by: Shahir Nazri
1. Person who suffers ischemic
heart disease may develop ischemic mitral regurgitation. Unlike mitral
regurgitation that occurs secondary to damaged valve leaflets or damaged chorda
tendinae, ischemic mitral regurgitation occurs due to abnormal wall contraction
secondary to myocardial injury. The valve leaflets remain normal in this case.
Minor ischemic mitral regurgitation can largely
benefit from coronary artery bypass grafting (CABG) alone. But in case of moderate
ischemic mitral regurgitation, surgeons are divided whether or not to include
mitral valve repair (not replacement) with CABG. Keep in mind that the valves
are completely normal in this case. Should we interfere?
A group argues that CABG alone can
sufficiently slows down remodelling. Revascularization can improve left ventricular
wall function, reducing left ventricular chamber size and increase mitral valve
function, thus reversing the regurgitation. Furthermore, valvular repair
operation can cause many complications (what can go wrong when you open the
heart?).
Yeay, new record! |
Another group advocates the inclusion of
mitral valve repair with CABG. It is like a pre-emptive strike, where they try
to stop the worsening of the regurgitation before it occurs, thus prevent
remodelling of the heart and later heart failure.
If you are interested to know which triumph
over which, here is a recent cohort study comparing both approaches: Surgical Treatment of Moderate Ischemic Mitral Regurgitation
2. Aortic root enlargement is
a major problem in Marfan’s syndrome. Standard therapy of Marfan’s syndrome
includes atenolol (Beta-blocker) administration in preventing aortic root
enlargement. Atenolol acts by relaxing the heart and blood vessels to decrease
the blood pressure, thus halting the expansion of root of aorta.
Mr. Marfan? |
Losartan (ARB) can also reduce blood
pressure by blocking the action of angiotensin-II (which cause
vasoconstriction). In addition to reducing blood pressure, losartan also has
the ability to block transforming growth factor- β (TGF-β) signalling.
Excessive signalling of TGF-β is currently thought to cause the phenotypic
character of Marfan’s syndrome, including the aortic root enlargement (read
more about this somewhere, for I am too lazy to know more). Therefore, theoretically,
losartan have the upper hand in preventing aortic root enlargement compared to
atenolol.
Or is it? Find out more from this recent
study here: Atenolol versus Losartan in Children and Young Adults with Marfan's Syndrome
3. By the way, feeling obese?
If so, you might want to drink more coffee after you read this: Chemical in coffee may help prevent obesity-related disease
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