Chapter 11 Flashcards
Electrocardiography
tricuspid valve?
controls the blood flow from the right atrium to the right ventricle
mitral valve?
also called the “bicuspid valve”. controls the blood flow from the left atrium to the left ventricle through the valve
superior vena cava?
sends blood that is deoxygenated to the right atrium. The blood comes from the head, neck, chest, and upper extremities
aorta?
transports oxygenated blood to the body
systole?
occurs when the heart is contracting
diastole?
occurs when the heart is at rest, and the atria fills with blood
Purkinje Fibers?
transmits the impulse quickly and efficiently to the ventricular cardiac cells
polarized state?
before the impulse hits the cell, the cell is at resting potential. The inside of the cell is negatively charged
repolarized state?
after the impulse passes over the cell, the sodium and potassium ions move back to their original locations. This causes the cells charge to change back to a negative charge
PR segments?
it follows the P wave and appears as an isoelectric line. The electric impulse moves slowly through the AV node. The PR segment is the time between the end of atrial depolarization and the start of ventricular depolarization, when the atrial chambers finish contracting
J Point?
the point where the QRS complex ends and the ST segment begins
T wave?
follows the ST segment and appears as a smooth, rounded, asymmetric wave form. created from the electrical activity from ventricular activity
PR interval?
starts at the beginning of the P wave and ends at the start of the Q wave. It represents atrial depolarization
ventricular fibrillization?
(v-fib), occurs when the ventricle quiver uncontrollably. Essentially ineffective at pumping blood. The patient has no pulse and is unresponsive
AC interference?
alternating current interference. artifact or 60-cycle interference artifact, appears as a series of small spikes that create a thick looking tracing
Bundle of His?
located in the upper interventricular septum. when the impulse leaves the AV node, it moves to the bundle of his, also called the AV bundle
atrial depolarization interval?
the PR interval
ground electrode?
the right leg electrode is required for ECG tracing
precordial leads?
unipolar leads, each is a positive pole. They provide information on the horizontal plane of the heart. The six leads are labeled V1-V6
default gain of sensitivity?
100mm/mV
dextrocardia?
a condition in which the heart is located on the right side of the chest, and the apex is pointing towards the right. The electrodes must be placed on the right side of the chest using the same intercostal spacing, but the right and left limb wires are switched
interrupted baseline?
also called intermittent signal artifact. occurs when the tracing looks normal at the beginning but disappears or goes all over when the electrical connection is interrupted
somatic tremor?
also called muscle artifact. appears as jagged peaks with irregular heights and spacing
SA node?
“pacemaker of the heart”. located in the posterior superior wall of the right atrium. The cardiac cells in the SA node generate the impulse, and starts each heartbeat. The impulse moves quickly across the intermodal tracts
isoelectric line?
a straight line, also called the baseline. represents a period of time with no electrical activity
maintenance of the electrocardiograph?
clean the lead wires as indicated in the users guide. Handle the lead wires and patient cable with care. Should be stored in a loose coil. Clean the tracing stylus and the machine casing as indicated in the users guide
Holter monitor?
used to monitor the heart over a 24-48 hour period while the patients go about their normal activities
wandering baseline?
an artifact that is an upward and downward movement of the wave form
positions of the leads?
Lead I- RA, LA
Lead II- RA, LL
Lead III- LL, LA
premature atrial contraction(PAC)?
occurs when the atria contracts sooner then they should. The P wave can be abnormally shaped, or an extra P wave can be seen. More than six PACs in a minute is considered abnormal
augmented leads?
provides information of the vertical plane of the heart. The unipolar leads are increased in size and uses the RA, LA, and LL electrodes
Thermal ECG paper?
either z-fold paper or 8.5x11 inch paper. A special heat sensitive coating on the paper allows the tracing to be “burned” onto the paper. The small boxes are 1x1mm, the large boxes are 5x5mm. The vertical lines measure the amplitude, the horizontal lines measure the time. Each small box is 0.1mV, and each large box is 0.5mV. when the charts speed is set at 25mm/mV, each small box equals 0.04 seconds, and each large box is 0.2 seconds
heart block?
occurs when there is a disruption or slowing of the electrical impulse through the heart
1st degree- the impulse slows as it moves from the atria to the ventricles
2nd degree- the impulses or is blocked as it moves to the ventricles, usually requires a pacemaker
3rd degree- the impulse does not reach the ventricles. special ventricular cells create an impulse that causes the ventricles to contract, and requires emergency treatment and a pacemaker
how to eliminate artifact from ECG?
the MA must identify the type of artifact and then take the specific actions to prevent it from happening more
sinus rhythm?
a normal heartbeat. electrical activity begins in the SA node and goes through the rest of the conduction system
drinking limits of an exercise stress test?
the patient should not consume caffeine or alcohol for at least 3 hours before the test
medication limits of an exercise stress test?
patient must indicate daily medications and should not take a does of erectile dysfunction medication
ECG training
isoelectric lines where there is no electric activity
measurement of the lead current touching from ____ pole to ______pole
negative, south
