Loss of Capture

Pacer spikes should always have a waveform immediately afterwards. Failure to stimulate a depolarization is called loss of capture.

An electronic pacemaker, or just pacemaker, delivers electrical current to the heart to stimulate depolarization. Pacemaker leads may connect with ventricular tissue and/or atrial tissue (permanent or transvenous pacemakers). Transcutaneous pacing delivers an electrical current through the chest wall to depolarize the ventricles.

Paced rhythms are fairly easy to detect because of the vertical spike present before the atrial (‘P’ waves) or ventricles depolarizations (QRS complexes). The spike represents the electrical impulse generated by the electronic pacemaker.

The wave immediately after the spike is the intended response to the initial electrical stimulus. If the spike is accompanied by a wave, the pacemaker is said to be capturing. Conversely, if spikes appear without accompanying waves, we have loss of capture.

Note that many older monitors will recognize the pacer spike as a QRS complex when determining rate, whether the spike captures the heart or not. As a result, many monitors do not alarm if the pacemaker is losing capture. Also, a monitor might provide a heart rate twice the pulse rate if both the pacer spike and the QRS complex are counted. Monitor your patient closely.

Pacer spikes should always have a waveform immediately afterwards. Failure to stimulate a depolarization is called loss of capture. Many older monitors will not inform you of any loss of capture. Again, always check the patient. The loss of capture of several complexes could result in poor cardiac output. Also, if the pacemaker is sensing the heart ineffectively, the pacemaker could deliver electrical impulses close to the T wave, potentially causing lethal dysrhythmias. Loss of capture or the presence of pacer spikes close to the T wave often requires an urgent response.

failure to capture

1. Six Second ECG Guidebook (2012), T Barill, p. 129

Our apologies for the recent ECG SIM outages. We've made some adjustments to our IT infrastructure. Please send us a note if it is not working.

Our new 12 Lead ECG SIM Deck is active!

We're planning a scheduled maintenance period.

Our website will be unavailable on Wed, Oct 16, 2024 starting at 8:00pm (PDT). We anticipate this will take about 1 hour.
Thank you for your understanding.

The SkillStat Team

×
  Six Second ECG Intensive Six Second ECG Mastery 12 Lead ECG & ACS 12 Lead Advanced
Prerequisite

None

None

Any Six Second ECG Course

12 Lead ECG & ACS

Time Frame

8 hours (1-day Course or 2 evenings)

20 hours 3-day Course

8 hours 1-day Course

8 hours 1-day Course

Tuition

$275

$675

$275

$275

Completion Card
Exam and Certification
SkillStat 2U-able
Reference materials included
Dynamic ECG rhythm interpretation
Static ECG rhythm interpretation
Clinical Impact Mapping
Acute Coronary Syndromes Overview
Acute Coronary Syndromes In-Depth
ST Segment & T Wave Differential
Identify Bundle Branch Blocks
15 | 18 Lead View Mapping
Electrical Axis
R Wave Progression
Left Bundle Branch Blocks with ACS
Atypical Findings
Acute Non-Ischemic Disease Conditions
Special Cases

•-included;     ○-reviewed
×