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Figure 2 Fluoroscopic Views During Transseptal Puncture

(A) Transseptal puncture performed in the anteroposterior projection with fluoroscopic imaging. The pigtail catheter marks the location of the aortic valve, and the tip of the transseptal dilator engages the fossa ovalis inferiorly and medially to the aortic valve. (B) Transseptal puncture performed in the lateral fluoroscopic projection. The transseptal dilator engages the fossa ovalis in the lower third of the imaginary line (thin dashed line) connecting the pigtail catheter (aortic valve) and the posterior wall of the left atrium (heavy dashed line). (C) Transseptal puncture performed in the right anterior oblique projection with fluoroscopic imaging. The transseptal dilator (TC) engages the fossa ovalis posterior to the pigtail catheter (aortic valve) but anterior to right atrial silhouette (dashed line).