"Fast Pathing" is a feature that it allows an organization to set a relatively long heartbeat interval to minimize traffic without losing up to date information about the security of clients.
Without this, important events like viral infections would only be uploaded during a heartbeat. Waiting for a heartbeat to forward events to the SEP Manager could slow down an organizations response time to an emerging threat.
With "Fast Pathing" enabled, the client checks if there are new detections (*) or new network security events every minute. If one of these critical events is found, the SEP client uploads all threat-detection and network security related information for the events from the logs (AVMan.log and seclog.log) but not any other log information.
* Excluding System Change events and Tracking Cookies