ECG Equipment Operation & Maintenance Flashcards
7 cards from real CET practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 ECG Equipment Operation & Maintenance flashcards as text
A 60 Hz interference pattern on an ECG tracing most commonly indicates which problem?
Answer: Poor electrode-to-skin contact or AC electrical interference
60 Hz (AC) interference appears as a rapid, regular oscillation on the baseline and is typically caused by poor electrode contact or nearby electrical devices.
Which lead configuration uses the left arm electrode as the positive terminal and the right arm as the negative terminal?
Answer: Lead I
Lead I measures the potential difference from right arm (negative) to left arm (positive), reflecting lateral heart activity.
What is the primary reason disposable adhesive ECG electrodes have a defined expiration date?
Answer: The conductive gel dries out, increasing impedance and reducing signal quality
Expired electrodes have dehydrated gel that increases skin-electrode impedance, producing poor signal quality and artifact.
During a 12-lead ECG, the technician observes that aVR, aVL, and aVF all show artifact but limb leads I, II, and III are clean. What is the most likely cause?
Answer: A faulty right leg (ground) electrode connection
The augmented leads (aVR, aVL, aVF) are derived differently than the bipolar leads; a faulty ground (RL) electrode selectively corrupts them while bipolar leads may appear relatively clean.
What thermal paper storage condition will cause premature darkening or degradation of ECG paper?
Answer: Exposure to heat, humidity, or direct sunlight
Thermal paper is heat-sensitive; exposure to heat, humidity, or UV light causes premature darkening and makes tracings unreadable.
Which ECG machine filter setting is most appropriate to reduce baseline wander caused by patient breathing?
Answer: High-pass (low-frequency) filter set at 0.05 Hz or higher
A high-pass filter removes low-frequency drift (like respiratory baseline wander) while preserving the higher-frequency ECG signal components.
When preparing a patient's skin for ECG electrode placement, what is the correct order of skin preparation steps?
Answer: Clip hair → clean skin with alcohol → dry skin → apply electrode
Proper sequence is: clip excess hair, clean with alcohol to remove oils/dead skin, dry thoroughly, then apply electrode for optimal adhesion and conductivity.