• Pacemaker
• Pacing and Sensing
• Nomenclature (NBG Codes)
• Stimulation Mode
• Position
• I. Position (Chamber(s) Paced)
• II. Position (Chamber(s) Sensed)
• III. Position (Response to Sensing)
• IV. Position (Rate Modulation)
• V. Position (Multisite Pacing)
• Single-Chamber Pacemaker Modes
• Dual-Chamber Pacemaker Modes
• Magnet and Pacemaker

Pacemaker

• PCM is a device implanted under the left clavicle
• It is used for controlling the heart rhythm
• Primarily, it protects the heart from symptomatic bradycardia
• It can have 1, 2, or 3 electrodes
• Each electrode is placed in a different heart chamber:
• Right atrium, right ventricle, left ventricle
• Through the electrodes, the pacemaker can
• Detect the electrical activity of the chamber (sensing)
• Stimulate the respective chamber (pacing)

Nomenclature (NBG Codes)

• A pacemaker can have 1 to 3 electrodes
• Each electrode can perform pacing and sensing of the respective chamber
• Each pacemaker can be programmed into a specific mode
• Modes are denoted by codes (AAI, DDDR, VVI, VDDR)
  
  
• The American (NASPE) and British (BPEG) electrophysiology societies:
• North American Society of Pacing and Electrophysiology (NASPE)
• British Pacing and Electrophysiology Group (BPEG)
• Adopted a unified classification in 1987: NBG Codes (NBG Code)
• NASPE / BPEG Generic Code (last revised in 2002)
  
  
• NBG codes are mandatory for every pacemaker manufacturer

Position

• The stimulation mode has a maximum of 5 capital letters
• Each letter has its own position (I - V)
• For example, modes: AAI, VVI, DDD, DDDR...
• The position of the letter is very important
• The letter in each position gives the pacemaker a certain property
• We will illustrate the principle with two examples: AAI, DDDR

II. Position (Chamber(s) Sensed)

• The second letter indicates which chamber has sensing
• The pacemaker senses the intrinsic electrical activity of the chamber via the electrode and decides on the pacing of a certain chamber
• The second position indicates which chamber is being sensed:
• O (Off) none
• A (Atrium) atria
• V (Ventricle) ventricles
• D (Dual) both atria and ventricles
• AAI: In the second position is "A". It indicates atrial sensing
• DDDR: In the second position is "D". It indicates sensing in both atria and ventricles - dual sensing

IV. Position (Rate Modulation)

• The fourth letter indicates whether the pacemaker can change the pacing rate
• R (Rate modulation). The pacemaker adjusts the pacing rate as needed (e.g., during physical activity)
• O (Off) means that "R" is turned off
• If both the IV and V positions are O, they are not included in the mode name (AAIO = AAI)
• AAI = AAIO. The pacemaker has Rate modulation turned off
• DDDR: In the fourth position is "R". The pacemaker adjusts the pacing rate

Single-Chamber Pacemaker Modes

• A single-chamber pacemaker has only one electrode
• Placed in the right atrium or the right ventricle
  
  
• Single-chamber pacemaker modes
• VOO
• VVI
• AOO
• AAI

Magnet and Pacemaker

• Each pacemaker has a reed switch
• Which connects and activates in a magnetic field
• A magnet is used for its activation
• Placed on the chest over the pacemaker
• The magnet when placed on the chest:
• Turns off sensing
• Turns on asynchronous pacing
• Magnet
• Switches the pacemaker to asynchronous pacing:
• VVI => V00
• AAI => A00
• DDD => D00
• Serves for battery check of the pacemaker
• If asynchronous pacing does not start, the battery is dead
• Deactivates ICD (Implantable Cardioverter Defibrillator)
• Stops pacemaker tachycardia
• Because it turns on asynchronous pacing