The prevalence of sustained electrical capture during prehospital transcutaneous pacing: a multicenter observational study.

INTRODUCTION: Transcutaneous pacing (TCP) is used to treat bradycardia with hemodynamic compromise. Prior data suggested that electrical capture was uncommon during prehospital TCP. We aimed to determine the prevalence of sustained electrical capture and identify associated factors in a multicenter cohort. METHODS: Four emergency medical services agencies contributed patients who received TCP from 2017 to 2024. Data were abstracted from electronic health records and cardiac monitor files. Sustained electrical capture was defined as a wide QRS complex with a T-wave after each pacer impulse for at least 90% of a 60 second period, followed by electrical capture for 90% of the remainder of the TCP attempt. Multivariable logistic regression modeling was used to estimate the association between variables of interest and sustained electrical capture. RESULTS: Of 299 patients, 29 (9.7%) had sustained electrical capture. Our cohort was a median 73 [62, 82] years of age, 48.5% (n = 145) female, and 33.8% (n = 101) had post-ROSC TCP. The median body weight was 78.3 [68-95.3] kilograms, pre-TCP heart rate was 38 [30, 45] beats per minute (bpm) and maximum TCP current was 90 [70-110] mA. Lower weight (aOR: 0.95 [0.93, 0.98] per kg; n = 208), lower pre-TCP heart rate (aOR: 0.96 [0.93, 0.99] per bpm; n = 297), and higher delivered current (aOR: 1.25 [1.08, 1.45] per 10 mA; n = 208) were associated with higher odds of sustained electrical capture. CONCLUSIONS: We found that sustained electrical capture during prehospital TCP was uncommon and associated with pre-TCP heart rate, pacing current, and body weight.