What does the ECG waveform standardization indicate regarding the deflection?

• A. 1 mV corresponds to a 5 mm vertical deflection on the paper
• B. 1 mV corresponds to a 10 mm vertical deflection on the paper
• C. 1 mV corresponds to a 15 mm vertical deflection on the paper
• D. 1 mV corresponds to a 20 mm vertical deflection on the paper

Answer: (B)

The standardization of the ECG waveform is based on the principle that a 1 mV electrical signal results in a specific vertical deflection on the ECG recording paper. In clinical practice, the standardization is set such that a deflection of 1 mV produces a 10 mm vertical deflection. This standardization allows for consistent interpretation of the ECG traces across different recordings and devices, facilitating accurate assessment of the heart's electrical activity.

This 10 mm standardization is particularly crucial for comparing ECG results, ensuring that any increases or decreases in the amplitude of the waveform are attributable to changes in the heart's electrical function rather than variations in the recording technique or equipment. By maintaining this standardization, healthcare professionals can effectively evaluate the presence of any cardiac abnormalities based on the amplitude of the waveform.