Is fatigue in Marfan syndrome related to orthostatic intolerance?

Patients with Marfan syndrome have a tall stature, which could be associated with low orthostatic tolerance. Fatigue, a common complaint of these patients, is also related to orthostatic intolerance. Treatment with beta-blockers, to prevent aortic complications, could be a reinforcing factor of both. This study aimed to investigate (1) the relationship between symptoms of orthostatic tolerance and in patients with Marfan syndrome, and (2) whether termination of beta-blocker therapy improves orthostatic tolerance. Symptoms of fatigue and orthostatic complaints were assessed in 49 subjects using questionnaires (MFI-20 and Autonomic Symptoms Profile). Marfan patients have a high level of fatigue and orthostatic complaints when compared to the general population. Fatigue and orthostatic tolerance are significantly correlated. Orthostatic tolerance was assessed in 9 additional subjects by an active-standing test and head-up tilt for 5 minutes, and 24 hours blood pressure monitoring, once during beta-blocker therapy and once after ceasing beta-blockers for 2 weeks. During hemodynamic testing Marfan patients frequently showed Initial Orthostatic Hypotension and an abnormally high initial heart rate response. Ceasing beta-blockers did not affect the initial blood pressure response. Patients with Marfan syndrome are fatigued and have low orthostatic tolerance, which are significantly correlated. Patients could be educated in physical counterpressure maneuvers to increase orthostatic tolerance.