Appendix D Pacemaker nomenclature

In 1987, the North American Society of Pacing and Electrophysiology (NASPE) and the British Pacing and Electrophysiology Group (BPEG) set up the NBG (NASPE/BPEG Generic) code to describe different pacing modes. To incorporate new technologies such as dual‑chamber pacing, this code was updated in 2002.

  • The first letter of the code signifies the chamber being paced:
    O = none
    A = atrium
    V = ventricle
    D = dual (A + V)
    (Manufacturers' designation only: S = single [A or V])

  • The second letter signifies the chamber being sensed:
    O = none
    A = atrium
    V = ventricle
    D = dual (A + V)
    (Manufacturers' designation only: S = single [A or V])

  • The third letter signifies the response to sensing:
    O = none
    I = inhibited
    T = triggered
    D = dual (T + I)

  • The fourth letter signifies rate modulation:
    O (or no letter) = none
    R = rate modulation

  • The fifth letter signifies multi‑site pacing:
    O (or no letter) = none
    A = atrium
    V = ventricle
    D = dual (A + V)

For example, 'DDD' indicates dual‑chamber pacing with no rate modulation or multi‑site pacing. 'AAI' indicates atrial pacing inhibited by sensed spontaneous atrial depolarisations; no rate modulation or multi‑site pacing.