Please click here to obtain permission to reproduce this image.
Click on image to view larger version.
Figure 4 Ectopic P-wave morphology before (A) and after (B) QRST subtraction in a patient with frequent ectopics, sometimes in a bigeminal pattern, after pulmonary vein (PV) disconnection. Postsubtraction ectopic P-wave morphology shows biphasic pattern (negative-positive) in lead II, III, and avF, and broad positivity in V1, which is clearly dissimilar to pacemapping P-wave morphologies from PVs (D: right superior PV, E: right inferior PV, F: left superior PV, G: left inferior PV), suggesting a non-PV focus. Pacemapping from several left atrial sites demonstrated that ectopic morphology closely matched the pacemap from the low posterior left atrium between two inferior PVs (C). Successful ablation was performed at a site very close (within 5 mm) to this pacemapping site.
|
