Question 1

When electrical activity is not detected on the ECG, a straight line is recorded called the "baseline" or "isoelectric line."

Accepted Answer

When electrical activity is not detected, a straight line is recorded. This line is called the baseline or isoelectric line.

Question 2

The ECG does not provide information about:

Accepted Answer

The ECG does not provide information about the mechanical (contractile) condition of the myocardium. To evaluate the effectiveness of the heart's mechanical activity, the patient's pulse and blood pressure are assessed.

Question 3

Where is the negative electrode placed in lead II?

Accepted Answer

Lead II records the difference in electrical potential between the left leg (+) and right arm (-) electrodes. The positive electrode is placed on the left leg and the negative electrode is placed on the right arm.

Question 4

In an adult, the normal duration of the QRS complex is:

Accepted Answer

The normal duration of the QRS complex in adult males is 110 ms (0.11 second) or less.

Question 5

Select the incorrect statement regarding the PR interval.

Accepted Answer

The PRI changes with heart rate but normally measures 0.12 to 0.20 second in adults. As the heart rate increases, the duration of the PR interval shortens.

Question 6

Where should the positive electrode for lead V₅ be positioned?

Accepted Answer

Lead V₄ is recorded with the positive electrode in the left midclavicular line in the fifth intercostal space. Lead V₅ is recorded with the positive electrode in the left anterior axillary line at the same level as V₄.

Question 7

Lead V₅ views the _____ of the left ventricle.

Accepted Answer

Lead V₅ views the lateral wall of the left ventricle.

Question 8

Which of the following leads should be used to view the right ventricle?

Accepted Answer

Lead V₄ is recorded with the positive electrode in the left midclavicular line in the fifth intercostal space. To evaluate the right ventricle, lead V₄ may be moved to the same anatomic location but on the right side of the chest. The lead is then called V₄R and is viewed for ECG changes consistent with acute MI.

Question 9

Lead V₁ views the:

Accepted Answer

Lead V₁ is recorded with the positive electrode in the fourth intercostal space, just to the right of the sternum. Lead V₁ views the septum.

Question 10

The portion of the ECG tracing between the T wave and P wave is called the:

Accepted Answer

The TP segment is the portion of the ECG tracing between the end of the T wave and the beginning of the following P wave. When the heart rate is within normal limits, the TP-segment is usually isoelectric. With rapid heart rates, the TP segment is often unrecognizable because the P wave encroaches on the preceding T wave.

Question 11

When leads I and aVF are used to determine electrical axis, left axis deviation is present if the QRS is:

Accepted Answer

Leads I and aVF divide the heart into four quadrants. These two leads can be used to quickly estimate electrical axis. In leads I and aVF, the QRS complex is normally positive. If the QRS complex in either or both of these leads is negative, axis deviation is present.Another popular shortcut using leads I and aVF to determine axis deviation is called the "thumbs method." Hold up your left and right hands and make a thumbs up/thumbs down position in the direction of the QRS in leads I and aVF, respectively. Two thumbs up reflects normal axis. Left thumb up, right thumb down = left axis deviation. Left thumb down, right thumb up = right axis deviation. Both left and right down = extreme right axis deviation.

Question 12

Complete the following chart: 
 $\begin{array}{lrr}
  \text {  Lead } & \text { Positive  } & \text {Negative  }  & \text {Heart Surface  }\
 \text {  } & \text {  Electrode} & \text { Electrode }  & \text {viewed  }\
 \text {   Lead I} &\underline{\quad\quad} &\underline{\quad\quad} &\underline{\quad\quad}\
 \text {   Lead II}  &\underline{\quad\quad} &\underline{\quad\quad} &\underline{\quad\quad}\
 \text {  Lead III }  &\underline{\quad\quad} &\underline{\quad\quad} &\underline{\quad\quad}\
\end{array}$

Accepted Answer

The answer of Complete the following chart: 
 \(\begin{array}{lrr}
 ...

Question 13

Complete the following chart:
 
 $\begin{array}{lrr}
  \text {  Lead } & \text { Positive  } & \text {Heart Surface  }\
 \text {  } & \text {  Electrode}  & \text {viewed  }\
 \text {   aVR} &\underline{\quad\quad} &\underline{\quad\quad} \
 \text {   aVL}  &\underline{\quad\quad} &\underline{\quad\quad} \
 \text {  aVF}  &\underline{\quad\quad} &\underline{\quad\quad} \
\end{array}$

Accepted Answer

The answer of Complete the following chart:
 
 \(\begin{array}{lrr}
 ...

Quiz 2: The Health Care Delivery System