Data is received characterizing an electrocardiogram (ECG) measured from a patient having a pacemaker. The pacemaker can intermittently provide a pace to a heart of the patient. By comparing at least a portion of the received data to a template a pace pulse can be detected from at least a portion of the received data. The template comprises one or more pace pulses measured from the patient. The template is modified, at least in part, by the detected pace pulse to update the template. Data characterizing the detected pace pulse is provided. Related apparatus, systems, techniques and articles are also described.
