NRSG 421 ECG Interpretation - Questions With
Reliable Solutions
Save
Terms in this set (88)
•Automaticity
Four properties of •Excitability
cardiac cells •Conductivity
•Contractility
Ability of cardiac pacemaker cells to spontaneously
•Automaticity
initiate an electrical impulse
What is this done by?
Done by SA node normally
Ability of cardiac cells to respond to an electrical
impulse generated by pacemaker cells or other
•Excitability
stimuli
What are the
components of
Depolarization occurs when the cells become
excitability, and what is
electrically excited
happening in them?
Repolarization occurs when cells return to the
resting state
Ability of the cardiac cells to transmit the electrical
•Conductivity
impulse to adjacent cardiac cells
-What are we seeing on
•Wave of depolarization creates the deflections
the ECG, what causes it?
seen on the ECG
Ability of the cardiac cells to shorten in response to
•Contractility
electrical stimulation; a mechanical event
K+ inside, Na+ outside
Na+ rush inside once threshold reached - K+ flow
Process of an action
out. Causes action potential
potential:
Ca come to stabilize membrane
Na/K+ pump reverts things back to normal
, Action potentials: Sodium enters
•What electrolyte enters Calcium
the cell during SA Node
depolarization? No - you need to depolarize to contract
•What electrolyte is PEA - pulseless electrical activity
primarily responsible for
contraction?
•What is normally
responsible for
automaticity in the heart?
•Is it possible to have
contraction without
depolarization?
•What is electrical activity
without a pulse called?
Cardiac conduction SA node, AV node, Bundle of His, Purkinje fibers
system order:
SA node: Role, impulse •Normal or dominant pacemaker of the heart
rate, where is it -Spontaneously generates impulses at 60-100 bpm
conducted through -Impulse conducted through both atria
SA node: Can it respond Yes, innervated by both
to SNS and PSNS?
Gatekeeper - only electrical path between atria and
AV node: Purpose, ventricles
function, (Includes AV node and Bundle of His)
delay purpose?
Impulse delayed at AV node - allows atrial kick
Suppose the SA node -Back up pacemaker with impulse generation at 40-
fails, what does the AV 60 bpm (if SA node fails)
node do?
Cardiac conduction Bundle of His bifurcates into left and right bundle
system: Ventricles branches into the Purkinje fibers
What's going on here?
-Cells occasionally demonstrate automaticity
What do the cells do (irritation/damage)
sometimes?
Reliable Solutions
Save
Terms in this set (88)
•Automaticity
Four properties of •Excitability
cardiac cells •Conductivity
•Contractility
Ability of cardiac pacemaker cells to spontaneously
•Automaticity
initiate an electrical impulse
What is this done by?
Done by SA node normally
Ability of cardiac cells to respond to an electrical
impulse generated by pacemaker cells or other
•Excitability
stimuli
What are the
components of
Depolarization occurs when the cells become
excitability, and what is
electrically excited
happening in them?
Repolarization occurs when cells return to the
resting state
Ability of the cardiac cells to transmit the electrical
•Conductivity
impulse to adjacent cardiac cells
-What are we seeing on
•Wave of depolarization creates the deflections
the ECG, what causes it?
seen on the ECG
Ability of the cardiac cells to shorten in response to
•Contractility
electrical stimulation; a mechanical event
K+ inside, Na+ outside
Na+ rush inside once threshold reached - K+ flow
Process of an action
out. Causes action potential
potential:
Ca come to stabilize membrane
Na/K+ pump reverts things back to normal
, Action potentials: Sodium enters
•What electrolyte enters Calcium
the cell during SA Node
depolarization? No - you need to depolarize to contract
•What electrolyte is PEA - pulseless electrical activity
primarily responsible for
contraction?
•What is normally
responsible for
automaticity in the heart?
•Is it possible to have
contraction without
depolarization?
•What is electrical activity
without a pulse called?
Cardiac conduction SA node, AV node, Bundle of His, Purkinje fibers
system order:
SA node: Role, impulse •Normal or dominant pacemaker of the heart
rate, where is it -Spontaneously generates impulses at 60-100 bpm
conducted through -Impulse conducted through both atria
SA node: Can it respond Yes, innervated by both
to SNS and PSNS?
Gatekeeper - only electrical path between atria and
AV node: Purpose, ventricles
function, (Includes AV node and Bundle of His)
delay purpose?
Impulse delayed at AV node - allows atrial kick
Suppose the SA node -Back up pacemaker with impulse generation at 40-
fails, what does the AV 60 bpm (if SA node fails)
node do?
Cardiac conduction Bundle of His bifurcates into left and right bundle
system: Ventricles branches into the Purkinje fibers
What's going on here?
-Cells occasionally demonstrate automaticity
What do the cells do (irritation/damage)
sometimes?
