The
dominant driving sources of atrial fibrillation are often found in the left
atrium, but the expression of left atrial activation on the body surface is poorly
understood. Using body surface potential mapping and simultaneous invasive measurements
of left atrial activation our aim was to describe the expression of the left
atrial dominant fibrillation frequency across the body surface.
20
patients in atrial fibrillation were studied. The spatial distributions of the dominant
atrial fibrillation frequency across anterior and posterior sites on the body
surface were quantified. Their relationship with invasive left atrial dominant
fibrillation frequency was assessed by linear regression analysis, and the
coefficient of determination was calculated for each body surface site.
The
correlation between intracardiac and body surface dominant frequency was
significantly higher with posterior compared with anterior sites (coefficient
of determination 67±8% vs 48±2%, p<0.001). The site with largest coefficient
of determination was 79.6% (p<0.001) and was a posterior site. In comparison
with the site closest to lead V1 it had a coefficient of determination of 23.0%
(p=0.033), and with the posterior body surface site closest to lead V9 had a
coefficient of determination of 70.3% (p<0.001).
Left
atrial dominant fibrillation frequency was more closely represented at
posterior body surface sites.
Credits: Marjan Bojarnejad; James R Blake; John Bourke; Ewan Shepherd; Alan Murray; Philip Langley