A nurse is reviewing a client’s cardiac monitor for dysrhythmias. Which of the following findings should the nurse identify as an indication for the placement of a permeant peacemaker?
A. Complete AV block with rates slower than 40/mm
B. Sinus tachycardia with rates faster than 80/mm
C. Vasovagal bradycardia without syncope
D.Asymptomatic second-degree AV block
The correct answer and explanation is:
The correct answer is A. Complete AV block with rates slower than 40 bpm.
Explanation:
A complete atrioventricular (AV) block, also known as third-degree heart block, is a serious condition where the electrical signals from the atria do not reach the ventricles. This results in a complete dissociation between the atrial and ventricular activity, meaning the atria and ventricles beat independently. In a complete AV block, the ventricular rate often becomes slow, usually under 40 bpm, which is too slow to maintain an adequate cardiac output. This slow rate can lead to symptoms such as dizziness, fatigue, or syncope (fainting), and in some cases, can be life-threatening.
The placement of a permanent pacemaker is indicated in patients with complete AV block and a slow ventricular rate (typically less than 40 bpm) because the pacemaker helps maintain an adequate heart rate by providing electrical impulses to stimulate the heart, ensuring the ventricles contract at a proper rate.
Other options explained:
- B. Sinus tachycardia with rates faster than 80 bpm: Sinus tachycardia is typically a physiological response to conditions like exercise, stress, or fever. It is not a reason to place a permanent pacemaker unless the tachycardia is sustained and symptomatic, which is not the case here.
- C. Vasovagal bradycardia without syncope: Vasovagal bradycardia is often triggered by stimuli like standing up too quickly or emotional stress. It typically results in a transient drop in heart rate but without long-term effects. If the patient is not experiencing symptoms like syncope, a pacemaker is usually not required.
- D. Asymptomatic second-degree AV block: Second-degree AV block can be either type I (Wenckebach) or type II. Type I is often benign and may not require intervention. Type II can progress to complete heart block, and a pacemaker may be considered in some cases, but in asymptomatic patients, it is not always immediately necessary. However, symptomatic second-degree AV block (especially type II) would warrant a pacemaker.