1. Normal sinus rhythm can normally have some slight variability in the regularity of the complexes. However, the difference between the longest and shortest intervals should never be greater than 0.16 seconds. True or False.
2. Sinus arrhythmia refers to a rhythm of sinus origin that has a variability in the regularity of the complexes of greater than 0.16 seconds. True or False.
3. There are two kinds of sinus arrhythmias:
A. Respiratory or phasic sinus arrhythmia
B. Circulatory or episodic sinus arrhythmia
C. Nonrespiratory or nonphasic sinus arrhythmia
D. A and B are correct
E. A and C are correct
4. Respiratory sinus arrhythmia is caused by:
A. Decreased blood pressure to the brain.
B. Transient vagal stimulation.
C. Excessive catecholamine upsurge.
D. Increased blood flow to the left side of the heart during inspiration.
E. All of the above
5. Respiratory sinus arrhythmia is a variant of normal. True or False.
6. The heart rate normally speeds up during:
A. Inspiration
B. Expiration
C. All of the above
D. None of the above
7. Respiratory sinus arrhythmia is normally seen in:
A. Adolescents.
B. Older patients.
C. Athletes.
D. MI patients.
E. Both A and C are correct
F. Both B and D are correct
8. You should always consider other possibilities closely before making the diagnosis of sinus arrhythmia because, frequently, multiple PVCs can be mistaken for sinus arrhythmia. True or False.