In symptomatic bradycardia, what is the initial milliamps setting for external pacing?

• A. 30 mA
• B. 50 mA
• C. 75 mA
• D. 100 mA

Answer: (B)

In external pacing for symptomatic bradycardia, you want to establish reliable capture with the least energy possible. Starting at 50 milliamps provides a low threshold that is often enough to test whether the chest will respond to pacing. If there’s no capture, you increase the output in small steps (about 10–20 mA) until the heart starts to follow the paced rhythm. Once capture is achieved, you can often reduce the setting slightly to the minimum level that still maintains capture. This approach minimizes patient discomfort and skin injury while ensuring effective pacing.

Capture means the heart actually responds to the pacing impulse with a beat, rather than just delivering energy without depolarization. Factors like pad placement, skin impedance, and contact quality can affect the threshold, which is why you adjust upward if needed.