Written by Jason Lesnick
Placing transcutaneous cardiac pacer pads in the anteroposterior position required less energy to successfully capture.
Why does this matter?
Temporary transcutaneous pacing saves lives in unstable bradycardia. If we can obtain better results with a certain pad placement, we should preferentially use that pad position.
How slow can you go? Wait, no – too slow, too slow!
This prospective crossover trial enrolled 20 patients in an electrophysiology lab who were scheduled for electrical cardioversion and, while still sedated, the patients were sequentially paced in both the anteroposterior (AP) and anterolateral (AL) positions.
Three patients had incomplete data due to further sedation being deemed unsafe, and four patients did not capture with either pad placement, despite max settings of 140 mA; thus, seven total were excluded from analysis.
The authors found a statistically significant difference in the primary outcome, with the mean capture values in the AP position at 93 mA compared to 126 mA in the AL group (p = 0.0001, 95%CI 20 to 45 – for the difference).
23.5% (4/17) of patients did not achieve capture. I agree with the authors that patients with symptomatic bradycardia would likely have higher rates of non-capture due to ischemia, metabolic abnormalities, etc.
A secondary outcome involved unblinded assessors scoring patients based on a novel scoring system developed to compare chest wall contraction severity. They found that AP pacing showed a statistically significant decrease in chest wall contraction severity compared to AL.
This tiny, but cleverly done, study gives us some clinically useful information on an important subject. I will be preferentially using the AP position in my unstable bradycardic patients. I’ll take anything that could help the next time I have an unstable, bradycardic person and am trying to balance sedation, pain control, setting up for a transvenous pacer, and calling cardiology.
Anteroposterior Pacer Pad Position Is More Likely to Capture Than Anterolateral for Transcutaneous Cardiac Pacing. Circulation. 2022;146(14):1103-1104. doi:10.1161/CIRCULATIONAHA.122.060735