Frequency of pulmonary embolism in patients admitted with chest pain and suspicion of acute myocardial infarction but in whom this diagnosis is ruled out.

Abstract

The purpose of this study was to determine the frequency of pulmonary embolism in patients admitted with acute chest pain but without myocardial infarction (non-AMI patients). We examined 175 consecutive non-AMI patients without unstable angina pectoris within the first 48 h of admission. The patients were first examined by perfusion pulmonary scintigraphy. If the scintigraphy was abnormal, it was combined with a 81mKr ventilation scintigraphy. Perfusion scintigraphy was abnormal in 21 patients, and the subsequent combined perfusion/ventilation scintigraphy was used to identify 5 patients (2.5%) who had a high probability for pulmonary embolism, which was not clinically suspected at the time of admission. Three of these 5 patients had a decreased arterial oxygen tension upon admission, and 3 had abnormalities in their electrocardiogram. Pulmonary embolism only occurred in 2.5% of the non-AMI patients. The prognosis of untreated patients, however, it markedly worse as compared with treated patients. We, therefore, suggest that pulmonary scintigraphy be performed in non-AMI patients who have uncharacteristic electrocardiographic changes and/or a low arterial partial oxygen tension when no other abnormality has been found within 24 h of admission.