Failure (Loss) to Capture - Course # 317-8


  • When a pacemaker loses its ability to cause depolarization (capture), the inherent rhythm of the patient will become present within the tracing.
  • As mentioned earlier in this presentation you will note the presence of a pacing spike, but you will not see a waveform immediately following it.
  • You will likely see a delay after the spike, then the presence of some waveform of different morphology
pacemaker ecg image 109

Practice Strip

  • Analyze this tracing using the five steps of rhythm analysis.
  • Compare your answers with the answers on the next slide.

pacemaker ecg image 110


  • Rhythm: Irregular
  • Rate: 80
  • P Wave: absent
  • PR interval: n/a
  • QRS: 0.14 sec, two non-captured complexes 0.16 sec, all wide and bizarre
  • Interpretation: Ventricular Pacemaker Rhythm with Loss of Capture
pacemaker ecg image 110b

317 Failure (Loss) to Capture - Course # 317-8