Flashcards in Cardiology I Deck (135):
What controls the opening and closing of the heart valves?
What occurs during ventricular systole?
Contraction of the ventricles which sends blood to the body and lungs.
What occurs during ventricular diastole?
Relaxation of the ventricles which allows them to refill
What are the two left coronary arteries?
Anterior descending and circumflex arteries
What part of the heart does the circumflex artery supply?
It supplies the left and around the back of the heart
What is the right coronary artery?
Posterior interventricular artery
What vein does the heart empty into (coronary)?
The great coronary vein.
The vein that filters the heart is called the _____ and it empties into the _______.
Great coronary vein; right atrium.
What is the blood flow through the heart?
______ is the contraction of the ventricles.
______ is the period in which the ventricles fill with blood from the atria.
What is the time of one contraction & one relaxation?
What is the length of one cardiac cycle?
Approx. 0.8 seconds
What is the length of systole?
Approx. 0.2 seconds
What is the length of diastole?
Approx. 0.52 seconds
_____ is the measurement of the amounts of blood pumped out the ventricles.
Ejection fraction is the measurement of the amounts of what?
Blood pumped out the ventricles.
What is the normal value of ejection fraction?
What part of the cardiac cycle lasts approximately 0.2 seconds?
What part of the cardiac cycle lasts for approximately 0.52 seconds
What lasts approximately 0.8 seconds?
One cardiac cycle
______ is the amount of blood pumped out of ventricles in a single beat.
___ is the pressure in the ventricles at the end of diastole.
What is preload?
The amount of pressure at the end of diastole.
Preload is directly affected by the volume of blood that what?
Returns to the right atrium
_____ is the resistance against which the heart must pump against.
Afterload is what?
The resistance against which the heart must pump against.
What law deals with the stretching of the myocardia?
What does Sterling's law state?
The myocardium can be stretched and will return to its normal state, but if overworked (stretched too far) it will lose its ability to return to its normal state.
What is peripheral vascular resistance?
How much pressure is in the arterioles that the heart must pump against.
______ is the amount of pressure in the arterioles that the heart must pump against.
Peripheral vascular resistance
Peripheral vascular resistance is determined by what?
Vasoconstriction and vasodilation
What is the correlation between the heart rate and the amount of CO2?
⬆️ HR, ⬇️ CO2
What is the formula for blood pressure?
Blood pressure = CARDIAC OUTPUT x PERIPHERAL VASCULAR RESISTANCE
_____ is the flight or fight response whereas ____ is the rest and digest response
Sympathetic — fight or flight
Parasympathetic — rest and digest
Sympathetic and parasympathetic nervous responses are a part of what,
The receptors in the sympathetic nervous system are ___ and ___.
Alpha and beta
What chemical neurotransmitters are in the sympathetic nervous system?
What nerve endings are in the sympathetic nervous system?
Alpha one receptors do what?
vasoconstriction which raises blood pressure
Alpha two receptors do what?
Beta one receptors are located where?
In the heart
Beta two receptors are located where?
In the lungs.
Beta two receptors cause what?
Bronchodilation and Vasodilation
What are the neurotransmitters for the parasympathetic nervous system?
Acetylcholine nerve endings are called what?
Cholinergic nerve endings are what?
Parasympathetic nerve fibers that use acetylcholine as neurotransmitters.
Adrenergic nerve endings are what?
Sympathetic nerve fibers that use epinephrine as neurotransmitters.
Myocardial working cells do what?
Generate the PHYSICAL contraction of heart cells.
What generates blood flow?
Physical contractions of myocardial working cells
What do pacemaker cells control?
Rate and rhythm by coordinating regular depolarization
Contractions of the heart.
What is the primers function of pacemaker cells?
To generate and conduct electrical impulses
A ____ is the point at which a stimulus will produce a cell response.
What are the four cardiac cell characteristics?
_____ is the ability of the cardiac cells to shorten and cause muscle contraction.
____ is the ability of the cardiac pacemaker cells to spontaneously generate electrical impulses w/o external stimulation.
____ is the ability of cardiac cells to respond to an electrical stimulus.
_____ is the ability of cardiac cells to receive/transmit stimulus to other cardiac cells.
Where is the location of automaticity?
SA NODE, AV JUNCTION, PURKINJE FIBERS
_____ is a substance or compound whose molecules dissociate into charged components (ions)
_____ performs a vital part in depolarization of myocardium
What occurs during cardiac depolarization?
Sodium ions rush into cell changing interio charge to positive after cell is stimulated.
What happens during cardiac repolarization?
Sodium ions returns to outside of the cell and potassium ions return to inside.
What is the charge of the inside and outside of the cell during resting membrane potential?
What occurs during action potential?
Changes in polarity produces change in cells.
____ are attempts to ensure muscle is totally relaxed before another depolarization can be initiated.
What is the refractory period for the atrial muscle?
What is the refractory period for the ventricular muscle?
Period of rest is called ____.
The ____ is the primary pacemaker of the heart.
What cardiac wave is caused by the SA node?
What is the firing rate of the SA node?
What receives the impulse as it exits the SA node?
The internodal pathways
The internodal pathways deliver the impulse where?
From the SA node, throughout the atria, and to the AV node
What delivers the impulse from the left atrium to the right atrium?
Bachmann's bundle (wenckebach's bundle)
At the AV node electrical activity delays _____
Why does the impulse delay at the AV node?
To allow for complete filling of the ventricles
What is the firing rate of the AV node?
What is the secondary pacemaker?
Where is the bundle of his located?
The top of the interventricular septum
What is the firing rate of the bundle of his?
What is the firing rate of the purkinje network?
Where does the impulse go from the purkinje network?
To the ventricular muscle cells.
What is the pathway of electrical conduction in the heart?
Bundle of his
Left and right branches
Ventricular muscle cells
EKG is the graphing of what activity in the heart?
What is placed on the skin to sense electrical activity?
How is EKG recorded?
The ____ are the pads that go on the patients skin whereas the ____ connect to the cardiac monitor.
Electrodes - skin
Leads - machine
Three leads are named because they must have what?
A positive, a negative and a ground
What is einthoven's triangle?
And imaginary inverted triangle formed around heart by proper positioning oft the bipolar leads.
Lead one goes where?
Left & right arm
Lead two goes where?
Left leg and right arm
Lead 3 goes where?
Left leg and arm
Time is measured on the ____ line of the ekg graph.
Voltage is measured on the ___ line of the ekg paper
One small box meaures ___ seconds
PRI is how long ?
One large box is equal to how long?
QRS is how long?
Less than 0.12 seconds
The ____ is the beginning and ending of all waves
A _____ is above the isoelectric line.
A ____ is below the isoelectric line.
The P wave is how long
What is the P wave
depolarization of the left and right atria
What is the PR interval
Start of the P wave to the start of the QRS complex
How long is the PRI?
The QRS complex represents what?
The S wave is how long?
Less than 0.12 seconds
The ST segment is what?
Ventricles are depolarizes and repolarization begins
Elevation and/or depression of the ST segment is indicative of what?
An acute myocardial infarction
STEMI is what?
An elevated ST segment
Angina is what?
A depressed ST segment
The T wave represents what?
The T wave is what phase of the cardiac cycle?
The P wave is what?
The QRS complex is what?
Atrial repolarization/ventricular depolarization
The T wave is what?
What are causes of sinus arrhythmia?
Sick Sinus Syndrome
What are causes of sinister arrest?
Damage to SA node
digitalis & salicylates
What are causes of atrial dysrrhythmia?
What are the 5 steps to interpret EKGs?
What are causes of PACs?
Increased sympathetic tone
How many PACs must happen for they to be called frequent?
More than 6
Two sequential PACs is called a…
When every other beat is a PAC that is called…
Every third beat being a PAC is called what?
What is the reactivation of myocardial tissue for a second or subsequent time by the same impulse?
What causes the short circuit of electrical conduction?
A delay or block
What are causes of reentry dysrhythmias?
Certain antidysrhythmia meds
What type of rhythms are reentry dysrhythmias?
What are 3 characteristics of A-Fibrillation
There are no p waves
F waves replace p waves
Ventricle response is irregularly irregular
What are causes of Atrial fibrillation?
Rheumatic heart disease
When your patient is in A-fibrillation and their heart rate is greater than 100 they are considered ______ if their heart rate is less than 100 they are considered _______.