Cardiovascular Function and Basic ECGs Flashcards
What is the definition of perfusion?
The flow of blood through arteries and capillaries delivering nutrients and oxygen to cells.
How is a sarcomere described?
it is the functioning unit of the cardiac muscle.
What are the three factors that effect stroke volume?
Preload, after load, contractility
What is the definition of preload?
The degree of stretch o the cardiac muscle fibers at the end of diastole. (Think volume)
What is the definition of after load?
The resistance to ejection of blood from the ventricle; affected by systemic vascular resistance and pulmonary vascular resistance. (Think pressure)
What is the definition of contractility?
Cardiac muscles forces Ex) inotropic capability
What increases the preload?
Hypervolemia and regurgitation of cardiac valves.
What increases the after load?
Hypertension and vasoconstriction
If the after load is increased what also gets increased?
the workload
How is hydrostatic pressure described
The driving force of the heart tends to push fluid out of the capillaries
How is oncotic pressure described?
The pressure exerted by plasma proteins tends to pull fluid into capillaries.
How is filtration pressure described?
The net force on fluid
How is filtration pressure determined?
By the balance between Hydrostatic Pressure (HP) and Oncotic Pressure (OP)
How is automaticity described?
The ability of cardiac cells to initiate an electrical impulse
How is excitability described?
The ability to respond to an electrical impulse and generate an action potential
How is conductivity described?
Ability to transmit an electrical impulse from one cell to another
How is contractility described?
Ability of the cardiac muscle to shorten in response to an electrical impulse
Why does perfusion only discuss the blood flow running through arteries, arterioles, and capillaries?
Because there is little oxygen in venous return
What does epicardium refer to?
Outer layer of heart including the hearts nerves and blood vessels
What does the myocardium refer to?
The middle layer or muscle of the heart
What does endocardium refer to?
The inner layer of the heart including the heart valves.
When do the arteries that supply the heart with oxygen fill up with blood?
During diastole
What node does the SA node communicate to when stimulating a heart beat?
The AV node
When the AV node gets the impulse for the heart to beat where does it send that information to?
The Bundle of His
When the Bundle of His gets the impulse for the heart to beat where does it send the information to?
The Purkinje fibers
When happens inside the calcium channels during depolarization?
Sodium and calcium enter the cell and potassium leaves
What happens inside the calcium channels during repolarization?
Sodium and calcium leaves the cell and potassium enters.
What percentage of the total blood volume in the heart gets ejected during each beat?
55-65%
What is the equation to find cardiac output or CO?
Heart Rate (HR) x Stroke Volume (SV)
How much blood is released from the left ventricle per minute? (in L)
4-6 L
How much blood is ejected from the heart during each stoke? (in mL)
60-130 mL
What is the equation to find the Ejection Fraction? (EF)
Stroke volume (SV)/ End Diastolic Volume (EDV)
What needs to remain the same regardless of how much end diastolic volume here is?
The residual left in the heart per stroke needs to remain the same regardless of the amount of volume was placed in the heart.
How is depolarization described?
Electrical activation of a cell causes the influx of sodium into the cell while potassium exits the cell
How is repolarization described?
Return of the cell to the resting state caused by re-entry of potassium into the cell while sodium exits.
How is the effective refractory period described?
Phase in which cells are incapable of depolarizing
How is the relative refractory period described?
Phase in which cells require a stronger-than-normal stimulus to depolarize
What are the two most common reported clinical symptoms in terms of issues of the heart?
Chest pain and dyspnea
What does JVD stand for?
Jugular Vein Distention
How can you tell if a patient has JVD?
They have a very large and rebounding jugular vein. You can see it pulsating.
What causes JVD?
hypervolemia
Where on the body can you hear the aortic valve?
On the right side, 2nd intercostal space, against the sternal boarder.
Where on the body can you hear the pulmonic valve?
On the left side, 2nd intercostal space, against the sternal boarder.
Where on the body can you hear Erb’s point?
On the left side, 3rd intercostal space, against the sternal boarder.
Where on the body can you hear the tricuspid valve?
On the right side, 4th intercostal space, against the sternal boarder.
Where on the body can you hear the mitral valve?
On the left side, 5th intercostal space, midclavicular line.
How is the S1 sound described?
The closing of the AV valves (tricuspid and mitral) “lub”
When do you hear the S1 sound?
At the beginning of ventricular systole.
Where is the S1 sound best heard?
At the apex aka the mitral valve
How is the S2 sound described?
The closing of the semi-lunar valves (aortic and pulmonic) “dub”
When do you hear the S2 sound?
The end of systole and the beginning of ventricular diastole
Where is the S2 sound best heard?
At the aortic or pulmonic area.
How are murmurs described?
A turbulent flow caused by the stenosis or regurgitation of a valve.
What do you need to document when describing a murmur?
Timing Location Loudness Pitch Quality
What type of creatine kinase is specific to the heart?
Creatine MB (CK-MB)
How is Holter Monitoring described?
A 5-lead EKG over 24 hours.
Why would a patient need to be on Holter Monitoring?
Because they are experiencing angina and the doctor is trying to pinpoint why.
What does a patient who is on Holter Monitoring need to tell the doctor?
When they experienced the angina pain and what activity they were doing.
Where do you assess the pulses on a patient who underwent a heart catheterization?
The pulse that is distal to the incision site.
How long should your patient lay flat after a heart catheterization?
2-6 hours
When the heart rate decreases what happens to the hearts work load?
It increases
How is dysrhythmias described?
Disorders of the formation or condition (of both) of the electrical impulses in the heart
What can cause disturbances of the heart?
Rate, rhythm or both
How are dysrhythmias diagnosed?
By analysis of ECG waveform
What do dysrhythmias have the potential to do?
Alter blood flow and cause hemodynamic changes
When the SA node is in charge: how many beats per minute does the heart conduct?
60-100 bpm
When the AV node is in charge: how many beats per minute does the heart conduct?
40-60 bpm
When the bundle branch and/or purkinje fibers are in charge: how many beats per minute does the heart conduct?
20-40 bpm
On a 5 lead EKG where do you place the white colored lead?
Upper right part on the chest. *Remember: white = right!
On a 5 lead EKG where do you place the green colored lead?
Lower right part on the chest. *Remember: Snow over trees or clouds on grass
On a 5 lead EKG where do you place the black colored lead?
Upper left part on the chest
On a 5 lead EKG where do you place the red colored lead?
Lower left part on the chest *Remember: Smoke over fire!
On a 5 lead EKG where do you place the brown colored lead?
On the center of the chest- centered between the four other leads.
What part of the heart is responsible for the P-wave?
The electric communication between the SA and AV nodes causing the atrial contraction
What part of the heart is responsible for the QRS complex?
The electrical signal going through from the AV node through the Bundle of His and Purkinje Fibers. Causing contraction of the ventricles.
What is occurring in the heart during the T-wave?
Ventricle repolarization
What are the 5 portions of a heart beat when represented on an EKG?
P-wave P-R interval QRS complex S-T segment T-wave
What are the 5 questions you need to answer in reference to the p-wave?
- Is it present? 2. Are they occurring regularly? 3. Is there a p-wave for every QRS complex? 4. Are they smooth, rounded and upright or are they inverted? 5. Do all the p-waves look similar?
How many seconds are in a PR interval?
0.12-0.2 seconds
How many seconds are in a QRS complex?
less than 0.12 seconds
What is the time significance between each QRS complex on EKG strip?
It is how you can tell if the patient has a normal heart rate
What are the components of a normal sinus rhythm?
-The measure of time between each R and R is constant. -Uniform P waves -60-100 BPM -One P-wave for each QRS -P-R Interval: 0.12-0.20 seconds and is constant -QRS: less than 0.12 seconds
What is the criteria for sinus bradycardia?
Meets all criteria for normal sinus rhythm EXCEPT: less than 60 BPM
If the sinus bradycardia is asymptomatic what treatment should be done?
None
If the sinus bradycardia is symptomatic what treatment should be done?
Treat the underlying cause
What may a patient need if they have sinus bradycardia?
A pacemaker
What medications do you need to check for if a patient has bradycardia?
Digoxin Beta blockers Calcium channel blockers
What are the criteria for sinus tachycardia?
Meets all criteria for normal sinus rhythm: EXCEPT: Greater than 100 BPM *Usually between 100 - 160
If a patient has sinus tachycardia what may it be secondary to?
Exercise Heightened emotions Caffeine Nicotine ETOH Cocaine Amphetamines
If a patient has sinus tachycardia what may this signal?
Massive heart damage Impending heart failure Shock
What underlying causes may there be if a patient has sinus tachycardia?
Blood or fluid loss MI Pulmonary Edema
What medication do you need to check for in a patient with sinus tachycardia?
Beta blockers Calcium channel blockers
What criteria does an EKG reading need to have in order for it to be labeled as a dysrhythmia?
-R to R varies: may change with respirations -Uniform P wave for each Q wave -Normal heart rates: 60-100 bpm -PR interval constant: 0.12-0.20 seconds -QRS complex: less than .12
Based on this EKG strip:
What would the patients diagnosis be?
Sinus Tachycardia
Based on this EKG: What would this patient be diagnosed with?
Dysrhythmia
Based on this EKG strip: What would this patient be diagnosed with?
Sinus Bradycardia
Based on this EKG strip: What would this patient be diagnosed wtih?
Normal Sinus Rhythm
Based on this EKG strip: What would this patient be diagnosed with?
Premature Atrial Contraction (PAC)
How many seconds do you need to look at an EKG strip to diagnose a patient with an abnormality?
6 seconds
In a Premature Atrial Contraction (PAC) what happens to the P-wave?
It is not rounded- it is spiky
What happens to the P and T waves during Premature Atrial Contraction (PAC)?
They almost connect. The p-wave starts directly after the t-wave
What is the heart not doing properly during Premature Atrial Contaction?
Repolarizing
What is happening to the PR interval and QRS complex during a Premature Atrial Contraction (PAC)?
Nothing- both of them are within normal limits
Why can pulmonary edema occur in a patient who has sinus tachycardia?
The heart is not pumping enough blood out of the heart so it is backing up in the lungs
