Hypertrophic Cardiomyopathy Association: How Does Hypertrophic Cardiomyopathy Affect the Heart?

How Does Hypertrophic Cardiomyopathy Affect the Heart?
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ustewjt on 10/12/2008 20:15:00


THE NORMAL HEART
It is helpful to be familiar with the structure and function of the normal heart
in order to understand the abnormalities in HCM. Fig. 3 shows a normal heart and
indicates the heart chambers, valves and the direction of blood flow. The walls
of the heart are composed of specialized muscle known as the myocardium. It is
this part of the heart which is abnormal in HCM.
STRUCTURE AND FUNCTION
This is a picture of the internal structure of a normal heart. The four chambers
and four one-way valves are indicated. The right atrium receives blood from the
body, transfers it to the lungs to the left atrium. It is transferred to the
left ventricle which pumps it around the body for another cycle. Figure 4 again
shows a normal heart but in this diagram the electrical activity of the heart is
shown. Every heartbeat results from an electrical signal starting at the top and
passing down through the heart. The abnormality of the heart muscle in
Hypertrophic Cardiomyopathy can sometimes interfere with this normal electrical
signal.
THE NORMAL ELECTRICAL IMPULSE IN THE HEART
The normal electrical impulse starts in the right atrium as shown by the arrows.
It travels by special conducting tissue down through the heart and into the
muscle to start a contraction.
THINK OF THE HEART LIKE A HOUSE
A house has walls, plumbing and electricity - so does your heart. In a normal
heart as in a normal house the walls are built well, for example with bricks
that are layed properly.  In an HCM heart those bricks that form the walls are
cells and some of the cells are not placed properly.
In a house the plumbing lets the fluid travel in a specific pattern and the same
goes for a normal heart.  In an HCM heart sometimes the plumbing in the heart
can cause the fluid - in this case blood - to get blocked temporarily while
attempting to leave the heart (obstruction).  This type of a "plumbing" problem
should not be confused with blocked arteries in the heart - that is coranary
artery disease and NOT HCM.
In a house there is an electical system that permits power to be sent though
circuts and the same goes for a normal heart.  In HCM there can be a number of
different types of electical problems with the heart- some minor and some
severe. In some cases the electrical system can get "stuck" in a bad circut and
send the wrong messages to your heart causesing some forms of "arrthymias".  In
other cases the eletrical system can have a serious malfunction, a more severe
"arrthymia",  and send the heart into a chaos, thus causing a cardiac arrest -
in a home this could be likened to a complete electrical failure.