Basic Electrocardiogram Flashcards

On standard ECG paper, how many seconds does one small (1 mm) box represent horizontally?

Answer: 0.04 seconds

At the standard 25 mm/sec speed, each small horizontal box equals 0.04 seconds.

Which limb electrode is considered the ground (neutral) and produces no tracing?

Answer: Right leg (RL)

The right leg electrode serves as the ground/reference and does not generate a lead tracing.

Which chest lead is placed at the fourth intercostal space to the right of the sternum?

Answer: V1

V1 is positioned at the fourth intercostal space just right of the sternal border.

A wandering baseline artifact on an ECG is most often caused by:

Answer: Patient movement or loose electrodes

Baseline wander typically results from patient motion, respiration, or poorly attached electrodes.

60-cycle (AC) interference on an ECG appears as:

Answer: A thick, fuzzy fine oscillation on the baseline

AC interference produces uniform fine, fuzzy oscillations from nearby electrical sources.

Before applying chest electrodes, the technician should first:

Answer: Prepare the skin by cleaning and, if needed, clipping hair

Proper skin prep, including cleaning and hair removal, ensures good electrode contact and a clear tracing.

The standard calibration mark on an ECG should produce a box that is:

Answer: 10 mm tall (1 millivolt)

Standard calibration displays a 10 mm deflection representing 1 millivolt.