摘要:

Sudden death as it relates to myocardial infarction (not necessarily acute) is discussed on the premise that most such deaths are due to a lethal electrical disturbance of the heart. The three sections of the first part deal with the rhythm of the heart, conduction in the heart, and neural control of the heart. In these sections consideration is made of those factors which stabilize cardiac electrical performance, and conversely how these factors may be deranged into electrical instability. In the second part a practical discussion is organized to interrelate the principles presented on maintenance and derangement of electrical stability of the heart; the electrical reserve of the heart, some unstabilizing factors, and clinical considerations are the subjects for this integrating synthesis. The entire review is designed to provide the clinical cardiologist a framework of reference in which logical decisions can be made in caring for the patient who has coronary disease and in whom myocardial infarction will be, is, or has been a complication. By a fuller appreciation of principles underlying maintenance of electrical stability of the heart, the risk of dying suddenly from electrical instability may be reduced.

ISSN:0009-7322    

出版商:OVID    

年代:1972

数据来源: OVID

摘要:

The coronary arteries are diffusely involved by atherosclerotic plaques in fatal acute myocardial infarction (AMI). The degree of luminal narrowing may vary but plaques are present in practically every millimeter of extramural coronary artery. Usually the lumens of at least two of the three major coronary arteries are narrowed > 75% by old plaques in patients who die suddenly (< 6 hours) from cardiac disease with or without myocardial necrosis. Coronary thrombi occur in about 10% of patients who die suddenly or in whom necrosis is limited to the left ventricular subendocardium, and in about 50% of patients with transmural myocardial necrosis. Coronary thrombi usually indicate the presence of shock or congestive heart failure or both during the development of myocardial necrosis. The infrequency of coronary thrombi in patients dying suddenly of cardiac disease and in those with transmural necrosis who never have shock or congestive heart failure suggests that the thrombi may be consequences rather than causes of AMI.Although it may not precipitate AMI, coronary thrombosis may still be the underlying cause of the atherosclerosis. The finding of fibrin deposits in old atherosclerotic plaques and the findings of atherosclerotic-type lesions (cholesterol clefts, foam cells, pultaceous debris, calcific deposits) in organized known thrombi (as in the left atrium in mitral stenosis) suggest a strong relationship between thrombosis and atherosclerosis.Coronary arterial emboli are not rare; they are located in distal portions of the coronary tree and are present in the small epicardial branches as well as in intramural coronary arteries. In contrast, coronary thrombi are located in proximal portions of major extramural vessels, are infrequent in the small epicardial branches, and are absent in intramural coronary arteries. Coronary atherosclerosis is limited to the extramural coronary arteries and spares the intramural coronary arteries.

ISSN:0009-7322    

出版商:OVID    

年代:1972

数据来源: OVID

摘要:

Investigations on left ventricular function in patients with acute myocardial infarction and the relatonship to clinical findings have shown: (1) limitations in the use and interpretation of central venous pressure; (2) pulmonary artery end-diastolic pressure accurately reflects left ventricular filling pressure in the absence of pulmonary vascular or mitral valve disease; (3) left ventricular filling pressure is frequently elevated in mild or clinical uncomplicated infarction; (4) left ventricular function frequently improves during the immediate as well as late convalescent period; (5) the hemodynamic and clinical evaluations may frequently be at variance; (6) a left ventricular gallop is usually associated with an abnormally elevated left ventricular filling pressure; (7) anterior infarctions present greater depression of left ventricular function than inferior infarctions; and (8) monitoring of hemodynamics can be useful in following the changes in left ventricular function and the response to therapy in patients with heart failure and cardiogenic shock.

ISSN:0009-7322    

出版商:OVID    

年代:1972

数据来源: OVID

ISSN:0009-7322    

出版商:OVID    

年代:1972

数据来源: OVID