Most people have heard the term a heart murmur, I first came across it before I was a doctor
when I heard someone wasn't able to join the army because of it, at the time I didn't know
what it was.
I'm here today to tell you all about what a heart murmur is.
Hello it's Dr Hope and welcome to Sick Notes, where we jargon bust medical terms.
Today we're talking about heart murmurs.
A heart murmur isn't a diagnosis, it simply means a doctor when listening to the heart
can hear the blood flowing through it.
Usually blood flows through the heart in a smooth way so cannot be heard.
For example if water was flowing through a nice straight pipe, we're not necessarily
going to hear it, yet if that pipe had a kink in it, its likely to disrupt the flow and
so cause turbulent water within the pipe and therefore making a noise.
So it's quite simple a heart murmur is caused by something disrupting the normal blood flow
through the heart.
So what can cause this disruption to flow?
Well the heart is a beautiful muscular pump with four chambers that blood go in and out
of, there are valves on the exit to each of these chambers to stop blood flow in the wrong
direction.
So I've basically described the 3 things that can cause a murmur.
The valves, the muscular wall, or specifically a hole in the muscular wall, and the last
one is a bit of cop out we call a functional murmur, where the heart itself normal but
the blood is flowing more rapidly through the heart.
So let's talk about murmurs caused by heart valves.
The normal sound of the heart, the lub-dub, lub-dub sound is caused by the valves closing.
Think of the valves like a one way door, they let blood through one way, but not through
the other way.
So there's two things that can go wrong with this door it could not fully open or it could
not fully close.
Both of these will cause turbulent blood flow.
When the valve becomes stiff and doesn't fully open we call this stenosis, from the Greek
narrow.
And when the valve doesn't fully close we call this regurgitation or insufficiency because
the blood is going to flow back through the valve in the wrong direction.
Both stenosis and regurgitation cause disruption in the blood flow, therefore turbulent blood
flow within the heart and therefore will cause a heart murmur.
So on to problems with the muscular wall of the heart.
The central muscular wall of the heart is called the septum, this separates the left
hand side of the heart with the right hand side of the heart.
If there is a hole within this septum blood will flow from one side of the heart to the
other side of the heart and this cause disruptive flow and therefore also cause a murmur.
Holes in the heart are most likely present from birth.
Finally, functional murmurs or innocent murmurs or sometimes called physiological murmurs.
This is where the heart itself is normal, but the blood is flowing more rapidly through
the heart.
Think of our water pipe example where more water is forced through the pipe therefore
creating turbulent flow and therefore creating a murmur.
These murmurs still warrant investigating even though they are called 'innocent' because
they can very rarely be caused by things like thyroid problems and anaemia.
These murmurs can also be present at pregnancy, where the blood volume increases to support
the baby.
So I hope this has helped your understanding of heart murmurs, I've put some clarifications
and further links in the description below.
This is my first video but please feel free to subscribe hopefully there is some more
videos on my channel by now.
Have a good day.