Radiological detection of clinically occult cardiac failure following myocardial infarction

One-third of the patients admitted with acute myocardial infarction showed radiological evidence of pulmonary oedema. 2. In 38 per cent of these patients with pulmonary oedema, radiological evidence preceded the onset of clinical signs. The most frequent radiological signs in these patients were vascular blurring and pulmonary clouding. Loss of definition of vascular markings extending from the right hilum to the right hemidiaphragm and loss of radiolucency of the lung bases are subtle but reliable signs of early oedema. 3. Dense alveolar oedema occurred in only six patients, but in no instance was “bat's-wing” oedema present. 4. Definite interlobular septal lines were seen infrequently in this series. 5. Pleural effusions were small, transient and frequently bilateral. 6. Three previously described signs of left heart failure were found to be unreliable in this study. These signs are pulmonary venous distension, cardiac enlargement and increased diameter of the descending branch of the right pulmonary artery. In view of the frequency of pulmonary oedema as demonstrated radiologically in the absence of clinical findings, monitoring by the use of daily or twice daily chest radiographs appears justified during the patient's stay in the coronary care unit. The early radiological changes are subtle but definite and provide a useful warning of early heart failure.