Electrocardiography in Acute Papillary Muscle Dysfunction and Infarction: A Clinicopathologic Study

¹ Cardiovascular Laboratory, First Department of Medicine, Helsinki University Central Hospital, Helsinki, Finland

The electrocardiograms of 30 patients dying of acute myocardial infarction were analyzed for changes held relevant to recognition of papillary muscle dysfunction and infarction. The findings before and after acquisition of acute papillary muscle dysfunction in 19 patients were compared with those in 11 patients without mitral systolic murmur and related to the papillary muscle necrosis found at subsequent autopsy. While mitral systolic murmur observed at auscultation correlated significantly with extensive infarction of the papillary muscles, the electrocardiographic features, including the ST segment and TU-U complex, had no value for a selective recognition of papillary muscle dysfunction or infarction in association with acute cardiac infarction. The location but not the size of the infarct was important in determining papillary muscle insufficiency: this was more common with inferior or posterior location of the infarction. Pump failure of the left ventricle, further compromised by acute mitral regurgitant flow, was sensitively and rapidly reflected by electrocardiographic changes of left atrial overloading.