Week 3 Flashcards
What is the pathway of blood flow through the heart?
Returns from the periphery, enter through the vena cave, it empties 1st into the R atrium then it crosses the AV valves into the R ventricles, R ventricles pump through the pulmonic valve into the pulmonary trunk, which then splits into the R and L pulmonary arteries, which goes to the lungs, gets oxygen diffused at the capillary alveolar interphase, blood then returns through the 2 pulmonary veins which converges to the L atrium, blood then flows from the L atrium, across the bicuspid valve(mitral valve), into the L ventricle, which then pumps blood through the aortic semilunar valve, then into the aorta, then into the systemic circulation that perfuses our tissues
What happens during diastole in regards to the heart valves?
The semilunar valves(pulmonary and aortic valves) are closed, because the ventricles is relaxed due to less pressure behind the valves. The AV valves(mitral and tricuspid) are open as blood is entering into the chambers
What happens during systole in regards to the heart valves?
The mitral and tricuspid valves are closed, which allow for them to create a high pressure chamber, to egress blood across the pulmonic valve and aortic valve
What are heart valves?
Passive structures that respond to pressure.
What helps keeps the AV valves closed during systole?
Chordae tendinae
What causes a valve to open?
When contraction increases pressure within a given chamber greater than the downstream pressure. (more related to semilunar valves, especially the pulmonic and the aortic valve)
What causes a valve to close?
When contraction ends and pressure decreases below downstream pressure
What is the pressure across the aortic valve?
Anywhere between 80-100
What are the AV valves on the left side?
Bicuspid or mitral valve
What are the AV valves on the right side?
Tricuspid (3 leaflets)
What do the Chordae tendinae and Papillary muscles do during systole in the AV valves?
They become taut to prevent them from opening.
- Prevent inversion of valves during ventricular systole.
- Can become damaged from MI causing back flow “regurgitation”.
What are the semilunar valves?
Aortic and Pulmonic
What are the characteristics of the semilunar valves?
- Three leaflets on each
- No papillary muscles or chordae tendonae
- Do not lie back against the walls of the aorta or pulmonary artery
What are the general symptoms of Cardiac Valvular Disease?
- Easy Fatigue
- Dyspnea
- Palpitations
- Murmur
- Chest Pain
- Pitting Edema
- Orthopnea
- Dizziness
What is a murmur?
What we hear when there is turbulent flow across the valve.
Why do patients with a cardiac valvular disease get chest pain?
If we impair the pressure gradient, we impair the egress of blood out of the heart, and across the valves, we may impair myocardial performance, especially as we increase workload, if we can’t maintain demand, we may get transient ischemia and chest pain
Why do patients with a cardiac valvular disease get pitting edema?
If we have an impaired ability to get blood out of the heart, we can create backflow. Backflow on the right goes into the peripheral veins and back flow on the L, it will eventually go back to the lungs and eventually impair the R side
What is orthopnea?
Shortness of breath when laying flat, due to the fact that when you lay flat, blood shunts into the central part of the body, which increases pre-load/stilling, which is essential putting more fluid into a flooded system, which it can’t handle, causing backflow into the lungs
What is concentric remodeling?
Classified as an increased relative thickness, with a normal L ventricular mass
What is concentric hypertrophy?
Classified as an increased relative thickness, with an increased L ventricular mass
What is concentric remodeling and concentric hypertrophy typically in response to?
L pressure overload, with the earliest response typically being concentric remodeling
Why is concentric remodeling and concentric hypertrophy done?
In an attempt to limit wall stress and to allow for normal L ventricular systolic function and performance
How does concentric remodeling and concentric hypertrophy become a pathological change?
If we have sustained elevated pressures like we see in HTN, or an aortic stenosis,
What does concentric remodeling and concentric hypertrophy lead to when it becomes pathological?
L ventricular diastolic dysfunction, an impaired ability to relax, and potentially diastolic heart failure
What is eccentric hypertrophy?
When ventricles have an increased mass, with a dilated ventricular chamber, with normal to low relative wall thickness. EX: ischemic cardio myelopathy
What are the types of congenital valvular disease?
- Genetic
- Maternal exposure
What are the types of acquired valvular disease?
- Rheumatic fever
- Endocarditis
- Gradual fibrosis
In what population does mitral stenosis primarily occur in?
Females
What is the main cause of mitral stenosis?
Rheumatic heart disease
What is mitral stenosis?
Condition where valve Leaflets don’t opening easily or completely
What are the effects of mitral stenosis?
Decreases area and increases
resistance to flow between A-V
What is the most common type of valvular disease?
Aortic stenosis
What are the other less common causes of mitral stenosis?
Congenital mitral stenosis, such as parachute mitral valve; marked mitral annular calcification and infective
endocarditis with large vegetations (often fungal, why you get antibiotics before dental work)
What happens in a parachuted valve?
All of the chordae tendonae attach to one valve, which impairs its ability to open
What are the things that we see in a case of mitral stenosis?
Pressure overload
- L atrium hypertrophy
- Limited L ventricle filling
- LA thrombus breeding
ground
- A fib
- Pulmonary congestion and
HTN
Upon Exertion
- Dyspnea: back flow of fluid from L side into lungs
Auscultation
- Opening snap, diastolic rumbleWhat does mitral stenosis cause?
- Hypertrophy occurs in chamber upstream from stenosis, concentric type
- Stretch of L Atrium creates multiple foci causing arrhythmias
- At risk for thrombus due to pooling in Left Atrium and increased turbulence
- Body may compensate early on with little or no symptoms
- May advance to right heart failure
What are the medical management methods for mitral stenosis?
Anti-coagulants and antiarrhythmics, surgery
What causes mitral regurgitation/incompetence?
Rheumatic heart disease, which affects the properties of connective tissue often seen rheumatic disease
How does mitral regurgitation/incompetence work?
Mitral valve does not close completely during
systole (Incompetence)
• Creates back flow (Regurgitation)
• Increase SV to compensate for back flow
• Upstream chamber (L Atrium) dilates out
• Eccentric hypertrophy to accommodate increased volume
What are the signs and symptoms of mitral regurgitation/incompetence?
Anxiety and palpitations w/ exercise
• Asymptomatic fine to exercise
• Symptomatic patients beta blockers
What is a mitral valve prolapse?
When the valve snaps open during systole. You would hear a click followed by a murmur
What are the characteristics of mitral valve prolapse?
Mostly asymptomatic, cause
unknown
What would you expect to see in mitral valve prolapse?
Volume overload - L atrium dilates - A - fib - Thrombus formation - Pulmonary congestion - LVH forward flow Upon exertion - Dyspnea Auscultation - Holosystolic murmur: regurgitation into L atrium
What are the most common types of aortic stenosis?
Calcific aortic stenosis and congenital bicuspid aortic valve stenosis
What is congenital bicuspid aortic valve stenosis?
A condition where there is only 2 instead of 3 leaflets in the aortic valve, which causes the resistance to flow to be a bit higher
What do we often see in aortic stenosis?
Mild thickening, calcification, or both of a tri-leaflet aortic valve without restricted leaflet motion
What would you expect to see in an aortic stenosis patient?
Volume overload - LV dilates out - LVH Upon exertion - Dyspnea Auscultation - Diastolic murmur "blowing"
What are the causes of Aortic Regurgitation/Incompetence?
Congenital, rheumatic, endocarditis, deterioration with age as well as long
standing HTN
What would you expect to see in an aortic regurgitation/incompetence patient?
Volume overload - LV dilates out - LV hypertrophy Upon exertion - Dyspnea Auscultation - Diastolic murmur "blowing"
- Eccentric hypertrophy
- Late stages maybe LA concentric hypertrophy?
- No pulmonary symptoms until very advanced stages
What are the exercise considerations for valvular stenosis?
- Close monitoring with RPE
- Low muscle perfusion may limit exercise
- Suppressed BP response to exercise, possibly exaggerated HR
- Low cardiac output
- Patients with symptomatic aortic stenosis clients are typically not candidates for exercise programs!
- Asymptomatic aortic stenosis: intensity should be low and progressed gradually
- Angina may be a symptom
What are the characteristics of valvular replacement and repair?
• Valves can be mechanical or biological
- Pig, cow, cadaver
- Typically requiring by-pass and a median sternotomy
• Mechanical typically bi-leaflet valve with 2 carbon
leaflets covered with polyester knit fabric
• Mechanical last a lifetime but require anticoagulant meds
• Biologic valves made of human, pig or cow tissue
(xenografts)
- Pig valves mounted on frames (stents) or can be stentless
• Young pts may be better candidate for mechanical due to limited life of biological valve
• Mechanical higher risk for infection, thrombus and
emboli.
- Will need life long anti-coagulation meds
What are the characteristics of the minimally invasive options for valvular replacement/repair?
- Da-Vinci Robot
- Becoming more and more common
- MIAVR is limited by the longer cross-clamp and cardiopulmonary bypass (CPB) times.
- They go through 3 or 4 ports in the body, allowing the surgeon to visualize the structure they are operating on, and replace the valve through that method
What are the pros of the minimally invasive options for valvular replacement/repair?
Reduced postoperative mortality and morbidity, shorter hospital stay and
better cosmetics
What are the characteristics of trans-cutaneous valve repairs?
- Transcutaneous Aortic Valve Repair/Implantation
- Typically reserved for patients at high risk for open heart surgery
- Usually Older patients, or those with significant compromise
- Promising early results comparing 4yr clinical outcomes to open heart
What are the layers of the pericardium?
- Fibrous
- Serous
- Pericardial Space
What is the fibrous layer of the pericardium?
Outermost layer, firmly bound to the central tendon of the diaphragm; sternum (sternopericardial ligaments) and mediastinal pleura
What is the serous layer of the pericardium?
Lines the inner surface of the fibrous pericardium (Parietal) and is reflected onto the heart as the visceral layer (Epidcardium), forms a closed sac
What is the pericardial space of the pericardium?
Potential space formed by the sac, filled with fluid that
lubricates the heart and reduces friction during movement
What is the epicardium?
Outer layer of connective tissue that covers heart, contains variable amounts of
adipose tissue that tends to aggregate along vessels and in the grooves on the surface of the heart.
What is pericarditis?
Swelling and Irritation of the pericardium
What are the common causes of pericarditis?
- Viral infections, Bacterial infections (less common), Fungal infections (rare)
- May occur due to a heart attack, radiation therapy and post open heart surgery
What are the signs and symptoms of pericarditis?
• Sharp retrosternal pain with radiation to the back (lasting hours), fever
• Pain worsens with deep breathing or coughing
and when laying flat.
• Pain is improved while sitting up and leaning forward
• Friction rub on auscultation
What is pericardial effusion?
Accumulation of fluid in the pericardial sac, which then impairs the ability for the heart to contract and for it to expand and fill
What are the causes of pericardial effusion?
- Viral infections, Bacterial infections (less common), Fungal infections (rare)
- May occur due to a heart attack, radiation therapy and post open heart surgery
What are the signs and symptoms of pericardial effusion?
• Symptoms
- Pressure pain in chest, dysphagia, dyspnea,
• Signs
- Muffled heart sounds, possibly JVD
What may pericardial effusion progress to?
Cardiac tamponade…Not good
What are the rarer conditions that can cause Aortic Regurgitation/Incompetence?
Marfan syndrome, ankylosing spondylitis and certain STDs
How do trans-cutaneous valve repairs work?
They insert a tracer wire through a catheter to get to the aorta, then they will implant a valve over or within the damaged valve
How is pericardial effusion treated?
By drainage, through a process called pericardiocentesis, where they remove fluid from the pericardium
What happens in cardiac tamponade?
The heart has very little movement, because there is so much pressure on it and it can lead to death
What is auscultation?
The propagation of sound from the heart through the chest wall, which allows us to assess the function of valves
What should auscultation include?
The 4 primary auscultation areas of the heart using the
diaphragm, staring with the patient in the supine or seated position.
How do you start auscultations?
• Start by finding the angle of Louis (sternal angle aka manubriosternal junction)
located at the 2nd rib, which is easily felt as a small protuberance along the sternum.
• Auscultate each point starting with the Aortic region using the following Mnemonic: All – Physical – Therapists – Move (Aortic, pulmonic, tricuspid, mitral)
How do you differentiate between systole and diastole during auscultations?
When doing auscultations, palpate an artery and when you feel a pulsation is the beginning of systole(AV valves). During the period when we don’t feel a pulse but we hear an auscultation is beginning diastole(semilunar valves)
What are the regions we want to listen to during auscultation and where are they?
- Aortic Region: Right 2nd
intercostal space, parasternal (angle of louie) - Pulmonic Region: Left 2nd
intercostal space, parasternal (angle of louie) - Erb’s point: Left 3rd intercostal space aka Left Lower Sternal Border (not a major region)
- Triscupid Region: Left 4th
intercostal space, parasternal - Mitral Region: Left 4th or 5th
intercostal space, midclavicular
What is the 1st heart sound we hear during normal heart sounds?
S1 “Lub” The first heart sound • Closure of the AV valves • (Tricuspid and Mitral) • Occurs with ventricular contraction • Marks the approximate beginning of systole.
What is the 2nd heart sound we hear during normal heart sounds?
S2 “Dub” The second heart sound
• Closure of the Semilunar valves
- (Aortic and Pulmonic).
• Marks the beginning of ventricular relaxation and end of systole.
• The second heart sound is of shorter duration and higher frequency than the first heart sound.
In what region do we often appreciate subtle changes to the heart?
Mitral region
What is splitting S1( 1st heart sound)?
The mitral and triscupid valve sounds (M1 and T1) are slightly asychronous.
What are the characteristics of splitting S1( 1st heart sound)?
• This is a normal findings as
- the mitral closure may precede tricuspid closure by 20 to 30 msec (0.02 to 0.03 sec.).
• This produces two audible components
• (M1-T1) referred to as normal or physiologic splitting of the first heart sound (S1).
• Wide splitting of the first sound is almost always
abnormal and warrants further medical examination
What are the characteristics of splitting S2( 2nd heart sound)?
• (S2) is of shorter duration and higher frequency than S1.
• It has two audible components, the aortic closure sound (A2) and the pulmonic closure sound (P2)
• Normal or Physiologic splitting is demonstrated during inspiration in normal healthy individuals, since the
splitting interval widens primarily due to the delayed P2.
- Common in children and well condition athletes
When may persistent splitting S2 occur?
Persistent splitting S2 may occur in supine or recumbent
position however, the split should resolve on expiration
following sitting, standing, or a Valsalva maneuver.
• If splitting of S2 does not change with these measures or if found in adults warrants further medical examination
What are extra heart sounds (Gallops) that may be heard?
• S3 occurs at the beginning of diastole after S2 and is lower in pitch than S1 or S2 as it is not of valvular origin.
• Indicative of ventricular/heart failure.
-SLOSH’-ing-in SLOSH’-ing-in
S1 S2 S3 S1 S2 S3
• S4 Occurs prior to S1, produced by the sound of blood being forced into a stiff
or hypertrophic ventricle. (pressure overload)
• Indicative of LVH or HCOM
• a-STIFF’-wall a-STIFF’-wall
S4 S1 S2 S4 S1 S2
What is a murmur?
Extra sounds during the cardiac cycle, such as whooshing or swishing made by turbulent blood flow often due to a faulty valve or structural changes in the myocardium.
• Onomatopoeia
What are the characteristics by which a murmur should be characterized?
• Shape - Crescendo (grows louder), decrescendo, crescendo-decrescendo, plateau • Location - Determined by the site where the murmur originates - A, P, T, M listening areas • Timing - Murmurs are longer than heart sounds - Systolic, diastolic, continuous • Intensity • Pitch • High, medium, low
What are the grades of intensity at which a murmur should be assessed?
• Graded on a 6 point scale
- Grade 1 = very faint
- Grade 2 = quiet but heard immediately
- Grade 3 = moderately loud
- Grade 4 = loud*
- Grade 5 = heard with stethoscope partly off the chest*
- Grade 6 = no stethoscope needed*
*Note: Thrills are assoc. with
murmurs of grades 4 – 6
What are the systolic murmurs we hear?
- Aortic stenosis - ejection type
- Mitral regurgitation - holosystolic
- Mitral valve prolapse - late systole
- HCOM-ejection type
- Ventral Septal Defect-holosystolic
What are the diastolic murmurs we hear?
- Aortic regurgitation - early diastole
2. Mitral stenosis - mid to late diastole
How should the sound of the murmur heard during aortic stenosis change with position?
When they stand it should decrease and when they sit it should increase
How should the sound of the murmur heard during hypertrophic cardiomyopathy change with position?
When they stand it should increase and when they sit it should decrease
What is heart failure (HF)?
A complex clinical syndrome that can result from any structural or functional cardiac disorder that results in the inability of the heart to eject blood to meet the demands of the body while maintaining
normal pressures in it’s chambers and the lungs. Cardiac pump dysfunction
What are the compensations that we see that helps manage reduced blood flow caused by heart failure?
Neurohormonal mechanisms (SNS & RAAS) to ↑ CO
(SV x HR); this is not good
natriuretic peptides
What are the symptoms of heart failure?
Shortness of breath, fluid retention, fatigue,
orthopnea, paroxysmal nocturnal dyspnea
What are the complications of heart failure?
Impaired exercise tolerance, increased risk of ventricular
arrhythmias, and shortened life expectancy
What is the etiology/cause of heart failure?
• Ischemic Heart Disease - (most common in the U.S.) • Hypertension* • Idiopathic Cardiomyopathy • Infections(e.g., viral myocarditis; Chagas disease) • Toxins (e.g., alcohol or cytotoxic drugs) • Valvular Disease • Prolonged Arrhythmias (Afib)
What are the neuro-hormonal Effects of HF?
• Kidney is not happy with
decreased blood flow, sets off the cascade of release of renin, which then converts to angiotensin and angiotensin 2, which leads to –>
• Increases Na+/H2O retention
to increase perfusion pressure
• Increased epi, renin, endothelin (all vasoconstrictors) and ANP (produced by heart for
vasodilation)
What are the factors that influence cardiac output?
- Pre load
- After load
- Contractile state (Contractility)
- Heart Rate
What are the components of preload that influences cardiac output?
• Preload is the degree of myocardial distension
prior to shortening.
• Largely depends on the amount of ventricular
filling
What are the components of after load that influences cardiac output?
- Force against which the ventricles must act in order to eject blood
- Largely dependent on the arterial blood pressure and vascular tone
What are the types of heart failure?
- Systolic
* Diastolic (DHF)
What are the characteristics of systolic heart failure?
- Impaired contractile function of the heart
* SHF most common etiology is ischemic heart disease, although many patients with DHF have coronary artery disease
What are the characteristics of Diastolic (DHF) heart failure?
- Impaired relaxation of the heart
- DHF more common in females and HTN is a more common risk factor, although substantial proportion of pts with SHF have HTN
What are the clinical outcomes of both types of heart failure?
• Clinical outcome is the same
- Patients usually have a combination of the two
What is paroxysmal nocturnal dyspnea?
Condition where patients, most often with heart failure will go to periods where they wake up from their sleep, most often because they are not breathing. They sleep with multiple pillows
What are the compensatory mechanism in heart failure as ti pertains to neurohormonal activation?
- Decreased cardiac output leads to
- Inc vascular resistance and renal sodium and water retention, which leads to
- Restoration of organ perfusion
What are the effects of neurohormonal activation in heart failure?
- Inc plasma norepinephrine
- Inc plasma renin activity
- Inc atrial natriuretic
- Inc Endothelin- 1
How does the Renin-Angiotensin System (RAAS) work?
Low perfusion of the juxtomedullary apparatus, which then releases renin, renin converts with angiotensinogens to form angiotensin 1, which travels to the lungs, interacts with angiotensin converting enzymes, which converts it to angiotensin 2, which has dramatic effects throughout the body like vasoconstriction, fluid retention, secretion of aldosterone(potent fluid retaining hormone), and increase sympathetic activity all with the goal of increasing BP to perfuse tissue
What is the cycle ignited by HF?
- Ventricular dysfunction –> dec cardiac output –> compensations(inc SNS, inc RAAS, inc arginine vasopressin) -> excessive vasoconstriction and inc Na/water retention -> increased afterload and excessive preload
What are the factors that the release of hormones in heart failure throw out of balance?
- NO
- BNP
- tANP
(all vasodilators)
What are the factors that influence cardiac output?
- Contractility
- Preload
- Afterload
- Stroke volume
- Heart rate
- Synergistic LV contraction, LV wall integrity, and valvular competence
Which of the types of heart failure is harder to treat?
Diastolic HF
What is the equation for Ejection Fraction?
EDV(end diastolic volume)-ESV(end systolic volume)/EDV
What is ejection fraction?
The total amount of blood we pump out after each heart beat to respect to how much blood was present in the heart previously. Poor relationship to VO2, so it has no relationship to tolerance of exercise
What is the normal value of ejection fraction?
55-75%
How does heart failure impact ejection fraction?
A reduction, we get pretty concerned if it drops below 50%
What is the NYHA classification?
A system used to classify the severity of HF
What is a class I on the NYHA classification?
No limitation of physical activity. Ordinary physical activity does not cause undue
fatigue, palpitation, dyspnea (shortness of breath)
What is a class II on the NYHA classification?
Slight limitation of physical activity. Comfortable at rest. Ordinary physical activity results in fatigue, palpitation, dyspnea (shortness of breath).
