Chapter 35: Dysrhythmias
A patient admitted with syncope has continuous ECG monitoring. An examination of the
rhythm strip reveals the following: atrial rate 74 beats/min and regular; ventricular rate
62 beats/min and irregular; P wave normal shape; PR interval lengthens progressively
until a P wave is not conducted; QRS normal shape. The priority nursing intervention
would be to
a. give epinephrine 1 mg IV push.
b. prepare for synchronized cardioversion.
c. observe for symptoms of hypotension or angina.
d. apply transcutaneous pacemaker pads on the patient.
Rationale: The rhythm is a second-degree atrioventricular (AV) block, type I (i.e., Mobitz
I or Wenckebach heart block). It is characterized by a gradual lengthening of the PR
interval. Type I AV block is usually a result of myocardial ischemia or infarction. It is
typically transient and well tolerated. The nurse should assess for bradycardia,
hypotension, and angina. The symptomatic patient may need atropine or a temporary
pacemaker.
The ECG monitor of a patient in the cardiac care unit after an MI shows ventricular
bigeminy with a rate of 50 beats/min. The nurse would
a. perform defibrillation.
b. administer IV amiodarone.
c. prepare for temporary pacemaker insertion.
d. assess the patient's response to the dysrhythmia.
Rationale: A premature ventricular contraction (PVC) is a contraction originating in an
ectopic focus in the ventricles. When every other beat is a PVC, the rhythm is called
ventricular bigeminy. PVCs are usually a benign finding in patients with a normal heart.
In patients with heart disease, PVCs may reduce the cardiac output and precipitate
angina and heart failure, depending on the frequency. Because PVCs in coronary artery
disease (CAD) or acute myocardial infarction indicate ventricular irritability, the patient's
physiologic response to PVCs must be monitored. Assessing the patient's
hemodynamic status is important for deciding the need for drug therapy.