Medical Surgical Homework
Describe the 5 listed Valvular Heart
Diseases.
MITRAL STENOSIS
It usually results from rheumatic carditis,
which can cause valve thickening by fibrosis and
calcification. In Mitral Sinosis, the valve
leaflets fuse and become fuse and become stiff,
and the chordae tendineae contract and shorten.
The valve opening narrows, preventing normal
blood flow from the left atrium to the left
ventricle.
MITRAL REGURGITATION
The fibrotic and calcific changes occurring in
mitral regurgitation prevent the mitral valve
from closing completely during systole.
Incomplete closure of the valve allows the
backflow of blood into the left atrium when the
left ventricle contracts. The primary causes of
mitral regurgitation are mitral valve prolapse
and rheumatic heart disease. Other causes
include infective endocarditis, papillary muscle
dysfunction, or rupture resulting from ischemic
heart disease or congenital anomalies.
MITRAL VALVE PROLAPSE
Occurs because the valvular leaflets enlarge and
prolapse into the left atrium during systole.
This abnormality is usually benign but may
progress to pronounced mitral regurgitation in
some patients. Most patients with MVP are
asymptomatic. However, some may report chest
pain, palpitations, or exercise intolerance.
Chest pain is usually atypical, with patients
describing a sharp pain localized to the left
side of the chest. Dizziness, syncope, and
palpitations may be associated with atrial or
ventricular dysrhythmias. A normal heart rate
and BP are usually found on physical
examination. A midsystolic click and a late
systolic murmur may be heard at the apex of the
heart. The intensity of the murmur is not
related to the severity of the prolapse.
AORTIC STENOSIS
It is the most common cardiac valve dysfunction
in the US and is often considered a disease of
“Wear and Tear”. In Aortic stenosis, the aortic
valve orifice narrows and obstructs left
ventricular outflow during systole. This
increased resistance to ejection or afterload
results in ventricular hypertrophy. As stenosis
worsens, cardiac output becomes fixed and cannot
increase to meet the demands of the body during
exertion. Symptoms then develop, eventually the
left ventricle fails, blood backs up in the left
atrium, and the pulmonary system becomes
congested.
AORTIC REGURGITATION
In aortic regurgitation, the aortic valve
leaflets do not close properly during diastole,
and the annulus may be dilated, lose, or
deformed. This allows flow of blood from the
aorta back into the left ventricle during
diastole. The left ventricle, in compensation,
dilates to accommodate the greater blood volume
and eventually hypertrophies. Patients with
Aortic regurgitation remain asymptomatic for
many years because of the compensatory
mechanisms of the left ventricle. As the disease
progresses and left ventricular failure occurs,
the major symptoms are exertional dyspnea,
orthopnea, and paroxysmal nocturnal dyspnea.
Palpitations may be noted with severe disease,
especially when the patient lies on the left
side. Nocturnal angina with diaphoresis often
occurs.
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