Advanced Concepts in Nursing
Lecture Notes
Exam II
Ch. 1 & 2-Basics
● Anatomy of the Heart:
○ 4 chambers
○ R side
■ Thinner walled
■ Lower pressure
■ Blood goes to pulmonary circulation then becomes oxygenated
■ Pulmonary veins to L circulation
■ Tricuspid valve between RA & RV
■ Pulmonic valve keeps blood flowing into the lungs
○ L side
■ Bicuspid (Mitral) LA & LV
■ Aortic valve keeps blood flowing up and into the aortic arch
■ Up through aortic valve
■ Out to systemic circulation
○ Deoxygenated blood comes in from periphery into the R side of heart
■ Pulm circulation
● Oxygenated
○ L side of heart
■ Out into systemic circulation
○ Coronary Arteries:
■ Circulation of the heart
■ Coronary arteries branch off the aorta**
● Oxygenated blood flows through the aorta to the system
■ R side
● R coronary
○ R side of the heart
○ Posterior part of the heart
■ L side
● L main coronary
○ Branches into L anterior descending wall
○ Circumflex coronary artery
■ For L side of the heart
● “Widow-maker” MI… blockage occurs at the top of the L main
coronary artery before it branches into the L anterior descending
and the circumflex coronary arteries
○ If it’s completely blocked, circulation to the anterior wall of
the heart is lost
DYS 1
,● Cardiac Cycle: rhythm strip
○ Each P-QRS-T sequence is one heartbeat
○ P wave:
■ Stands for atrial depolarization (contraction)
■ at the beginning of the strip
■ While atria is contracting, the ventricle is in resting mode
■ From the sinus node to the atrium
○ PR Interval: from the beginning of the P wave to the beginning of the R wave
■ The time it takes the electrical signal to get from the atria down to the SA
node
■ The time it takes to get to the AV junction
○ QRS: middle of the strip
■ represents ventricular systole (contraction)
■ Ventricular depolarization
■ From the AV to the ventricle (QRS complex)
○ ST Segment: the time it takes the electrical impulse to get through to start
ventricular repolarization (T wave)
■ This will give info about any cardiac ischemia or MI injury
● ST segment will be depressed in ischemia
● If injury has already occured, ST segment will be elevated above
baseline
■ Assess for abnormalities here
○ T wave: end of the strip
■ represents ventricular repolarization
■ Atria are at rest
○ U wave: late ventricular repolarization… not usually seen
■ Don't need to focus on this
○ Don't need to know all of the phases of the cardiac cycle, but need to know
what’s happening w/ each part of the cycle
○ Nomenclature:
■ Q wave: downward wave preceding an upward wave
■ R wave: any upward wave
■ S wave: downward wave following an R wave
■ QS wave: downward wave w/ no upward wave at all
○ Mechanical:
■ Diastole: relaxation phase
● rapid filling phase:AV valves open because of the pressure
gradient and ventricles rapidly fill
● Diastasis: flow into ventricles slows as pressures equalize
● Atrial Kick: atria contract, squeezing the remainder of blood into
the ventricles
○ Happens at the end of atrial contraction
■ Atrial contraction sends much of the blood though
contraction
DYS 2
, ○ Remainder of blood is squeezed into the ventricles
○ Is responsible for 10-20% of cardiac output
■ Pts w/ Afib loose this “kick”
● CO is lost in circulation
■ Systole: contraction phase
● Isovolumetric Contraction: ventricles contract but no blood is
flowing
● Ventricular Ejection: valves open, blood pours out of ventricles
● Protodiastole: blood flow slows as pressure equalizes
● Isovolumetric Relaxation: ventricles relax, valves close
■ contraction/relaxation are mechanical, stimulated by the electrical
component
■ Mechanical events are measured through pulse & BP
○ Electrical:
■ Depolarization: change in the cardiac cell’s electrical charge from
negative to positive... ultimately results in contraction of the muscle
● Accomplished by Na & K ion changing place
○ Move in and out of cells
○ Causes a wave of electrical charge to course from cell to
cell, resulting in a discharge of electricity
● Should result in heart muscle contraction
■ Repolarization: return of the cardiac cell to its electrically negative charge
● Accomplished by way of the sodium potassium pump- active
transport
● Should result in relaxation
■ Depolarization and repolarization are the electrical events that lead to the
mechanical events of contraction/relaxation
■ Refractory Periods: r/t the electrical portion
● There are areas on the electrical heart muscle that could be
stimulated again if they had a strong enough impulse
● Absolute: no amount of stimulus can cause depolarization of the
cardiac muscle again
○ At the beginning of the QRS complex to the middle ⅓ of T-
Wave
● Relative: strong stimulus can cause depolarization in the heart
○ From the first ¼ of T-wave to the last ¼
○ Depolarization in this portion can cause serious
dysrhythmias such as ventricular tachycardia
● Supernormal Period: weak stimulus can cause depolarization and
therefor contraction
○ At the tail end of the T-wave
○ Can cause severe dysrhythmias as well-ventricular tachy
● Cardiac Conduction System: pathway of specialized cells that create and conduct
electrical impulses through the heart
DYS 3
, ○ SA (sinoatrial node): where conduction starts
■ Rate is 60-100
■ P wave
■ Goes through intranodal paths that carry over to LA and to AV node
● AV (atrioventricular) node
■ Rate is 40-60
○ Bundle of his
■ Right bundle branches & Left bundle branches
● Purkinje fibers
■ Rate is 20-40
○ Results in ventricular contraction
● Heart Cells:
○ Have specific properties that allow them to perform specific functions that may
not be possible in other parts of the body
○ Automaticity: ability to create an impulse
○ Conductivity: ability to conduct an impulse to neighboring cells
○ Excitability: ability to depolarize
○ Contractility: ability to contract
● Sinus Fails:
○ AV junction escapes:
■ MI affects sinus node… tissues are dead/no longer work
■ No rhythm is ejected from sinus node
■ AV junction/node & ventricle likely still work
● Pacemaker is 40-60 here
● “Back up” pacemaker
○ Ventricle Escapes:
■ Last backup is the ventricular rate… when sinus, atrium, AV junction all
fail
■ No P wave
■ Complex is wide & abnormal
■ Rate is very slow d/t the rate being only 20-40
● EKG Paper:
○ The paper used doesn’t change regardless of the amount of leads
○ Divided into small blocks, 1 mm in height/width
○ Counting horizontally measures time (intervals)***
■ Counting 5 big /25 small boxes=1 second
■ 1 big box/5 small boxes=0.2 seconds***
■ 1 small box= 0.04 seconds***
○ Counting vertically measures amplitude
● 12 Lead EKG:
○ Don't need to know how to evaluate a 12 leak EKG
○ Putting the leads in different places affects the “view of the camera” when looking
at the heart-this is the value of an EKG
○ Pt may have 1-2 rhythm strips
DYS 4
Lecture Notes
Exam II
Ch. 1 & 2-Basics
● Anatomy of the Heart:
○ 4 chambers
○ R side
■ Thinner walled
■ Lower pressure
■ Blood goes to pulmonary circulation then becomes oxygenated
■ Pulmonary veins to L circulation
■ Tricuspid valve between RA & RV
■ Pulmonic valve keeps blood flowing into the lungs
○ L side
■ Bicuspid (Mitral) LA & LV
■ Aortic valve keeps blood flowing up and into the aortic arch
■ Up through aortic valve
■ Out to systemic circulation
○ Deoxygenated blood comes in from periphery into the R side of heart
■ Pulm circulation
● Oxygenated
○ L side of heart
■ Out into systemic circulation
○ Coronary Arteries:
■ Circulation of the heart
■ Coronary arteries branch off the aorta**
● Oxygenated blood flows through the aorta to the system
■ R side
● R coronary
○ R side of the heart
○ Posterior part of the heart
■ L side
● L main coronary
○ Branches into L anterior descending wall
○ Circumflex coronary artery
■ For L side of the heart
● “Widow-maker” MI… blockage occurs at the top of the L main
coronary artery before it branches into the L anterior descending
and the circumflex coronary arteries
○ If it’s completely blocked, circulation to the anterior wall of
the heart is lost
DYS 1
,● Cardiac Cycle: rhythm strip
○ Each P-QRS-T sequence is one heartbeat
○ P wave:
■ Stands for atrial depolarization (contraction)
■ at the beginning of the strip
■ While atria is contracting, the ventricle is in resting mode
■ From the sinus node to the atrium
○ PR Interval: from the beginning of the P wave to the beginning of the R wave
■ The time it takes the electrical signal to get from the atria down to the SA
node
■ The time it takes to get to the AV junction
○ QRS: middle of the strip
■ represents ventricular systole (contraction)
■ Ventricular depolarization
■ From the AV to the ventricle (QRS complex)
○ ST Segment: the time it takes the electrical impulse to get through to start
ventricular repolarization (T wave)
■ This will give info about any cardiac ischemia or MI injury
● ST segment will be depressed in ischemia
● If injury has already occured, ST segment will be elevated above
baseline
■ Assess for abnormalities here
○ T wave: end of the strip
■ represents ventricular repolarization
■ Atria are at rest
○ U wave: late ventricular repolarization… not usually seen
■ Don't need to focus on this
○ Don't need to know all of the phases of the cardiac cycle, but need to know
what’s happening w/ each part of the cycle
○ Nomenclature:
■ Q wave: downward wave preceding an upward wave
■ R wave: any upward wave
■ S wave: downward wave following an R wave
■ QS wave: downward wave w/ no upward wave at all
○ Mechanical:
■ Diastole: relaxation phase
● rapid filling phase:AV valves open because of the pressure
gradient and ventricles rapidly fill
● Diastasis: flow into ventricles slows as pressures equalize
● Atrial Kick: atria contract, squeezing the remainder of blood into
the ventricles
○ Happens at the end of atrial contraction
■ Atrial contraction sends much of the blood though
contraction
DYS 2
, ○ Remainder of blood is squeezed into the ventricles
○ Is responsible for 10-20% of cardiac output
■ Pts w/ Afib loose this “kick”
● CO is lost in circulation
■ Systole: contraction phase
● Isovolumetric Contraction: ventricles contract but no blood is
flowing
● Ventricular Ejection: valves open, blood pours out of ventricles
● Protodiastole: blood flow slows as pressure equalizes
● Isovolumetric Relaxation: ventricles relax, valves close
■ contraction/relaxation are mechanical, stimulated by the electrical
component
■ Mechanical events are measured through pulse & BP
○ Electrical:
■ Depolarization: change in the cardiac cell’s electrical charge from
negative to positive... ultimately results in contraction of the muscle
● Accomplished by Na & K ion changing place
○ Move in and out of cells
○ Causes a wave of electrical charge to course from cell to
cell, resulting in a discharge of electricity
● Should result in heart muscle contraction
■ Repolarization: return of the cardiac cell to its electrically negative charge
● Accomplished by way of the sodium potassium pump- active
transport
● Should result in relaxation
■ Depolarization and repolarization are the electrical events that lead to the
mechanical events of contraction/relaxation
■ Refractory Periods: r/t the electrical portion
● There are areas on the electrical heart muscle that could be
stimulated again if they had a strong enough impulse
● Absolute: no amount of stimulus can cause depolarization of the
cardiac muscle again
○ At the beginning of the QRS complex to the middle ⅓ of T-
Wave
● Relative: strong stimulus can cause depolarization in the heart
○ From the first ¼ of T-wave to the last ¼
○ Depolarization in this portion can cause serious
dysrhythmias such as ventricular tachycardia
● Supernormal Period: weak stimulus can cause depolarization and
therefor contraction
○ At the tail end of the T-wave
○ Can cause severe dysrhythmias as well-ventricular tachy
● Cardiac Conduction System: pathway of specialized cells that create and conduct
electrical impulses through the heart
DYS 3
, ○ SA (sinoatrial node): where conduction starts
■ Rate is 60-100
■ P wave
■ Goes through intranodal paths that carry over to LA and to AV node
● AV (atrioventricular) node
■ Rate is 40-60
○ Bundle of his
■ Right bundle branches & Left bundle branches
● Purkinje fibers
■ Rate is 20-40
○ Results in ventricular contraction
● Heart Cells:
○ Have specific properties that allow them to perform specific functions that may
not be possible in other parts of the body
○ Automaticity: ability to create an impulse
○ Conductivity: ability to conduct an impulse to neighboring cells
○ Excitability: ability to depolarize
○ Contractility: ability to contract
● Sinus Fails:
○ AV junction escapes:
■ MI affects sinus node… tissues are dead/no longer work
■ No rhythm is ejected from sinus node
■ AV junction/node & ventricle likely still work
● Pacemaker is 40-60 here
● “Back up” pacemaker
○ Ventricle Escapes:
■ Last backup is the ventricular rate… when sinus, atrium, AV junction all
fail
■ No P wave
■ Complex is wide & abnormal
■ Rate is very slow d/t the rate being only 20-40
● EKG Paper:
○ The paper used doesn’t change regardless of the amount of leads
○ Divided into small blocks, 1 mm in height/width
○ Counting horizontally measures time (intervals)***
■ Counting 5 big /25 small boxes=1 second
■ 1 big box/5 small boxes=0.2 seconds***
■ 1 small box= 0.04 seconds***
○ Counting vertically measures amplitude
● 12 Lead EKG:
○ Don't need to know how to evaluate a 12 leak EKG
○ Putting the leads in different places affects the “view of the camera” when looking
at the heart-this is the value of an EKG
○ Pt may have 1-2 rhythm strips
DYS 4
