The leading cause of premature death in patients with Marfan syndrome is aortic dissection due to progressive dilation of the aorta. The abnormal fibrillin protein which results from the genetic defect that causes the disease gives rise to pathology of the aortic wall, especially of the proximal aorta. Elective repair of the aortic root has greatly improved survival of patients with Marfan syndrome. It has been recommended to replace the aortic root before the aortic diameter exceeds 50 to 55 mm.1-3 Adherence to these guidelines may lead to a substantial reduction of type A dissections in Marfan syndrome.4,5 Measurement of aortic diameters have, therefore, become a strongly recommended strategy of management (figures 1 and 2). Asymmetric dilation of the aortic root may go unnoticed as in the majority of Marfan patients the largest aortic diameter (from left to right coronary cusp) might not be detected with the standard echocardiography measurements in the long-axis view (right to noncoronary cusp).6
