From the Guidelines
The key EKG finding consistent with appropriate lead placement and transcutaneous pacing is the presence of pacing spikes followed by wide QRS complexes, as this indicates successful ventricular capture and proper pacemaker function. When evaluating the EKG for appropriate lead placement and transcutaneous pacing, consider the following key findings:
- Regular, narrow vertical spikes (pacing artifacts) preceding each QRS complex
- Wide QRS complexes following each pacing spike
- A consistent relationship between the pacing spike and the QRS complex To ensure proper lead placement and pacing, follow these guidelines:
- Place the anterior pad to the left of the sternum, near the apex of the heart
- Position the posterior pad between the spine and left scapula
- Adjust the pacing rate and output as needed to achieve consistent capture, as the pacing artifact may obscure or mimic the QRS complex, making it difficult to determine the presence of ventricular capture 1. The pacing spikes represent the electrical stimulus delivered by the transcutaneous pacemaker, and when placed correctly, this stimulus triggers ventricular depolarization, resulting in the wide QRS complexes, which is a critical aspect of transcutaneous pacing, as noted in the update to practice standards for electrocardiographic monitoring in hospital settings 1. If you don't see these findings, or if you see pacing spikes without subsequent QRS complexes (failure to capture), you may need to adjust the pad placement or increase the pacing output, and consider using different electrocardiographic monitoring leads to minimize the pacemaker artifact and maximize the QRS complex 1.
From the Research
EKG Findings for Transcutaneous Pacing
The EKG finding consistent with appropriate lead placement and transcutaneous pacing is a QRS pattern resembling left bundle branch block 2.
Key Characteristics
- The QRS complex is wider than normal, indicating ventricular pacing
- The QT interval is prolonged, which is a common finding in ventricular pacing 2
- The QRS duration may be narrower in patients with structural heart disease and narrow QRS at baseline 2
Comparison to Transvenous Pacing
- Transcutaneous pacing (TCP) and transvenous pacing (TVP) induce similar QRS and QTc prolongations compared to baseline measures 2
- TCP may create narrower QRS than TVP in patients with structural heart disease and narrow QRS at baseline 2