False Electrical Capture in Prehospital Transcutaneous Pacing by Paramedics: A Case Series

Historical discrepancies in transcutaneous pacing trials: A call to overcome false electrical capture

“…In total, three clinical trials including symptomatic bradycardia cases were identified, with Hedges et al (1987) excluded due to the inability to separate bradyasystolic cardiac arrests from symptomatic bradycardia. 2,5,12 While such separation was impossible in 2006, a closer review reveals these cases were separated in a publication by Hedges et al in 1991. 5 Per Sherbino et al these authors combined a subgroup of 42 patients with symptomatic bradycardia from the 1987 trial 2 with a case series of nine enrolled at a later date.…”

“…We argue that these differences likely reduced the risk of false electrical capture, an event where pacer artifact mimics a true-paced QRS complex, leading to inappropriate assessment of hemodynamic effects. [6][7][8][9][10][11][12] These historical discrepancies necessitate multi-disciplinary collaboration between cardiology, electrophysiology, and prehospital research communities, leading to investigations of modern best practices to reliably obtain electrical capture with this therapy.…”

“…(1988) this leaves a total sample size of 24-11 and 13, respectively, from these historical trials. 12 While this error impacts evidence quality, a closer review of Hedges'…”

“…High false electrical capture rates in modern practice were confirmed in our previous work. 12 Pacer artifact frequently generated QRS-like "phantom complexes," which sometimes "pseudo-fused" with the QRS or were otherwise dissociated (Figure 1). Our clinicians are directed to follow AHA guidelines, which recommend slow up-titration of current with real-time ECG interpretation as opposed to Hedges' protocol where no ECG was used and current started at the maximum of 200 mA.…”

“…[24][25][26][27] Additionally, we argue there is a need for swift investigation as our work showed clinicians may be unable to recognize post-TCP cardiac arrest due to false electrical capture, as seen in case #1. 12 In a recent national cohort, 1618 (20.4%) who received prehospital TCP experienced post-TCP cardiac arrest, exacerbating these concerns. 28 In summary, these data suggest a correction of the Sherbino et al…”