CPT II - Midterm Flashcards
(211 cards)
What is automaticity?
Ability of muscle cells to generate their own action potentials
What is rhythmicity?
Action potentials that occur at regular intervals.
What is the function of the intercalated discs in the myocardium?
Gap junctions allow AP to spread and polarize all cells at the same time.
What is a vulnerable period for dysrhythmias in the heart cycle?
During relative refractory period
What does diastole look like on EKG?
Flat line (no electrical activity)
Where is the SA node?
At the base of the superior vena cava (right atrium)
How do you LOOK for cardiac output?
Signs and symptoms
Blood pressure
EKG only shows what kind of heart activity?
Electrical (not mechanical)
When does the SA node fire typically?
When ventricles fill to 80%
What is the AV junction?
Where AV node meets bundle of His (near tricuspid valve)
Dysrhythmias occur as a result from…
altered conduction, rhythmicity, or both
What is an ectopic rhythm?
Rhythm in which the origin is not the SA node
How do dysrhythmias occur?
Hypoxia Ischemia or Irritability Sympathetic stimulation Drugs Electrolyte Disturbances Bradycardias Stretch
How many electrodes are in a 12-lead EKG? What is the purpose of having so many?
10 - each lead has a different view of the heart
What is a bipolar lead?
1 positive and 1 negative electrode
What are the 3 bipolar leads?
Leads I, II, III
What are the 3 unipolar leads?
Leads aVR, aVL, aVF
augmented views - right, left, foot
What is a unipolar lead?
1 positive electrode and 1 reference point
How many views do you need to diagnose a heart condition by EKG?
All 12
Dysrhythmias occur as a result from…
altered conduction, rhythmicity, or both
What is an ectopic rhythm?
Rhythm in which the origin is not the SA node
How do dysrhythmias occur?
Hypoxia Ischemia or Irritability Sympathetic stimulation Drugs Electrolyte Disturbances Bradycardias Stretch
How many electrodes are in a 12-lead EKG? What is the purpose of having so many?
10 - each lead has a different view of the heart
What are the inferior view leads?
II, III, AVF