Ask Dr. Z

When coding an EP study, and the left atrial roof line is mentioned after the PVI is performed, what else needs to be documented to be able to bill this code? This is an example i have come across: "...All four pulmonary veins were isolated with radiofrequency ablation followed by a left atrial roof, floor line, anterior mitral isthmus and a complex fractionated electrogram ablation. Pulmonary vein isolation was demonstrated with entrance and exit block and loss of pulmonary vein potential signals." Is this enough to bill, or does it need to be documented that an additional rhythm was detected? What exactly is the verbiage needed to compliantly bill this code?