Pacemaker outputs are poorly recorded and displayed by the standard ECG. A new high resolution ECG system optimized for recording outputs from electronic pacemakers was evaluated. Three ECGs with different pulse settings were recorded in 42 patients with pacemakers at a sampling rate of 75 kHz using a new ECG acquisition module. Atrial and ventricular pulses were detected and the measured pulse widths and amplitudes were compared to the programmed values. For the atrium, the correlations between programmed and measured width and amplitude were 0.85 and 0.74, while for the ventricle they were 0.99 and 0.8. Leads II and V1 had the highest atrial amplitude, and leads V3, V4 and V5 had the highest ventricular amplitude. The new high resolution ECG pacemaker system dramatically improved the reproduction of pacemaker outputs, allowing accurate measurement of pulse duration for both atrial and ventricular pulses.