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Figure 3 Transseptal Needle Puncture of the LA in the First Patient

Pressure tracing shows severe mitral regurgitation evidenced by giant V waves on the left atrial pressure tracing; pressure was also recorded as the needle was withdrawn from the left atrium (LA) across the interatrial septum into the right atrium (RA), where the pressure was normal. Reprinted with permission from Ross et al. (4).