Basic Arrhythmias Flashcards
What do electrical cells do?
Initiate and conduct impulses
What do mechanical cells do?
Contract in response to stimulation
What is polarization?
Electrical charges are balanced and ready for discharge
What is depolarization?
Discharge of energy that accompanies the transfer of electrical charges across the cell membrane
What is repolarization?
Return of electrical charges to original state
What part of the heart pathway stimulates the mechanical cells?
Perkinje fibers
What is the inherent rate of the SA node?
60-100
What is the inherent rate of the AV junction?
40-60
What is the inherent rate of the ventricles?
20-40
What determines what will be the pacemaker?
The site with the fastest rate
What is the normal pacemaker?
SA node
What is it called when a site speeds up and takes over as pacemaker?
Irritability
What is it called when the normal pacemaker slows down or fails and a lower site assumed pacemaker responsibility?
Escape
Sympathetic stimulation causes what three things with the heart?
Increase heart rate
Increase AV conduction
Increase irritability
Parasympathetic stimulation causes what three things in the heart?
Decreased heart rate
Decreased AV conduction
Decreased irritability
What does the sympathetic branch influence in the heart?
Both the atria and the ventricles
What does the parasympathetic branch influence in the heart?
Atria
Is it negative or positive inside a cardiac cell?
Negative
Is it positive or negative outside a cardiac cell?
Positive
What electrolyte is inside cardiac cells?
Potassium
What electrolyte is outside a cardiac cell?
Sodium
What is the isoelectric line?
Straight line produced on EKG machine that means no current is flowing
If the flow of electricity is toward the positive electrode what will the EKG machine produce?
An upward deflection
If the flow of electricity is toward the negative electrode what will the EKG machine produce?
A downward deflection
How much time in between two tic marks?
3 seconds
What does the height of the deflection indicate?
The voltage
Which lines measure voltage?
Horizontal
Which line measures time?
Vertical lines
How much time is in between two heavy vertical lines on an EKG graph?
.20 seconds
How much time is in between two lite vertical lines on an EKG graph?
.04 seconds
1/5th the time of bold vertical lines