By: Alan D. Bernstein, Ph D Table of Contents
Introduction
In clinical pacing, as in other fields, clear and efficient communication is a necessary resource. In 1974 the Inter-Society Commission for Heart Disease Resources addressed an increasingly apparent need for a concise way of communicating three pacemaker fundamentals: the chamber or chambers paced, the chamber or chambers in which native depolarizations were sensed, and how sensing affected pacing patterns. They introduced the three-position ICHD Code, based on a concept suggested four years earlier by Nicholas P. D. Smyth. In 1981, when noninvasive adjustment of pacing function (i.e., programmability) and antitachycardia-pacing functions became available to varying degrees in pacemaker pulse generators, the same authors designed the five-position ICHD Code to add a means of conveying basic information about these features. The NASPE Specific Code (1984), based on a concept proposed earlier by Robert R. Brownlee, is not a generic, or "conversational," code, but provides more information in a ratio format. Some specialists have found it useful, especially in teaching and record-keeping. The NASPE/BPEG Generic Pacemaker Code (1987) is simpler than the five-position ICHD Code in describing the response to sensing, and addresses a new and very important capability of some pacing systems: adaptive-rate pacing. The NASPE Defibrillator Code (1993) is quite similar in design to the NBG Code. It provides the locations of antitchycardia interventions, the means of tachycardia detection, and the locations of antibradycardia pacing that some implanted cardioverter/defibrillators offer. The NASPE/BPEG Lead Code (1996) identifies fundamental lead properties in a very concise fashion. A revised version of the NBG Code, updated to include designations for the multisite pacing, was published in 2002. The first three positions remain essentially the same as those of the earliest (1974) ICHD Code.
Precursors of the NASPE and NASPE/BPEG Codes
The 1974 Three-Position ICHD Pacemaker Code
| FIRST LETTER | SECOND LETTER | THIRD LETTER |
| Chamber paced | Chamber sensed | Mode of response |
| V = Ventricle A = Atrium D = Double-chamber | V = Ventricle A = Atrium D= Double-chamber O = Not applicable | I = Inhibited T = Triggered O = Not applicable |
Adapted with permission from Parsonnet V, Furman S, Smyth, NPD: Implantable cardiac pacemakers; Status report and resource guideline. Pacemaker Study Group, Inter-Society Commission for Heart Disease Resources (ICHD). Circulation 1974; 50:A21-A35.
The 1981 Five-Position ICHD Code
| Position | I | II | III | IV | V |
| Category: | Chamber(s) paced | Chamber(s) sensed | Modes of
response(s) | Program- mable functions | Special antitachy-
arrhythmia functions |
| Letters used: | V = venticle A = atrium D = double | V = venticle A = atrium D = double | T = Triggered I = Inhibited D = double* O = none R = reverse
| P = program- mable (rate
and/or output) M = multi -programmable O = none | B = bursts N = normal rate
competition S = scanning E = external |
| Manufac- turers'
designation only: | S = Single
chamber | S = Single
chamber |
(Comma optional here)
|
* Triggered and inhibited response
Adapted with permission from Parsonnet V, Furman S, Smyth NPD: A revised code for pacemaker identification. PACE 1981; 4:400-403.
The 1982 Five-Position ICHD Code
| Position | I | II | III | IV | V |
| Category: | Chamber(s) paced | Chamber(s) sensed | Modes of
response(s) | Program- mable functions | Special antitachy-
arrhythmia functions |
| Letters used: | V = venticle A = atrium D = double | V = venticle A = atrium D = double | T = Triggered I = Inhibited D = double* O = none R = reverse
| P = program- mable (rate
and/or output) M = multi- programmable C = communicat- ing O = none | B = bursts N = normal rate
competition S = scanning E = external |
| Manufac- turers'
designation only: | S = Single
chamber | S = Single
chamber | (Comma optional here) |
* Triggered and inhibited response
Adapted with permission from Parsonnet V, Furman S, Smyth NPD, Bilitch M: Implantable cardiac pacemakers: Status report and resource guidelines, 1982. Pacemaker Study Group, Inter-Society Commission for Heart Disease Resources (ICHD). Circulation 1983; 68:226A-244A.
The NASPE and NASPE/BPEG Codes
The 1987 NASPE/BPEG Generic (NBG) Pacemaker Code
| Position | I | II | III | IV | V |
| Category: | Chamber(s) paced | Chamber(s) sensed | Response(s) to sensing | Program- mability,
rate modulation | Antitachy- arrhythmia function(s) |
| | 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 P = Simple
program- mable M = Multi- program- mable C = Communi- cating R = Rate modulation | O = None P = Pacing (anti-
tachyarrhyth-
mia) S = Shock D = Dual (P+S) |
| Manufac- turers'
designation only: | S = Single
(A or V) | S = Single
(A or V) | Note: Positions I through III are used exclusively for
antibradyarrhythmia function. |
Bernstein AD, Camm AJ, Fletcher R, Gold RD, Rickards AF, Smyth NPD, Spielman SR, and Sutton R: The NASPE/BPEG Pacemaker Code for antibradyarrhythmia and adaptive-rate pacing and antitachyarrhythmia devices. PACE, 10:794-799, 1987. Reproduced with permission.
The NASPE Specific Code
| Basic Structure | Atrial-channel and ventricular-channel functions are described in the numerator and denominator, respectively, of a ratio-format code, or separated by a virgule (slash) or hyphen when restriction to a single line is unavoidable. Example: 
|
| Antibradycardia-pacing symbols | Function: O = none
P = pace S = sense U = underdrive B = burst R = ramp | Pacing type: T = triggered I = inhibited X = extrastimulus C = cardioversion D = defibrillation | Signal source: a = atrium b = ventricle Activation: a = atrial sensing v = ventricular sensing e = external |
| Antitachycardia - therapy symbols | Antitachycardia-therapy symbols are appended in parentheses as needed. Thus, a multiprogrammable DDD pacemaker with atrial-burst capability, either automatically or externally activated, plus automatic defibrillation, would be represented as follows: 
|
Bernstein AD, Brownlee RR, Fletcher R, Gold RD, Smyth NPD, Spielman SR: Report of the NASPE Mode Code Committee. PACE 1984; 7:395-402. Reproduced with permission. Based on Brownlee RR, Shimmel JB, Del Marco CJ: A new code for pacemaker operating modes. PACE 1981; 4:396-399.
The NASPE/BPEG Defibrillator (NBD) Code
| I | II | III | IV |
| Shock
chamber | Antitachycardia- pacing chamber | Tachycardia detection | Antibradycardia- pacing chamber |
| O = None A = Atrium V = Ventricle D = Dual (A+V) | O = None A = Atrium V = Ventricle D = Dual (A+V) | E = Electrogram H = Hemodynamic | O = None A = Atrium V = Ventricle D = Dual (A+V) |
The Short Form of the NASPE/BPEG Defibrillator (NBD)Code:
ICD-S = ICD with shock capability only
ICD-B = ICD with bradycardia pacing as well as shock
ICD-T = ICD with tachycardia (and bradycardia) pacing as well as shock
ICD = implanted cardioverter/defibrillator
Bernstein AD, Camm AJ, Fisher JD, Fletcher RD, Mead RH, Nathan AW, Parsonnet V, Rickards AF, Smyth NPD, Sutton R, Tarjan PP. The NASPE/BPEG Defibrillator Code. PACE, 16:1776-1780, 1993. Reproduced with permission.
Bernstein AD, Camm AJ, Fisher JD, Fletcher RD, Mead RH, Nathan AW, Parsonnet V, Rickards AF, Smyth NPD, Sutton R, Tarjan PP. The NASPE/BPEG Defibrillator Code. J Interven Cardiol 6:235-239, 1993. Reproduced with permission.
The NASPE/BPEG Pacemaker-Lead Code (NBL Code)
| I | II | III | IV |
| Electrode
Configuration | Fixation
Mechanism | Insulation
Material | Drug
Elution |
| U = Unipolar | A = Active | P = Polyurethane | S = Steroid |
| B = Bipolar | P = Passive | S = Silicone rubber | N = Non-steroid |
| M = Multipolar | O = None | D = Dual (P+S) | O = None |
Bernstein AD, Parsonnet V. The NASPE/BPEG Pacemaker-Lead Code. PACE 1996; 19:1535-1536. Reproduced with permission.
The NASPE/BPEG Generic (NBG) Pacemaker Code (Revised 2000) | 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) |
| Mfr
designation only: | S = Single
(A or V) | S = Single
(A or V) | |
Bernstein AD, Daubert J-C, Fletcher RD, Hayes DL, Lüderitz B, Reynolds DW, Schoenfeld MH, Sutton R. The Revised NASPE/BPEG Generic Code for antibradycardia, adaptive-rate, and multisite pacing. PACE 2000; 25:260-264.
