A pacemaker digital electrocardiogram for accurate assessment of implanted cardiac pacemakers

During the past 8 yr over 170 patients in the Glasgow area have received cardiac pacemaker implants. All such patients attend pacemaker clinics at which both clinical and electronic examinations are carried out. The Pacemaker Frontal Plane Vector technique developed in Glasgow has enabled many changes in pacing function to be detected, often before clinical symptoms appear. Hitherto, measurements have been made using a calibrated differential oscilloscope: the Pacemaker Digital Electrocardiographic described in this paper offers improved accuracy in the measurement of the pacemaker frontal plane vector thus enabling further development of the above technique. The instrument also measures pacemaker pulse width and rate with an accuracy of ±0·1 per cent which should be sufficient to detect ageing of the newer Medtronic ‘rate-stable’ generators (type 5862—fixed rate and type 5842—QRS blocking).