BCIT - TEST 1 - ECG PACEMAKERS - CARD 3330 EXAM WITH
COMPLETE SOLUTIONS 100% VERIFIED!!!! ALREADY GRADED A+
phases of action potential - (answer)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 - (answer)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 - (answer)conduction and contraction
cellular properties - (answer)excitability, automaticity, conductivity, contractility, and refractoriness
Excitability - (answer)the ability of a cell to respond to a given electrical stimulus when it is not in a state
of refractoriness
Automaticity - (answer)the ability of the cell to spontaneously initiate an action potential. (commonly SA
node)
Conductivity - (answer)the ability of a cardiac cell to transmit an electrical impulse to another cell. (Gap
junctions)
Refractoriness - (answer)the cell's inability to be re-stimulated after depolarization. This is a preventive
mechanism that allows the cell time to contract.
,BCIT - TEST 1 - ECG PACEMAKERS - CARD 3330 EXAM WITH
COMPLETE SOLUTIONS 100% VERIFIED!!!! ALREADY GRADED A+
sinoatrial cells - (answer)P - pacemaker calls
T - Transitional cells
Norepinephrine (NE) - (answer)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: - (answer)SA nodal artery, 2/3 of pop originates in first branch or right
coronary artery.
AV nodal delay - (answer)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 - (answer)the greater the ventricles stretch, enlarging their volume, the more
blood will be pumped out.
AV node may assume the role of pacemaker. - (answer)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 - (answer)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
, BCIT - TEST 1 - ECG PACEMAKERS - CARD 3330 EXAM WITH
COMPLETE SOLUTIONS 100% VERIFIED!!!! ALREADY GRADED A+
Left Anterior Fascicular Block (LAFB) - (answer)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) - (answer)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
bifascicular block - (answer)Blockage of any combination of two of the fascicles or conduction pathways:
a right bundle branch block (RBBB) and anterior hemiblock, a RBBB and posterior hemiblock, or an
anterior hemiblock and posterior hemiblock
Trifascicular block (complete 3rd degree block) - (answer)A blockage or impairment of all three
components of the ventricular conduction system, with one working occasionally to provide AV
conduction
Sinus Node Dysfunction - (answer)refers to deterioration of the propagation of normal beats originating
in the SA node, sometimes coupled with enhanced sinus or atrial automaticity.
sinus arrest, pause, SA block, bradycardia.
COMPLETE SOLUTIONS 100% VERIFIED!!!! ALREADY GRADED A+
phases of action potential - (answer)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 - (answer)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 - (answer)conduction and contraction
cellular properties - (answer)excitability, automaticity, conductivity, contractility, and refractoriness
Excitability - (answer)the ability of a cell to respond to a given electrical stimulus when it is not in a state
of refractoriness
Automaticity - (answer)the ability of the cell to spontaneously initiate an action potential. (commonly SA
node)
Conductivity - (answer)the ability of a cardiac cell to transmit an electrical impulse to another cell. (Gap
junctions)
Refractoriness - (answer)the cell's inability to be re-stimulated after depolarization. This is a preventive
mechanism that allows the cell time to contract.
,BCIT - TEST 1 - ECG PACEMAKERS - CARD 3330 EXAM WITH
COMPLETE SOLUTIONS 100% VERIFIED!!!! ALREADY GRADED A+
sinoatrial cells - (answer)P - pacemaker calls
T - Transitional cells
Norepinephrine (NE) - (answer)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: - (answer)SA nodal artery, 2/3 of pop originates in first branch or right
coronary artery.
AV nodal delay - (answer)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 - (answer)the greater the ventricles stretch, enlarging their volume, the more
blood will be pumped out.
AV node may assume the role of pacemaker. - (answer)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 - (answer)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
, BCIT - TEST 1 - ECG PACEMAKERS - CARD 3330 EXAM WITH
COMPLETE SOLUTIONS 100% VERIFIED!!!! ALREADY GRADED A+
Left Anterior Fascicular Block (LAFB) - (answer)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) - (answer)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
bifascicular block - (answer)Blockage of any combination of two of the fascicles or conduction pathways:
a right bundle branch block (RBBB) and anterior hemiblock, a RBBB and posterior hemiblock, or an
anterior hemiblock and posterior hemiblock
Trifascicular block (complete 3rd degree block) - (answer)A blockage or impairment of all three
components of the ventricular conduction system, with one working occasionally to provide AV
conduction
Sinus Node Dysfunction - (answer)refers to deterioration of the propagation of normal beats originating
in the SA node, sometimes coupled with enhanced sinus or atrial automaticity.
sinus arrest, pause, SA block, bradycardia.
