Detection and Evaluation of Myocardial Infarction by Image Amplification and Cinefluoroqraphy

Abstract

Changes in the mode of contraction of the left ventricle following myocardial infarction are frequent. That fluoroscopic recognition of these changes is possible in a large number of such cases has been known for many years (4). Indeed, over the last quarter century a considerable body of literature has been developed dealing with abnormal ventricular pulsations as observed fluoroscopically (2, 8, 10) or as recorded by roentgen kymography (2, 3, 6, 11) and electrokymography (1, 10, 12). Until recently, however, the art of fluoroscopy was necessarily a black art, practiced in solitude, providing no means of documenting the dynamic changes seen on the screen. Perhaps as a consequence of this, the possibility of making an important diagnosis by so simple a method has been neglected. Because of their greater objectivity, roentgenkymography and electrokymography have received attention, but neither of these modalities has proved to be popular or widely used. Image amplification with motion-picture recording not only provides an opportunity to increase the accuracy of the primary fluoroscopic observation of ventricular pulsations, but also furnishes a method of recording these observations for detailed study and as a permanent record. Methods Fifty patients with myocardial infarction considered unequivocal electrocardio-graphically were studied by means of image-amplification fluoroscopy and cinefluorography. Some of this number were examined three weeks after their acute attack; in others the infarctions were remote. A like group without clinical or electrocardiographic evidence of myocardial infarction was studied in the same manner. The control series consisted primarily of patients with other cardiovascular disease, e.g., various valvular or degenerative lesions. Motion-picture films were obtained at 30 frames per second in straight frontal, left anterior oblique, and lateral projections. A sufficient run of film was made to permit ease of study without excessive reversals. Approximately 40 feet of film was used per patient. Attention was focused primarily along the left ventricular border in the various projections. In those instances in which there was a disagreement between the fluoroscopic observation and the findings on review of the movies, the cine studies were considered definitive. Results Paradoxical systolic expansion of a portion of the ventricular wall, flatness of a portion of the left ventricle during systole, and other types of abnormal pulsation, such as various forms of rippling movements of the left ventricular musculature, are the changes in ventricular contraction believed to be directly related to myocardial infarction. Such changes were found in 39 of our 50 patients (78 per cent). Paradoxical systolic bulging of the left ventricle, though not pathognomonic, was considered to be the most significant finding and was observed in 25 (50 per cent).