Quiz 1: Cardiac Pathologies Flashcards
Where does the right coronary artery supply blood to?
-R atrium
-Most of R ventricle
-Inferior wall of left ventricle
-AV and SA node (60% of population)
-Bundle of His
Where does the left coronary artery supply blood to?
-Left anterior descending (LAD)
-Left ventricle, septum, inferior apex
-Left circumflex
-Lateral and inferior walls of left ventricle
-SA node (40% of population)
What are the tissue layers of the heart?
-Endocardium
-Myocardium
-Pericardium
What does the pericardium consist of?
-Fibrous pericardium
-Parietal pericardium
-Visceral pericardium (epicardium)
What does the serous pericardium consist of? What is inside the serous pericardium?
-Visceral and parietal pericardium
-Fluid is between these two layers
What is myocardium? How is it different from skeletal muscle?
-Heart muscle
-Different from skeletal muscle due to automaticity
-Pacemaker cells keep the heart moving without conscious voluntary movement
How does the sympathetic and parasympathetic systems influence the heart?
-Vagus nerve bundle (parasympathetic)
-Vasovagal syncope (aka neurocardiogenic syncope)
What external factors can influence the heart rate?
-Stress
-Exercise
-Caffeine
-Drugs
What does the myocardium consist of?
-Contractile elements of the heart
-Conductive elements of the heart
What is the endocardium? What is its function?
-Thin layer of cells lining the inside of the myocardium, valves, and atria
-Has some connective tissue, some elastic fibers, and muscle tissue
-Provides a smooth surface to allow blood and platelets to flow freely and not adhere to heart walls
-Strengthens the valves and supports other heart tissue
-Supports the subendocardial layer which houses the Purkinje fibers
What are the names of the two atrioventricular valves? What chambers are they between?
-Tricuspid/R AV: between R atrium and R ventricle
-Mitral/L AV: between L atrium and L ventricle
What are the names of the two semilunar valves? What two structures are they between?
-Pulmonary: between R ventricle and pulmonary artery
-Aortic: between L ventricle and aorta
What is cardiac output (CO)?
Amount of blood ejected out of the left ventricle into the systemic system per minute
What is a normative value of cardiac output at rest?
4-5 L/min
How is cardiac output calculated?
-Cardiac output (CO)= heart rate (HR) x stroke volume (SV)
-CO= HR x SV
How long does it take blood to travel through the pulmonary and systemic circuits?
About 1 minute
What is stroke volume?
Amount of blood ejected out of the L ventricle/beat
What is a normative value of stroke volume?
55-100 mL/beat
What is stroke volume affected by?
-Left ventricular end diastolic volume (LVEDV)
-End systolic volume (ESV)
What is left ventricular end diastolic volume (LVEDV)?
Amount of blood left in the ventricle at the end of diastole
What is end systolic volume (ESV)?
Volume of blood returning to the heart
What is preload? What is it directly proportional to?
-The amount of stretch experienced by cardiac sarcomeres pre-contraction
-Directly proportional to stroke volume
What affects preload?
Affected by venous return and volume of returning blood
What is Starling’s Law?
The greater the LVEDV the greater the stretch and volume pumped
What is afterload? What is it inversely related to?
-Force left ventricle must generate to overcome aortic pressure to open aortic valve
-Inversely related to SV
What is contractility?
The squeezing pressure of the left ventricle
What is ejection fraction (EF)? What is it used for? What is a normative value for EF?
-Percentage of blood emptied from the ventricle during systole
-Clinically useful way to understand left ventricular function
-Normal values is 60-70% (greater than 55%)
How is ejection fraction calculated?
-EF=SV/LVEDV
What is low EF usually an indicator of?
Usually an indicator of cardiomyopathy or heart failure
What is myocardial oxygen demand? How is it measured? When does it increase?
-Energy cost to myocardium
-Measured with rate pressure product
-Rate pressure product= HR x SBP
-Increases with activity and with HR or BP
What are the neurohumerol influences on sympathetic stimulation (adrenergic) of the heart?
-Control in the medulla via T1-T4
-SA node, AV node, conduction pathways
-Increases HR and force of myocardial contraction
-Coronary artery vasodilation
-Sympathomimetics: antihypertensives are sympathetic blockers
What are the neurohumerol influences on the parasympathetic stimulation (cholinergic) of the heart?
-Control in the medulla via vagus nerve (CN X) and cardiac plexus
-Innervates the SA and AV node
-Slows rate and force of myocardial contraction
-Coronary artery vasoconstriction
What are baroreceptors? Where are they located?
-Pressure receptors
-Located in walls of aortic arch and carotid sinus
What is the circulatory reflex? What changes occur if BP is increased? What changes occur if BP is decreased?
-Responds to BP changes
-Increased BP triggers parasympathetic response, decrease rate and force of contraction, sympathetic inhibition
-Decreased BP triggers sympathetic response, increases HR and BP, vasoconstriction
What are chemoreceptors? Where are they located?
-Detect changes in O2, CO2, and lactid acid (pH) and will effect HR and RR
-Located in the carotid body
-Increased CO2 or decreased O2 or pH= increased HR and RR
-Increased O2= decreased HR
What is hyperkalemia? What effects will this have on the heart?
-Increased concentration of potassium ions
-Decreased HR
-Decreased contractile force
-Arrhythmias and EKG changes
What EKG changes will you see with hyperkalemia?
-Widened PR and QRS intervals
-Tall T waves
What is hypokalemia? What effects will this have on the heart?
-Decreased concentration of potassium ions
-EKG changes
What EKG changes will you see with hypokalemia?
-Flattened T waves
-Prolonged PR intervals
What is hypercalcemia? How does it effect the heart? What other symptoms might someone have?
-Increased calcium concentration
-Increased HR and increased contractility
-Kidneys would also be effected
-Confusion
-Coma
What is hypocalcemia? How does it effect the heart?
-Decreased calcium concentration
-May cause arrythmias
What is hypermagnesmia? How does it effect the heart? How does it effect other systems?
-Increased magnesium concentration
-Calcium blocker
-Arrythmias
-Cardiac arrest
-Hypotension
-Confusion and lethargy
What is hypomagnesmia? How does it effect the heart?
-Decreased magnesium concentration
-Ventricular arrythmias
-Coronary artery vasospasm
What is the cardiac cycle?
The period from one heart beat to the beginning of the next heartbeat
How does the action potential go through the heart?
-Starts at SA node
-Depolarizes atria
-Spreads to AV node
-Bundle of His
-Bundle branches
-Purkinje fibers
What is systole?
The period of contraction that the heart undergoes while it pumps blood into circulation
What is diastole? What occurs during diastole?
-The period of relaxation that occurs as the chambers fill with blood
-The coronary arteries perfuse the myocardium during diastole through capillaries
-As the aortic valve snaps shut, leftover blood is shunted to the coronary arteries
How long is the delay between the action potential getting sent from the SA node to the AV node? What does this delay allow?
-0.1 second
-It allows the atria to contract and the ventricles to fill
What is phase I of the cardiac cycle?
-Diastole/filling period
-Both atria and ventricles are relaxed
-Blood flows into the R atrium from sup. and inf. vena cava and the coronary sinus
-Blood flows into the L atrium from the pulmonary veins
-Both AV valves are open (blood flows from atria into ventricles)
-Semilunar valves are closed
-SA node depolarizes causing atrial contraction (atrial systole)
How much of ventricular filling occurs when the AV valves are open?
70-80%
How much of ventricular filling occurs because of “atrial kick”? When does “atrial kick” occur?
-20-30%
-Occurs during SA node depolarization which causes atrial contraction
How much blood is in the ventricles at the end of atrial systole and just prior to atrial contraction? What is the term that describes this?
-The ventricles contain approximately 130 mL of blood in a resting adult in standing position
-This is known as end diastolic volume (EDV) or preload
What is phase II of the cardiac cycle?
-Isovolumic/isovolumetric contaction
-AV node depolarizes, spreads to the bundle of His
-Muscles in the ventricle start to contract but semilunar valves are not yet open
-Pressure quickly rises above that in the atria, closing the AV valves
-Pressure is not high enough yet to be ejected from ventricles
What is phase III of the cardiac cycle?
-Ejection
-Continued depolarization through the bundle branches and Purkinje fibers creates stronger ventricular contraction
-Pressure in the ventricles rise until it is greater than the pulmonary trunk and aorta, pushing open the semilunar valves
-Blood is ejected from the ventricles (stroke volume)
How much blood remains in the ventricles following phase III of the cardiac cycle (ejection)? What is the term for this?
-50-60 mL of blood remain in the ventricle after ejection
-End systolic volume (ESV)
What is phase IV of the cardiac cycle?
-Isovolumic/isovolumetric relaxation phase
-Ventricular relaxation/diastole follows repolarization of the ventricles
-Early phase of ventricular diastole, the ventricular muscles relax
-Pressure in the ventricles begins to fall and drops below pressure in the pulmonary trunk and aorta
-Semilunar valves close
-AV valves have not yet opening
How many lobes are there in the R lung? How many are there in the L lung?
-R lung: 3 lobes (superior, middle, and inferior)
-L lung: 2 lobes (superior and middle, + lingula)
How many independent segments are there in the R lung? What are their names?
-9 independent segments
-Apical
-Anterior
-Medial
-Lateral
-Anterior basal
-Posterior
-Superior
-Posterior basal
-Lateral basal
How many independent segments are there in the L lung? What are their names?
-10 independent segments
-Apical
-Anterior
-Anterior superior
-Posterior superior
-Inferior
-Anterior basal
-Superior
-Posterior basal
-Lateral basal
-Posterior
What does the conducting zone consist of?
-Trachea
-Primary bronchus
-Secondary bronchus
-Bronchi
-Bronchioles
What does the respiratory zone consist of?
-Respiratory bronchioles
-Alveolar ducts
-Alveolar sacs
What are the pleura of the lungs? What do these layers make up?
-Two layered membrane that folds back on itself
-Visceral pleura (innermost)
-Parietal pleura (outermost)
-These two layers make up the pleural cavity
What is inside the pleural cavity? What is the function of the pleural cavity? What happens if it is not functioning correctly?
-Pleural fluid
-Creates surface tension to keep the lungs in place in the thorax and allows the lungs to expand when the thorax expands
-It also cushions and lubricates the lungs during expansion and retraction
-It it is not functioning, a pneumothorax can occur
What is the parietal pleura innervated by?
Phrenic and intercostal nerves
What are accessory muscles of inspiration?
-SCM
-Scalenes
-Pec minor
What are the principal/main muscles of inspiration?
-External intercostals
-Diaphragm
What is quiet breathing?
-Expiration is quiet breathing because it results from passive recoil of lungs and rib cage
What muscles are involved in active expiration?
-Internal intercostals
-Innermost intercostals
-Rectus abdominis
-Transverse abdominis
-External and internal obliques
What three pressures does breathing depend on?
-Atmospheric (pressure exerted on lungs by atmosphere)
-Intra-alveolar (pressure inside the alveoli)
-Intrapleural (pressure in the pleural cavity)
What keeps the lungs inflated?
-Competing forces of pressure keeps the lungs inflated
-Elasticity of the lungs and surface tension of alveoli creates an inward pull
-Surface tension in the pleural cavity creates an outward pull
-The outward pull is just slightly higher than the inward pull, so the lungs stay inflated
What is the role of surfactant?
Surfactant is a fluid in the alveoli that prevents them from collapsing
What is pulmonary ventilation?
The air that is moving in and out of the lungs
What is the pulmonary cycle?
Inspiration and expiration
What occurs during inspiration?
-Diaphragm contracts, thorax expands inferiorly
-External intercostals contract, pulls ribs up and out to expand thorax anteriorly
-Creates a pressure gradient and drives air into the lungs
What occurs during expiration?
-Expiration is largely passive
-Diaphragm and external intercostals relax which returns thorax to resting position and reduces volume
-Creates a pressure gradient and drives air out of the lungs
What physical properties do the lungs have that facilitate breathing?
-Lung compliance
-Tendency of lungs to recoil (collapse)
-Elastic recoil or elasticity
-Surface tension at air-liquid interface on the alveolar surface acts to collapse the alveoli (surfactant counters this)
-Resistance to airflow at the level of the airways
What conditions can effect the mechanics of breathing?
-Scoliosis
-Pulmonary fibrosis (impairs compliance of lungs)
-COPD
-Asthma
-Premature babies (reduced surfactant)
-TBI (neural control of breathing may be effected)
How is breathing controlled?
-Primarily controlled by medulla and pons (requires repetitive stimulation from brain)
-Respiration driven by CO2 and pH levels in the blood which stimulate central chemoreceptors in the medulla
What is the response if CO2 increases and pH decreases in the blood?
-Stimulates respiratory centers in the medulla to contract diaphragm and external intercostals
-Increases rate and depth of respiration
What is the response if CO2 decreases and pH increases in the blood?
Stimulated respiratory centers in the medulla to lower rate and depth of repiration
What role do the peripheral chemoreceptors in the carotid artery and aortic arch play in the control of breathing?
-They detect changes in CO2, O2, and pH in the blood
-Increase in ventilation occurs when CO2 levels increase or decrease of O2
What is the hypoxic drive to breath? What patient population is this common with? What precautions should be taken in these cases?
-Some patients with COPD trap CO2 and start to rely more on O2 receptors
-Supplemental O2 should be prudently administered because increases of O2 in the blood can suppress the hypoxic drive to breath
How does the hypothalamus and limbic systems effect breathig?
-Anxiety or stress can increase breathing rate
-Extreme fear can cause one to hold their breath
What is inspiratory reserve volume?
The extra volume of air that can be inspired with maximal effort after reaching the end of a normal, quiet inspiration
What is tidal volume?
The amount of air that moves in and out of the lungs during each breath
What is expiratory reserve volume?
The amount of air that can be forcefully exhaled after a normal, quiet breath
What is residual volume?
The amount of air that remains in the lungs after a person has forcefully exhaled as much as they can
What is inspiratory capacity?
-The maximum volume of air a person can inhale after a normal exhale
-Inspiratory reserve volume + tidal volume
What is the functional residual capacity?
-The amount of air remaining in the lungs after a normal exhalation
-Expiratory reserve volume + residual volume
What is vital capacity?
-The maximum amount of air that can be exhaled from the lungs after a maximum inhalation
What is the total lung capacity?
-The volume of air in the lungs upon the maximum effort of inspiration
-Vital capacity + residual volume
Where does gas exchange occur? How does it occur?
-Alveoli
-Respiratory zone
-Diffuses across membranes down a concentration gradient
-Driven by concentration of various gases in the air we breath and blood pH
What needs to occur for effective gas exchange?
Alveoli must be both ventilated and perfused
What is the V/Q match?
The goal is for ventilation (V) to be matched with perfusion (Q)
What does V/Q mismatch indicate?
A pathological state
What can effect the V/Q ratio?
-Positioning
-Pneumonia, emphysema, pulmonary edema, atelectasis
What is atelectasis?
Partial or complete collapse of the lung
Why is V/Q not uniform across the lungs?
Because there are areas of the lungs with greater perfusion and areas with greater ventilation
How does transport of O2 and CO2 occur in the blood?
-Veins carry CO2 to be expelled
-Arteries carry O2 from heart to tissues
-Hemoglobin (4 iron molecules, heme group, and 4 protein molecules/globins)
-Transports 98% of O2 delivered to the periphery (2% in plasma)
-O2 carrying capacity of body is determine by concentration of HgB
What is SaO2?
-Oxyhemoglobin/total hemoglobin (blood gas analysis)
-Called SpO2 when measure with pulse oximeter
What are the normative values for O2 carrying capacity? How does low O2 carrying capacity effect the body?
-Women: 12-16 g/dL
-Men: 13-16 g/dL
-Lower than normal concentrations impairs the body’s ability to circulate O2 and can cause anemia
What is the oxygen hemoglobin dissociation curve? What would a right shift in the curve indicate? What about a left shift?
-Describes the relationship between SaO2 and the partial pressure of arterial O2
-Right shift: reduced oxygen affinity
-Left shift: increases oxygen affinity
What is pericarditis? What are causes of this?
-Inflammation of pericardium or pericardial fluid
-Viral infection (most common)
-Other infection (bacterial, uremia, acute MI, tuberculosis, etc.)
-Systemic diseases (autoimmune disorders, inflammatory disorders, drug toxicity, etc.)
-Trauma
What would be the clinical presentation of acute pericarditis?
-May not present with any signs or symptoms
-Retrosternal chest pain (sharp/stabbing or dull achey)
-Often intensifies with cough and deep breathing
-Often relieved with sitting up and leaning forward
-Dyspnea (non-exertional)
-General malaise/fever
-EKG abnormalities are not common
-Auscultation: friction rub causes by inflammed pericardial layers rubbing against one another
-Usually seen in young and healthy individuals
What is included in the medical work up and management of acute pericarditis?
-Labs will reveal acute inflammation (elevated WBCs, erythrocyte sedimentation rate, C-reactive protein, and troponins may be elevated)
-Echocardiogram to evaluate pericardial effusion
-Management: rest, pain relief usually with NSAIDS
-High dose of antibiotics or pericardial drainage
How long does acute pericarditis usually last?
-Self limited disease
-Usually lasts 1-3 weeks
What is constrictive percarditis?
Chronic pericarditis or pericardial effusion results in thickening and scarring of the pericardium
What is the clinical presentation of constrictive pericarditis?
-Dyspnea and fatigue due to reduced CO
-LE and abdominal swelling
-Dizziness or syncope
-Vague retrosternal chest pain
-Jugular venous distention
What would a medical work up for constrictive pericarditis include?
-Chest X-ray
-Echocardiogram
-CT scan
-Cardiac catheterization
What is pericardial effusion? How does this effect heart function?
-An abnormal accumulation of fluid in the pericardial sac
-Pericardium is relatively stiff and doesn’t tolerate large fluctuations in fluid over a short amount of time
What is a normal amount of fluid to be in the pericardial sac?
15-50 mL
What can cause pericardial effusion?
Pericarditis and other pathologies or trauma can cause pericardial effusion
What is the clinical presentation of pericardial effusion?
-Feeling of fullness in chest
-Cough
-Hoarseness
-Dysphagia
-Serious, sometimes fatal
What is included in the medical work up and treatment of pericardial effusion?
-Muffled heart and lung sounds, dullness of left lung at angle of scapula
-Chest X-ray may show enlarged cardiac silhouette
-Echocardiogram
-Pericardiocentesis to drain fluid
What is cardiac tamponade?
-Excessive over accumulation of fluid in the pericardial space that exerts pressure on the heart
-Any pericarditis can progress to tamponade but most common is neoplastic, post viral, blunt or penetrating chest trauma, or dissecting aortic aneurysm
What is the clinical presentation of cardiac tamponade?
-Poor filling of the heart
-Decreased BP
-Hypotension shock and possibly death
-Decreased CO signs: dyspnea, fatigue, syncope, dizziness
-Cough, tachycardia, tachypnea
-Beck’s triad: hypotension, jugular venous distention with pulsus parodoxus, and decreased heart sounds
What is included in the medical work up and treatment for cardiac tamponade?
-Echocardiogram
-Emergency cardiac tamponade is treated with “cardiac window” or “pericardial window” where they cut a whole in the fibrous pericardium to allow fluid to drain and relieve pressure
-Pericardiocentesis
What is endocarditis? What are common causes?
-Infection of the endocardium from bacteria or fungi
-Travels from another part of the body- most often after dental work or GI/urinary problems
-Catheters, tattoos, IV drug abuse
-Rheumatic fever
What is endocarditis usually treated with? What can untreated endocarditis lead to?
-Treated with long term antibiotics
-Untreated can lead to destruction of valves and is often fatal
What is the clinical presentation of endocarditis?
-Flu like symptoms
-Pain with breathing
-SOB
-Swelling
-Fever
-Rapid onset of flu like symptoms (acute endocarditis)
-May hear mitral valve regurgitation on auscultation
Who is at highest risk for developing endocarditis?
-People with artificial heart valves as they are reservoirs for germs/bacteria
-Damaged valves or congenital heart defect
What are potential complications of endocarditis?
-Bacterial vegetation can travel to other areas of the body
-Heart valve damage
-Abscesses
-Pulmonary embolism
-Kidney and spleen issues
What is included in the medical workup and treatment of endocarditis?
-Labs for inflammation: sed rate, C-reactive protein, WBCs, blood cultures to isolate organism
-EKG
-Echocardiogram
-Long term, high dose antibiotics
-Cardiac supportive measures
-Possible valve replacement
What are some measures for preventing endocarditis?
Prophylactic antibiotics before dental work, upper respiratory procedures involving incisions or biopsies, GI/GU procedures if infection is present
What is myocarditis? What is it typically caused by?
-Inflammatory cardiomyopathy
-Infection or inflammation of the heart walls/muscle
-Generally viral or bacterial infection, rarely is it drug induced
-Rheumatic fever
-Affects both pump and electrical conduction
-Weakens pump action
What is the clinical presentation of myocarditis?
-Diffuse chest pain
-Fatigue
-SOB
-Edema
-Arrhythmias
-Fever
-General malaise
What are complications of myocarditis if it goes untreated?
-Heart failure due to damaged cardiac muscle
-MI or CVA
-Arrhythmias
What is the NIH definition of cardiovascular disease?
The term for all types of diseases that affect the heart or blood vessels, including coronary artery disease which can cause heart attacks, strokes, heart failure, and peripheral artery disease
What is hypertension?
Blood pressure readings consistently over established guidelines
What is the NIH definition of coronary artery disease (CAD)?
A heart condition that involves atherosclerotic plaque formation in the vessel lumen which can lead to impairment in blood flow and oxygen delivery to myocardium
What is the ACC definition of coronary artery disease?
A condition where the blood vessels that supply blood to the heart become damaged or diseased
What is the clinical presentation of someone with cardiovascular disease or CAD?
-Chest pain
-SOB
-Palpitations
-Fatigue
-Syncope
-Social history
-Risk factors for cardiovascular disease
What is included in the medical workup for someone who may have cardiovascular disease?
-Diagnostic tests/imaging
-Lab values
-EKGs
-PMH/PSH, hospital course
-Medications and nutritional intake
-Social history, cognitive and language ability
What are the modifiable risk factors for cardiovascular disease?
-Cholesterol levels
-Stress
-Diabetes
-Diet
-HTN
-Weight (BMI >30kg/m2)
-Activity level
-Tobacco or smoking
What are the non-modifiable/relatively non-modifiable risk factors?
-Age: > 65 men, >55 women
-Family history: cardiac event 1st male relative <55, 1st degree female relative < 65 increases risk 1.5-2 fold
-Genetics
-Gender male > premenopausal women; after menopause risk is =
-Race: African American
-Chronic kidney disease
-Low socioeconomic status
What would be included in the PT evaluation for someone with CAD or high risk for cardiovascular disease?
-General observation: posture, breathing mechanics, cough ability
-Skin: color (is it blue, pale, etc.)
-Vitals: pulse, rhythm, BP, SpO2
-Heart and lung sounds
-Chest wall motion and palpation
-EKG (refer out)
-Circulation and lymphatic system (observe any edema, temp of skin, etc.)
What is the prevalence of ischemic cardiovascular disease?
- > 83 million Americans have one or more forms of cardiovascular disease (1 in 3 adults)
What percentage of people with HTN are undiagnosed? What can unmanaged HTN cause?
-25% of those with HTN are undiagnosed
-Unmanaged HTN can lead to ischemic heart disease such as stroke, CAD, MI, CVA
What are the 2 types of HTN?
-Primary or essential
-Secondary
What is primary HTN?
-Most of the population (90-95%)
-No discernible/readily identifiable cause but associated with CV risk factors
-Largest number of office visits of non-pregnant US adults
What is secondary HTN?
-Small % of population
-Results from another identifiable disease process (kidney disease, endocrine disorders)