13 - Cardiovascular Pathology IV Flashcards
What are the two types of mitral valve disease?
Stenosis and regurgitation
What are the top causes of stenosis in mitral valve disease?
- Rheumatic mitral disease
- Atrial myxoma (Tumor)
- Calcified mitral annulus
What are the top causes of regurgitation in mitral valve disease?
- Postinflammatory scarring
- Infective endocarditis
- Calcified mitral annulus (“Mitral annular ring” which happens in older people)
- Mitral valve prolapse (MOST COMMON IN THE YOUNGER POPULATION
The problem is that it is mostly asymptomatic and it isn’t recognized until symptoms develop) - Drugs (fen-phen)
- Rupture or dysfunction of papillary muscle
- Rupture of chordae tendineae
Which one is the main cause of regurgitation in older people?
Calcified mitral annulus
“Mitral annular ring”
Happens in older people
Which one is the most common in the younger population?
Mitral valve prolapse
The problem is that it is mostly asymptomatic and it isn’t recognized until symptoms develop
What specific population is mitral annular calcification most common in?
Mitral annular calcification is most common in women over age 60.
** THINK OLDER POPULATIONS **
What comorbidities do we see with calcified mitral annulus?
Higher incidence in individuals with mitral valve prolapse or elevated left ventricular pressure as in systemic HTN, aortic stenosis, or hypertrophic cardiomyopathy.
How can you diagnose calcified mitral annulus (mitral annular calcification)?
You can see this very easily under x-ray
Describe what happes in calcified mitral annulus (mitral annular calcification)
Degenerative calcific deposits can develop in the annulus of the mitral valve.
What can calcified mitral annulus lead to?
- Regurgitation
- Stenosis
- Arrhythmias
- Embolism
- Sudden death
Explain how calcified mitral annulus can lead to regurgitation
regurgitation by interfering with physiologic contraction of the valve ring.
Explain how calcified mitral annulus can lead to stenosis
stenosis by impairing opening of the mitral leaflets.
Explain how calcified mitral annulus can lead to arrhythmias, thrombosis and sudden death
arrhythmias and occasionally sudden death by penetration of calcium deposits to a depth sufficient to impinge on the atrioventricular conduction system.
Also a site that thrombi can embolize
What happens in mitral valve prolapse?
One or both mitral valve leaflets are “floppy” and prolapse, or balloon back, into the left atrium during systole.
You will hear it close suddenly in mid systole –> “click”
Usually an incidental finding on exam
What is the key histoligical change in mitral valve prolapse?
The key histologic change in the tissue is myxomatous degeneration.
How many people in the US are affected by mitral valve prolapse
** 3% of adults **
It is most often an incidental finding on physical examination (particularly in young women), but in a small minority of affected individuals may lead to serious complications.
What syndrome can mitral valve prolapse be associated with?
Marfan’s syndrome
Patients with Marfan syndrome usually have a more serious prolapse
Are most people diagnosed with mitral valve prolapse symptomatic or asymptomatic?
Most individuals diagnosed with MVP are asymptomatic.
If you hear a midsystolic click, what do you do?
Confirm by echocardiography
What symptoms will a minority of patients experience?
A minority of patients have chest pain mimicking angina, dyspnea, and fatigue.
What will a small number of mitral valve prolapse patients develop?
- Infective endocarditis
- Chordal (cordae tendinae) rupture – med emergency
- Thromboembolism
- Arrhythmias, both ventricular and atrial
How do you repair mitral valve prolapse?
Surgery
MVP is presently the most common cause for surgical repair or replacement of the mitral valve.
What is infective endocarditis?
Infective endocarditis is a serious infection characterized by colonization or invasion of the heart valves or endocardium of the heart by a microbe.
What are vegetations in infective endocarditis composed of?
Vegetations composed of thrombotic debris and organisms, often associated with destruction of the underlying cardiac tissues (sub-acute form usually).
What are most cases of infective carditis caused by?
Most cases are caused by bacterial infections (bacterial endocarditis), but other organisms can be involved ie fungi.
What is important when dealing with infective endocarditis?
Prompt diagnosis and effective treatment of IE is important.
Why do dentists give you antibiotics when you get dental work done?
So you don’t get infective endocarditis
What are the two types of infective endocarditis?
Acute and subacute
What bacteria causes acute infective endocarditis?
Staph aureus - HIGH virulence
What bacteria causes subacute infective endocarditis?
Strep viridans - LOWER virulence
Describe acute endocarditis
Remember: staph aureus
- High virulence
- Produces necrotizing, ulcerative, destructive lesions on normal or deformed valves
- Difficult to cure with antibiotics and usually requires surgery
- High mortality rate
Describe subacute endocarditis
Remember: Strep viridans
- Lower virulence
- Insidious infection of deformed valves that are less destructive
- May pursue as a protracted course of weeks to months
- Can often be cured by antibiotics (IV, long term)
Can an organism always be isolated in endocarditis?
No - in 10-15% of all cases no organism is isolated
Is diagnosis of infective endocarditis simple and straight forward?
No
What are the clinical criteria?
- Two major
- One major and three minor
- Five minor