Resting ECG Procedures Flashcards
6 cards from real CCT practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 Resting ECG Procedures flashcards as text
What is the correct intercostal space and anatomical location for electrode V4?
Answer: 5th intercostal space at the midclavicular line
V4 is placed at the 5th intercostal space in the midclavicular line (the line descending vertically from the midpoint of the clavicle). This landmark must be correctly identified before placing V5 and V6.
During a resting ECG, a patient continues to shiver despite being asked to relax. What is the most likely artifact that will result, and how can it be minimized?
Answer: Muscle tremor artifact (rapid, irregular oscillations obscuring the baseline); warm the patient with a blanket and re-attempt
Shivering produces rapid, irregular, high-frequency muscle potentials that overlay the ECG baseline (somatic tremor artifact). Warming the patient with a blanket to stop shivering is the most effective solution.
A technician is performing an ECG on a morbidly obese patient and finds it difficult to identify the sternal angle. What is the best approach to locating the correct intercostal spaces?
Answer: Palpate the sternum from the top to find the manubriosternal junction (sternal angle/angle of Louis) and count ribs methodically from that landmark
The sternal angle (angle of Louis) is a palpable bony landmark at the junction of the manubrium and sternal body that marks the 2nd rib. Counting down from this point provides accurate intercostal space identification regardless of body habitus.
Which of the following ECG findings is an artifact rather than a true cardiac finding?
Answer: A perfectly regular, high-frequency oscillation at 60 Hz (AC interference) superimposed on all leads
60 Hz AC interference is an artifact caused by electromagnetic interference from electrical power lines and devices, not a cardiac electrical event. It appears as a regular, fine oscillation superimposed uniformly on all leads.
When is it appropriate to use the 'half-standardization' (5 mm/mV) setting on an ECG machine?
Answer: When QRS complexes are so tall that they overlap adjacent leads, making interpretation impossible at standard gain
Half-standardization (reducing gain to 5 mm/mV instead of 10 mm/mV) is used when QRS or T wave amplitudes are so large at standard gain that complexes overflow into adjacent channels, overlapping and making the tracing uninterpretable.
What is the purpose of the Wilson Central Terminal in ECG recording?
Answer: It creates a reference zero potential by connecting the right arm, left arm, and left leg electrodes through resistors, serving as the negative reference for unipolar leads
The Wilson Central Terminal (WCT) connects the RA, LA, and LL limb electrodes through high-value resistors to create a theoretical zero potential reference point, which serves as the negative reference for the six unipolar precordial leads (V1-V6) and the augmented limb leads.