Question 1

All ECG tracings should be recorded in standard calibration and the calibration pulse should be included in the tracing.

Accepted Answer

Proper calibration is critical when analyzing ST-segments. When an ECG monitor is in standard calibration, a 10 mm (two big boxes) deflection is produced for every millivolt that is sensed. All tracings should be recorded in standard calibration and the calibration pulse should be included in the tracing.

Question 2

Proper preparation of the patient's skin and evaluation of the equipment (electrodes, wires) before use can minimize the problems associated with artifact.

Accepted Answer

The presence of artifact can interfere with a 12-lead machine's ability to acquire and/or interpret the ECG. One of the methods that can used to reduce artifact is to help the electrode gel penetrate the patient's skin. If the gel can penetrate the skin well, then the result is an increased signal strength and reduced artifact. Remove excessive hair in the area where the electrodes will be applied. Remove skin oil and dead cells using a brisk, dry rub of the skin before applying the electrode. Always use fresh electrodes when obtaining a 12-lead ECG. If the electrode gel has dried out, it is not able to penetrate the skin. If the gel does not penetrate the skin, the signal to the monitor is weak and artifact results. The signal from the patient's heart is conducted through the cables to the monitor. If the cable's insulation is cracked or if a lead wire is damaged, the signal to the monitor is affected and artifact can result. Check and reconnect the cable connections. Inspect the cables and replace them if damaged.

Question 3

When the baseline on an ECG wanders, ST segments may appear elevated when in fact they are not.

Accepted Answer

When the position of the baseline is in a state of flux, ST-segment analysis is very difficult. As the baseline wanders, the isoelectric point changes from moment to moment. In this situation, the J-point, though it may have been isoelectric when inscribed, can appear elevated above the PR and TP segments. Therefore it is important to be very cautious about analyzing ST-segment elevation in leads with a wandering baseline.

Question 4

The maximum number of leads that a cardiac monitor can obtain is limited by the number of cables attached to the monitor.

Accepted Answer

The maximum number of leads that a cardiac monitor can obtain is not limited by the number of cables attached to the monitor. In fact, any number of leads can be produced from a three-lead monitor.

Question 5

To use ST-segment elevation as an indicator of infarction, the monitor must be set to standard calibration, and in diagnostic quality.

Accepted Answer

An accurate 12-lead requires placing the electrodes correctly, positioning the patient, and selecting the correct settings for a diagnostic quality tracing. To use ST-segment elevation as an indicator of infarction, the monitor must be set to standard calibration, and in diagnostic quality.

Question 6

Lead MCL₁ views the lateral wall of the left ventricle.

Accepted Answer

Lead MCL₁ is a variation of the chest lead V₁ and views the ventricular septum. The negative electrode is placed below the left clavicle toward the left shoulder, and the positive electrode is placed to the right of the sternum in the fourth intercostal space. In this lead the positive electrode is in a position to the right of the left ventricle. Because the primary wave of depolarization is directed toward the left ventricle, the QRS complex recorded in this lead will normally appear negative.

Question 7

Proper ECG machine calibration is critical when analyzing ST segments.

Accepted Answer

The significance of standard calibration is moot when the monitor is used only to determine rate and rhythm. However, proper calibration is critical when analyzing ST segments.

Question 8

When viewing a standard 12-lead ECG, waveforms that are aligned vertically represent a simultaneous recording of the same beat.

Accepted Answer

When viewing a standard 12-lead ECG, the QRS complexes that are aligned horizontally are consecutive while QRS complexes that are aligned vertically represent a simultaneous recording of the same beat.

Question 9

To enhance the quality of the ECGs electrical signal, the patient's skin should be prepared before applying the electrodes. Skin oil and dead skin cells should be removed by:&#10;A) applying alcohol and slowly rubbing the skin surface with fine sandpaper.&#10;B) briskly rubbing the skin with alcohol and then using electric clippers.&#10;C) briskly rubbing the skin with alcohol.&#10;D) briskly rubbing the skin with the abrasive area on the disposable backing of the electrode or a gauze pad.

Accepted Answer

Remove skin oil and dead cells using a brisk, dry rub of the skin with the abrasive area on the disposable backing of the electrode or a gauze pad before applying the electrode.

Question 10

To clearly see the signal produced by the heart and look for signs of possible infarction, the 12-lead ECG's frequency response should be set to:&#10;A) diagnostic quality.&#10;B) monitor quality.

Accepted Answer

The more appropriate frequency response depends on the intended use. Monitor quality aids in rhythm analysis, while diagnostic quality is necessary for accurate ST-segment analysis.

Question 11

Standard calibration for an ECG recording is:&#10;A) 0.1 mV = 10 mm.&#10;B) 0.5 mV = 10 mm.&#10;C) 1 mV = 10 mm.&#10;D) 5 mV = 1 mm.

Accepted Answer

The answer of Standard calibration for an ECG recording is:&#10;A)...

Question 12

The spectrum in which an ECG can accurately reproduce the signals it is sensing is referred to as the _____________ _____________ .

Accepted Answer

The answer of The spectrum in which an ECG can...

Question 13

List the three goals of 12-lead ECG acquisition.

Accepted Answer

The answer of List the three goals of 12-lead ECG...

Question 14

What is artifact on an ECG tracing?

Accepted Answer

The answer of What is artifact on an ECG tracing?...

Question 15

When should normal ECG calibration settings be changed?

Accepted Answer

The answer of When should normal ECG calibration settings be...

Question 16

List two natural barriers that can keep ECG electrode gel from penetrating the skin.

Accepted Answer

The answer of List two natural barriers that can keep...

Deck 3: Community-Based Nursing Practice