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This is a graded assertiveness tool that can be used when faced with challenging behaviour from other health care professionals. The letters stand for:

  • P – Probe—this means, in a non-critical situation, obtain the person's attention and ask probing or clarifying questions. Use questions beginning with ‘I’.

  • A – be more Assertive—means making ‘we’ statements and stating specific concerns.

  • C – express Concern—direct statements; state your concerns outright and the need to discuss them with higher authorities.

  • E – use Emergency language—’stop’; ‘no’; ‘cease and desist’; ‘you are wrong’.


There are three types of pacemakers:

  1. Implanted pacemakers—these may or may not have defibrillation/cardioversion capabilities.

  2. Transcutaneous pacing.

  3. Transvenous pacing.

Pacemaker technology is constantly evolving, and the anaesthetist will be exposed to multiple generations and types of pacemakers.

Implanted pacemakers/defibrillators


  1. Bradycardia due to various causes e.g. complete heart block, sick sinus syndrome.

  2. Overdrive pacing to treat some tachyarrhythmias.

  3. Cardioversion of malignant arrhythmias/anti-tachycardia pacing. This type is termed an automatic implantable cardioverter defibrillator (AICD).

  4. Cardiac resynchronisation therapy (CRT) for heart failure.


  1. Pulse generator and battery.

  2. Lead to right ventricle (RV). If this is the only lead, this is termed a single-chamber pacemaker.

  3. Lead to RV and right atrium (RA). This is termed a dual-chamber pacemaker.

  4. Biventricular pacemakers have a third lead planted in the coronary sinus, allowing pacing of the left ventricle.

  5. AICDs have defibrillator electrodes. These are visible on the CXR as thick, opaque sections terminating in the RV.


Modes of pacing are described by 3, 4 or, rarely, 5 code letters. These code letters stand for:

  • Position 1 – the chamber paced—A-atrium, V-ventricle, D-dual.

  • Position 2 – the chamber sensed—A, V, D or O (O means the pacemaker paces without sensing).

  • Position 3 – the response to sensing—T-triggered, I-inhibited, D-dual (pacemaker pulses can be inhibited or triggered) or O-nil.

  • Position 4 – indicates programmability/rate modulation—either O-nil or R-rate modulation. The rate changes on the basis of perceived physiological need e.g. movement of an accelerometer in the pacemaker.

  • Position 5 – indicates multisite pacing capability—either O-nil, A-atrial (one or both atria), V – one or both ventricles or D – combination of A and V. This is almost never used.

Common terms used to describe pacing modes

  1. Asynchronous e.g. VOO. The RV is paced and there is no sensing or inhibition. This is wasteful of the pacemaker's battery and can cause competition with the patient's intrinsic rhythm, leading to pacemaker syndrome (see below). Almost every pacemaker will revert to asynchronous mode if a pacemaker ...

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