ECG Analysis

1. Which of the following must be included when interpreting an ECG strip?

RT interval

PR interval

PU segment

RS segement

The PR interval must be included when interpreting an ECG strip. The PR interval represents the time it takes for the electrical impulse to travel from the atria to the ventricles. It is an important measurement in determining the conduction system's functionality and can help identify abnormalities such as heart block. By analyzing the PR interval, healthcare professionals can gain insights into the electrical activity of the heart and make appropriate diagnoses or treatment decisions.

Explanation

The PR interval must be included when interpreting an ECG strip. The PR interval represents the time it takes for the electrical impulse to travel from the atria to the ventricles. It is an important measurement in determining the conduction system's functionality and can help identify abnormalities such as heart block. By analyzing the PR interval, healthcare professionals can gain insights into the electrical activity of the heart and make appropriate diagnoses or treatment decisions.

2. The nurse correlates the QRS complex to the cardiac cycle by stating, “The QRS complex represents…”

“atrial depolarization.”

"ventricular repolarization.”

“atrial repolarization.”

"ventricular depolarization.”

The nurse correctly correlates the QRS complex to the cardiac cycle by stating that it represents ventricular depolarization. Depolarization refers to the change in electrical charge that occurs in the heart muscle cells, causing them to contract. The QRS complex is a waveform on an electrocardiogram (ECG) that represents the depolarization of the ventricles, which are the lower chambers of the heart responsible for pumping blood to the rest of the body. Therefore, the nurse's statement is accurate in explaining the role of the QRS complex in the cardiac cycle.

Explanation

The nurse correctly correlates the QRS complex to the cardiac cycle by stating that it represents ventricular depolarization. Depolarization refers to the change in electrical charge that occurs in the heart muscle cells, causing them to contract. The QRS complex is a waveform on an electrocardiogram (ECG) that represents the depolarization of the ventricles, which are the lower chambers of the heart responsible for pumping blood to the rest of the body. Therefore, the nurse's statement is accurate in explaining the role of the QRS complex in the cardiac cycle.

3. When assessing the ECG of a client who is experiencing chest pain, the nurse observes that the ST segment is 3 millimeters below the isoelectric line. The nurse determines that this is

A result of artifact.

Suggestive of myocardial ischemia.

Not significant unless it is greater than 5mm.

An expected finding

The nurse determines that the ST segment being 3 millimeters below the isoelectric line is suggestive of myocardial ischemia. In a normal ECG, the ST segment should be at the isoelectric line. However, when it is depressed or elevated, it can indicate myocardial ischemia, which is a lack of blood flow to the heart muscle. This finding should be taken seriously as it may indicate an ongoing heart problem and requires further evaluation and intervention.

Explanation

The nurse determines that the ST segment being 3 millimeters below the isoelectric line is suggestive of myocardial ischemia. In a normal ECG, the ST segment should be at the isoelectric line. However, when it is depressed or elevated, it can indicate myocardial ischemia, which is a lack of blood flow to the heart muscle. This finding should be taken seriously as it may indicate an ongoing heart problem and requires further evaluation and intervention.

4. When analyzing an ECG strip, the nurse ascertains which of the following measurements are outside of normal limits?

PR Interval 0.16, QRS 0.04

PR Interval 0.30, QRS 0.06

PR Interval 0.12, QRS 0.04

PR Interval 0.18, ORS 0.06

The PR Interval of 0.30 and the QRS of 0.06 are outside of normal limits. The PR Interval represents the time it takes for the electrical signal to travel from the atria to the ventricles, and a prolonged PR Interval may indicate a conduction delay. The QRS complex represents ventricular depolarization, and a widened QRS complex may suggest a conduction abnormality or bundle branch block. Therefore, the given measurements indicate abnormalities in the conduction system of the heart.

Explanation

The PR Interval of 0.30 and the QRS of 0.06 are outside of normal limits. The PR Interval represents the time it takes for the electrical signal to travel from the atria to the ventricles, and a prolonged PR Interval may indicate a conduction delay. The QRS complex represents ventricular depolarization, and a widened QRS complex may suggest a conduction abnormality or bundle branch block. Therefore, the given measurements indicate abnormalities in the conduction system of the heart.

5. When analyzing an ECG, the nurse correlates movement of the waveform horizontally across ECG paper with

Amplitude.

Voltage.

Intensity.

Time.

When analyzing an ECG, the nurse correlates movement of the waveform horizontally across ECG paper with time. This means that the nurse is looking at how the waveform changes over a specific period, which helps in identifying abnormalities or patterns in the heart's electrical activity. The amplitude refers to the height of the waveform, voltage refers to the electrical potential difference, and intensity refers to the strength or power of the waveform, none of which are directly related to the horizontal movement on the ECG paper.

Explanation

When analyzing an ECG, the nurse correlates movement of the waveform horizontally across ECG paper with time. This means that the nurse is looking at how the waveform changes over a specific period, which helps in identifying abnormalities or patterns in the heart's electrical activity. The amplitude refers to the height of the waveform, voltage refers to the electrical potential difference, and intensity refers to the strength or power of the waveform, none of which are directly related to the horizontal movement on the ECG paper.

6. When studying an ECG strip, the nurse observes the presence of a Q wave and determines that this waveform is

The first downward deflection following the P wave.

Only visible if pathology is present.

Considered normal if less than 0.04 sec duration and less than 25% of the amplitude of the R wave.

Both A and C.

The correct answer is "Both A and C." The nurse observes the presence of a Q wave in an ECG strip. A Q wave is defined as the first downward deflection following the P wave. This means that option A is correct. Additionally, a Q wave is considered normal if it is less than 0.04 sec duration and less than 25% of the amplitude of the R wave. Therefore, option C is also correct. Both options A and C accurately describe the characteristics and significance of a Q wave in an ECG strip.

Explanation

The correct answer is "Both A and C." The nurse observes the presence of a Q wave in an ECG strip. A Q wave is defined as the first downward deflection following the P wave. This means that option A is correct. Additionally, a Q wave is considered normal if it is less than 0.04 sec duration and less than 25% of the amplitude of the R wave. Therefore, option C is also correct. Both options A and C accurately describe the characteristics and significance of a Q wave in an ECG strip.

7. Which of the following statements indicates the nurse is analyzing an ECG strip appropriately?

"The rate is not important as long as the R waves are spaced equally.”

“Evaluating the overall appearance of the strip is the most important aspect of analyzing ECGs.”

“As long as the measurements are correct, it is not necessary to follow any particular order.”

“It is important to analyze the ECG strip in a systematic fashion.”

The correct answer is "It is important to analyze the ECG strip in a systematic fashion." This statement indicates that the nurse understands the importance of following a specific order or method when analyzing an ECG strip. This systematic approach ensures that all necessary measurements and evaluations are performed accurately and thoroughly, leading to a more accurate interpretation of the ECG.

Explanation

The correct answer is "It is important to analyze the ECG strip in a systematic fashion." This statement indicates that the nurse understands the importance of following a specific order or method when analyzing an ECG strip. This systematic approach ensures that all necessary measurements and evaluations are performed accurately and thoroughly, leading to a more accurate interpretation of the ECG.

8. Which of the following statements indicates that the student nurse understands the sequence method of measuring ECGs?

“I need to count the number of R waves during a six second period and multiply that number by 10.”

“I need to count the number of large boxes present and divide that number by 1500.”

“I need to count the number of small boxes present and divide that number by 300.”

The correct answer indicates that the student nurse understands the sequence method of measuring ECGs because it explains the process of selecting an R wave that falls on a dark vertical line and numbering the next 6 dark vertical lines as 300, 150, 100, 75, 60, and 50. This method is commonly used to measure heart rate on an ECG by counting the number of dark vertical lines between R waves and using the assigned numbers to calculate the heart rate.

Explanation

The correct answer indicates that the student nurse understands the sequence method of measuring ECGs because it explains the process of selecting an R wave that falls on a dark vertical line and numbering the next 6 dark vertical lines as 300, 150, 100, 75, 60, and 50. This method is commonly used to measure heart rate on an ECG by counting the number of dark vertical lines between R waves and using the assigned numbers to calculate the heart rate.

9. Which of the following conditions put a client at risk for developing dysrhythimas? (Please select all that apply)

Chronic Obstructive Pulmonary Disease (COPD)

An SaO2 of 95%

Sick Sinus Syndrome

A serum potassium level of 4.1 mEq/L

Both Chronic Obstructive Pulmonary Disease (COPD) and Sick Sinus Syndrome can put a client at risk for developing dysrhythmias. COPD can lead to hypoxia and acidosis, which can disrupt the electrical conduction system of the heart. Sick Sinus Syndrome is a condition where the sinus node, the natural pacemaker of the heart, does not function properly, leading to irregular heart rhythms. An SaO2 of 95% and a serum potassium level of 4.1 mEq/L are within normal ranges and do not directly put a client at risk for developing dysrhythmias.

Explanation

Both Chronic Obstructive Pulmonary Disease (COPD) and Sick Sinus Syndrome can put a client at risk for developing dysrhythmias. COPD can lead to hypoxia and acidosis, which can disrupt the electrical conduction system of the heart. Sick Sinus Syndrome is a condition where the sinus node, the natural pacemaker of the heart, does not function properly, leading to irregular heart rhythms. An SaO2 of 95% and a serum potassium level of 4.1 mEq/L are within normal ranges and do not directly put a client at risk for developing dysrhythmias.

Submit

10. Which of the following ECG findings require further evaluation? (Select all that apply)

PR interval of 0.14sec

PR interval of 0.18sec

QRS complex of 0.14sec

QRS complex of 0.06sec

The PR interval measures the time it takes for the electrical signal to travel from the atria to the ventricles. A PR interval of 0.18sec is longer than the normal range (0.12-0.20sec), indicating a possible conduction delay. This finding requires further evaluation as it could be a sign of atrioventricular (AV) block or other cardiac conduction abnormalities. On the other hand, a QRS complex of 0.14sec falls within the normal range (0.06-0.10sec) and does not require further evaluation. A QRS complex of 0.06sec is abnormally narrow, indicating a possible conduction abnormality, and also requires further evaluation.

Explanation

The PR interval measures the time it takes for the electrical signal to travel from the atria to the ventricles. A PR interval of 0.18sec is longer than the normal range (0.12-0.20sec), indicating a possible conduction delay. This finding requires further evaluation as it could be a sign of atrioventricular (AV) block or other cardiac conduction abnormalities. On the other hand, a QRS complex of 0.14sec falls within the normal range (0.06-0.10sec) and does not require further evaluation. A QRS complex of 0.06sec is abnormally narrow, indicating a possible conduction abnormality, and also requires further evaluation.

Submit