1. A computer-implemented method for processing ECG data, comprising: receiving, over an electronic network, ECG data, wherein the ECG data represents a plurality of heartbeats; analyzing the ECG data, by at least one processor, to determine whether each of the plurality of heartbeats is a normal heartbeat or an abnormal heartbeat; associating, by the at least one processor, each of the abnormal heartbeats with at least one template of: a) a plurality of existing templates, or b) a new template; receiving, from a user, input related to each new template, wherein the input includes either: a) a confirmation that the new template represents an abnormal heartbeat, or b) a reclassification of the new template as representing a normal heartbeat or a different abnormal heartbeat; in response to the user input, updating, by the at least one processor, a label of each of the heartbeats associated with each confirmed new template representing an abnormal heartbeat and each of the heartbeats associated with each reclassified new template; and determining, by the at least one processor, a number of confirmed abnormal heartbeats, wherein confirmed abnormal heartbeats include each heartbeat associated with each confirmed new template representing an abnormal heartbeat and each heartbeat associated with each new template reclassified as a different abnormal heartbeat, wherein the processor determines the number of confirmed abnormal heartbeats using data contained in the labels associated with the confirmed abnormal heartbeats.