| Position | I | II | III | IV | V |
| Category | Chamber(s) paced | Chamber(s) sensed | Response to sensing | Rate modulation | Multisite pacing |
| O = None A = Atrium V = Ventricle D = Dual (A+V) | O = None A = Atrium V = Ventricle D = Dual (A+V) | O = None T = Triggered I = Inhibited D = Dual (T+I) | O = None R = Rate modulation | O = None A = Atrium V = Ventricle D = Dual (A+V) | |
| Manufacturer's designation only: | S = Single (A or V) | S = Single (A or V) | |||
