Figure 3.

Voltage mapping of the left atrium in a patient with a post–pulmonary vein isolation atrial tachycardia showing 2 regions of reconnection along the posterior region of the right superior pulmonary vein (RSPV) and right inferior pulmonary vein (RIPV). Entrainment confirmed involvement of these regions during tachycardia. Local electrograms recorded from the distal electrodes on the HD Grid (Abbott Technologies, Minneapolis, MN) at the superior region of reconnection revealed 2:1 mid-diastolic potentials, which indicated slow conduction through a critical isthmus. LAA = left atrial appendage; LIPV = left inferior pulmonary vein; LSPV = left superior pulmonary vein.