ASD closure for migraine: is there a scientific basis?

Mortelmans et al. 1 studied the closure of atrial septal defect (ASD) for preventing migraine. These investigators speculate about small right-to-left shunt (RLS) in ASD during Valsalva or exercise,1 blurring the characteristic haemodynamic difference between patent foramen ovale (PFO)–RLS and ASD–left-to-right shunt (LRS).2 Additionally, in contrast to PFO with unpredictable RLS, a predictable LRS is maintained in ASD. Migraine, however, particularly the menstrual variant, is frequently predictable. Secondly, there are no significant differences in the basal haemodynamic values ( Table 1 )1 that might predict the occurrence of intermittent RLS in this cohort. A higher basal right atrial (RA) pressure might …