Cardiovascular Part 2 Flashcards
What is Mitral Valve Prolapse (MVP)
A bulging of one or both mitral valve leaflets that are displaced into the left atrium
What is the etiology of mitral valve prolapse (MVP)?
Most frequently due to myxomatous degeneration of connective tissue within mitral valve
What are complications of MVP?
mitral regurgitation, infective endocarditis, sudden cardiac death, and stroke
What is Mitral Regurgitation (Mitral Insufficiency or Incompetence)
retrograde blood flow through the left atrium secondary to an incompetent mitral valve
What is the etiology of Mitral Regurgitation (Mitral Insufficiency or Incompetence)
caused by organic disease (e.g., myxomatous degeneration/mitral valve prolapse, or a functional abnormality
What is a clinical presentation for Mitral Regurgitation (Mitral Insufficiency or Incompetence)
Patients with MR have an increased risk for atrial fibrillation
What is a complication of Mitral Regurgitation (Mitral Insufficiency or Incompetence)
may cause left ventricular (LV) failure
What is Mitral Stenosis
narrowing of the mitral valve orifice that prevents proper opening during diastole
What is the etiology of mitral stenosis?
predominant cause of is rheumatic fever/rheumatic heart disease
What is a clinical presentation of mitral stenosis?
fatigue and exertional dyspnea
What is Aortic Regurgitation (Aortic Incompetence or Insufficiency)
retrograde blood flow into the left ventricle from the aorta secondary to an inadequately closing (incompetent) aortic valve
What is Aortic Valve Stenosis (Aortic Stenosis)
obstruction to systolic left ventricular outflow across the aortic valve due to aortic valve thickening/calcification
What is the etiology of Aortic Valve Stenosis (Aortic Stenosis)
- most commonly acquired
- idiopathic calcification of the aortic valve (calcific aortic stenosis) or rheumatic fever/rheumatic heart disease
- may be congenital
What are early clinical symptoms of Aortic Valve Stenosis (Aortic Stenosis)
- decreased exercise tolerance
- dyspnea on exertion
- exertional dizziness
What are late clinical symptoms of Aortic Valve Stenosis (Aortic Stenosis)
- exertional angina (secondary mainly to reduced coronary blood flow)
- left-sided congestive heart failure
What is Nonbacterial Thrombotic Endocarditis (Marantic Endocarditis or NBTE)
a condition characterized by small, sterile lesions (vegetations) composed of platelets, fibronectin, fibrin, and other matrix ligand which develop on the damaged or denuded cardiac endothelium, and are randomly arranged along the line of closure of the cardiac valve leaflets (and/or adjacent endocardium)
What is the etiology of Nonbacterial Thrombotic Endocarditis (Marantic Endocarditis or NBTE)
known to occur in a wide group of predisposing conditions including:
- Rheumatic heart disease
- cardiac valvular dysfunction
- congenital heart disease
- structural heart disease characterized by increased (high) turbulence of blood flow in the heart resulting in endothelial damage
What are complications of Nonbacterial Thrombotic Endocarditis (Marantic Endocarditis or NBTE)
- can result in peripheral embolization but, unlike infective endocarditis, the emboli are sterile
- increases the risk of infective endocarditis
What is Infective Endocarditis (IE)
a microbial infection of the endocardial surfaces of the heart, usually affecting of one or more cardiac valves
What is the etiology of infective endocarditis (IE)?
- bacteria (in over 90% of cases) leading to bacterial endocarditis
(Staphylococcus aureus and viridans group streptococci (VGS))
What are the 4 classifications of infective endocarditis (IE)?
- Acute [Bacterial] Endocarditis
- Subacute [Bacterial] Endocarditis
- Endocarditis in Injection (Intravenous) Drug Users
- Prosthetic Valve Endocarditis (PVE)
What is Acute [Bacterial] Endocarditis usually caused by
by Staphylococcus aureus
What is Subacute [Bacterial] Endocarditis usually caused by
Viridans group streptococci (VGS)
What is the pathogenesis of Infective Endocarditis (IE)
Precise mechanism not fully known, but is result of several factors involving cardiac endothelium, bacteria, and the host immune response
Where do most cases of Infective Endocarditis (IE) / bacterial endocarditis (BE) occur?
occur on an altered, injured or damaged endothelial surface (most often on a cardiac valve leaflet) → pathogenic bacterial attachment (adherence) and colonization.
In patients without a prosthetic cardiac valve, BE develops most frequently on the ______ valve
mitral
in most cases of BE, the common denominator for adherence and invasion or cardiac valves by pathogenic bacteria is what?
the prior formation of non-bacterial thrombotic endocarditis (NBTE)
Other conditions that increase the risk for BE include? (5)
- prosthetic cardiac valve
- previous heart surgery using a prosthetic patch or prosthetic device
- previous heart surgery with a residual hemodynamic (high blood flow turbulence) defect
- intravenous drug abuse (IVDA)
- previous infective endocarditis
In Infective Endocarditis (IE), pathogenic bacteria must then reach the site of ______ via the bloodstream (bacteremia), _______ to the damaged endothelial surface, and ______ the involved tissue to produce bacterial ______ and persistence.
- endothelial damage
- adhere
- invade
- colonization
What are complications of Infective Endocarditis (IE)/ bacterial endocarditis (BE)?
- valvular damage and insufficiency
- congestive heart failure
- myocardial abscesses
- cardiac arrhythmias
Cardiac valves affected by BE develop what?
friable vegetations composed of fibrin, platelets, inflammatory cells and bacterial colonies
In the friable vegetations affected by BE, what happens when they detach?
detach forming septic (infected) emboli and may travel through the bloodstream and cause tissue and organ infarctions and infections (stroke)
The overall mortality rate for IE approaches _____ % with medical treatment. If diagnosis is unduly delayed or treatment is inadequate, IE inevitably is ______.
- 40%
- fatal
What are the signs and symptom of IE
fever, heart murmurs, those due to immunological responses and emboli
_____ is the most common sign of IE
Fever
Other clinical presentations of IE include
- heart murmurs
- Sustained bacteremia resulting in blood culture
- Peripheral manifestations of IE caused by emboli or immunologic responses
What are the dental implications for IE?
Dental patients who have cardiovascular conditions that place them at high risk for IE require antibiotic prophylaxis prior to invasive dental procedures known to cause bacteriemias
What is (Acute) rheumatic fever (ARF, RF)?
a multisystem autoimmune inflammatory disease with major cardiac manifestations
Rheumatic fevers occurs after an infection caused by what?
group A streptococci
(Acute) rheumatic fever (ARF, RF) classic clinical presentation includes what?
- carditis
- migratory polyarthritis
- subcutaneous nodules
- erythema marginatum
- chorea.
What is the etiology of rheumatic fever
occurs after an episode of group A streptococcal pharyngitis/tonsillitis
What is evidence of a recent streptococcal infection?
An elevated antistreptolysin O (ASO) titer
T/F RF is a result of direct bacterial infection
False
RF is not a result of direct bacterial infection
What does RF occur as a result of?
streptococcal antigens that elicit an autoantibody response
What type of hypersensitivity reaction is RF an example of?
a type II hypersensitivity reaction
(common antigenic determinants)
RF is an autoimmune-mediated tissue injury characterized by
nonsuppurative inflammatory lesions of the joints, heart, subcutaneous tissue, and central nervous system
What are microscopic findings for rheumatic fever
Aschoff body is the classic, pathognomonic myocardial lesion of RF and is an area of focal interstitial myocardial inflammation
What is the Aschoff body characterized by?
- large activated macrophages with an elongated nuclear chromatin pattern (known as Anitschkow cell or Anitschkow myocytes)
- occasional multinucleated giant cells (known as Aschoff cells)