Cardiopulmonary exercise testing in Fabry disease

Fabry disease is a rare X-linked disorder that results from a deficiency in a lysosomal enzyme known as alpha-galactosidase A, with accumulation of globotriaosylceramide (Gl3). Early manifestations include angiokeratomas, acroparesthesias, and hypohidrosis and may progress to renal failure, cardiac dysfunction, and stroke. Patients exhibit decreased exercise tolerance and often complain of fatigue.

Our study evaluates the cardiopulmonary characteristics in a cohort of Fabry disease patients at rest and during exercise.

Thirty-nine patients with a diagnosis of Fabry disease underwent a health screening history and physical examination, an electrocardiogram, an echocardiogram, pulmonary function testing (spirometry), and a non-invasive cardiopulmonary exercise test. A control group was selected for comparison.

Eighteen of the 39 Fabry patients (46%) exhibited a significant decrease in diastolic blood pressure (DBP) during exercise. The average decrease in DBP was 10 mm Hg. The maximum drop in DBP was 44 mm Hg. The drop in DBP was evident in 9 of the 24 female patients (38%). None of the control patients had a significant drop in DBP during exercise.

Our finding of a significant decrease in DBP in patients with Fabry disease may explain deficits in exercise tolerance. It is notable that this abnormality is manifested in female patients, even though they are typically not as severely affected as males.