Page 197 - Critical Care Nursing Demystified

182 CRITICAL CARE NURSING DeMYSTIFIED

• RATE: Atrial/ventricular rate = normal
• RHYTHM: Atrial/ventricular rhythm = normal

• CONDUCTION
• PRI = normal
• QRS = normal
• QTI = normal
This is an expected outcome for patients. We want to see them in this
rhythm, especially if this is their baseline or normal rhythm.

Sinus Bradycardia (SB)
In sinus bradycardia, the SA node pacemaker slows to a rate of less than 60. The
problem with this is that the vital organs may not get needed oxygen with a
heart rate this low. So a symptomatic bradycardia is nothing to ignore. Some-
times people with very athletic hearts are in bradycardias. This is normal as
their hearts hypertrophy and become much more efficient when they exercise.
Sometimes people have an asymptomatic bradycardia when they sleep because
their metabolic demands are low. The idea is, if they are not having symptoms,
we do not treat this rhythm. Downloaded by [ Faculty of Nursing, Chiangmai University 5.62.158.117] at [07/18/16]. Copyright © McGraw-Hill Global Education Holdings, LLC. Not to be redistributed or modified in any way without permission.
In an SB, all is normal except for the HR; it is less than 60.
• RATE: Atrial/ventricular rate = less than 60.
• RHYTHM: Atrial/ventricular rhythm = regular.
• CONDUCTION: All intervals are normal except the QTI may be pro-
longed.

NURSING ALERT

A patient should not be treated unless he or she has signs/symptoms of decreased
cardiac output or a symptomatic bradycardia. Find the underlying cause and treat it!
If the patient is digitoxic, give digoxin immune Fab (digibind); if the patient has been
given Lopressor (metoprolol), hold the drug. If the patient is symptomatic, consider
atropine, epinephrine, and possible transcutaneous or transvenous temporary pacing.

Sinus Tachycardia (ST)
In a sinus tachycardia, the SA node pacemaker speeds up so the heart rate goes
above 100. This is a problem for the heart because it increases the energy
needed for fast contraction. Unrelieved, it can cause undue stress and strain on
the heart, increasing metabolic needs, which can cause an MI and heart failure.
Any unexplained ST needs to be evaluated for the cause. Fever, hypoxia, and