Module 7.2 - Valvular Disease Flashcards
What is/causes mitral stenosis?
- It is an incomplete opening of the mitral valve during diastole which limits antegrade flow.
- Rheumatic heart disease including endocarditis from rheumatic heart disease is the most common cause of MS.
- Other causes include SLE, rheumatoid arthritis, congenital malformation, substantial mitral annular calcification, LA thrombus or endocarditis with a large vegetation.
What diagnostic tests are used to diagnose Mitral Stenosis?
- Transthoracic echocardiogram (TTE) – confirms diagnosis, demonstrates restricted motion of the valve and quantifies the severity of the stenosis
- EKG – presence of arrhythmias, especially atrial fibrillation. AF occurs in 30-40% of patients with severe MS. It may be paroxysmal, persistent or permanent. If patient is in sinus rhythm, tall and peaked P waves (Lead II) may be seen if there is severe pulmonary hypertension
- CXR – assess cardiac border, enlarged chambers (left atrial enlargement), prominent pulmonary arteries, displacement of the esophagus and Kerley B lines
- Cardiac catheterization – assess for associated lesions and presence of CAD. As the disease worsens, pulmonary hypertension is noted.
What medical therapy is given to patients with Mitral Stenosis?
1. Anticoagulation – warfarin or heparin is indicated in patients with:
- mitral stenosis (MS) and atrial fibrillation (AF) - paroxysmal, persistent or permanent;
- MS and a prior embolic event;
- MS and a left atrial thrombus.
- Efficacy of anticoagulation in MS alone to prevent embolic events has not been studied.
2. Diuretics and sodium restriction – may be needed if there is evidence of volume overload
3. Heart rate control – can be beneficial in patients with MS if they develop AF with RVR (atrial fibrillation with rapid ventricular response)
4. Heart rhythm control – cardioversion may be necessary to improve hemodynamic stability in select patients. In stable patients, multiple factors need to be considered including duration of arrhythmia, left atrial size. It is much more difficult to achieve rhythm control in patients with MS because of the rheumatic process.
5. Antibiotic prophylaxis – for surgical or dental procedures to prevent endocarditis – per guidelines.
What are the surgical interventions available to patients with mitral stenosis?
- Percutaneous mitral balloon commissurotomy (PMBC) is recommended for symptomatic patients with severe MS. Generally, there is no role for mitral balloon or commissurotomy if the MS is due to calcification but may be considered by the surgeon depending on the valve morphology.
- Mitral valve replacement or repair is indicated in symptomatic patients who are not high risk for surgery and who are not candidates for or have a failed previous PMBC.
What is/causes mitral regurgitation?
- It is a backflow of blood into the left atrium as a result of deficient mitral valve closure
- It is caused by rheumatic disease, MVP, “floppy” mitral valve, papillary muscle dysfunction related to ischemic heart disease, infective endocarditis, ruptured chordae tendineae, hypertrophic obstructive and dilated cardiomyopathy, systemic lupus erythematosus.
- It is commonly associated with the heart failure in elderly patients.
What are the symptoms associated with acute mitral regurgitation
can present with a rapid onset of shortness of breath that can quickly lead to respiratory failure.
What are the symptoms associated with chronic mitral regurgitation?
fatigue, weakness, exertional dyspnea, palpitations – associated with atrial fibrillation, S3 heart sounds and holosystolic murmur that radiates to the axilla, apical thrill
What diagnostic tests are done to diagnose mitral regurgitation?
- Transthoracic echocardiogram (TTE) – assess valves, hemodynamic severity, regurgitant flow into left atrium
- Transesophageal echocardiogram (TEE) – better visualization of the valve structure and competency
- EKG –look for AF and LVH, rate and rhythm. Peaked P waves (Lead II) can be seen with severe pulmonary hypertension
- CXR – enlarged left atrium or ventricle seen?
- Cardiac catheterization – same as MS
- MRI –assess EF in patients with severe MR when you cannot adequately assess by echo.
- Nuclear studies can also be used to assess EF for same reason. Can also be used to assess viability of the cardiac muscle if CAD is present.
How do you manage patients with acute mitral regurgitation?
- These pts are in the hospital setting for hemodynamic and circulatory support.
- While they are waiting for surgery to repair the valve, aggressive afterload reduction with IV nitroprusside or/and a balloon pump may be needed to decrease the amount of MR.
- This will stabilize the patient and reduce the risk of pulmonary edema and the possible need for intubation and mechanical ventilation
How do you manage patients with chronic mitral regurgitation?
If the mitral regurgitation is caused by an abnormality in the mitral valve:
- If they are asymptomatic w/ normal LV function there is generally no accepted medical therapy.
- Beta blockers, ACE inhibitors or ARBS, potential surgery should be considered but only if there is a clear indication.
What is/causes mitral valve prolapse?
- It is a protrusion of the MV into the left atrium as a result of damaged leaflets of the valve.
- Etiology unknown - There may be a genetic disposition to collagen disorders such as Marfan syndrome, osteogenesis imperfecta and Ehlers-Danlos syndrome.
- It is more prevalent in women between the ages of 15-30. If seen in men, it is usually after age 50.
What are the subjective/physical findings associated with mitral valve prolapse?
- Often is asymptomatic
- Fatigue
- Dizziness or lightheadedness
- Dyspnea
- Chest pain or palpitations
- Syncope
- Dysrhythmias – premature ventricular contractions (PVC), paroxysmal supraventricular tachycardia (PSVT), ventricular tachycardia (VT), atrial fibrillation (AF)
What diagnostic tests are used to diagnose mitral valve prolapse?
- Transthoracic echocardiogram (TTE) – assess valves, hemodynamic severity, regurgitant flow into left atrium
- Transesophageal echocardiogram (TEE) – better visualization of the valve structure and competency
- EKG – Look for abnormalities
- CXR – enlarged left atrium or ventricle seen?
- Cardiac catheterization
- MRI –assess EF
How do you manage a patient with mitral valve prolapse?
- Abx prophylaxis for procedures only for those with a prior history of endocarditis. Overall, there is a low risk of endocarditis in this group
- Avoid stimulants that may exacerbate arrhythmias
- Beta blockers only if tachycardia is uncontrolled
- Aspirin 81-325 mg daily for pts with documented neurological focal events are in sinus rhythm with no evidence of thrombus in the atria by echocardiogram
What is/causes aortic stenosis?
- The most common cause of LV outflow obstruction. It is a narrowing of the aortic valve resulting in obstructed forward flow of blood
- It is the most common fatal valvular disorder in the US among the elderly population.
Causes:
- Aortic sclerosis – degenerative calcification in patients > 65 is most common cause. It is now considered an inflammatory process related to atherosclerosis
- Rheumatic disease – common cause but incidence is declining
- Idiopathic
- Congenital - bicuspid valve
