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Foundations of Nursing
Test 3, ECG
73
Medical
Undergraduate 4
09/21/2008

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Cards

Term
The ____ side of the heart pumps through pulmonary circulation to get the oxygen and returns it to the heart.
Definition
right
Term
The _____ side of the heart pumps systemically to oxygenate our tissues.
Definition
left
Term
Blood is oxygenated through ventilation, perfusion and transport of respiratory gases. When might our bodies require more oxygen? When might we have less oxygen demands?
Definition
More = something physical, less - sleeping
Term
_____ & ________ regulators control the rate and depth of respiration.
Definition
neural & chemical
Term
The myocardial pump is made up of 2 _______ and 2 __________. A healthy heart stretches in proportion to the _________ of ________. (Starlings Law)
Definition
2 atria & 2 ventricles. strength of contraction.
Term
The blood flow in the heart is unidirectional b/c of the 4 valves. What is happening with the valves when S1 & S2 occur?
Definition
S1 = mitral & tricuspid open. S2 = aortic & pulmonic close.
Term
Our coronary arteries supply the myocardium with ____ and remove ______.
Definition
nutrients, wastes.
Term
Arteries and veins deliver ______ and remove ______ products to the systemic circulation.
Definition
nutrients, wastes
Term
_________ ________ is the amount of blood ejected from the left ventricle each minute.
Definition
Cardiac output
Term
_______ _______ is the amount of blood ejected from the left ventricle with each contraction.
Definition
Stroke volume
Term
________ is the end disatolic pressure.
Definition
Preload
Term
_________ is the resistance to left ventricular ejection.
Definition
Afterload
Term
__________ nervous system influences the rate of impulse generation and the speed of conduction pathways.
Definition
Autonomic
Term
The SYMPATHETIC nervous system ________ the rate of impulse generation and impulse transmission and innervates all parts of atria and ventricle.
Definition
INCREASES
Term
The PARASYMPATHETIC system _______ the rate and innervates atria, ventricles, sinoatrial and atrioventricular nodes.
Definition
decreases
Term
How does the conduction system (electrical impulse) run through the heart?
Definition
It originates with the SA node or pacemaker, transmits to the AV node, and bundle of HIS and Purkinje fibers.
Term
Regular heart rhythms are: Sinus Rhythm (a _________ HR), Sinus Bradycardia (a ________ HR), and Sinus Tachycardia (a _____ HR).
Definition
normal, slow, fast
Term
An irregular HR is called an __________.
Definition
arrhythmia
Term
An ____________ monitors the regularity and path of the electrical impulse through the conduction system.
Definition
electrocardiogram - (aka ECG)
Term
Can an ECG predict future heart disease?
Definition
No, only after the heart attack do you see the rhythm of the strip change. ECG's DO NOT PREDICT THE FUTURE!
Term
The P wave is conduction through the _____.
Definition
atria
Term
A PR interval is the impulse travel time through the AV node, bundle of his and purkinje fibers. A normal PR interval is ____ -____ seconds.
Definition
.12-.20
Term
The QRS complex is the duration of electrical impulse as it travels through the ventricle. Normal will be faster than the atrial b/c it is more forceful. If normal it will be ___-___.
Definition
.04-.10
Term
The QT interval is the time needed for ventricle depolarization and repolarization. If the HR goes up there is a _____ QT wave . If the HR goes down there is a ______ Qt wave.
Definition
shortened, lengthened
Term
What sequence is one heart beat?
Definition
P-QRS-T sequence
Term
Atrial/ventricle contraction is _________. Atrial/ventricle relaxation is ________.
Definition
systole, diastole.
Term
THe ___ to ___ interval measures the regularity of the cardiac rhythm. (this letter is the peak point during the cardiac cycle)
Definition
R to R. If it is short then long = we know there is some type of irregularity.
Term
The ________ line is aka the baseline. It is the flat line between the T-wave and the P-wave - between each contraction.
Definition
isoelectric
Term
How do you calculate when reading an ECG for a normal HR?
Definition
With a regular HR (know this by measuring equal distances between R intervals). Take 1500 divided by the number of squares between each QRS complex/R to R interval.
Term
Each small square on the ECG strip tells you a duration of time that measures ___ seconds. Each larger square is 5 mm in length and measures ____ seconds when you're looking horizontally at the squares.
Definition
.04, .20
Term
So, you count there are 20 squares between each R to R interval. How do you get the HR?
Definition
It is regular if there are 20 between each. So, 1500/20=75 HR
Term
How do you calculate an irregular HR if the number between each R to R interval is different??
Definition
An irregular HR requires a different calculation. You will instead count the number of QRS complexes in a 6 second strip and multiply by 10. Ex/ 11 peaks within a 6 second strip. 11 x 10 = 110.
Term
A sinus rhythm or normal HR will be between:
Definition
rate between 60-100. It is the same as with pulses, for the ECg, just look at it in a different form.
Term
If you have a normal sinus rhythm, then what rates do you have for bpm, PR intervals, and QRS length time?
Definition
rate=60-100 bpm, PR interval=0.12-0.20 seconds, QRS=0.04-0.10 seconds. Your QRS complex time will get narrower the faster your heart goes.
Term
What rate is sinus bradycardia? Can this be normal... in who?
Definition
Less then 60 bpm. It can be normal in some people. It is normal during sleep. It may be normal if you are a very physical athlete too. Perhaps even during vagal maneuver (taking a bowel movement might slow down your heart rate if you're holding your breath, it can give you an abnormal rhythm.)
Term
The key ones to remember for sinus bradycardia are: sleep, exercise (good athletes) and vagal stimulation. But what else can cause sinus bradycardia?
Definition
Acute wall MI, vagal stimulation, hypothermia (getting VERY cold), sleep apnea, increased intracranial pressure, SSS (sick sinus syndrome). Drugs: calcium channel blockers, Digitalis.
Term
Sinus Tachycardia causes rates of ____ - _____ bpm. The sinus node increases the rate to keep up with the body's demands.
Definition
100-150
Term
When is it normal to be tachycardic?
Definition
during exercise
Term
Other causes of tachycardia include:
Definition
fever, infection, septic shock, exercise, exertion, excitement, drugs, anemia (low Hb which normally carries oxygen), hypoxia, hypovolemia, hypotension, pain (everything goes up with pain), hyperthyroidism, heart failure, pulmonary embolism, acute MI. Key ones to remember: FEVER, PAIN & DURING EXERCISE WILL CAUSE TACHYCARDIA.
Term
The SA node is the normal pacemaker of the heart. It fires at a rate of ___ - ___ bpm. Where is it located?
Definition
60-70. SA node is located in the superior vena cava and where it enter the right atrium.
Term
Impulse travels to the left atrium via __________ bundle.
Definition
Bachmann's
Term
Where is the AV node located? WHy are the impulses delayed by 0.04 seconds?
Definition
Inferior right atrium. Impulses are delayed by 0.04 seconds to give ventricles a change to fill while the atria contract.
Term
Can the AV nodes generate impulses?
Definition
No, but the junctional tissue can
Term
The _____ of ___ is the beginning of the ventricular conduction system. It divides into right & left bundle branches.
Definition
Bundle of HIS
Term
The Bundle ________ extend down right and left side of the interventriuclar septum.
Definition
branches
Term
The ___________ fibers cover the endocardial surfaces of both ventricles, spread to the myocardium and epicardium.
Definition
Purkinje
Term
The ___ wave represents the wave of depolarization that spreads from the SA node throughout the atria.
Definition
P
Term
The __ interval represents the time between the onset of atrial depolarization & the onset of ventricular depolarization.
Definition
PR
Term
The normal duration of a PR interval is:
Definition
0.12-0.20 seconds.
Term
The ___ complex represents ventricular depolarization.
Definition
QRS
Term
THe QRS complex follows the __ interval.
Definition
PR
Term
What is the normal duration of a QRS complex?
Definition
0.04-0.20 seconds (it gets skinnier if the heart goes faster)
Term
The __ segment represents the end of ventricular depolarization and the beginning of ventricular repolarization.
Definition
ST
Term
The __ _________ follows QRS, from end of S wave to the beginning of the T wave.
Definition
ST segment
Term
The __ wave represents ventricular repolarization and follows the ST segment. It is slightly rounded & smooth.
Definition
T
Term
The __ interval reporesents ventricular depolarization & repolarization cycle.
Definition
QT
Term
The duration of a QT interval ranges from __ - ___ seconds, depending on HR.
Definition
0.2-0.4
Term
What is the SA node?
Definition
a specialized bundle of neurons at the right atrium, acting as the hearts natural pacemaker
Term
The SA node is sometimes called...
Definition
the pacemaker of the heart
Term
What is the AV node?
Definition
an electrical relay station between the atria and the ventricles. Electrical signals form the atria must pass through the AV node to reach the ventricles. The function of the AV is the act as a gate the electrical conduction system must pass through before going from atria to the ventricles. The delay ensures that the atria have a chance to fully contract before the ventricles are stimulated.
Term
What is the bundle of His?
Definition
It emerges from the AV node to begin the conduction of the impulses from the AV node to the ventricles. The AV node and Bundle of His make up the AV junctional tissue and if the SA node goes out the AV junctional tissue can take over and make the rhythm of the heart.
Term
What are the bundle branches?
Definition
the bundle branches give rise to the purkinje fibers
Term
Together the bundles and the purkinje fobers comprise the ventricular conduction system. It takes about ___ - ___ seconds for the impulse to travel from the bundle of his to the ventricular muscle.
Definition
0.03-0.04
Term
What are the rates of the SA node, AV node and purkinje fibers?
Definition
SA node: 60-70 bpm for regular rhythm, AV node: 40-60 bpm and purkinje fibers: 0.03-0.04 seconds
Term
What is a P wave represent?
Definition
caused by atrial depolarization. It is usually no longer then 0.12 seconds.
Term
How long is a normal PR interval?
Definition
The PR interval is the time (in seconds) from the beginning of the of P wave (onset of atrial depolarization) to the beginning of the QRS complex (onset of ventricular depolarization). The normal PR interval duration ranges from 0.12-0.20 seconds.
Term
What does the QRS complex represent?
Definition
It represents the time it takes for depolarization of the ventricles
Term
How long is the normal QRS complex?
Definition
0.04-0.12 seconds
Term
What does the ST segment represent?
Definition
represents the period form the end of ventricular depolarization to the beginning of ventricular repolarization. The ST segment lies between the end of the QRS complex and the initial deflection of he T wave and is normally isoelectric. It is clinically important if elevated or depressed as it can be a sign of ischemia and hyperkalemia.
Term
What does the T wave represent?
Definition
corresponds to the rapid ventricular repolarization
Term
How does the hearts conduction system correlate with an ECG reading?
Definition
the P wave represents the conduction through the atria. The actual contraction of the atria follows the P wave of the ECG. The P wave can tell you how much time it takes for the conduction to travel through the AV node, the bundle of his and the purkinje fibers. The QRS complex can show you how long the electrical impulse takes to travel through the ventricle. Ventricular contraction will follow. The QT interval is where the heart is depolarizing and repolarizing.
Term
Describe the set-up of ECG monitoring on a client...
Definition
basic set will have one lead on the right arm, one on the left arm, one on the right leg, one on the left leg. and at least one lead over the eheart or ventricles (most ECG's have 12 leads and 8 leads surround the heart, two leads are somewhere above the heart and two are below the heart.)
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