Editing Pacemaker (section)

== Other devices ==
Sometimes devices resembling pacemakers, called [[implantable cardioverter-defibrillator]]s (ICDs) are implanted. These devices are often used in the treatment of patients at risk from sudden cardiac death. An ICD has the ability to treat many types of heart rhythm disturbances by means of pacing, [[cardioversion]], or [[defibrillation]]. Some ICD devices can distinguish between ventricular fibrillation and [[ventricular tachycardia]] (VT), and may try to pace the heart faster than its intrinsic rate in the case of VT, to try to break the tachycardia before it progresses to ventricular fibrillation. This is known as ''fast-pacing'', ''overdrive pacing'', or ''anti-tachycardia pacing'' (ATP). ATP is only effective if the underlying rhythm is ventricular tachycardia, and is never effective if the rhythm is ventricular fibrillation.

{| class="wikitable" style="margin: 1em auto 1em auto"
|+ NASPE / BPEG Defibrillator (NBD) code – 1993<ref name=NASPE_defib_code>{{cite journal |last1=Bernstein |first1=Alan D. |last2=Camm |first2=A. John |last3=Fisher |first3=John D. |last4=Fletcher |first4=Ross D. |last5=Mead |first5=R. Hardwin |last6=Nathan |first6=Anthony W. |last7=Parsonnet |first7=Victor |last8=Rickards |first8=Anthony F. |last9=Smyth |first9=Nicholas P.D. |last10=Sutton |first10=Richard |last11=Tarjan |first11=Peter P. |title=The NASPE */BPEG ** Defibrillator Code |journal=Pacing and Clinical Electrophysiology |date=September 1993 |volume=16 |issue=9 |pages=1776–80 |doi=10.1111/j.1540-8159.1993.tb01809.x |pmid=7692407 }}</ref>
! I || II || III || IV
|-
| Shock chamber || Antitachycardia pacing chamber || Tachycardia detection || Antibradycardia pacing chamber
|-
| O = None || O = None || E = Electrogram || O = None
|-
| A = Atrium || A = Atrium || H = Hemodynamic || A = Atrium
|-
| V = Ventricle || V = Ventricle || || V = Ventricle
|-
| D = Dual (A+V) || D = Dual (A+V) || || D = Dual (A+V)
|}

{| class="wikitable" style="margin: 1em auto 1em auto"
|+ Short form of the NASPE/BPEG Defibrillator (NBD) code<ref name="NASPE_defib_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
|}