Aortic distensibility decreases during exercise in normal volunteers

Abstract

Methods 24 healthy volunteers (17 males, mean age 35) underwent magnetic resonance imaging in the supine and prone position using a 1.5 T CMR system (Siemens) at rest. Imaging was then repeated immediately after 2-6 mins of prone lower limb exercise, and again after 4 minutes of recovery. Aortic cross-sectional area was measured at the ascending aorta and proximal desending aorta (at the level of the bifurcation of the pulmonary artery) and at the descending abdominal aorta (12-14 cm below this plane) throughout the cardiac cycle. BP was measured simultaneously. Aortic distensibility was defined as (maximum aortic area minimum aortic area/minimum aortic area)/ pulse pressure. Two-sided, paired t-tests for preand postexercise distensibility were undertaken using SPSS, and data presented as means with standard deviations.