NHA CCMA UPDATED EXAMS STUDY GUIDE
QUESTIONS AND ANSWERS SURE A+
✔✔EKG - ✔✔Graphical presentation of heart electricity (voltage) over time. This
electricity is created by specialized cells called pacemaker cells. These cells generate
electrical impulses spontaneously (without outside influence) and rhythmically
(automatically).
✔✔4 Cardiac Cell Properties - ✔✔-Automaticity
-Excitability
-Conductivity
-Contractility
✔✔Define Automaticity - ✔✔The ability to spontaneously trigger electrical impulses
without being stimulated by another source.
✔✔Define Excitability - ✔✔(also called irritability) the ability to respond and react to a
stimulus.
✔✔Define Conductivity - ✔✔The ability to receive and transmit electrical impulses to
adjacent cells.
,✔✔Define Contractility - ✔✔A myocardial cell's ability to shorten (or contract) in
response to a stimulus.
✔✔Define Depolarization - ✔✔Occurs when positively charged ions (such as sodium
and calcium) rapidly move from outside the myocardial cell membrane to the inside,
changing the overall charge from negative to a positive.
✔✔Define Repolarization - ✔✔Occurs immediately after depolarization and is the
movement of positively charged ions back to the outside of the cell, returning the cell
back to its original polarized state. A cell must repolarize before it can depolarize again.
✔✔Absolute Refractory Period - ✔✔Is the 1st phase of repolarization in which a
myocardial cell is unable to react to any electrical stimulus.
✔✔Relative Refractory Period - ✔✔Is the 2nd phase of repolarization during which time
a strong enough electrical stimulus might cause new depolarization and contraction.
✔✔Conduction System of The Heart - ✔✔Generates and delivers (conducts) the
electricity to all the muscle fibers of the heart resulting in a smooth, complete
contraction of the cardiac muscle fibers, which forcefully ejects the blood outside the
heart.
✔✔SA Node - ✔✔Found in the upper posterior portion of the right atrial wall just below
the opening of the superior vena cava. It is the primary pacemaker of the heart and has
a normal firing rate of 60-100 bpm.
✔✔Define Internodal Pathways - ✔✔Consists of anterior, middle and posterior division
that distribute electrical impulses generated by the SA node throughout the right and left
atria to the atrio-ventricular (AV) node.
✔✔Define AV Junction (AV node) - ✔✔This node is located at the posterior septal wall
of the right atrium just above the tricuspid valve. There is normally a .12-.20 second
delay of electrical activity at this level to allow blood to flow from the atria and fill the
ventricles with blood.
✔✔Bundle of His - ✔✔Found at the superior portion of the interventricular septum, it is
the pathway that leads out of the AV node and connects to the Bundle Branches.
✔✔Bundle Branches - ✔✔Located at the interventricular septum, the Bundle His divides
into the right and left bundle branches, the function of which is to conduct the electrical
impulse to the Purkinje fibers throughout the ventricles,
✔✔Purkinje Fibers - ✔✔Found within the ventricular endocardium, it consists of a
network of small conduction fibers that deliver the electrical impulses from the Bundle
Branches to the ventricular myocardium.
,✔✔EKG is a _____ that measures the heart electricity traveling through the conductive
system and an important tool for patient's diagnosis. - ✔✔Galvanometer
✔✔EKG Evaluation: - ✔✔-Monitoring patient's HR
-Evaluates injuries to the heart muscle
-Evaluates the pacemakers and conductive system function
-Evaluate the response toward medication
-Provides a baseline record for medical procedure
✔✔Define Electrode - ✔✔Is a paper, plastic or metal sensor placed on the patient's skin
on a specific location and transmit it to the cable.
✔✔Define Cable - ✔✔Is a wire that connects the electrode to the EKG machine (cardiac
monitor).
✔✔Define Lead - ✔✔Is a recorded tracing of the heart electricity from one or two
electrodes that provides a specific view of the heart.
✔✔Standard Bipolar Limb Leads - ✔✔Record electrical activity in the frontal plane.
Electrodes are applied to the left arm (LA), the right arm (RA) and the left leg (LL).
These leads record the difference in electricity between two electrode.
✔✔Lead I - ✔✔The left arm is positive and the right arm is negative. (LA-RA)
✔✔Lead II - ✔✔The left leg is positive and the right arm is negative. (LL-RA)
✔✔Lead III - ✔✔The left leg is positive and the left are is negative. (LL-LA)
✔✔Define Augmented Unipolar - ✔✔Also records electrical activity in the frontal plane.
✔✔Define Augmented Unipolar Leads - ✔✔Record the heart electricity from one limb
and compare it with a zero voltage lead in the center of the heart.
✔✔AV stands for - ✔✔Augmented Coltage
✔✔R stands for - ✔✔Right Arm (RA)
✔✔L stands for - ✔✔Left Arm (LA)
✔✔F stands for - ✔✔Left Leg (LL)
✔✔Lead aVR - ✔✔The right arm is positive and the other limbs are negative.
, ✔✔Lead aVL - ✔✔The left arm is positive and the other limbs are negative.
✔✔Lead aVF - ✔✔The left leg (or foot) is positive and the other limbs are negative.
✔✔Precordial Chest Unipolar Leads - ✔✔All these electrodes are positive and record
the heart electricity in the horizontal plane. They include leads: V1, V2, V3, V4, V5, and
V6.
✔✔V1 - ✔✔Fourth intercostal space, right sternal border.
✔✔V2 - ✔✔Fourth intercostal space, left sternal border.
✔✔V3 - ✔✔Equidistant between V2 and V4.
✔✔V4 - ✔✔Fifth intercostal space, left midclavicular line.
✔✔V5 - ✔✔Fifth intercostal space, anterior axillary line.
✔✔V6 - ✔✔Fifth intercostal space, midaxillary line.
✔✔The Electrocardiographic Grid and Waves - ✔✔The EKG paper is a graph paper
with horizontal and vertical lines at 1-mm intervals. A heavy line appears every 5mm.
✔✔The horizontal axis represents time: - ✔✔1mm = 0.04 seconds
5mm = 0.2 seconds
✔✔The vertical axis represents: - ✔✔voltage, measures in millivolts (1/1000 part of a
volt) but expressed in millimeters: 0.1mV-1mm.
✔✔The tracing is marked on the paper by a stylus using _____. - ✔✔heat
✔✔The running speed of an EKG machine is _____. - ✔✔25mm/sec
✔✔The EKG machine must be properly standardized so that 1mV will produce a
deflection of _____. - ✔✔10mm
✔✔Define Waveform - ✔✔Refers to movement away from the isoelectric line either
upward (positive) deflection or downward (negative) deflection.
✔✔Define Segment - ✔✔Line between two waveforms.
✔✔Define Interval - ✔✔Waveform plus a segment.
QUESTIONS AND ANSWERS SURE A+
✔✔EKG - ✔✔Graphical presentation of heart electricity (voltage) over time. This
electricity is created by specialized cells called pacemaker cells. These cells generate
electrical impulses spontaneously (without outside influence) and rhythmically
(automatically).
✔✔4 Cardiac Cell Properties - ✔✔-Automaticity
-Excitability
-Conductivity
-Contractility
✔✔Define Automaticity - ✔✔The ability to spontaneously trigger electrical impulses
without being stimulated by another source.
✔✔Define Excitability - ✔✔(also called irritability) the ability to respond and react to a
stimulus.
✔✔Define Conductivity - ✔✔The ability to receive and transmit electrical impulses to
adjacent cells.
,✔✔Define Contractility - ✔✔A myocardial cell's ability to shorten (or contract) in
response to a stimulus.
✔✔Define Depolarization - ✔✔Occurs when positively charged ions (such as sodium
and calcium) rapidly move from outside the myocardial cell membrane to the inside,
changing the overall charge from negative to a positive.
✔✔Define Repolarization - ✔✔Occurs immediately after depolarization and is the
movement of positively charged ions back to the outside of the cell, returning the cell
back to its original polarized state. A cell must repolarize before it can depolarize again.
✔✔Absolute Refractory Period - ✔✔Is the 1st phase of repolarization in which a
myocardial cell is unable to react to any electrical stimulus.
✔✔Relative Refractory Period - ✔✔Is the 2nd phase of repolarization during which time
a strong enough electrical stimulus might cause new depolarization and contraction.
✔✔Conduction System of The Heart - ✔✔Generates and delivers (conducts) the
electricity to all the muscle fibers of the heart resulting in a smooth, complete
contraction of the cardiac muscle fibers, which forcefully ejects the blood outside the
heart.
✔✔SA Node - ✔✔Found in the upper posterior portion of the right atrial wall just below
the opening of the superior vena cava. It is the primary pacemaker of the heart and has
a normal firing rate of 60-100 bpm.
✔✔Define Internodal Pathways - ✔✔Consists of anterior, middle and posterior division
that distribute electrical impulses generated by the SA node throughout the right and left
atria to the atrio-ventricular (AV) node.
✔✔Define AV Junction (AV node) - ✔✔This node is located at the posterior septal wall
of the right atrium just above the tricuspid valve. There is normally a .12-.20 second
delay of electrical activity at this level to allow blood to flow from the atria and fill the
ventricles with blood.
✔✔Bundle of His - ✔✔Found at the superior portion of the interventricular septum, it is
the pathway that leads out of the AV node and connects to the Bundle Branches.
✔✔Bundle Branches - ✔✔Located at the interventricular septum, the Bundle His divides
into the right and left bundle branches, the function of which is to conduct the electrical
impulse to the Purkinje fibers throughout the ventricles,
✔✔Purkinje Fibers - ✔✔Found within the ventricular endocardium, it consists of a
network of small conduction fibers that deliver the electrical impulses from the Bundle
Branches to the ventricular myocardium.
,✔✔EKG is a _____ that measures the heart electricity traveling through the conductive
system and an important tool for patient's diagnosis. - ✔✔Galvanometer
✔✔EKG Evaluation: - ✔✔-Monitoring patient's HR
-Evaluates injuries to the heart muscle
-Evaluates the pacemakers and conductive system function
-Evaluate the response toward medication
-Provides a baseline record for medical procedure
✔✔Define Electrode - ✔✔Is a paper, plastic or metal sensor placed on the patient's skin
on a specific location and transmit it to the cable.
✔✔Define Cable - ✔✔Is a wire that connects the electrode to the EKG machine (cardiac
monitor).
✔✔Define Lead - ✔✔Is a recorded tracing of the heart electricity from one or two
electrodes that provides a specific view of the heart.
✔✔Standard Bipolar Limb Leads - ✔✔Record electrical activity in the frontal plane.
Electrodes are applied to the left arm (LA), the right arm (RA) and the left leg (LL).
These leads record the difference in electricity between two electrode.
✔✔Lead I - ✔✔The left arm is positive and the right arm is negative. (LA-RA)
✔✔Lead II - ✔✔The left leg is positive and the right arm is negative. (LL-RA)
✔✔Lead III - ✔✔The left leg is positive and the left are is negative. (LL-LA)
✔✔Define Augmented Unipolar - ✔✔Also records electrical activity in the frontal plane.
✔✔Define Augmented Unipolar Leads - ✔✔Record the heart electricity from one limb
and compare it with a zero voltage lead in the center of the heart.
✔✔AV stands for - ✔✔Augmented Coltage
✔✔R stands for - ✔✔Right Arm (RA)
✔✔L stands for - ✔✔Left Arm (LA)
✔✔F stands for - ✔✔Left Leg (LL)
✔✔Lead aVR - ✔✔The right arm is positive and the other limbs are negative.
, ✔✔Lead aVL - ✔✔The left arm is positive and the other limbs are negative.
✔✔Lead aVF - ✔✔The left leg (or foot) is positive and the other limbs are negative.
✔✔Precordial Chest Unipolar Leads - ✔✔All these electrodes are positive and record
the heart electricity in the horizontal plane. They include leads: V1, V2, V3, V4, V5, and
V6.
✔✔V1 - ✔✔Fourth intercostal space, right sternal border.
✔✔V2 - ✔✔Fourth intercostal space, left sternal border.
✔✔V3 - ✔✔Equidistant between V2 and V4.
✔✔V4 - ✔✔Fifth intercostal space, left midclavicular line.
✔✔V5 - ✔✔Fifth intercostal space, anterior axillary line.
✔✔V6 - ✔✔Fifth intercostal space, midaxillary line.
✔✔The Electrocardiographic Grid and Waves - ✔✔The EKG paper is a graph paper
with horizontal and vertical lines at 1-mm intervals. A heavy line appears every 5mm.
✔✔The horizontal axis represents time: - ✔✔1mm = 0.04 seconds
5mm = 0.2 seconds
✔✔The vertical axis represents: - ✔✔voltage, measures in millivolts (1/1000 part of a
volt) but expressed in millimeters: 0.1mV-1mm.
✔✔The tracing is marked on the paper by a stylus using _____. - ✔✔heat
✔✔The running speed of an EKG machine is _____. - ✔✔25mm/sec
✔✔The EKG machine must be properly standardized so that 1mV will produce a
deflection of _____. - ✔✔10mm
✔✔Define Waveform - ✔✔Refers to movement away from the isoelectric line either
upward (positive) deflection or downward (negative) deflection.
✔✔Define Segment - ✔✔Line between two waveforms.
✔✔Define Interval - ✔✔Waveform plus a segment.
