EKG Ch. 4 Flashcards
Rate (27 cards)
What are the five main areas to master for EKG interpretation?
Rate, rhythm, axis, block, and infarction.
What is the standard calculation used to convey heart rate?
Beats per minute (bpm).
What is the normal heart rate range that originates in the sinus node?
60 to 100 bpm.
What does the term automaticity refer to in the context of the heart?
Areas of the heart that can initiate a pacemaker impulse.
Which areas of the heart are capable of initiating a cardiac impulse?
- Sinus node
- Atrioventricular (AV) node
- Ventricles
What is the intrinsic rate of the sinus node?
60 to 100 bpm.
What is the intrinsic rate of the AV node?
40 to 60 bpm.
What is the intrinsic rate of the ventricles?
20 to 40 bpm.
True or False: The lower in the conduction system the focus is located, the more stable and reliable the focus is.
False.
What happens if an automaticity area fails to generate an impulse in a timely fashion?
The next fastest pacemaker will become the dominant one.
What does the presence of a P wave indicate?
Sinus node activity.
How is the heart rate calculated using R waves?
Identify an R wave on a thick black line and count 300, 150, 100, 75, 60, 50, 40 for each large box until the next R wave.
If the calculated heart rate is between 60 and 100 bpm with a normal P wave, what does this indicate?
The automaticity focus generating that impulse is within the sinus node.
What is consistent with sinus tachycardia?
Heart rates greater than 100 bpm with a normal-appearing P wave.
What is consistent with sinus bradycardia?
Heart rates less than 60 bpm with a P wave before every QRS.
How do you estimate heart rate if it is less than 40 bpm?
Count QRS complexes in a 10-second rhythm strip and multiply by 6.
What is an escape rhythm?
Anything that originates below the sinus node.
What is an AV junctional escape rhythm?
A heart rate of 40 to 60 bpm with no P wave before each QRS.
What is a ventricular escape rhythm?
A heart rate of 20 to 40 bpm with no P wave before each QRS.
What characterizes an AV nodal junctional focus?
Narrow or only slightly prolonged QRS.
What characterizes a ventricular focus?
Very wide QRS.
What is chronotropic incompetence?
Inability of the sinus node to effectively increase the sinus rate with activity.
What symptoms may patients with chronotropic incompetence experience?
Persistent fatigue and exercise intolerance.
What can indicate a need for permanent pacing in patients with chronotropic incompetence?
Inadequate heart rate response to activity.
