EP Flashcards
____ state of a cardiac cell
Resting
_____ _____ of a cardiac cell
Early depolarization
_____ ______ in a cardiac cell
Depolarization complete
____ ______ in a cardiac cell
Early repolarization
Myocardial cells consist of contractile protein filaments called
Actin and myosin
Automaticity
The ability of the pacemaker cells to generate their own electrical impulses spontaneously
Specific to pacemaker cells (not myocardial)
Excitability
The ability of cardiac cells to respond to an impulse
All cardiac cells
Conductivity
The ability of cardiac cells to receive an electrical impulse and transmit it to other cardiac cells
All cardiac cells
Contractility
The ability of the myocardial cells to shorten and cause muscle contraction
Specific to myocardial cells (not pacemakers cells)
Primary intracellular ion
Potassium (K+)
Primary extracellular ion
Sodium (Na+)
In the resting cardiac cell, the inside of the cell is more ____ than outside
Negative
The depolarization process proceeds from the ______ layer to the ______ layer of the heart
Innermost to outermost
The repolarization process proceeds from the _____ layer to the _____ layer of the heart
Outermost to innermost
SA Node Rate
60-100 bpm
AV Node Rate
40-60 bpm
Secondary pacemaker
Ventricular pacemaker cell rate
30-40 bpm
How many intranodal tracts are located in the RA?
3
Interatrial tract conducting impulses from the SA node to the LA
Bachmann’s bundle
Period in which cardiac cells cannot respond to a stimulus no matter the strength
Absolute refractory period
Absolute refractory period on ECG tracing
Onset of the QRS complex to the peak of the T wave
Period in which cardiac cells have the potential to respond to a stronger than normal stimulus
Relative refractory period
AKA the vulnerable period of repolarization
Relative refractory period on an ECG tracing
Peak of the T wave to the end of the T wave
Why is the relative refractory period also referred to as the vulnerable period of repolarization
Cardiac cells could respond to a stronger than stimulus which could usurp the primary pacemaker of the heart
Period in which cardiac cells will respond to a weaker than normal stimulus
Supernormal period
Near the end of the T wave
