What is the Precordium and where does it lay in the body?
- It's the area on the anterior chest directly overlying the heart and the great vessels.
- It's located between the lungs in the middle third of the thoracic cage (aka. mediastinum).
- It extends to from the 2nd to 5th ICS and from the right border of the sternum to the left midclavicular line.
What are the major anatomic features of the heart? [Hint: 7]
- Chordae tendineae.
What makes up the heart wall?
Describe the Pericardium.
- It's a tough, fibrous, double-walled sac that surrounds and protects the heart.
- It has 2 layers that contain a few mL
of serous pericardial fluid.
- Ensures a smooth, friction-free contraction of the heart muscle.
- It's adherent to the great vessels, esophagus, sternum, and pleurae.
- Anchored to the diaphragm.
Describe the Myocardium.
- The muscular wall of the heart that does the pumping.
Describe the Endocardium.
- The thin layer of the endothelial tissue that lines the inner surface of the heart chambers and valves.
What does the right side of the heart do?
- Pumps blood into the lungs.
What does the left side of the heart do?
- Pumps blood into the body.
The heart is considered two pumps; what separates the two?
- An impermeable wall, aka the Septum.
Describe the Atrium.
- A thin-walled reservoir that holds the blood.
Describe the Ventricle.
- The thick-walled, muscular pumping chamber.
Describe the main purpose of the Valves.
- Prevents back flow of blood.
- Unidirectional (can only open one way).
- Open and close passively in response to pressure gradients in the moving blood.
What are the four valves of the heart?
- Two Atrioventricular (AV) valves:
- Right AV = Tricuspid valve
- Left AV = Mitral valve (aka bicuspid).
- Two Semilunar (SL) valves:
- Pulmonic valve
- Aortic valve
Where do the AV valves lie inside the heart chamber?
- They both separate the atria (atriums) and the ventricles.
The Tricuspid AV lies between...
- The RA and the RV.
The Mitral AV lies between...
- The LA and the LV.
Describe the Cardiac cycle of Diastole.
- The AV valves open during the heart's filling phase.
- Allowing the ventricles to fill with blood.
Describe the Cardiac cycle of Systole.
- During the pumping phase, the AV valves close
to prevent regurgitation of blood back up into the atria.
- The SL valves open to allow blood to be ejected from the heart.
- The papillary muscles contract at this time, so that the valve leaflets meet and unite to form a perfect seal without turning inside out.
Where do the SL valves lie inside the heart chamber?
- Between the ventricles and the arteries.
The Pulmonic valve is in the...
- Right side of the heart.
The Aortic valve is in the...
- Left side of the heart.
Why does a person with abnormally high blood pressure in the left side of the heart have symptoms of pulmonary congestion?
- Because there are no valves between the pulmonary veins and the LA.
Why does a person with abnormally high blood pressure in the right side of the heart have symptoms in the neck veins and abdomen?
- Because there are no valves between the Vena Cava and the RA.
List the steps of the direction of blood flow. Starting with the unoxygenated RBCs being drained downstream into the Vena Cava from the Liver...
- Into the RA through the inferior vena cava.
- Superior vena cava drains venous blood from the head and upper extremities.
- From the RA, venous blood flows through the Tricuspid (AV) valve to the RV.
- From RV, venous blood flows through the Pulmonic (SL) valve to the pulmonary artery to be delivered to the lungs.
- Lungs oxygenate the blood and then the it returns to the heart through the pulmonary veins into the LA.
- From LA, arterial (oxygenated) blood goes through the Mitral (AV) valve to the LV.
- LV ejects the blood through the aortic valve into the aorta, which delivers it to the body.
What are the two phases of the rhythmic cardiac cycle which moves the blood through the heart?
What occurs during Diastole?
- Ventricles relax and fill with blood.
- 2/3 of the cardiac cycle.
What occurs during Systole?
- Heart contacts and blood is pumped from the ventricles and fills the pulmonary and systemic arteries.
- 1/3 of the cardiac cycle.
What occurs during the Early or Protodiastolic filling?
- It's the first passive filling phase.
- The ventricles relax and the AV valves (Tricuspid and Mitral) open silently.
- The pressure in the atria is higher than in the ventricles, so blood pours in rapidly.
What occurs during Presystole or Atrial Systole phase?
- Aka "atrial kick."
- Toward the end of diastole, the atria contract and push the last among of blood into the ventricles.
- It causes a small rise in left ventricle pressure.
When does Atrial Systole occur?
- During ventricular diastole.
Which pressure is higher during the beginning of Systole? What happens because of it?
- Ventricle pressure is higher than the atria pressure.
- The AV valves swing shut, preventing regurgitation.
What is the S1 sound and what does it signal?
- The first heart sound.
- Signals the beginning of systole.
- The closure of the AV valves.
Define Isometric contraction.
- A contraction against a closed system (all four valves are closed) works to build up pressure inside the ventricles to a high level.
How do the Aortic valves open during Systole?
- Briefly all four valves are closed when the ventricular walls contract.
- Pressure builds in the ventricles until it finally exceeds the pressure in the aorta.
- Aortic valve opens and blood ejects rapidly.
How do the Aortic valves close?
- Pressure falls when contents (blood) is emptied from the ventricles.
- When it falls below the Aorta pressure, some blood flows backwards toward the ventricle.
- This causes the aortic valve to swing shut.
What is the S2 sound and what does it signal?
- The closure of the SL valves.
- Signals the end of systole.
Define Isometric (or Isovolumic) Relaxation.
- After systole, all four valves are closed and the ventricles relax.
- The atria are filing up passively with blood delivered from the lungs.
- Atrial pressure is higher now than the relaxed ventricular pressure.
- Mitral (AV) valve opens and diastolic filling begins again.
The first heart sound, the mitral component (M1) closes just before which component?
- The tricuspid component (T1)
With S2, aortic closure (A2) occurs slightly before which component?
- Pulmonic closure (P2)
- First heart sound.
- Loudest at the apex of the heart.
- Second heart sound.
- Loudest at the base of the heart.
Respiration has an affect on cardiac cycle. What occurs during Inspiration on the right side of the heart?
[Hint: MoRe to the Right heart, Less to the Left]
The intrathoriacic pressure is decreased =
more blood is pushed into the vena cava.
- RV stroke volume increases, prolonging RV systole and delays the pulmonic (SL) valve closure.
Respiration has an affect on cardiac cycle. What occurs during Inspiration on the left side?
[Hint: MoRe to the Right heart, Less to the Left]
- A greater amount of blood is sequestered in the lungs during inspiration.
- Momentary decreased return amount to the left side of the heart = decreasing LV stroke volume.
- Decreased volume shortens LV systole and allows the aortic (SL) valve to close earlier.
Respiration has an affect on cardiac cycle. What is the overall significance of the affects of Inspiration on the heart?
[Hint: MoRe to the Right heart, Less to the Left]
- When the aortic valve closes earlier than the pulmonic valve significantly, two components are heard separately.
- Split S2.
Describe the Third Heart Sound (S3).
- Diastole normally is quiet, but in some conditions ventricular filling creates a vibration that could be heard because the ventricles are resistant to filling during protodiastole.
- Occurs after S2 when AV valves open and atrial blood first pours into the ventricles.
Describe the Fourth Heart Sound (S4).
- Occurs at the end of diastole (at presystole) when the ventricles resist filling.
- The atria contract, pushing blood into a noncompliant ventricle, creating vibrations that could be heard.
- Occurs just before S1.
Define a Murmur.
- Normally blood circulation through the cardiac chambers and valves is quiet.
- Some conditions create turbulent blood flow and collision currents.
- Like nosey water flow over a pile of stones or a sharp turn in the stream.
What are the conditions of a murmur?
- Velocity of blood increases (flow murmur).
- Ex. In exercise or thyrotoxicosis.
- Viscosity of
- Ex. In anemia.
- Structural defects in the valve or an unusual opening in the
- Ex. Narrowed valve, incompetent valve; or dilated chamber, wall defect.
Describe Chest Pain.
- May also have pulmonary, musculoskeletal, or GI origin.
- Severe chest pain.
- Occurs when the heart's own blood supply can't keep up with metabolic demand.
- Feels like a squeezing "clenched fist."
What other symptoms have an anginal equivalent when there's an absence of chest pain?
- Diaphoresis (excessive sweating)
- Cold sweats
- Dyspnea (SOB)
What is DOE mean?
- Dyspnea on exertion.
- The need to assume a more upright position to breathe.
- Note the exact number of pillows used.
- Dependent when caused by heart failure.
Describe Cardiac Edema.
- Is worse at evening and better in the morning after elevating legs all night.
- Bilateral, but unilateral swelling has a local vein cause.
What is CAD?
Coronary artery disease.
Define the abnormal pulsation, Heave or Lift.
- A sustained forceful thrusting of the ventricle during systole.
- Occurs with ventricular hypertrophy as a result of increased workload.
Where is a RV heave seen?
- At the sternal border.
Where is a LV heave seen?
- At the apex.
Where is the aortic valve auscultated?
- At the 2nd, right ICS.
Where is the pulmonic valve auscultated?
- At the 2nd, left ICS.
Where is the tricuspid valve auscultated?
- Left, 5th ICS near the sternal border.
Where is the mitral valve auscultated?
- Left, 5th ICS at MC line.
Where is the Erb's point auscultated?
- Left, 3rd ICS near sternal border.
Do all murmurs indicate a heart disease? Why or why not?
- No, an innocent murmur or systolic murmur may occur with a normal heart.
- But a diastolic alway indicates heart disease.
Describe a Grade 1 Murmur.
- Barely audible, heard only in a quiet room, with difficulty.
Describe a Grade 2 Murmur.
- Clearly audible, but faint.
Describe a Grade 3 Murmur.
- Moderately loud, easy to hear.
Describe a Grade 4 Murmur.
- Loud, associated with a thrill palpable on the chest wall.
Describe a Grade 5 Murmur.
- Very loud, heard with one corner of stethoscope lifted off of the chest wall.
Describe a Grade 6 Murmur.
- Loudest, still heard with entire stethoscope lifted just off the chest wall.
Define Sinus Arrhythmia. When is it normal?
- Rhythm varies with the person's breathing, increasing at the peak of inspiration and slowing with expiration.
- Normal in young adults and children.
Normal heart rate.
- 50-100 beats per minute
Define Congestive Heart Failure (CHF).
- The cardiac output is inadequate causing blood to not effectively pump through the pulmonic or aortic valves.
What are the two types of CHF?
- Left CHF
- Right CHF
What is the Objective (O) and Subjective (S) findings of Left Ventricular Failure?
- Patient c/o Fatigue & Dyspnea.
- S3 may be present.
- Rales/Crackles may be present on exam.
How does Right Sided HF look like?
- Increase in the Jugular Vein Pressure
- Dependent peripheral edema
- Weight gain
- S3 may be auscultated on exam.
What causes Myocardial Infraction (MI)?
- Caused by ischemia (lack of oxygen) to the myocardium resulting in infarction (death) of the cells.
What are the subjective findings of MI in males?
- c/o crushing chest pain
- With pain and numbness down the left arm.
- Pain does not improve with rest.
What are the subjective findings of MI in females?
- c/o fatigue
- Abdominal bloating/discomfort
- Jaw pain
What are objective of MI?
- Weak, thready pulse.
- Heart sounds may be distant.
- Hypotension may be present.
- Cyanosis may be present.
- Irregular heart rhythm (Dysrhythmia).
- Inflammation of either the parietal & visceral layers of the pericardium or the outer myocardium (Wilson & Giddens, 2009).
- Can be a result of an MI, cardiac surgery, infections, etc.
What are the subjective and objective findings of Pericarditis?
- O: Pt. c/o chest pain.
- S: Friction rub auscultated.
Define the Congenital Heart Defect: Patent Ductus Arteriosus (PDA).
- Persistence (non-closure) of the channel joining between the L pulmonary artery to the aorta.
What are the O and S findings of PDA?
- S: None
- O: Blood pressure has a wide pulse
pressure and bounding peripheral pulses from rapid runoff
of blood into low-resistant pulmonary bed during diastole.
- The continues murmur heard in systole and diastole is called "machinery murmur."
- Holosystolic & holodiastolic murmur auscultated.
Describe Atrial Septal Defect (ASD).
- Abnormal opening in the atrial septum (open communication between atria), resulting usually in left-to-right shunting, which causes a large increase in pulmonary blood flow.
What are the S and O findings of ASD?
- S: Defect well tolerated. Children and young adults have mild
fatigue and DOE.
- May have weight gain as shunt increase.
- O: Systolic
murmur (II-III/VI), ejection, medium pitch, best heard
at base in 2nd, left ICS.
- Murmur not caused by shunt, but by increased blood flow through pulmonic valve.
- Sternal lift often present.
- S2 w/fixed split, with P2 louder than A2.
Describe Ventricular Septal Defect (VSD).
- Abnormal opening in septum between ventricles, usually sub-aortic area.
- The size and exact position vary.
- Blood shunting through ventricular septum from left-to-right.
What are the S and O findings of VSD?
- S: In infants with large defects:
- Poor growth
- Slow weight gain
- CHF (severe condition)
- Feeding problems
- Frequent respiratory infections
- O: May have a
loud, harsh holosystolic murmur with small
- Best heard at the left sternal border and may be accompanied by thrill.
- With a large shunt (defect), a soft diastolic murmur.
- Heard at the apex (mitral flow murmur) due to increased blood flow through mitral valve.
Define Claudication distance.
The number of blocks walked or stairs climbed to produce pain.