BCIT - TEST 1 - ECG / PACEMAKERS -
CARD 3330 EXAM QUESTIONS AND
ANSWERS 2026 VERIFIED.
Phases of action potential - ANS 1 - resting state - -90mv - Sodium out, potassium in.
2 - depolarization phase - +20mv sodium in, potassium out
3 - repolarization phase - Close sodium channels, loss of potassium, calcium channels open.
Calcium flows out too.
4 - hyperpolarization/terminal - calcium out, potassium in, sodium out.
cardiac conduction system - ANS a system of specialized muscle tissues which conduct
electrical impulses that stimulate the heart to beat.
the sinoatrial node (SA node), internodal tracts, atrioventricular node (AV node), bundle of His,
right and left bundle branches, and the Purkinje fibres
Cardiac cells can be divided into two basic types - ANS conduction and contraction
cellular properties - ANS excitability, automaticity, conductivity, contractility, and
refractoriness
@COPYRIGHT ALL RIGHTS RESERVED PAGE 1 OF 25
,Excitability - ANS the ability of a cell to respond to a given electrical stimulus when it is not in
a state of refractoriness
Automaticity - ANS the ability of the cell to spontaneously initiate an action potential.
(commonly SA node)
Conductivity - ANS the ability of a cardiac cell to transmit an electrical impulse to another
cell. (Gap junctions)
Refractoriness - ANS the cell's inability to be re-stimulated after depolarization. This is a
preventive mechanism that allows the cell time to contract.
sinoatrial cells - ANS P - pacemaker calls
T - Transitional cells
Norepinephrine (NE) - ANS the neurotransmitter used by the sympathetic division of the
autonomic nervous system at the post-ganglionic organ-level (synapse).
innervates both the atria and ventricles. It governs increases in heart rate and AV conduction. It
is also responsible for the "irritability" of cardiac cells.
SA node receives blood from: - ANS SA nodal artery, 2/3 of pop originates in first branch or
right coronary artery.
AV nodal delay - ANS The unique crisscross matrix of the AV node provides the necessary
delay in impulse conduction so that atrial contraction can precede ventricular contraction.
Starling's law of the heart - ANS the greater the ventricles stretch, enlarging their volume, the
more blood will be pumped out.
@COPYRIGHT ALL RIGHTS RESERVED PAGE 2 OF 25
, AV node may assume the role of pacemaker. - ANS If the SA node is diseased or impaired.
Beats around 40 to 60 beats per minute (bpm). The resulting rhythm is considered a nodal or
junctional rhythm.
Hemiblocks - ANS Involve conduction failure in one of the divisions of the left bundle branch (
anterior or posterior)
Anterior block: affects the superior portion of the ventricle
Posterior: affects the inferior portion
Left Anterior Fascicular Block (LAFB) - ANS This presents with an unexplained left-axis
deviation
Left axis deviation, usually >-60 degrees
Small Q in leads I and aVL, small R in II, III and AVF
Usually normal QRS duration
Late intrinsicoid deflection in a VL (>0.045 secs)
Increased QRS voltage in limb leads
Left Posterior Fascicular Block (LPFB) - ANS This presents with an unexplained right-axis
deviation
Right axis deviation (usually > +120 degrees)
Small R in leads I and AVL, small Q in II, III and aVF
Usually normal QRS duration
Late intrinsicoid deflection in aVF (>0.045 secs)
No evidence for right ventricular hypertrophy
@COPYRIGHT ALL RIGHTS RESERVED PAGE 3 OF 25
CARD 3330 EXAM QUESTIONS AND
ANSWERS 2026 VERIFIED.
Phases of action potential - ANS 1 - resting state - -90mv - Sodium out, potassium in.
2 - depolarization phase - +20mv sodium in, potassium out
3 - repolarization phase - Close sodium channels, loss of potassium, calcium channels open.
Calcium flows out too.
4 - hyperpolarization/terminal - calcium out, potassium in, sodium out.
cardiac conduction system - ANS a system of specialized muscle tissues which conduct
electrical impulses that stimulate the heart to beat.
the sinoatrial node (SA node), internodal tracts, atrioventricular node (AV node), bundle of His,
right and left bundle branches, and the Purkinje fibres
Cardiac cells can be divided into two basic types - ANS conduction and contraction
cellular properties - ANS excitability, automaticity, conductivity, contractility, and
refractoriness
@COPYRIGHT ALL RIGHTS RESERVED PAGE 1 OF 25
,Excitability - ANS the ability of a cell to respond to a given electrical stimulus when it is not in
a state of refractoriness
Automaticity - ANS the ability of the cell to spontaneously initiate an action potential.
(commonly SA node)
Conductivity - ANS the ability of a cardiac cell to transmit an electrical impulse to another
cell. (Gap junctions)
Refractoriness - ANS the cell's inability to be re-stimulated after depolarization. This is a
preventive mechanism that allows the cell time to contract.
sinoatrial cells - ANS P - pacemaker calls
T - Transitional cells
Norepinephrine (NE) - ANS the neurotransmitter used by the sympathetic division of the
autonomic nervous system at the post-ganglionic organ-level (synapse).
innervates both the atria and ventricles. It governs increases in heart rate and AV conduction. It
is also responsible for the "irritability" of cardiac cells.
SA node receives blood from: - ANS SA nodal artery, 2/3 of pop originates in first branch or
right coronary artery.
AV nodal delay - ANS The unique crisscross matrix of the AV node provides the necessary
delay in impulse conduction so that atrial contraction can precede ventricular contraction.
Starling's law of the heart - ANS the greater the ventricles stretch, enlarging their volume, the
more blood will be pumped out.
@COPYRIGHT ALL RIGHTS RESERVED PAGE 2 OF 25
, AV node may assume the role of pacemaker. - ANS If the SA node is diseased or impaired.
Beats around 40 to 60 beats per minute (bpm). The resulting rhythm is considered a nodal or
junctional rhythm.
Hemiblocks - ANS Involve conduction failure in one of the divisions of the left bundle branch (
anterior or posterior)
Anterior block: affects the superior portion of the ventricle
Posterior: affects the inferior portion
Left Anterior Fascicular Block (LAFB) - ANS This presents with an unexplained left-axis
deviation
Left axis deviation, usually >-60 degrees
Small Q in leads I and aVL, small R in II, III and AVF
Usually normal QRS duration
Late intrinsicoid deflection in a VL (>0.045 secs)
Increased QRS voltage in limb leads
Left Posterior Fascicular Block (LPFB) - ANS This presents with an unexplained right-axis
deviation
Right axis deviation (usually > +120 degrees)
Small R in leads I and AVL, small Q in II, III and aVF
Usually normal QRS duration
Late intrinsicoid deflection in aVF (>0.045 secs)
No evidence for right ventricular hypertrophy
@COPYRIGHT ALL RIGHTS RESERVED PAGE 3 OF 25
