Clinical diagnosis of acute aortic dissection

Despite the availability of modern imaging technology, 35% of aortic dissec tions remain undiagnosed in vivo because clinical criteria for aortic disse ction are not available to date. The present study analyzed 250 patients wi th acute chest and/or back pain, absence of an established differential dia gnosis of the pain syndrome and clinical suspicion of acute aortic dissecti on for presence of 26 clinical variables. Multivariate analysis identified an aortic pain syndrome with immediate onset and/or tearing or ripping char acter (P < 0.0001), mediastinal and/or aortic widening on chest radiography (P < 0.0002) and pulse- and/or blood pressure differentials (P < 0.0001) a s predictors of acute aortic dissection. Probability of dissection was low (7%) with absence of all three variables, intermediate (31 and 39%, respect ively) with isolated findings of "aortic pain" or "mediastinal widening", a nd high (> 83%) with either isolated "pulse- and/or blood pressure differen tials" or any combination of the three variables. This model appears useful to improve selection of patients for emergency imaging of the thoracic aor ta.