Valvular heart disease - ND Flashcards
Which side of the heart is the mitral valve on?
Left
Between left atrium and ventricle
What is mitral stenosis?
Thickening of the mitral valve causing the size of the opening to decrease
What are the causes of mitral stenosis?
Rheumatic heart disease (chronic)
Congenital MS
Systemic conditions:
- systemic lupus erythematosus
- rheumatoid arthritis
How small does the mitral orifice need to be before it is stenosed?
< 2cm^2
What is the effect of mitral stenosis on the CVS?
A-V pressure gradient increases
Left atrial pressure increases
Pulmonary venous & capillary pressure increases
Pulmonary Vascular Resistance increases
Pulmonary artery Pressure increases & Pulmonary Hypertension develops
Right heart dilation with Tricuspid regurgitation & Pulmonary Regurgitation
What remains normal despite mitral stenosis?
Left Ventricle pressures
Systolic function
(basically the Left ventricle is fine)
Mitral stenosis affects the Trans-valvular pressure gradient & trans-valvular flow rate
How is flow affected overall?
In order to maintain cardiac output, heart rate must increase - tachycardia
Tachycardia has secondary effects on:
- Exercise
- Acute illness
- Pregnancy
- Atrial fibrillation (irregular fast heart beat)
Describe the clinical manifestations of mitral stenosis
Dyspnoea: can be mild exertional to pulmonary oedema
Haemoptisis
Systemic embolisation: enlargement of left atrium & left atrial appendage
Infective endocarditis
Chest pain
Hoarseness
What causes haemoptisis in a patient with mitral stenosis?
Rupture of thin walled veins
What causes hoarseness of the voice in a patient with mitral stenosis?
Compression of the Left recurrent laryngeal nerve
Describe the signs on examination, of a patient with mitral stenosis
Mitral facies
Normal pulse
JVP - prominent ‘a’ wave
Tapping apex beat & diastolic thrill
Right ventricular heave
Auscultation:
- Snapping after 2nd heart sound
- Murmur after Snap until mid diastole
What is Mitral facies?
Facies = facial expression/look associated with a condition
Mitral facies:
- Rosy cheeks
- Rest of face is cyanosed
What are the investigative techniques for mitral stenosis?
ECG
Cardiac catheter
Chest radiograph
Echocardiography
Cardiac Magnetic resonance
How would an ECG indicate mitral stenosis?
P wave > 0.12s
= RVH
Why is a chest radiograph useful for diagnosing mitral stenosis?
One of the effects of mitral stenosis is enlargement of the left atrium
LA enlargement visible on CXR
Why is echocardiography a useful imaging technique for mitral stenosis?
Shows thickening & scarring of the leaflets
and Fusion of the commissures
Treatment for mitral stenosis involves both pharmalogical & interventional management
What groups of drugs are used to treat mitral stenosis?
Diuretics & drugs to restrict intake of Na+
Atrial fibrillation: drugs to restore Sinus rhythm or control ventricular rate
Anticoagulants
What interventional options are used to treat mitral stenosis?
Valvotomy (balloon or surgical)
Mitral valve replacement
What are the causes of mitral regurgitation?
Rheumatic heart disease
Mitral valve prolapse (MVP)
Infective endocarditis
Degenerative diseases
Left ventricular & annular dilation causes functional MR
What is annular dilation?
Dilation of the annulus (collagen ring things) surrounding the valve
The greater the annular enlargement - the larger the regurgitation
What is the difference between acute & chronic mitral regurgitation?
Difference in the way the left ventricle deals with the MR:
Acute:
- End systolic pressure & volume decrease
- Wall tension decreases
Chronic:
- End diastolic volume increases and ESV returns to normal
- Eccentric Left ventricular hypertrophy develops
