Pacemaker and ICD simulator

For learning how a pacemaker and a cardioverter-defibrillator work through the ECG and the marker channel: normal operation, malfunctions and the therapy sequence.

Pacemaker

Change the mode, rate, AV delay, pulse and sensitivity: a 10-second strip and the marker channel show how the device saw each beat.

Preset scenarios

AS / VS: sensed atrial / ventricular beat
AP / VP: stimulus (orange — no capture)
AR / VR: sensed in the refractory period, not counted

Patient's intrinsic rhythm

Mode

Lower rate limit60 /min

Upper tracking rate130 /min

AV delay180 ms

Atrial lead

Pulse amplitude2,50 V

Capture threshold0,75 V

Sensitivity0,50 mV

P wave at the lead: 2 mV. The higher the number, the less the device senses.

Ventricular lead

Pulse amplitude2,50 V

Capture threshold1,00 V

Sensitivity2,50 mV

R wave at the lead: 7 mV. The higher the number, the less the device senses.

Ventricular rate

78/min

Longest pause

770ms

Ventricular pacing

100 %

Atrial pacing

0 %

The pacemaker is working correctly: sensing and capture are normal

ICD: detection and therapy

Set the zones and choose an arrhythmia: the device counts fast intervals, delivers ATP first in the VT zone and, if needed, charges and delivers a shock.

VTVFNo therapy

100200300 /min

VS: sinus beat
TS / FS: fast beat in the VT / VF zone
TP: ATP pulse
CD: shock

Arrhythmia

VT rate190 /min

VT zone cut-off170 /min

VF zone cut-off220 /min

VT detection: consecutive intervals16

ATP result

Terminated by ATP

0,0 sSinus rhythm 75 /min
2,6 sVentricular tachycardia at 190 /min began
7,7 sDetected in the VT zone: 16 consecutive intervals
7,9 sATP: 8 pulses, 88 % of the cycle length (278 ms)
11,0 sATP effective: sinus rhythm restored

In the model: 18 fast intervals in the VF zone, redetection after ATP 12 intervals, charge 6 seconds. Real values depend on the device and its programming.

The model is simplified: blanking periods, mode switching (mode switch), rate response and SVT discriminators are not shown. The values are a teaching example; real programming is chosen according to the device, the manufacturer and the patient.