Predisposing factors that cause SAM are (1)
excessive anterior or posterior leaflet tissue
; (2) any anatomical or surgical translocation of the mitral valve anteriorly; (3) aortomitral angle
What is Sam in heart disease?
Systolic anterior motion
(SAM) is defined as displacement of the distal portion of the anterior leaflet of the mitral valve toward the left ventricular outflow tract obstruction.
What does Sam stand for in cardiology?
Systolic anterior motion
(SAM) of the mitral valve (MV) can be a life-threatening condition. The SAM can result in severe left ventricular outflow tract obstruction and/or mitral regurgitation and is associated with an up to 20% risk of sudden death (which is substantially lower in hypertrophic cardiomyopathy (HCM)).
What is Sam of the mitral valve?
Systolic anterior motion (SAM) of the mitral valve is defined as
displacement of the distal portion of the anterior leaflet of the mitral valve toward the left ventricular outflow tract obstruction
. It can occur in patients with and without hypertrophic cardiomyopathy.
What is mild Sam?
If mild SAM is present, defined as
less than mild MR and a LVOT gradient of less than 50 mm Hg
, we usually use no additional surgical intervention and proceed to reversal of heparin and decannulation.
What is Lvoto?
Left ventricular outflow tract obstruction
(LVOTO) can occur at the valvular, subvalvular, or supravalvular level. In general, there is an obstruction to forward flow which increases afterload, and if untreated, can result in hypertrophy, dilatation, and eventual failure of the left ventricle.
Why is the heart muscle so thick?
Hypertrophic cardiomyopathy
is usually caused by abnormal genes (gene mutations) that cause the heart muscle to grow abnormally thick. In most people with hypertrophic cardiomyopathy, the muscular wall (septum) between the two bottom chambers of the heart (ventricles) becomes thicker than normal.
When does Sam occur?
SAM peaks
at the end of systole
in non-HCM hypertrophied ventricles but peaks at approximately two-thirds the way through systole in HCM [26].
What causes chordal Sam?
Systolic anterior motion (SAM) of the mitral chordae tendineae (chordal SAM) is commonly observed with septal hypertrophy in hypertrophic cardiomyopathy (HCM) and may cause
severe hypotension by obstructing the left ventricular outflow tract (LVOT)
during the systole phase.
How is Sam treated?
Ready-to-use therapeutic foods (RUTFs)
, such as Plumpy'Nut are designed for the treatment of uncomplicated SAM. Ready-to-use supplementary foods (RUSFs), such as Plumpy'Sup, are designed as a supplement to treat MAM.
What causes the mitral valve to close?
The valve opens and closes because of
pressure differences
, opening when there is greater pressure in the left atrium than ventricle and closing when there is greater pressure in the left ventricle than atrium.
How many mitral valves are there?
The
four valves
are to open and close to let blood flow through the heart.
What does chordal Sam mean?
Chordal SAM was defined as
systolic anterior motion involving only the chordae tendineae
(Fig. 2) [31]. The LVOT area was calculated from the length of the LOVT in the parasternal long- axis view at early systole.
Does Sam cause mitral regurgitation?
The SAM can result in
severe left ventricular outflow tract obstruction
and/or mitral regurgitation and is associated with an up to 20% risk of sudden death (which is substantially lower in hypertrophic cardiomyopathy (HCM)).
What does Lvot stand for?
Left ventricular outflow tract velocity time integral
(LVOT VTI) is a measure of cardiac systolic function and cardiac output. Heart failure patients with low cardiac output are known to have poor cardiovascular outcomes. Thus, extremely low LVOT VTI may predict heart failure patients at highest risk for mortality.
What is normal Lvot gradient?
Amyl Nitrite: LVOT gradient =
77 – 100 mmHg
.
5.0 m/sec
.
