EKG Quiz

The nurse is participating in a class on rhythm strip interpretation. Which statement by the nurse indicates an understanding of a PR interval of 0.20?

• "This is a normal finding."

• "This is indicative of atrial flutter."

• "This is indicative of atrial fibrillation."

• "This is indicative of impending reinfarction."

Answer explanation

The PR interval represents the time it takes for the cardiac impulse to spread from the atria to the ventricles. The normal range for the PR interval is 0.12 to 0.20 seconds. The remaining options are incorrect and indicate that further education is needed.

A client's electrocardiogram (ECG) strip shows atrial and ventricular rates of 70 complexes/minute. The PR interval is 0.16 second, the QRS complex measures 0.06 second, and the PP interval is slightly irregular. How would the nurse report this rhythm?

• Sinus tachycardia

• Sinus bradycardia

• Sinus dysrhythmia

• Normal sinus rhythm

Answer explanation

Sinus dysrhythmia has all of the characteristics of normal sinus rhythm EXCEPT for the presence of an irregular PP interval. This irregular rhythm occurs because of phasic changes in the rate of firing of the sinoatrial node, which may occur with vagal tone and with respiration.

Which laboratory test results may be associated with peaked or tall, tented T waves on a client's electrocardiogram (ECG)?

• Chloride level of 98 mEq/L

• Sodium level of 135 mEq/L

• Potassium level of 6.8 mEq/L

• Magnesium level of 2.0  mEq/L

Answer explanation

Potassium levels of 5.0 mEq/L or greater indicate hyperkalemia. Hyperkalemia can cause tall, peaked, or tented T waves on the ECG.

Memory Tip: [P]o[T]assium = [P]eaked [T] waves

A client is attached to a cardiac monitor, and the nurse notes the presence of this cardiac rhythm on the monitor. The nurse quickly assesses the client, knowing that this rhythm is indicative of which of the following? (Refer to figure)

• Atrial fibrillation

• Ventricular fibrillation (VF)

• Ventricular tachycardia (VT)

• Premature ventricular complexes

  Submit

Answer explanation

In ventricular tachycardia (VT), it usually is not possible to determine the atrial rhythm. The ventricular rhythm usually is regular or nearly regular. The P waves usually are not visible and are obscured in the QRS complexes. VT occurs with repetitive firing of an irritable ventricular ectopic focus, usually at a rate of 140 to 180 beats/min or more.

The nurse is reviewing the procedure for performance of an electrocardiogram (ECG). Which action by the nurse indicates understanding of the correct position for the V1 lead when performing a 12-lead electrocardiogram?

• The lead is placed on the 4th intercostal space left sternal border.

• The lead is placed on the 4th intercostal space right sternal border.

• The lead is placed on the 5th intercostal space left midaxillary line.

• The lead is placed on the 5th intercostal space left midclavicular line.

Answer explanation

The correct location for the V1 lead is the fourth intercostal space right sternal border.