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Clinical studyNontransmural versus transmural myocardial infarction: A morphologic study☆AbstractAlthough “nontransmural” and “transmural” are morphologic terms used widely to distinguish patients with myocardial infarction, controversy exists as to their meaning regarding clinical course. For this study, a transmural infarct was defined as one that involves essentially the full thickness of the ventricular wall, and nontransmural was defined as something less. The purpose of this study was to identify true morphologic nontransmural acute (less than 21 days old) infarcts at autopsy and compare them with transmural (full-thickness) infarcts in age-matched subjects, for clinical and pathologic similarities and differences. Among the autopsy subjects, comparing 35 nontransmural and 35 transmural infarcts, there was no significant difference with regard to subjects' race or sex, chest pain, arrhythmias, heart block, or cause of death; transmural myocardial infarctions did have a higher frequency of new Q waves (30 of 35 versus six of 35, p < 0.001) and presented more often with increasing dyspnea. At autopsy, there were no significant differences regarding heart weight, location of infarcts, severity of coronary disease, age of acute infarct, or total size of infarct (18 percent of left ventricle for nontransmural versus 22 percent for transmural). There was, however, a significantly greater tendency for those with nontransmural infarct to have evidence of prior infarction at autopsy (27 of 35 versus 19 of 35, p < 0.05). Acute coronary thrombi in the distribution of the infarct were significantly more common among transmural myocardial infarcts (32 of 35 versus 18 of 35, p < 0.001). Morphologically, the nontransmural infarcts showed mural involvement ranging from 20 to 90 percent of the left ventricle, and histologically showed more contraction band (i.e., reflow) injury (57 percent with more than 30 percent contraction band necrosis) compared with transmural infarcts (32 percent with more than 30 percent contraction band necrosis) (p < 0.05). Fatal nontransmural and transmural infarcts have major clinical and pathologic similarities, but differences in number of prior infarcts, type of necrosis, and occurrence of coronary thrombi suggest differing pathophysiology. The heterogeneity of both transmural and nontransmural infarcts likely accounts for existing differences among clinical studies regarding prognosis. Although this classification system has value in the clinical setting, that at times it represents an imprecise oversimplification of infarct type should be recognized in assessing individual patients.
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Recommended articles (6)Copyright © 1983 Published by Excerpta Medica Inc. What is the most common complication of acute myocardial infarction?Ventricular free wall rupture. VFWR is the most serious complication of AMI. VFWR is usually associated with large transmural infarctions and antecedent infarct expansion. It is the most common cause of death, second only to LV failure, and it accounts for 15-30% of the deaths associated with AMI.
What is transmural myocardial infarct?A transmural myocardial infarction refers to a myocardial infarction that involves the full thickness of the myocardium. It was one believed that the development of Q waves indicated the infarction was “transmural;” however, autopsy studies failed to confirm this.
What are the consequences of myocardial infarction?An MI results in irreversible damage to the heart muscle due to a lack of oxygen. An MI may lead to impairment in diastolic and systolic function and make the patient prone to arrhythmias. In addition, an MI can lead to a number of serious complications. The key is to reperfuse the heart and restore blood flow.
What is the most common complication of myocardial infarction 1 to 3 days after?Days 1-3 are marked by “acute inflammation”, in which neutrophils infiltrate the ischemic tissue. A major complication during this period is fibrinous pericarditis, particularly in transmural ventricular wall damage (an infarct that impacted all 3 layers of the heart, the epicardium, myocardium, and endocardium).
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