Acute dissection of the thoracic aorta

Abstract

Untreated patients with acute dissection of the thoracic aorta have a mortality of more than 1% per hour.1 Lowering the systolic blood pressure reduces the risk of extension, so every patient who might have a dissection should receive antihypertensive treatment while waiting for a definitive diagnosis by imaging. Such patients should be treated in a high dependency area, where the electrocardiogram can be monitored continuously. The systolic blood pressure should be kept below 110 mm Hg by an infusion of labetalol. This is the drug of choice as it causes a rapid reduction in blood pressure that can be controlled by altering the rate of infusion. Which diagnostic imaging technique should be used? It should provide a fast and accurate diagnosis and identify damage to the ascending aorta. Ideally, it should also show the site of the intimal tear, the distal extent of any dissection, and the presence of associated complications including tamponade, aortic regurgitation, and the involvement of the origins of the coronary arteries and aortic branches.2 Aortography has long been the standard investigation, but it has disadvantages. These include delay while the angiography team is …