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VALVULAR HEART DISEASE
Dr. Poland Room 3-007, Sanger Hall, Phone: 828-9557
E-mail: [email protected]
Departemen Fisiologi
Fakultas Kedokteran
Universitas Sumatera Utara
VALVULAR HEART DISEASE
• Dysfunctional cardiac valves can be classified as:
– narrow (stenosis) or,– leaky (regurgitation).
AORTIC STENOSISNormal aortic valve area is approximately
3,5-4,0 cm2. Critic aortic stenosis is usually present when the area is less than 0,8 cm2.
If this opening is narrowed (stenotic), resistance to flow through the valve increases.
intraventricular pressures may rise to very high levels during systole while aortic pressure rises more slowly than normal
Pulse pressure is usually low with aortic stenosis.
AORTIC STENOSISHigh intraventricular pressure development is a
strong stimulus for cardiac muscle cell hypertrophy, and an increase in left ventricular muscle mass invariably accompanies aortic stenosis.
This tends to produce a leftward deviation of the electrical axis.
Blood being ejected through the narrowed orifice may reach very high velocities, and turbulent flow may occur as blood enters the aorta. This abnormal turbulent flow can be heard as a systolic (or ejection) murmur with a properly placed stethoscope.
Most commonly a sequela of rheumatic heart disease. Infrequently, it maycaused by congenital lesions or calcium deposition. Atrial masses (myxomas) can cause intermittent obstruction of mitral valve.
Mitral valve is normally bicuspid, with anterior cusp approximately twice the area of posterior cusp.
Mitral valve area is usually 5-6 cm2 , cinically relevant mitral stenosis usually occurs when the valve area decreases to less than 1 cm2
characteristic elevation in left atrial pressures
main pathophysiologic abnormality in mitral stenosis is elevated pulmonary venous pressure and elevated right-sided pressures (pulmonary artery, right ventricle, and right atrium).
Dilation and reduced systolic function of the right ventricle are commonly observed in patients with advanced mitral stenosis
The high left atrial pressure is reflected back into the pulmonary bed and, if high enough, causes pulmonary congestion and "shortness of breath.“
A diastolic murmur associated with turbulent flow through the stenotic mitral valve can often be heard
AORTIC REGURGITATIONWhen the leaflets of the aortic valve do not
provide an adequate seal, blood regurgitates from the aorta back into the left ventricle during the diastolic period.
Aortic pressure falls faster and further than normal during diastole, which causes a low diastolic pressure and a large pulse pressure.
In addition, ventricular end-diastolic volume and pressure are higher than normal because of the extra blood that reenters the chamber through the incompetent aortic valve during diastole.
Turbulent flow of the blood reentering the left ventricle during early diastole produces a characteristic diastolic murmur. Often the aortic valve is altered so that it is both stenotic and insufficient. In these instances, both a systolic and a diastolic murmur are present.
When the mitral valve is insufficient, some blood regurgitates from the left ventricle into the left atrium during systole.
A systolic murmur may accompany this abnormal flow pattern.
Left atrial pressure is raised to abnormally high levels, and left ventricular end-diastolic volume and pressure increase.
Mitral valve prolapse is a common form of mitral insufficiency in which the valve leaflets evert into the left atrium during systole.
PATENT DUCTUS ARTERIOSUS
Patent ductus arteriosus (PDA) is a congenital disorder in the heart where in a neonate’s ductus arteriosus fails to close after birth.
ductus arteriosus (DA) is the vascular connection between the pulmonary artery and the aortic arch.
PATENT DUCTUS ARTERIOSUS
In normal newborns, the DA is substantially closed within 12–24 hours after birth, and is completely sealed after three weeks.
When the newborn takes its first breath, the lungs open and pulmonary vascular resistance decreases.
After birth, the lungs release bradykinin to constrict the smooth muscle wall of the DA and reduce bloodflow through the DA as it narrows and completely closes, usually within the first few weeks of life
PATENT DUCTUS ARTERIOSUS
patent ductus arteriosus is associated with a continuous murmur because of a persistent connection between the pulmonary artery and the aorta.
A patent ductus arteriosus allows a portion of the oxygenated blood from the left heart to flow back to the lungs by flowing from the aorta (which has higher pressure) to the pulmonary artery.
Tetralogy of Fallot (TOF, Latin: Train of Four) is a congenital heart defect which is classically understood to involve four anatomical abnormalities (although only three of them are always present).
It is the most common cyanotic heart defect, and the most common cause of blue baby syndrome
(1) pulmonary stenosis(2) overriding aorta; an aortic valve
with biventricular connection.(3) ventricular septal defect (VSD);
hole between the two bottom chambers (ventricles) of the heart
(4) right ventricular hypertrophy
Let it beat!
