NUR 3463 CARDIAC RHYTHMS QUICK REFERENCES WITH ANSWERS
NUR 3463 Cardiac Rhythm Quick Reference Sheet
Skill #1: Estimate the heart rate from a six second strip
Each segment between the dark lines (above the monitor strip) represents 3 seconds. To estimate the heart
rate, count the QRS complexes in a 6-second strip and multiply that number by 10 to estimate the rate for 1
minute. In this example, there are 9 QRS complexes in 6 seconds. Therefore the heart rate can be
estimated to be 90 beats/min.
Skill #2: Differentiate a regular rhythm from an irregular rhythm
In the example at left, the top rhythm
is regular because the distance
between each QRS complex is
roughly consistent (look at the green
stars). The bottom rhythm is
irregular because there is no
consistency in the distance between
each QRS complex (look at the red
stars)
Skill #3: Identify the basic waves of an ECG strip and know what they indicate
, P Wave: Represents atrial depolarization
(AKA when the atria “squeeze” or “contract” to
pump blood into the ventricles)
QRS Complex: Represents ventricular depolarization
(AKA when the ventricles “squeeze” or “contract” to
pump oxygenated blood to the body and
deoxygenated blood to the lungs)
T Wave: Represents ventricular repolarization
(AKA, when the ventricles “relax” and fill back up
with the blood being pumped in from the atria)
Normal Sinus Rhythm
Rate: 60 to 100 BPM Notes: This is a healthy, normal rhythm. There is one P wave before each QRS
Rhythm: Regular complex, and all the P waves are of a consistent shape.
P Wave: Present
QRS Complex: Normal
T Wave: Present
Sinus Bradycardia
Rate: <60 BPM Causes:
Rhythm: Regular Excessive vagal (parasympathetic) stimulation to the heart
P Wave: Present Vomiting, suctioning, Valsalva maneuvers (e.g., bearing down for a bowel
NUR 3463 Cardiac Rhythm Quick Reference Sheet
Skill #1: Estimate the heart rate from a six second strip
Each segment between the dark lines (above the monitor strip) represents 3 seconds. To estimate the heart
rate, count the QRS complexes in a 6-second strip and multiply that number by 10 to estimate the rate for 1
minute. In this example, there are 9 QRS complexes in 6 seconds. Therefore the heart rate can be
estimated to be 90 beats/min.
Skill #2: Differentiate a regular rhythm from an irregular rhythm
In the example at left, the top rhythm
is regular because the distance
between each QRS complex is
roughly consistent (look at the green
stars). The bottom rhythm is
irregular because there is no
consistency in the distance between
each QRS complex (look at the red
stars)
Skill #3: Identify the basic waves of an ECG strip and know what they indicate
, P Wave: Represents atrial depolarization
(AKA when the atria “squeeze” or “contract” to
pump blood into the ventricles)
QRS Complex: Represents ventricular depolarization
(AKA when the ventricles “squeeze” or “contract” to
pump oxygenated blood to the body and
deoxygenated blood to the lungs)
T Wave: Represents ventricular repolarization
(AKA, when the ventricles “relax” and fill back up
with the blood being pumped in from the atria)
Normal Sinus Rhythm
Rate: 60 to 100 BPM Notes: This is a healthy, normal rhythm. There is one P wave before each QRS
Rhythm: Regular complex, and all the P waves are of a consistent shape.
P Wave: Present
QRS Complex: Normal
T Wave: Present
Sinus Bradycardia
Rate: <60 BPM Causes:
Rhythm: Regular Excessive vagal (parasympathetic) stimulation to the heart
P Wave: Present Vomiting, suctioning, Valsalva maneuvers (e.g., bearing down for a bowel
