsuccessful. Among the 19 patients with successful thrombolysis, there was no significant correlation between the duration of ischemia and the improvement of regional EF (r = -0.03, difference not significant). These data suggest that the extent of coronary collateral vessels in the early period of AMI is an important determinant of restoration of left ventricular function after intracoronary thrombolysis.

Effects of percutaneous transluminal coronary angioplasty: Intracoronary thrombolysis with urokinase in acute myocardial infarction

Coronary angiography and percutaneous transluminal coronary angioplasty (PTCA) were performed in 32 patients with evolving acute myocardial infarction. Of the 25 patients with complete occlusion of an infarct-related coronary artery, in 18 (72%) the occluded vessel was successfully opened by an intracoronary infusion of urokinase. With a small dose of urokinase the successful recanalization was achieved in only 25%; with a larger dose it was achieved in 94%. After PTCA, all patients received glucose-insulin-potassium solution for 76 hours. Repeat angiography 42 days later showed a patent coronary artery in 12 (group A) of 18 patients with successful PTCA. In group A, left ventricular ejection fraction increased from 51 +/- 13% to 72 +/- 10% (p less than 0.01) and regional wall shortening from 4.5 +/- 9.5% to 29 +/- 19% (p less than 0.01). In contrast, these variables did not change significantly in patients with unsuccessful PTCA or late reocclusion of an infarct-related vessel (group B). These data suggest that successful PTCA with sustained patency of an infarct-related coronary artery has a beneficial effect on the salvage of the jeopardized myocardium, and glucose-insulin-potassium therapy may enhance the beneficial effect of PTCA.

Myocardial Infarction After Acute Carbon Monoxide Poisoning: Case Report

A 28-year-old man with acute myocardial infarction after carbon monoxide poisoning is reported. He had chest pain after the exposure to carbon monoxide. The electrocardiogram, serum enzymes, and technetium-99m pyrophosphate scintigrams showed anterior myocardial infarction. The coronary angiogram, which was performed one month after the onset, showed no visible atheroscler otic lesion. As to the cause of myocardial infarction, it is assumed that carbon monoxide reduced the oxygen supply to the myocardium and might induce coro nary artery spasm with or without accompanying coronary thrombosis.

A Case of Acute Myocardial Infarction Intracoronary Thrombosis in Two Major Coronary Arteries Due to Hormone Therapy

A fifty-four-year-old woman was admitted to the hospital for a sensation of tightness in the chest of one hours duration. She had undergone surgery for breast cancer two years previously and had been taking 30 mg of tamoxifen and 1200 mg of medroxyproges terone daily after surgery. Emergency coronary angiography on admission revealed thrombi in both the right coronary artery and the left anterior descending coronary artery. Tissue-type plasminogen activator was injected into both coronary arteries, resulting in diminution of thrombus size. Repeat coronary angiography on the next day disclosed no thrombus in either artery and no significant stenosis. Electrocardiographic and laboratory data indicated myocardial infarction. These findings strongly suggest that the combination hormone therapy altered the patients blood coagulability and played an important role in the formation of the intracoronary thrombi and subsequent acute myocardial infarction.

Risk Factors for Carotid Atherosclerosis and Silent Cerebral Infarction in Patients with Coronary Heart Disease

In this study, the authors examined relations between coronary and carotid atherosclerosis and between coronary atherosclerosis and silent cerebral infarc tion. They ascertained the risk factors for carotid atherosclerosis and silent cerebral infarction complicating coronary heart disease (CHD) in 77 Japanese subjects. As coronary atherosclerosis progressed, the carotid ultrasonographic score and the brain computed tomographic score increased. Multivariate analy ses showed that the significant and independent risk factors for carotid athero sclerosis in patients with CHD were age (p < 0.01) and apolipoprotein (apo) B (p < 0.05) and the factors for silent cerebral infarction were age (p < 0.05) and hypertension (p < 0.05). Their study confirms a positive relation between coronary atherosclerosis and carotid atherosclerosis and between coronary atherosclerosis and silent ce rebral infarction in patients with CHD. Their data suggest that carotid athero sclerosis should be looked for in patients with CHD who are old and have a high value of apo B, and silent cerebral infarction should be looked for in those who are old and have hypertension, to prevent complicating symptomatic cerebral vascular disease (CVD). If severe carotid atherosclerosis or silent cerebral in farction are detected, antithrombotic medication should be given.

Angiographic and Pathologic Evidence of Hemorrhage Into the Myocardium After Coronary Reperfusion

Severe myocardial hemorrhage can occur as a potential adverse effect of reperfusion therapy in evolving myocardial infarction. This report describes a 83-year-old man, who showed angiographic evidence of extravasation of con trast medium from the reperfused right coronary artery into the inferoposterior left ventricular wall. At autopsy, severe hemorrhage was transmurally observed in the inferoposterior wall of the left ventricle. The finding of extravasation is a useful angiographic sign of the production of hemorrhage during coronary re perfusion therapy, and great attention should be focused to the existence of this sign to prevent further hemorrhage.

Takayasu's Arteritis with Collateral Circulation from the Right Coronary Artery to Intracranial Vessels— A Case Report

A forty-four-year-old woman with Takayasus arteritis and involvement of the aortic arch and its main branches complained of precordial pain on effort. Exercise electrocardiograms revealed significant ST segment depression in leads II, III, aVF, and V4-6. Coronary arteriograms demonstrated no stenosis. However, the right coronary arteriogram revealed collateral circulation arising from the sinus node artery to the bilateral vertebral arteries and the left internal carotid artery. The collateral circulation was considered to be an important route of blood flow supply to the brain and, at the same time, a cause of coro nary steal syndrome and, consequently, of angina pectoris.