Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
111 Cards in this Set
- Front
- Back
When at rest, do cardiac cells hold a positive or negative electrical charge?
|
Negative
|
|
How do resting cardiac cells maintaing their polarity?
|
Membrane Pump
|
|
Name the process by which cardiac cells dramatically lose their resting polarity.
|
Depolarization
|
|
Name the process by which cardiac cells regain their resting polarity?
|
Repolarization
|
|
Name the three types of cells that make up the heart.
|
Packemaker Cells
Electrical Conducting Cells Myocardial Cells |
|
Name the process of one electrical cycle of depolarization and repolarization of a single cell.
|
Action Potential
|
|
True or False:
Unlike typical cells, a cardiac pacemaker cell does NOT have a true resting potential. |
TRUE
The charge of a cardiac pacemaker cell rises from a minimal negative potential which it maintains for just a moment prior to depolarization, but it does not rest there. |
|
The dominant pacemaker cells in the heart located high up in the right atrium.
|
Sinoatrial Node
(aka: SA Node or Sinus Node) |
|
Region of intra-atrial septum that allows for rapid activation of the left atrium from the right.
|
Bachman's bundle
|
|
Contractile proteins contained within myocardial cells.
|
actin and myosin
|
|
Process of cellular contraction upon depolarization in which calcium plays a key role.
|
Excitation-contraction coupling
|
|
Depolarization causes what element to be released within the myocardial cell.
|
Calcium
|
|
True or False:
Myocardial conduction is slower than electrical conducting cell conduction. |
True
Electrical current flows through myocardial cells less effeciently that it does through cardiac conduction cells. |
|
Name the three chief characteristics of EKG waves.
|
Duration
Amplitude Configuration (morphology) |
|
Size of small squares on EKG paper
|
1 x 1 mm
|
|
Size of large squares on EKG paper
|
5 x 5 mm
|
|
Horizontal duration of small squares on EKG paper
|
0.04 seconds
|
|
Horizontal duration of large squares on EKG paper
|
0.2 seconds
|
|
Number of small squares per length of a large square on EKG paper.
|
5
|
|
Vertical amplitude of one small square on EKG paper
|
0.1 mV
|
|
Vertical amplitude of one large square on EKG paper
|
0.5 mV
|
|
Verticle amplitude of two large squares on EKG paper
|
1 mV
|
|
Horizontal duration of five large squares on EKG paper
|
1 second
|
|
True or False:
Sinus node firing is visible on EKG. |
False
While the associated firing of the atria are visible as a P-wave, in fact the sinus node itself does not produce a large enough signal to be visible on EKG. |
|
True or False:
The P-wave is the sinus node firing. |
False
The right side of the P-wave corresponds with the right atrium firing; the left side of the P-wave corresponds with the left atrium. Sinus node firing itself is actually not visible on EKG. |
|
True of False:
In a healthy heart, atrial depolarization is blocked from transmission to the ventricles by the heart valves between the atria and ventricles. |
True
In a healthy heart, depolarization can only proceed to the ventricles through the AV node at the top of the septum. |
|
True or False:
Both the SA node and the AV node are under the influence of the autonomic nervous system. |
True
|
|
Name the three main parts of the ventricular conduction system.
|
Bundle of His
Bundle Branches Terminal Purkinje Fibers |
|
Name the three segments of the left bundle branch.
|
Septal Fascicle
Anterior Fascicle Posterior Fascicle |
|
Name of EKG deflection that represents ventricular depolarization.
|
QRS Complex
|
|
If the first deflection is downward, what is it called?
|
Q wave
|
|
What is the first upward deflection called?
|
R wave
|
|
If there is a second upward deflection, what is it called?
|
R-prime
|
|
What is the first downward deflection following an upward deflection called?
|
S wave
|
|
If the entire configuration consists of only one downward deflection, what is it called?
|
QS wave
|
|
What are two upward deflections called?
|
RSR
|
|
Small, discreet negative deflection that indicates septal depolarization.
|
Q wave
|
|
Ventricular repolarization wave
|
T wave
|
|
True or False:
There is no such thing as an atrial repolarization wave. |
False
There is an atrial repolarization wave, but it is generally hidden behind the more prominent QRS complex. |
|
What measures the time from the start of atrial depolarization to the start of ventricular depolarization?
|
PR interval
|
|
What measures the time from the end of atrial depolarization to the start of ventricular depolarization?
|
PR segment
|
|
What records the time from the end of ventricular depolarization to the start of ventricular repolarization?
|
ST segment
|
|
What measures the time from the start of ventricular depolarization to the end of ventricular repolarization?
|
QT interval
|
|
What measures the time of ventricular depolarization?
|
QRS interval
|
|
What kind of deflection is produced by a wave of depolarization moving toward a positive electrode?
|
a positive deflection
|
|
What kind of deflection is produced by a wave of depolarization moving away from a positive electrode?
|
a negative deflection
|
|
What kind of deflection is produced by a wave of repolarization moving away from a positive electrode?
|
a positive deflection
|
|
What kind of deflection is produced by a wave of repolarization moving toward a positive electrode?
|
a negative deflection
|
|
How many electrodes are used to provide the basis for the six limb leads?
|
four
(two arm/two leg) |
|
What are the two kinds of limb leads?
|
Standard Leads (3)
Augmented Leads (3) |
|
What are the leads that are positioned around the horizontal plane of the heart called?
|
Precordial Leads (6)
|
|
On which plane do the limb leads view the heart's electrical activity?
|
Frontal Plane
|
|
On which plane do the precordial leads view the heart's electrical activity?
|
Horizontal (Transverse) Plane
|
|
On the frontal plane, are superiorly oriented angles of orientation expressed in positive or negative degrees?
|
Superior is Negative
|
|
On the frontal plane, are inferiorly oriented angles of orientation expressed in positive or negative degrees?
|
Inferior is Positive
|
|
Each lead has its own specific view of the heart, called what?
|
Angle of Orientation
|
|
An angle of orientation can be determined by drawing a line from what to what?
|
from a negative to
a positive electrode |
|
Name the three standard limb leads.
|
Lead I
Lead II Lead III |
|
Which lead is created by making the left arm positive and the right are negative?
|
Lead I
|
|
What is the angle of orientation for Lead I?
|
0 degrees
|
|
Which lead is created by making the legs positive and the right arm negative?
|
Lead II
|
|
What is the angle or orientation of Lead II?
|
60 degrees
|
|
Which lead is created by making the legs positive and the left arm negative?
|
Lead III
|
|
What is the angle of orientation of Lead III.
|
120 degrees
|
|
With respect to the three augemented limb leads, what does the term 'augmented' refer to?
|
EKG machine must amplify (augment)the tracings of these three leads to get an adequate recording.
|
|
Which lead is created by making the left arm positive and the rest of the limbs negative?
|
AVL
|
|
What is the angle of orientation of AVL?
|
Negative 30 degrees
|
|
Which lead is created by making the right arm positive and the rest of the limbs negative?
|
AVR
|
|
What is the angle of orientation of AVR?
|
Negative 150 degrees
|
|
Which lead is created by making the legs positive and the arms negative?
|
AVF
|
|
What is the angle of orientation of AVF?
|
90 degrees
|
|
Name the inferior leads.
|
II, III, AVF
|
|
Name the left lateral leads.
|
I, AVL, V5, V6
|
|
Name the anterior leads.
|
V1, V2, V3, V4
|
|
Which lead runs superiorly and to the right?
|
AVR
|
|
Precordial leads view the electrical activity of the heart on which plane?
|
horizontal plane
|
|
Which lead is placed in the fourth intercostal space to the right of the sternum.
|
V1
|
|
Which lead is placed in the fourth intercostal space to the left of the sternum.
|
V2
|
|
Which lead is placed in the fifth intercostal space in the midclavicular line?
|
V4
|
|
Which lead is placed in the fifth intercostal space in the midaxillary line?
|
V6
|
|
What is the correct placement of the V3 lead?
|
between V2 and V4
|
|
What is the correct placement of the V5 lead?
|
between V4 and V6
|
|
What part of the heart do the V1 and V2 leads lie directly over?
|
right ventricle
|
|
What part of the heart do the V3 and V4 leads lie directly over?
|
septum
|
|
What part of the heart do the V5 and V6 leads lie directly over?
|
left ventricle
|
|
True or False:
The vector's angle of orientation represents the average direction of current flow. |
True.
The EKG electrode records only the average current flow at any given moment. |
|
The amplitude of a P-wave does not normally exceed this value in any lead.
|
0.25 mV
(2.5 mm or 2.5 small squares) |
|
Normal range of the P-wave vector
|
0-70 degrees
|
|
Normal duration of the PR interval
|
0.12 to 0.2 seconds
(3 to 5 mm on EKG paper) |
|
Which portion of the heart is the first to depolarize during ventricular depolarization?
|
interventricular septum
|
|
In which direction does the interventricular septum depolarize.
|
left-to-right
|
|
A tiny negative deflection in one or several left lateral leads is likely to reflect what event?
|
Septal depolarization
|
|
What is the normal maximum amplitude of septal Q waves?
|
0.1 mV
|
|
Normal vector range for ventricular depolarization.
|
0-90 degrees
|
|
What term describes an R-wave and an S-wave of nearly equal amplitude?
|
Biphasic QRS
|
|
The zone in which leads V3 and V4 are positioned, normally associated with biphasic waves.
|
Transition zone
|
|
What term describes the pattern of progressively increasing R-wave amplitude moving right to left across the precordial leads?
|
R-wave progression
|
|
True or False:
R-wave progression steadily increases from V1 to V6. |
False:
The R-wave in V6 is usually a little smaller than that in V5. |
|
The normal transition zone occurs in which leads?
|
V3 and V4
|
|
What is the duration of a normal QRS interval?
|
0.06 to 0.1 seconds
(2.5 small squares or 1/2 large square) |
|
True or False:
The ST segment is usually downsloping in all leads. |
False.
The ST segment is usually horizontal or gently upsloping in all leads. |
|
The T-wave represents what cardiac event?
|
ventricular repolarization
|
|
True or False:
Repolarization requires more cellular energy than depolarization. |
True.
Depolarization is largely passive; repolarization is an active product of the cell's membrane pump. |
|
True or False:
The first cells to depolarize are also the first to repolarize in a healthy heart. |
False.
Repolarization usually begins at the last area of the heart to have been depolarized and travels backward. |
|
True or False:
It is typical and normal to find positive T-wave in the same leads that have tall R waves. |
True
|
|
What is the amplitude or height of a normal T-wave?
|
one third to two thirds that of the corresponding R wave
|
|
True or False:
The duration of the QT interval is proportionate to the heart rate. |
True.
The faster the heart rate, the shorter the QT interval. |
|
What percentage of the normal cardiac cycle (R to R) does the QT interval generally compose?
|
40%
|
|
What is the orientation of V1 deflections in a normal EKG?
|
Predominantly Negative
|
|
What is the orientation of V6 deflections in a normal EKG?
|
Predominantly Positive
|
|
Mnemonic for the 11-step method for reading EKGs.
|
Slowly Read It, Always Read All, But Pray He Doesn't Crash!
Standardization Rate Intervals Axis Rhythm (4 questions) AV Block Bundle Branch Block Preexitation Hypertrophy Disease (AMI) Confusion (peculiarities) |