Patent foramen ovale (PFO) has been linked to migraine headache (MH), probably resulting from an unidentified vasoactive substance bypassing pulmonary metabolism. The prevalence of pulmonary arteriovenous malformations (PAVM) in a population without respiratory symptoms or hereditary hemorrhagic telangiectasia (HHT), a disease associated with PAVM, has not been described and may also be associated with MH.
Sixteen patients ages 20-55 undergoing a transthoracic echo for reasons other than pulmonary disease or symptoms were consented to also undergo a saline contrast echocardiogram (SCE) with and without Valsalva. If ≥ 1 clear bubble(s) appeared in the left heart ≤ 3 cardiac cycles of right heart opacification at rest or with Valsalva, it was classified a PFO. If ≥ 1 bubble(s) were evident in the left heart at ≥ 5 cardiac cycles of right heart opacification at rest AND with Valsalva, it was labeled late left heart contrast (LLHC), compatible with presence of a PAVM. Patients then completed a questionnaire previously shown in studies to be accurate in diagnosis of MH.
Three of the 16 patients (19%) had LLHC (5-20 bubbles), compatible with small PAVM. All 3 patients had questionnaires diagnostic of MH.
Small amounts of LLHC during SCE is not uncommon in patients without respiratory symptoms or HHT, and is compatible with the presence of small PAVM. Small PAVM appear to be significantly associated with MH. The presence of right-to-left shunt appears associated with MH independent of the shunt mechanism.
Small amounts of LLHC are compatible with small PAVM and are not uncommon in patients without respiratory disease. They should not be ignored when interpreting a SCE, as it appears they have clinical significance. The mechanism linking small PAVM and MH may involve a vasoactive substance escaping pulmonary endothelial metabolism, and requires further investigation.
SCE ResultMigraine Presentp Compared to NormalNormal91PFO42p = 0.04p = 0.035PAVM33p = 0.013TOTAL166
Timothy Woods, None.