Pacemaker Operating Modes
1 - Chamber paced

Pacemaker Operating Modes

1 - Chamber paced

     A (atrium), V (ventricle), D (dual/both)

2 - Chamber sensed

     A, V, D, O (if sensing is temporarily disabled)

3 - Response to sensed events

     I - Inhibits pulse in response to sensed event

     T - Triggers pulse in response to sensed event (A triggered only response has no clinical purpose)

     D - Pulses can be either inhibited or triggered

     O - No response to sensed events

4 - Rate modulation

     R - Paced rate changes based on perceived physiologic need

     (4th position is left blank if this function is not present)


 • Lower rate limit (50-60 bpm) - The lowest rate at which the device will allow the heart to beat

 • Maximum tracking rate (a.k.a. upper rate limit) (120-130 bpm) - The fastest rate at which the device will pace the heart

 • AV Delay (150-200 bpm) - The period of time the pacemaker waits after a sensed or paced atrial depolarization before pacing the ventricle if intrinsic ventricular conduction is not sensed

 • Post-ventricular atrial refractory period (PVARP) (250-300 bpm) - The period of time after ventricular depolarization during which an atrial impulse sensed by the atrial lead will be ignored for timing cycle purposes.  (PVARP is a safety feature: prevents sensing and inappropriate tracking of retrograde P waves which would trigger pacemaker-mediated tachycardia)

Additional Settings: 

 • Sensitivity - The voltage a lead must measure in order to respond to an intrinsic depolarization (i.e. either inhibit or trigger a pacing spike)

 • Output - The voltage the pacemaker delivers to the myocardium in order to initiate depolarization (programmed as voltage x pulse width)

 • Mode Switching - Mode can automatically change with changes in heart rhythm

- Dr. Eric Strong @DrEricStrong - Strong Medicine

#Pacemaker #PPM #Operating #Modes #Pacing #settings #cardiology #management 
Contributed by

Dr. Gerald Diaz
Board Certified Internal Medicine Hospitalist, GrepMed Editor in Chief 🇵🇭 🇺🇸 - Sign up for an account to like, bookmark and upload images to contribute to our community platform. Follow us on IG: | Twitter:

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