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)
What are the main ways RF can present in patients?
- Carditis (specifically, pancarditis)
- Several noncardiac manifestations
- (Chronic) rheumatic heart disease (RHD)
What does carditis consist of?
inflammation of the pericardium, myocardium, and endocardium
What can myocarditis lead to?
congestive heart failure
(cause of most deaths occurring during the early stages of RF)
Endocarditis leads to what?
valvular damage
Rheumatic endocarditis usually occurs in areas subject to what?
greatest hemodynamic stress, such as the points of valve closure
what are some noncardiac manifestations of RF?
- Fever
- malaise
- increased erythrocyte sedimentation rate (ESR)
- joint involvement
Joint involvement in RF includes what?
- Migratory polyarthritis: occurs in 75% of patients
What are some examples of skin lesions and CNS problems that occur from RF?
- Skin lesions: subcutaneous nodules & erythema marginatum
- Central nervous system: Sydenham’s chorea (St. Vitus’s dance)
What is rheumatic heart disease (RHD)?
results from single or repeated attacks of RF and consists of the cardiac valve damage (chronic valvulitis)
What happens to the valves in rheumatic heart disease (RHD)?
As a consequence of fibrotic healing, the valves eventually become thickened, fibrotic, rigid and deformed, often with fusion of valve commissures and calcification, as well as thickening of the chordae tendineae
Which valve is most frequently involved in RHD? What other valves are affected?
- most = mitral valve
- aortic valve
- tricuspid valve
Where do MacCallum plaques appear? What are they caused by?
- wrinkled part of the endocardium in the left atrium
- caused by regurgitant jets of blood flow due to incompetence of the damaged mitral valve
What is an arrhythmia?
An alteration of the normal site or rate of electrical impulse generation within the heart or an alteration of the impulse’s orderly spread through the cardiac conducting system
T/F Arrhythmias vary greatly in their clinical significance
true
What are some general causes of cardiac arrhythmias
- Primary cardiovascular disease: Ischemic injury (e.g., myocardial infarction)
- Drugs
Where does the normal sequence of electrical conduction begin? Where does it go next?
- part of the atrium called the sinoatrial (SA) node
- an area at the junction of the atria and ventricles called the atrioventricular (AV) node
Where does electrical activity in the heart travel after the AV node?
(right and left bundle branches
What is the P wave
The electrical impulse starting in the sinoatrial node causes depolarization of the atria
What is the PR interval?
the time between atrial depolarization and ventricular depolarization
What is the QRS complex?
represents the depolarization of ventricles
What is the T wave?
represents repolarization of the ventricular myocardium
What is a tachyarrhythmia?
an abnormal rhythm with a ventricular heart rate of 100 beats per minute (bpm) or more
What is a Supraventricular Tachyarrhythmia
An arrhythmia originating from above the AV node
What is a Ventricular Tachyarrhythmia
An arrhythmia originating from below the AV node
What is a Bradyarrhythmia
a heart rate below 60 bpm and comprises several rhythm disorders and conduction abnormalities
What is a heart muscle disease attributable to intrinsic myocardial dysfunction
Cardiomyopathy
What are the three morphologic patterns of cardiomyopathy?
- Dilated (Congestive)
- Hypertrophic
- Restrictive (Obliterative or Infiltrative)
In cardiomyopathy, the three morphologic patterns can be caused by what?
a specific identifiable etiology, or can be idiopathic
What is Dilated (Congestive) Cardiomyopathy characterized by?
by dilation and impaired, ineffective contraction of one or both ventricles
In Dilated cardiomyopathy (DCM), the _______ function of the heart is impaired and patients may develop overt heart failure, atrial and/or ventricular arrhythmias, and can experience sudden ______.
- systolic
- cardiac death
What is the most common of the 3 patterns of cardiomyopathy
Dilated (Congestive) Cardiomyopathy
Understand the etiology of Dilated (Congestive) Cardiomyopathy
(see notes)
What are clinical presentations of Dilated Cardiomyopathy?
- symptoms of congestive heart failure
- may be asymptomatic and identify via cardiomegaly on a chest X-ray
- Mitral (or tricuspid) regurgitation
Patients with DCM have a significantly increased incidence of what?
ventricular or atrial arrhythmias
How does the heart appear in Dilated (Congestive) Cardiomyopathy
usually enlarged, heavy, and flabby, due to dilation of all four chambers
What are microscopic findings of dilated cardiomyopathy?
Nonspecific abnormalities:
- Most myocardial cells are hypertrophied
- Interstitial and endocardial fibrosis of variable degree is present
What is Hypertrophic Cardiomyopathy (HCM) characterized by?
marked thickening (hypertrophy) of the left ventricular wall [>15 mm], without dilation
(The (inter)ventricular septum is also profoundly enlarged and hypertrophied)
Hypertrophic Cardiomyopathy (HCM) may result in hemodynamically significant ____?
obstruction within the left ventricular outflow tract (LVOT
HCM associated with LVOT obstruction is called _______
idiopathic hypertrophic subaortic stenosis (IHSS)
In Hypertrophic Cardiomyopathy (HCM) there is usually reduced ______ due to impaired diastolic filling (_____ ventricular diastolic dysfunction).
- stroke volume
- left
T/F Most cases of Hypertrophic Cardiomyopathy are genetic
True
caused by mutations in multiple genes encoding proteins of the cardiac sarcomere and calcium regulation
T/F At the time of diagnosis of HCM, most patients are highly symptomatic
False
At the time of diagnosis, most patients are asymptomatic
What are some possible clinical presentations of Hypertrophic Cardiomyopathy (HCM)?
- dyspnea, syncope or presyncope (usually seen with exercise)
- Arrhythmias (Ventricular arrhythmias & sudden cardiac death)
- Possible Stroke
What are gross morphologic findings of HCM?
- massive left ventricular hypertrophy
- thickening (hypertrophy) of the ventricular septum relative to the left ventricle free wall
- left ventricular cavity becomes “banana-shaped”
- a functional obstruction of the left ventricular outflow tract (LVOT)
What are microscopic findings of HCM?
- Massive myocyte hypertrophy
- disorganized myocyte architecture / myofiber disarray
- interstitial and replacement fibrosis
What is Restrictive (Obliterative or Infiltrative) Cardiomyopathy
restrictive ventricular filling
In Restrictive (Obliterative or Infiltrative) Cardiomyopathy, there is a decrease in what?
ventricular compliance and distensibility (i.e., the ventricles are abnormally “stiff”)
What do the stiff ventricles in restrictive cardiomyopathy (RCM) result in?
impaired ventricular filling during diastole (diastolic dysfunction)
What frequently becomes enlarged after chronic exposure to high filling pressures in restrictive cardiomyopathy (RCM)
the atria
What can lead to restrictive cardiomyopathy (RCM)
- amyloidosis
- progressive systemic sclerosis (scleroderma)
- Myocardial fibrosis
Patients with RCM often have pronounced cardiopulmonary symptoms primarily due to what?
biventricular congestive heart failure
T/F In RCM, the right atria is typically dilated as a consequence of restricted ventricular filling and pressure overloads
False
Both atria are typically dilated as a consequence of restricted ventricular filling and pressure overloads
Idiopathic RCM demonstrates variable degrees of ______ of the myocardium
interstitial fibrosis
What are two examples of noninflammatory conditions of the pericardium?
- Hydropericardium
- Hemopericardium
What is Hemopericardium? What is it caused by?
- an accumulation of blood in the pericardial sac.
- trauma to the chest resulting in rupture of the myocardium, coronary arteries or aortic root, or by myocardial rupture secondary to acute myocardial infarction
What is Hydropericardium
- accumulation of serous transudate in the pericardial space
What is hydropericardium caused by?
- congestive heart failure
- nephritic syndrome
- chronic liver disease
What is acute pericarditis
An acute inflammation (or infiltration) of the pericardium
The _____ is an avascular fibrous double-walled sac containing the heart and the roots of the great vessels
pericardium
Acute pericarditis is characterized by at least 2 of the following 4 criteria:
(1) Chest pain
(2) Specific electrocardiographic changes
(3) Pericardial friction rub
(4) New or worsening pericardial effusion
What are the 4 classifications of acute pericarditis
- Serous pericarditis
- Fibrinous or serofibrinous pericarditis
- Purulent or suppurative pericarditis
- Hemorrhagic pericarditis
What is serious pericarditis?
characterized by production of a protein-rich exudate
What is serous pericarditis associated with?
systemic lupus erythematosus, rheumatic fever, and a variety of viral infections
What is Fibrinous or serofibrinous pericarditis? What is it caused by?
- characterized by a fibrin-rich exudate
- uremia, acute myocardial infarction, or rheumatic fever
What is Purulent or suppurative pericarditis characterized by? What is it caused by?
- purulent inflammatory exudate
- bacterial infection
What is hemorrhagic pericarditis characterized by?
a bloody inflammatory exudate
What is hemorrhagic pericarditis caused by?
metastatic tumor invasion of the pericardium but can also result from tuberculosis or other bacterial infection
What are the most common primary tumors of the adult heart?
Myxomas
What are the most common primary tumors of infants and children?
Rhabdomyomas
Cardiac rhabdomyomas occur with high frequency in patients with ______
tuberous sclerosis
______ constitute the most common malignancy of the heart
Metastatic tumors
Which tumors have a higher predilection for cardiac metastases?
lung cancer
