Which recording setting would you adjust if an ECG stylus runs off the paper?

When an ECG stylus runs off the paper, it typically indicates that the amplitude of the electrical signals being recorded is too high for the current settings, causing the waveform to exceed the limits of the paper. Adjusting the settings to run at 1/2 standard deviation (STD) reduces the sensitivity of the ECG recording, allowing the stylus to fit the waveform within the available space on the paper. This adjustment effectively scales down the amplitude of the recorded signals, preventing them from running off the edges and ensuring that the full waveform is visible on the page.

In contrast to this option, adjusting voltage may not be the most effective choice in all situations, as it can either lead to under-representation or over-representation of the signals depending on the current setup. Changing lead placement typically affects the position of the signals rather than their amplitude and may not address the issue of the stylus running off the paper. Increasing paper speed would result in a faster output, but if the amplitude remains unchanged, it could still run off the paper; it does not specifically address the problem of high amplitude signals. Thus, setting to run at 1/2 STD is the most appropriate adjustment to mitigate the issue.