Heart (Chapter 15) Flashcards
What are the different layers of the heart? Describe each layer.
- Pericardium - tough, double walled fibrous sac that encases and protects the heart. Has two layers, the fibrous layer which is more external and provides a “shell” covering, and the serous layer. The serous layers are separated by a small (a couple mL) amount of serous fluid which helps reduce friction as the heart does it’s beating.
- Epicardium - outer layer of the heart. Located under the pericardium. Thin. Muscles.
- Myocardium - middle layer of the heart. Thick and muscular. This is the layer of the heart that contracts and relaxes with each heart beat.
- Endocardium - Inner most layer. Lines the heart chambers, valves.
What are the atria main function?
What about the ventricles?
Atria - the atria work to collect blood returning from the circulator system (right) and the lungs (left). They act as reservoirs holding the blood until the ventricles are ready to receive it.
The ventricles main functions differ on the side of the heart. The right ventricles is less muscular as it has less of a pressure gradient to work against. It pushes it’s blood through the pulmonary artery and into the lungs to become oxygenated. The left ventricles is larger and more muscular because it has a high pressure gradient it has to work against. It pumps freshly oxygenated blood throughout the body.
What is going on during the:
1. P wave
2. PR interval
3. QRS
4. ST segment and T wave
5. U wave
6. QT interval
- The P wave represents atrial depolarization
- The PR interval represents the time between atrial contraction and ventricular contraction. The time frame should be between .12 and .20 seconds.
- QRS complex represents ventricular depolarization. The time frame should be under .12 seconds.
- The ST segment and T wave represent ventricular repolarization.
- The U wave is thought to play a role in ventricular repolarization. It is commonly absent from the EKG and is associated with electrolyte abnormalities and hypothermia.
- QT interval is the amount of time between ventricular depolarization and repolarization.
What is the PMI? Where is it found?
The PMI is the point of maximal impulse. Also known as the apical pulse. This is the area of the heart that is best seen and heard during assessment. It represents where the L. ventricle is. Typically, left 5th intercostal space midclavicular.
What is S1? What causes it?
S1 denotes the beginning of the cardiac cycle and the beginning of systole. “Lub” is auscultated as the pressure in the ventricles exceeds the pressure in the atria (which were just filling the ventricles with blood). This pressure differences causes the AV valves (mitral and tricuspid) to snap close. This snapping close is what produces the S1 sound.
What is the S2? What causes it?
S2 sound is the “dub” of the cardiac cycle, or the end before a new cycle starts. The sound is created by the closure of the semilunar valves (pulmonic and aortic) as the pressure difference between the atria and ventricles forces them shut.
What is the S3 heart sound? What causes it?
The S3 heart sound is not always heard. It represents passive ventricular filling before the atrial kick.
What is the S4 heart sound? What causes it?
The S4 heart sound is an abnormal heart sound that is not always present. It is caused by blood rushing from the atria into a noncompliant ventricle.
How is fetal circulation different than adult circulation?
- Fetal circulation does not include the lungs. Fetuses are suspended in amniotic fluid without access for respiration. The heart has a structure called the patent ductus arteriosus which allows the right ventricle to pump blood into the systemic circulation instead of through the pulmonary artery into the lungs as it would with an adult.
- The fetal heart has ventricles that are approximately the same size. This is because both the right and left ventricle are pumping out into the systemic circulation via the patent ductus arteriosus.
- The fetal heart is more horizontal than the adult heart. The apex and the base of the fetal heart are much more level than in the adult.
- The fetal heart’s atria have a communication point in the septal wall, allowing flow to pass between the atria (primarily passes from R to L). This opening is the foramen ovale.
When do the differences between fetal and adult hearts normalize?
- The patent ductus arteriosus (allows RV and LV to both pump to the systemic circulation and bypass the lungs) and the foramen ovale (communication point between the R and L atria) typically close within the first 24-48 hours after conception due to pressure differences.
- The heart’s ventricles differentiate into the adult 2:1 proportions around 1 year of age.
- The hearts axis becomes more vertical as seen with adults around age 7.
What are some cardiovascular changes seen with pregnancy? When do they return to normal?
Pregnancy - a pregnant woman’s blood volume increases by 40-50% of the prepregnant levels. This change is primarily made up in plasma and helps provide the growing fetus with the necessary circulation. However, this increase places greater stress on the mother, leading to increased ventricular size to compensate for the increase in SV and CO. These changes correct 3-4 weeks post delivery.
What are some cardiovascular changes seen with advanced age?
Elderly patients can see a decrease in the heart’s size. HTN and HD can alter this change.
The left ventricle and the valves fibrose. This leads to stiffer, less compliant valves.
Characteristics of cardiac chest pain
Quality - crushing, pressure
Location - substernal
Provoking - effort, exertion, emotion, eating
Relieving - rest and nitro
Accompany - diaphoresis and nausea
Characteristics of pleural chest pain
Quality - sharp
Location - generalized
Provoking - deep breathing, coughing
Relieving - shallow breathing or holding breath
Characteristics of esophageal chest pain
Quality - burning
Location - substernal, can radiate to shoulder
Provoking - laying flat, APPEARS AT NIGHT MOST OFTEN
Relieving - eating, antacids
Characteristics of peptic ulcer chest pain
Quality - burning, gnawing
Location - infradiaphragmatic and epigastric
Provoking - hunger
Relieving - eating food
Characteristics of musculoskeletal chest pain
Quality - often localized
Provoking - twisting or costochondral bending
Mitral Stenosis
1. Where is it best heard?
2. What is stenosis?
3. Description of the murmur?
4. Physical exam findings/ common causes?
- The mitral stenosis murmur is best heard at the apex of the heart (L 5th intercostal space midclavicular line). The patient positioned in the left lateral recumbent position.
- Stenosis is a narrowing of the valve; this is always a chronic issue. The stenosis causes a more forceful forward ejection from the atria to the ventricle; think of placing a thumb over a hose.
- Diastolic murmur described as a low frequency rumble. Palpable thrill at the apex is common.
- Mitral stenosis often occurs alongside mitral regurgitation. The most frequent causes of mitral stenosis are rhematic fever or cardiac infection.
Aortic Stenosis
1. Best auscultated?
2. How is the murmur described?
3. What is stenosis?
4. Common causes and who is this seen in?
- Aortic stenosis is best heard at the base of the heart, R 2nd intercoastal space alongside the right sternal border.
- Mid-systolic, medium pitched, diamond shaped crescendo-decrescendo, with radiation along the left sternal border.
- Stenosis is narrowing of the valve opening, often due to calcification, this narrowing places greater pressure on the blood traveling from the left ventricle into the aorta.
- Rheumatic fever, congenital bicuspid valve (normally has three cusps), and atherosclerosis.
- Associated with sudden death, more commonly in children and adolescents. Can happen at rest or with exercise. Depends on the degree of stenosis.
Pulmonic stenosis
1. Best auscultated?
2. How is the murmur described?
3. What is stenosis?
4. Common causes?
- Pulmonic stenosis is best heard over the pulmonic area, located at the left 2nd intercostal space at the left sternal border.
- Pulmonic stenosis is a systolic murmur that is described as a diamond-shaped, medium pitched, coarse.
- Stenosis is a narrowing of the valve opening which results in more turbulent blood passing through the opening.
- Right ventricular hypertrophy. Almost always a congenital cause.
Mitral Valve Prolapse
1. Best heard?
2. How is this murmur described?
3. What is prolapse?
4. Common causes?
- Mitral valve prolapse is best heard at the apex of the heart, at the left sternal border. It is easily missed with the patient in the supine position.
- Late systolic murmur preceded by mid-systolic clicks.
- Mitral valve prolapse is when the mitral valve gives way into the atrium during systole. This reduces cardiac output headed to the body.
- Pectus excavatum is a common cause
Mitral Regurgitation
1. Best heard?
2. How is the murmur described?
3. What is regurgitation?
4. Common causes?
- Mitral regurgitation is best heard at the apex of the heart, transmitted into the left axilla.
- Holosystolic. Plateau-shaped intensity, high pitch, harsh blowing quality.
- Regurgitation is the allowance of blood to back flow from aorta back into the mitral chamber. This is caused by the inability of the valve to fully close.
- Seen with rheumatic fever, MI, myxoma
Aortic Regurgitation
1. Best heard?
2. How is the murmur described?
3. What is regurgitation?
4. Common causes?
- Aortic regurgitation is best heard at the base of the heart, near the 2nd right intercostal space at the right sternal border. Best heard with the patient sitting up and leaning forward.
- Early diastolic, high pitched, blowing, mid-systolic murmur.
- Valve incompetence allows backflow from aorta to the ventricle.
- Rheumatic heart disease, endocarditis, Marfan syndrome, syphilis, dissection, trauma.
How are heart sounds graded?
Grade 1 - barely audible in a quiet room
Grade 2
Grade 3 - Moderately loud
Grade 4
Grade 5 - Very loud, thrill is palpable
Grade 6 - Audible without stethoscope
Crescendo/ Decresendo
Which murmurs are described in this way?
Crescendo - Intensity of noise increases with blood velocity
Decrescendo - Intensity of the noise decreases with decreased blood velocity
Together these two characteristics can be called “diamond shaped”.
Aortic stenosis is the classic answer. Pulmonic stenosis and aortic regurgitation can also cause this type of sound.
S1
1. Where is it best heard?
2. What heart valves are involved?
3. Does it occur during systole or diastole?
4. Preferred patient position?
5. Pitch?
- S1 is best heard over any of the precordium.
- S1 is caused by the closure of the AV valves at the beginning of systole.
- S1 sound occurs during systole.
- Any position allows audible S1.
- High pitched
S2
1. Where is it best heard?
2. What heart valves are involved?
3. Does it occur during systole or diastole?
4. Preferred patient position?
5. Pitch?
- S2 is best heard toward the base of the heart, either at R or L 2nd intercostal spaces.
- S2 is caused by the closure of the semilunar valves during diastole.
- S2 occurs during diastole.
- S2 is best heard if the patient is sitting or supine
- High pitched
S3
1. Where is it best heard?
2. What heart valves are involved?
3. Does it occur during systole or diastole?
4. Preferred patient position?
5. Pitch?
- S3 is best heard at the apex of the heart. This is because the sound is caused by passive flowing of blood through the AV valves into the ventricles.
- S3 involves blood passing through the AV valves into the ventricles during diastole.
- Occurs during early diastole
- S3 is best heard with the patient in the supine or left lateral position
- Best heard with the bell of the stethoscope, low pitched
S4
1. Where is it best heard?
2. What heart valves are involved?
3. Does it occur during systole or diastole?
4. Preferred patient position?
5. Pitch?
- S4 is best heard at the apex of the heart this is because S4 is caused by the atria forcefully pushing blood into a distended ventricle.
- S4 involves the AV valves. Blood is being pushed from the atria into the ventricles through the AV valves.
- S4 occurs during late diastole.
- S4 is best heard when the patient is in the supine or left lateral position.
- Best heard with the bell of the stethoscope, low pitched sound
Pericardial Friction Rub
1. Location best heard?
2. What is pericardial friction rub?
3. Diastole or systole?
4. How does it sound?
- Pericardial friction rub is widely heard over the precordium. Best heard at the apex of the heart.
- A pericardial friction rub is caused by inflammation of the pericardial sac. This inflammation causes roughening that produces a rubbing, machine-like sound.
- The pericardial friction rub can occupy both systole and diastole.
- Has a rubbing, machine like quality.
Gallops
1. Location best heard?
2. What are gallops?
3. When do they occur in the cardiac cycle?
4. How does it sound?
- Best heard with the bell of the stethoscope at the apex of the heart. Position the patient supine or in the left lateral recumbent position.
- Gallops are additional heart sounds auscultated during diastole. S3 and S4 are common gallops.
- They occur during diastole.
- Intense and easily heard when present.
Systolic Clicks
1. Location best heard?
2. Types?
3. Cause?
4. Sound quality?
- Toward the base of the heart. Aortic clicks will be better heard toward the right second intercostal space while pulmonic clicks will be better heard toward the left second intercostal space.
- There are aortic valve ejection clicks and pulmonic valve clicks.
- Caused by aortic or pulmonic valves opening, occur at the point of maximal pressure.
- Clicks make a high pitched sound that is best heard with the bell of the stethoscope.
Opening snap
1. What valve is involved?
2. What kind of sound does it make?
- Mitral valve
- High pitched, sharp snap or click
What organs should be given special consideration when examining the cardiovascular system in an infant?
The liver, lungs, and skin.
Why is the liver an important consideration during examine of the heart function in an infant?
An enlarged liver is associated with right sided heart failure in infants.
Purplish plethora seen on infants skin. What causes this discoloration?
This is a sign of polycythemia. An increased amount of RBC causes the discoloration.
Ashen white color seen on an infant skin
Indicates shock.
Cyanosis of the skin, mucous membranes, and of the face and body found in a newborn.
How is this different than cyanosis noted in the hands and feet of a newborn?
Cyanosis of the skin, mucous membranes, face, and body is an abnormal finding that is indicative of congenital heart defect.
Acrocyanosis is the blueish discoloration of a newborns hands and feet without central cyanosis. This is an expected finding and should resolve within the first couple days after birth.
What disease accounts for most acquired murmurs in infants?
Kawasaki disease
Sinus arrhythmias in infancy and childhood
These can be normal findings in infancy and childhood.
Still or innocent murmurs
These are heart murmurs that occur in childhood. They are nonpathological. They occur due to vigorous expulsion of blood from the LV into the aorta during childhood exertion. The murmur quiets when the child is still (at rest)
What are some important assessments to complete on a child with known heart failure?
Assessment of weight gain/loss. Developmental delays. Cyanosis. Clubbing of fingers or toes.
How does the cardiac examination differ between adults and:
1. Children
2. Pregnant women
3. Elderly
- Children - will typically have a faster resting heart rate. Sinus arrhythmias can be a normal finding. Heart murmurs, known as still or innocent murmurs, are not of consequence and will disappear with age. The PMI is slightly shifted, located at the left 4th intercostal space medial to the nipple. Kawasaki disease is the most common cause of acquired murmurs in children.
- Pregnant patients have increased blood volume, this blood volume places a greater strain on the heart. During auscultation, splitting of S1 and S2 and the presence of S3 are common findings due to this increased workload. The heart’s position can shift due to uterine enlargement, this can shift the PMI. Systolic pulmonic area murmurs are found in 90% of pregnant patients. S4 is always abnormal.
- Elderly patients often require a slower exam pace. They may not tolerate laying supine or in the left lateral recumbent positions for prolonged periods of time. S4 heart sound is more common due to age related decrease in LV compliance. Heart rhythm abnormalities are more common, these include AFIB, 1st degree AV block, left ventricular hypertrophy.
What is the SAFER approach to assessing for heart defects?
The SAFER approach is used to detect underlying heart defects in children.
S - syndromic features - children who are affected by syndromes or chromosomal abnormalities are more likely to also suffer from heart defects.
A - age - murmurs found in infants are more likely to be pathological than ones found in children.
F - family history - congenital heart defects are slightly more common in infants with family history of them
E - evaluation of feeding and growth - murmur in a child who presents with poor growth, feeding difficulties, sweating during feeds, tachypnea, and/or cyanosis are important warning signs of underlying cardiac conditions. How long does the infant take to finish a bottle? Does the infant take frequent breaks while taking a bottle?
R - rheumatic fever or other significant previous medical history - history of rheumatic fever or Kawasaki disease are red flags.
Angina
1. What is it?
2. What causes it?
3. How does the patient typically present?
- Angina is chest pain caused by myocardial ischemia
- Angina is caused by a myocardial oxygen demand higher than myocardial oxygen supply
- Patients with angina typically present with pain descriptions of pressure, elephant on chest, intense substernal. The pain can radiate to the neck, jaws, and arms (particularly the left). Associated symptoms include diaphoresis, shortness of breath, fatigue, faintness, and syncope.
Bacterial endocarditis
1. What is it?
2. Who is at greatest risk?
3. Subjective and Objective data
4. Specific characteristics
- Bacterial infection of the endothelial layer of the heart and valves.
- Patients with a history of congenital or acquired valve defects and patients who have a history of IV drug use.
- Fever, sudden onset of CHF, janeway lesions, osler nodes
- Janeway lesions - small lesions that appear on the palms of the hands and soles of the feet.
Oslner nodes - painful, red, raised lesions that appear 0on the fingers and toes. Caused by septic emboli.
What is pericarditis? How does pericarditis pain present?
Inflammation of the pericardium. Pain with pericarditis presents with sharp and stabbing chest pain. The pain can worsen with coughing, swallowing, deep breathing, or lying flat.
What is cardiac tamponade?
Cardiac tamponade is an emergent condition where fluid or blood accumulates in the pericardial sac which surrounds the heart. This excess fluid constricts the heart’s movements and impedes cardiac output.
What is cor pulmonale?
Enlargement of the right ventricle secondary to chronic lung disease
Myocardial infarction
Ischemic myocardial necrosis caused by abrupt decrease in coronary blood flow to a segment of the myocardium.
Myocarditis
Diffuse inflammation of the myocardium
How does heart failure present in infants?
Infants with right sided heart failure tend to have enlarged livers. These children might present with fatigue, shortness of breath (especially during feedings), and poor growth.
Ventricular Septal Defect
1. What is the defect?
2. What happens in the heart because of this defect?
3. How does this defect affect the patient?
4. Is this defect ever a normal finding?
- An opening between the left and right ventricles.
- During ventricular contraction some blood passes through the defect from the LV into the RV.
- The defect can lead to recurrent respiratory infections. If large it can cause tachypnea, poor growth and CHF
- 30-50% of small defects close during the first 2 years of life
Tetralogy of Fallot
1. What is the defect?
2. What happens in the heart because of this defect?
3. How does this defect affect the patient?
4. What are tet spells?
- A congenital heart defect compromised of four different cardiac defects: VSD, pulmonic stenosis, dextroposition of the aorta, and right ventricular hypertrophy.
- There is an increased right to left shunting of blood which bypasses the lungs, leading to deoxygenated blood entering the systemic circulation. The amount of deoxygenated blood increases during times of hypercontractile episodes (during agitation/crying).
- Dyspnea - reduced oxygenation leads to frequent episodes of dyspnea. Feeding is difficult and may lead to poor growth. Exercise or activity intolerance. Tet spells. Older children can have clubbing of fingers and toes. Can develop heart failure if not surgically corrected.
- Tet spells are periods of hypercyanosis which can result in loss of consciousness and central cyanosis.
Patent Ductus Arteriosus
1. What is the defect?
2. What is the ductus arteriosus?
3. What happens in the heart because of this defect?
- This is a failure of the ductus arteriosus to close after birth.
- The ductus arteriosus is a normal structure in the fetus that allows blood to bypass the immature lungs and travel from the RV into the pulmonary artery and then into the aorta instead of the lungs.
- If the ductus arteriosus does not close after birth then blood can flow from the aorta and into the pulmonary circulation during diastole and systole increasing the workload of the right heart.
Atrial Septal Defect
1. What is this defect?
2. What happens in the heart because of this defect?
- ASD is a congenital condition that results in a communication between the right and left atria.
- Allows a left to right shunting of blood during ventricular contraction. Because the left side of the heart contracts more forceful, it forces blood toward the right. This increased blood volume in the right side of the heart can cause volume overload in the right heart. Chronic increased workload in the right heart can lead to heart failure.
What pathogen is responsible for rheumatic fever?
Streptococcal
What heart sound does the carotid pulse coincide with?
The carotid pulse and S1 (systole) should be synchronous, this is because the carotid artery is in close proximity to the heart.
What is a thrill? What does it indicate?
Thrills are fine, palpable, rushing vibrations that are most often felt in the right and left second intercostal space at the sternal border. Thrills indicate turbulence or disruption of expected blood flow and are associated with defects of the aortic or pulmonic valves, pulmonary hypertension, or atrial septal defect. +/
