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Elective cardioversion is similar to defibrillation except that the electrical stimulation waits to discharge until an R wave appears. What does this prevent?
- A. Disrupting the heart during the critical period of atrial repolarization
- B. Disrupting the heart during the critical period of ventricular repolarization
- C. Disrupting the heart during the critical period of ventricular depolarization
- D. Disrupting the heart during the critical period of atrial depolarization
Correct Answer: B
Rationale: It is similar to defibrillation. One difference is that the machine that delivers the electrical stimulation waits to discharge until it senses the appearance of an R wave. By doing so, the machine prevents disrupting the heart during the critical period of ventricular repolarization.
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The client has just been diagnosed with a arrhythmia. The client asks the nurse to explain normal sinus rhythm. What would the nurse explain is the characteristic of normal sinus rhythm?
- A. Heart rate between 60 and 150 beats/minute.
- B. Impulse travels to the atrioventricular (AV) node in 0.15 to 0.5 second.
- C. The ventricles depolarize in 0.5 second or less.
- D. The sinoatrial (SA) node initiates the impulse.
Correct Answer: D
Rationale: The characteristics of normal sinus rhythm are heart rate between 60 and 100 beats/minute, the SA node initiates the impulse, the impulse travels to the AV node in 0.12 to 0.2 second, the ventricles depolarize in 0.12 seconds or less, and each impulse occurs regularly.
The nurse is providing instruction to a group of new nurses orienting on the unit, highlighting the benefits of the implantable cardioverter defibrillator (ICD). While pointing at a diagram of the heart, at which location would the nurse identify the placement of the electrical lead?
- A. On the right atrium near the SA node
- B. In the right ventricle near the septum
- C. At the left atrium on the anterior wall
- D. On the left ventricle on the posterior wall
Correct Answer: B
Rationale: The nurse is correct to explain that an ICD consists of a generator with a battery and one or two electrical leads that resemble a wire. The generator is placed under the skin, and the lead wire is inserted transvenously through the subclavian or cephalic vein to the apex or septum of the right ventricle. The other options are incorrect.
The client has just been admitted with bradycardia and scheduled for the insertion of a pacemaker. The nurse notifies the physician that the client's heart rate has dropped into the 40 beats/minute range. The physician orders a temporary pacemaker. The nurse knows that there are different types of temporary pacemakers. What types of temporary pacemakers are there? Select all that apply.
- A. Transatrial
- B. Transcutaneous
- C. Transvenous
- D. Transthoracic
- E. Transabdominal
Correct Answer: B,C,D
Rationale: The three types of temporary pacemakers are transcutaneous, transvenous, and transthoracic. Transatrial and transabdominal are not types of temporary pacemakers.
The client has returned to the floor with a transthoracic pacemaker ready to be connected. The nurse knows that a transthoracic pacemaker is a temporary pacemaker used in what situation?
- A. Transthoracic pacemakers are used in a client who has had open heart surgery.
- B. Transthoracic pacemakers are used when a client has an MI.
- C. Transthoracic pacemakers are used after a coronary bypass graft surgery.
- D. Transthoracic pacemakers are used for tachyarrhythmias.
Correct Answer: A
Rationale: The leads of a transthoracic pacemaker are inserted during open heart surgery. They extend from the chest incision. If the client requires cardiac pacing during postoperative recovery, the leads are connected to a temporary pacing unit.
The nurse is caring for a client with an arrhythmia. While assessing the data in the history of the chart, the nurse anticipates the cause of the arrhythmia to be which of the following?
- A. Peripheral vascular disease
- B. Ischemic heart disease
- C. Aortic stenosis
- D. Atherosclerotic heart disease
Correct Answer: B
Rationale: The nurse realizes that the most common cause of arrhythmias is ischemic heart disease. When the heart does not obtain sufficient blood to meet demands, the heart works harder to circulate body fluids and becomes inefficient in the process. Problems with the peripheral vessels, narrowing of the aorta and plaque build-up in the vessels may be a component of the disease process but not the best answer.