3.4. Low-voltage area assessment
Low-voltage areas were defined as areas with a bipolar peak-to-peak voltage < 0.50 mV covering > 5 cm2 of left atrium. On the voltage map, the bipolar voltage color bar was set to range from 0.10 to 0.50 mV and scar level was set at < 0.05 mV. Each low-voltage-area size was manually measured, and the summation of all low-voltage-area sizes was defined as the low-voltage-area size in the patient. The left atrium was divided into six regions - septal, anterior, roof, posterior, inferior, and posterolateral - as reported previously.8