Cardiovascular System Flashcards
What is the purpose of the cardiovascular system
To perfuse the organs and tissues with oxygenated blood
What three protective layers make up the pericardial sac?
Fibrous pericardium
Parietal pericardium
Visceral pericardium (Epicardium)
What is the fibrous pericardium?
A loose fitting sac that outlines and hold the heart
What is the parietal pericardium?
A serous membrane, fluid lines this area & helps reduce friction
What is the visceral pericardium (epicardium)
The inner most protective layer of the pericardial sac
Covers the heart muscle directly
The outermost cardiac layer
Prevents friction as the heart beats
Name the cardiac layers
Epicardium
Myocardium
Endocardium
What is the myocardium
Thick layer of muscle within the heart
Aides in contraction of the heart
What is the endocardium
The inside cardiac chamber
Lines the inside of the heart
Lines all cardiac chambers and valves
What are coronary arteries?
Arteries that surround the heart and provide the heart with oxygenated blood
Oxygenated blood travels from the aorta to the cardiac arteries
Without the coronary arteries, the heart wouldn’t receive oxygenated blood and would not function / would die
Name the four cardiac chambers
Superior Chambers:
Right Atrium
Left Atrium
Inferior Chambers:
Right Ventricle
Left Ventricle
What is the purpose of cardiac valves?
Prevent the back flow of blood
Keep blood moving in a forward direction
What are the two classes of cardiac valves?
Atrioventricular valves (AV Valves) Semilunar Valves
What are the two atrioventricular valves?
Right Atrioventricular Valve (Tricuspid Valve)
Left Atrioventricular Valve (Bicuspid Valve)
Always “tri” to do the “right” thing
What are the two semilunar valves?
Pulmonary/Pulmonic Valve
Aortic Valve
When blood is flowing from the atria to the ventricles, what valves are open?
The atrioventricular valves (tricuspid and bicuspid)
The semilunar valves are closed (pulmonic and aortic)
When blood is flowing from the ventricles to the lungs and body, what valves are open?
The semilunar valves (pulmonic and aortic)
The atrioventricular valves are closed (tricuspid and bicuspid)
In order, list the structures that blood flows through in the heart
Inferior/Superior Vena Cava » Right Atrium » Tricuspid Valve » Right Ventricle » Pulmonic/Pulmonary Valve » Pulmonary Artery » Lungs (oxygenation occurs) » Pulmonary Veins » Left Atrium » Mitral Valve » Left Ventricle » Aortic Valve » Aorta » Body Tissue/Organs
The only vein within the body that carrys oxygenated blood is what?
Pulmonary vein
The only artery within the body that carrys deoxygenated blood is what?
Pulmonary artery
Which cardiac chamber has the greatest workload and greatest demand? Because of this, what can result?
Left ventricle
It can fail first if overworked too long
It is vital for electrolytes to be in appropriate range for which cardiac system to run effectively?
Cardiac Electrical System / Cardiac Conduction Pathway
Name the parts of the Cardiac Conduction Pathway in order
- Sinoatrial (SA) Node
- Interatrial Node/Pathway/Bundle (Bachmann’s Bundle)
- Atrioventricular (AV) Node
- Bundle of His
- Right and Left Bundle Branches
- Purkinje Fibers
Where is the Sinoatrial Node located?
In the wall of the right Atrium
The rate of the Sinoatrial Node is dictated by what?
The needs of the body
Which part of the Cardiac Conduction Pathway is known as the “pacemaker” of the heart?
Sinoatrial Node
If the Sinoatrial Node fails, which part of the Cardiac Conduction Pathway will initiate a heartbeat? What is the rate?
Atrioventricular Node at a rate of 40 to 60 beats per minute
One cycle of cardiac activity can be divided into what two phases?
Systole and Diastole
Define systole
Systole is when the chambers are contracting (squeezing)
Blood is being pushed from the chambers
Define diastole
Diastole is when the chambers are relaxing (filling with blood)
Blood is filling into the chambers
While systole is happening with one set of chambers, what is happening with the other set of chambers?
Diastole
If the right atrium is in systole, what other chamber is in systole?
Left atrium
If the right atrium is in diastole, what other chamber is in diastole?
Left atrium
If the left atrium is in diastole, what other chamber is in diastole?
Right atrium
If the left atrium is in systole, what other chamber is in systole?
Right atrium
If the right ventricle is in systole, what other chamber is in systole?
Left ventricle
If the right ventricle is in diastole, what other chamber is in diastole?
Left ventricle
If the left ventricle is in diastole, what other chamber is in diastole?
Right ventricle
If the left ventricle is in systole, what other chamber is in systole?
Right ventricle
What is occurring during atrial systole?
Atria are contracting, squeezing blood out
Atrioventricular valves (tricuspid and bicuspid) are open, allowing blood to flow from atria to ventricles
Ventricles are in diastole, filling with blood sent from atria
Semilunar valves (pulmonic and aortic) are closed, to keep blood in ventricles
What is occurring during atrial diastole?
Atria are relaxing and filling (blood is flowing from the body via inferior and superior vena cava) Atrioventricular valves (tricuspid and bicuspid) are closed, to keep blood in the atria Ventricles are in systole, contracting and squeezing blood into the lungs and body Semilunar valves (pulmonic and aortic) are open, allowing blood to flow out of the ventricles
What is occurring during ventricular systole?
Ventricles are contracting, squeezing blood out
Semilunar valves (pulmonic and aortic) are open, allowing blood to flow out of the ventricles
Atria are relaxing and filling (blood is flowing from the body via inferior and superior vena cava)
Atrioventricular valves (tricuspid and bicuspid) are closed, to keep blood in the atria
What is occurring during ventricular diastole?
Ventricles are relaxing, filling with blood from the atria
Semilunar valves (pulmonic and aortic) are closed, to keep blood in ventricles
Atria are contracting, squeezing blood out
Atrioventricular valves (tricuspid and bicuspid) are open, allowing blood to flow from atria to ventricles
Heart sounds are made from what?
Closure of valves
The first heart sound heard, S1, known as the “lubb” sound, is made from what?
Closure of the atrioventricular valves
The second heart sound heard, S2, known as the “dubb” sound, is made from what?
Closure of the semilunar valves
What is the equation for cardiac output?
Cardiac Output = Stroke Volume * Heart Rate
CO = SV * HR
What are the units of measurement for cardiac output?
mL/min
or
L/min
What is stroke volume? What are its units of measurement?
The amount of blood pumped out of the left ventricle in one beat
mL/beat
What is heart rate? What are its units of measurement?
The number of times the heart beats in one minute
beats/minute
If the heart rate begins to increase, but stroke volume remains the same, will cardiac output:
increase, decrease, remain the same?
Increase
If stroke volume begins to decrease, what must happen in the body in order for the cardiac output to remain unchanged?
Heart rate must increase
Define preload
The amount of pressure stretching the ventricle at the end of ventricular diastole
Define afterload
The amount of resistance the heart/left ventricle must overcome to open the aortic valve and push the blood out in to systemic circulation
If afterload (i.e. systemic vascular resistance) is increased, what must increase to keep up with body’s demands?
Cardiac workload
The heart has to work harder to overcome the resistance and push the blood into circulation
Define ejection fraction
Total amount of blood the left ventricle pumps out with each contraction
Ejection fraction is measured in what unit of measurement?
Percentage
Normal range for ejection fraction for a healthy adult?
55% to 70%
What does the following phrase mean:
“Ejection fraction of 65%”
65% of the total amount of blood in the left ventricle is being pumped out with each contraction/squeeze of the ventricle
If an ejection fraction is less than 40%, what may be present?
Heart failure
What test is performed to determine the ejection fraction?
Echocardiogram
What affect does epinephrine and norepinephrine have on the heart?
Activates beta one receptors
Increases heart rate Increases force of cardiac contraction Increases cardiac output Dilates coronary vessels Blood pressure increases due to increased cardiac output
How does aldosterone work?
Tells the kidneys to hold on to sodium and release potassium
When sodium is retained, fluid follows
This increases intravascular volume within the body, thus increasing blood pressure
What organ regulates the Renin-Angiotensin-Aldosterone System?
Kidneys
The kidneys will release renin to activate RAAS
What conditions would cause the kidneys to activate the Renin-Angiotensin-Aldosterone System?
Decreased blood flow to the kidneys (decreased renal perfusion/renal ischemia)
Decreased arterial blood pressure (i.e. hypotension)
Decreased blood volume
Decreased serum sodium (hyponatremia)
Increased urine sodium
What is the purpose of the Renin-Angiotensin-Aldosterone System?
To retain sodium, thus retaining fluid
Increasing blood volume and increasing blood pressure
Increasing serum sodium levels
Increase renal perfusion
What are the steps of the Renin-Angiotensin-Aldosterone System?
- Kidneys release Renin
- Renin meets up with Angiotensinogen (which comes from the liver)
- Chemical reaction occurs between Renin and Angiotensinogen –> Angiotensin I is created
- Angiotensin Converting Enzyme (which comes from the lungs) converts Angiotensin I to Angiotensin II
- Angiotensin II promotes vasoconstriction of the arteries/arterioles
- Angiotensin II acts on the adrenal cortex, releasing aldosterone
- Aldosterone acts on the kidneys to retain sodium
- Retention of sodium causes fluid to be retained and potassium to be excreted
- Blood volume increases, blood pressure increases, renal perfusion increases, serum sodium levels increases
- When blood pressure is an appropriate level, the kidneys will stop releasing Renin and will stop RAAS
List what occurs within the cardiovascular system as a person ages
Atherosclerosis Resting blood pressure increases Left ventricle workload increases, causing the heart muscle to become less efficient Vein valves are less competent Resting heart rate decreases Dysrhythmias are common Heart sounds are distant due to kyphosis
If a patient presents with complaints of dizziness, fatigue, and chest tightness, what are the first assessments the RN should do?
Assess vital signs
Assess heart rhythm
Pain
Dyspnea, SOB
The nurse knows if blood pressure is taken on the leg, the reading will be..
About 10 mmHg higher
A nurse takes a blood pressure in both arms, which blood pressure is recorded? The higher or lower?
Higher blood pressure should be recorded
What is the purpose of a heart rate reading on the pulse oximeter?
To compare with a radial or apical heart rate, this determines if the pulse oximeter is accurate or not.
The student nurse assesses a radial pulse and it is 59 bpm. What do they do?
Take an apical pulse for a minute.
What is the purpose of palpating a pulse?
To assess volume and pressure quality
A pulse is palpated and the finding is “normal.” How is this documented?
Strong, 2+
When assessing the right radial pulse, the nurse should also do what…?
Assess the left radial pulse. Assess for equality
Before performing orthostatic vitals, the nurse should gather what supplies?
A gait belt, possibly a partner for safety measures
Before performing orthostatic vitals, the nurse should ask what?
Ask about current dizziness
What are normal blood pressure and heart rate variations when body position is changed?
Systolic BP decreases up to 15 mmHg
Diastolic BP decreases up to 10 mmHg
HR increases up to 20 bpm
What vital sign changes indicate orthostatic hypotension is present?
Systolic BP decreases greater than 15 mmHg
Diastolic BP decreases greater than 10 mmHg
HR increases greater than 20 bpm
What must the nurse ask with each position change when performing orthostatic vital signs?
Ask about feeling dizzy/lightheaded
Why may a patient have orthostatic hypotension?
Dehydrated
Analgesic medication
Pain
When does dependent rubor occur
When there is decreased arterial blood flow to the lower extremities
If a patient has decreased arterial blood flow to the lower extremities, what position should be encouraged?
Keep legs in the dependent position
Avoid elevating legs above the level of the heart, this will decrease blood flow
If a patient has venous blood flow problems to the lower extremities, what color will appear?
Brown discoloration, purple skin, possible cyanosis when in the dependent position
If venous blood flow problems of the lower extremities are present, what position should be encouraged?
Elevation of extremities above the heart
When does a cardiac murmur present?
When a cardiac valve doesn’t close completely
If heart sounds are distant, what position can the patient be placed in?
Lean the patient forward or on their left side
A capillary refill < 3 seconds indicates what?
Appropriate arterial blood flow and oxygenation to the extremities
A capillary refill > 3 seconds indicated what?
A decrease in arterial blood flow and oxygenation to the extremities
What are the six P’s in a neurovascular assessment?
Pain Paresthesia Pallor Pulselessness Paralysis Poikilothermia
What is cardiac monitoring? What can it detect?
Continuous monitoring of cardiac activity
It can detect changes in heart rate and heart rhythm immediately
When will a cardiac monitor be ordered?
If a patient has cardiac complaints
If a patient is receiving medications that can change cardiac activity
When a patient is acutely ill
When a patient is experiencing electrolyte imbalances
When a patient is receiving IV electrolyte replacement
A typical cardiac monitor has how many leads?
5
What does EKG/ECG stand for?
Electrocardiogram
What abnormalities can an Electrocardiogram identify?
Issues with: Cardiac conduction Heart rate Heart rhythm Heart chamber enlargement Myocardial ischemia/infarction Electrolyte imbalances
What is an Echocardiogram?
Ultrasound of the heart
What does an Echocardiogram record/determine?
Determines the ejection fraction
Determines blood flow through the heart
Shows heart size, heart shape, heart position
Shows motion of heart chambers and valves
What is the most concerning cardiac lab?
An elevated troponin.
Shows acute myocardial damage
When is a cardiac troponin elevated?
During acute myocardial damage/ischemia
Other than a troponin, what elevation of what lab can show injury to cardiac muscle?
Creatine Kinase MB (CK-MB)
When is Brain Natriuretic Peptide (BNP) measured?
To identify and monitor individuals with chronic heart failure
To determine cause of SOB: cardiac (CHF) or pulmonary
Elevation of what labs can put a patient at risk for developing coronary artery disease (CAD)?
LDL
Total Cholesterol
Triglycerides
What is atherosclerosis
Plaque build up within arteries of the body
What is coronary artery disease
Plaque build up within the coronary arteries
Narrowed coronary arteries
Decreased blood flow and oxygen delivery to cardiac tissue
What therpeutic measures can be taken to improve cardiovascular health?
Improve diet
Exercise
Smoking cessation
Wear compression stockings
Coronary artery disease can lead to what issues?
Angina
Myocardial infarction
Sudden death
What are modifiable risk factors for coronary artery disease?
Excessive alcohol use Obesity Sedentary lifestyle Emotional stress Tobacco use
What medications can be prescribed to help with coronary artery disease?
Antiplatelet aggregator (Aspirin, Plavix) Lipid lowering agent (Statins)
What lifestyle changes should be made to improve coronary artery disease?
Smoking cessation
Alcohol cessation
Low cholesterol diet and decreased saturated fats
Increase exercise
What is a normal BNP level?
<100 pg/nL
If BNP is elevated >400 pg/mL, what is the likely cause?
Heart failure
