Background: The relationship between migrainous aura and patent foramen ovale (PFO) remains uncertain
Methods: We performed 'bubble' contrast transthoracic echocardiography on 80 migraineurs with 4-15 headache days per calendar month, mean age 45 (75% female) with mean 9.4 headache days. A large PFO was defined by passage of an uncountable bolus of bubbles or complete opacification of the left-heart in ≤3 cycles, while a moderate PFO was defined by passage of ≥20 bubbles but not sufficient to form a bolus or opacify the whole of the left heart.
Results: There was a moderate or large PFO in 28 (35%; 95% CI 24-46%). There were atrial septal aneurysms in 11 (15%) and the relationship with PFO was moderately strong (spearman rank correlation 0.493, CI 0.308 to 0.643; p < 0.0001). Seven (9%) had a valve abnormality and one had a closure device for an atrial septal defect. Aura were reported in 31 (39%) and in these the PFO was large in 9 (29%) compared with 8 (16%; p = 0.143) without aura. There was no relationship between the size of the PFO and the number of headache days (difference between no PFO and large PFO = -0.6 days; 95% CI -2.6 to +1.4; p-value for any difference between groups = 0.316).
Conclusions: The prevalence of moderate or large patent foramen ovale was 35% and was not associated with the presence of aura or the frequency of the headache.
Keywords: Atrial septal aneurysm; Migraine; Patent foramen ovale.