Flashcards in Thirteen B Deck (27)
Describe the pathophysiology of rheumatic fever.
Initial infection with group A ͆-hemolytic streptococcus
Exaggerated immune response
Acute rheumatic fever develops 2-4 weeks after initial
Rheumatic heart valve involvement can take 10-30 years to develop
Repeated episodes of acute rheumatic fever leads to more severe valvular disease
Mitral valve is always affected first
Extremely rare to see aortic/pulmonic/tricuspid involvement
without mitral involvement
Mitral > Aortic >> Tricuspid > Pulmonic
When do patients become symptomatic with mitral valve stenosis? What are some etiologies?
Obstruction of normal mitral inflow during diastole
Abnormal pressure gradient between the left atrium and left ventricle
The normal mitral valve orifice area is between 4-6 cm2
Patients typically become symptomatic when the mitral vale orifice area is less than 2 cm2
Rheumatic heart disease
Up to 40% of patients with a history of acute rheumatic fever develop mitral stenosis
Age-related mitral annular calcification
Mitral calcification in patients with end-stage renal disease
Congenital mitral stenosis
Describe the pathophysiology of mitral valve stenosis.
Obstruction to left ventricular filling
Chronic elevation in left atrial pressure
Left atrial enlargement
Ortner Syndrome (recurrent laryngeal nerve palsy)
Pulmonary venous hypertension
Pulmonary venous hypertension results from chronic elevation in left atrial pressure
Left atrial enlargement leads to atrial fibrillation
Higher risk of forming left atrial thrombi
Pulmonary arterial hypertension
Ultimately, changes in pulmonary arterial vasculature can lead to ᾿reactive῀ pulmonary arterial hypertension
Long-standing pulmonary hypertension affects right
Right side of the heart was not designed to handle high
Right ventricular hypertrophy, dilation and failure
Decreased cardiac output
Results from decreased blood flowing into the left ventricle
What are the symptoms of mitral valve stenosis?
Signs and symptoms of congestive heart failure
Palpitations (if there is atrial fibrillation)
Seen only in severe mitral stenosis
Mild cyanosis of the lips, cheeks, and malar prominences
Caused by chronic hypoxemia and low cardiac output
Ortner Syndrome Recurrent laryngeal nerve palsy
Bronchiolar vein rupture
What physical exam and test findings occur in mitral valve stenosis?
Low-pitched diastolic murmur
Best heard with the bell of the stethoscope at the cardiac apex
Intensity of murmur increases with MS severity
Timing of OS also correlates with disease severity
Loud P2 component if there is significant
Signs of congestive heart failure
Lower extremity edema
ECG may show:
Left atrial enlargement (᾿P mitrale῀)
Right atrial enlargement
Right ventricular hypertrophy
Chest x-ray may show:
Left atrial enlargement
Pulmonary vascular congestion
Pulmonary arterial dilation
Right ventricular dilation
How is rheumatic mitral stenosis diagnosed?
Echocardiography is the mainstay of diagnosis
Typical findings from rheumatic mitral stenosis include:
Calcified mitral valve with diastolic ᾿doming῀
Left atrial enlargement
Varying degrees of pulmonary hypertension
How is MVS treated?
Medical therapy (non-surgical) is limited
Patients develop profound dyspnea and pulmonary edema, particularly when tachycardic
Beta-blockers, non-DHP calcium channel blockers
Surgical and percutaneous options are available
Open surgical replacement versus percutaneous balloon
Describe some examples of how mitral regurgitation is caused?
Rheumatic mitral valve
Typically causes mitral stenosis
Shortening of the chordae tendinae and commissural fusion can cause mitral regurgitation
+ Mitral Valve Prolapse
AKA ᾿Floppy mitral valve syndrome῀
Most common cause of isolated MR
FeMale > male
Association with connective tissue diseases (marfans
Vegetations can damage the surface of the valves
Congenital (cleft mitral valve)
+ Defective Tensor Apparatus
Rupture of chordae tendinae
Papillary muscle dysfunction
Ruptured papillary muscle (associated with acute
+ Abnormal LA and LV
Alterations in ventricular geometry alter mitral annular geometry
Describe the pathophys of the two different kinds of MR?
Minimally compliant left atrium experiences sudden rise in pressure
Rapid development of pulmonary edema
Left atrium more compliant
LA and LV dilate
Ultimately leads to LV dysfunction
What are the symptoms and presentation of the two kinds of MR?
Symptoms reflect the more acute rise in left atrial pressure
Sudden onset of dyspnea
Symptoms develop slowly over time
Atrial fibrillation can cause palpitations
What findings are found in the physical exam for MR? Diagnostic Exam findings?
Typically loudest at the apex
Radiates to axilla
In acute settings, an S3 can be heard
Distinguishing acute from chronic MR (by physical
examination) can be tough
ECG will show non-specific findings
Evidence of left atrial enlargement
Q waves consistent with prior myocardial infarction
CXR can show pulmonary edema and left atrial enlargement
Echocardiogram can assess severity and etiology of disease
How is MR treated?
Medical management limited
5-year survival of unrepaired severe MR is 30-45%
Diuretics for symptomatic relief
Afterload reducing agents
Percutaneous options also available
What are some etiologies of aortic stenosis?
Age-related calcific degeneration
Similar risk factors with atherosclerotic vascular disease
Congenital aortic stenosis
Bicuspid aortic valve
Rheumatic aortic stenosis
Seen in conjunction with rheumatic mitral disease
Describe the pathophys of stenosis.
Increasing obstruction to left ventricular outflow
Creates an abnormally elevated systolic pressure
gradient between the left ventricle and aorta
Pathologic left ventricular hypertrophy leads to impaired
diastolic relaxation of the left ventricle
Cardiac output becomes heavily dependent upon atrial
contraction to adequately fill the left ventricle during diastole
Patients who develop atrial fibrillation (loss of atrial
contraction) can become dyspneic and hypotensive
Elevation of left ventricular pressure leads to elevated left atrial pressure
Ultimately leads to pulmonary edema
What are the symptoms and presentation of aortic stenosis?
Angina due to increased myocardial oxygen demand
Dyspnea (congestive heart failure) due to pulmonary edema
Syncope due to reduced cardiac output and reduced cerebral perfusion
What physical and diagnostic exam findings are there in aortic stenosis?
Crescendo-decrescendo (diamond-shaped) systolic
ejection murmur heard best at the right upper sternal border
Intensity of murmur does not necessarily correlate with
Time to peak intensity and S2 quality
ECG may show LVH, left atrial enlargement
CXR can reveal pulmonary edema, aortic calcification
Echocardiogram will show reduced aortic valve leaflet mobility and increased aortic valve pressure gradient
Left heart catheterization can invasively measure the aortic valve pressure gradient
What is the prognosis for aortic stenosis? How is it managed? Not managed? Treated?
Long-term survival poor in symptomatic patients with
Once symptoms develop, median survival is between 2
to 5 years without surgery
Medical therapy is limited and consists of symptomatic relief
Changes in loading conditions (particularly reducing preload) can have disastrous consequences
Surgical aortic valve replacement is the current gold standard
Catheter based techniques (valvuloplasty and transcatheter aortic valve replacement)
What are the two classifications of etiologies of aortic regurg?
Etiologies can be classified as:
Disorders/abnormalities of the aortic valve leaflets
Disorders of the aorta/aortic root
Describe various causes of disorders of the aortic valve leaflets.
Bicuspid aortic valve
Two of the three leaflets fused
Abnormal geometry obscures normal valve closure
Typically causes aortic stenosis
Commissural fusion leads to a central gap in the valve during diastole
Concomitant aortic stenosis
Describe various causes of disorders of the aorta/aortic root.
Cystic medial necrosis
What is the pathophys of the two kinds of aortic regurg?
Acute vs chronic aortic regurgitation
Acute AR can lead to a rapid increase in left ventricular
diastolic pressure and cause acute pulmonary edema
Chronic aortic regurgitation characterized by a widened
aortic pulse pressure
What are the classical presentation and symptoms of the two kinds of AR?
Acute AR causes an acute/abrupt rise in left ventricular diastolic pressure
Left ventricle is not able to handle this rapid increase in volume (decreased compliance)
Acute pulmonary vascular congestion and pulmonary edema causes severe dyspnea
Frequently a surgical emergency!
Chronic AR is characterized by a more compliant left ventricle which is able to better handle the increased blood volume
Eventual development of left ventricular dilation and failure
Symptoms include exertional dyspnea, fatigue, palpitations
What physical exam finds and diagnostic eval findings are there in AR?
Decrescendo diastolic murmur
Heard best in the right upper sternal border, with the patient sitting upright at end-expiration
Systolic ejection murmur typically heard
Bounding peripheral pulses (from widened pulse pressure)
Laterally displaced point of maximal impulse
ECG can be non-specific
Inferior STEMI can be seen in cases of aortic dissection causing acute AR
May show LVH
CXR with pulmonary edema in acute AR and decompensated chronic AR
Chest CT can diagnose acute aortic dissection
Echocardiography can establish cause and severity
How is AR treated/managed?
Acute AR is typically a surgical emergency
Patients may present with cardiogenic shock (hypotension, severely reduced cardiac output and reduced end-organ perfusion)
Treatment of chronic AR includes diuretic therapy for
Anecdotal evidence that ACE-I and dihydropyridine CCBs can be helpful
Once symptoms of CHF develops or when there is evidence of LV cavity dilation or dysfunction, surgical intervention is indicated
Which right sided valvular disorder is frequently encountered? When is it usually seen? Is it clinically relevant?
Tricuspid regurgitation is frequently encountered
Typically it is clinically irrelevant
Commonly seen in pulmonary hypertension
IV drug users at risk of infective endocarditis
Describe Carcinoid syndrome. What does it cause? How? What doesn't it usually cause? Why?
Neuroendocrine tumor typically located in the small bowel or appendix
Secretes serotonin and other vasoactive metabolites
Direct toxic effect on heart valves
Left sided heart valve disease is rare
Serotonin is inactivated in lung parenchyma
Tricuspid regurgitation is common
Tricuspid stenosis can also occur
Scarring of the valve restricts leaflet mobility