PPRuNe Forums - View Single Post - Heart Murmur
Thread: Heart Murmur
View Single Post
Old 7th Jul 2007, 08:58
  #17 (permalink)  
slim_slag
 
Join Date: Jan 2001
Location: He's on the limb to nowhere
Posts: 1,981
Likes: 0
Received 0 Likes on 0 Posts
Good man ginger, stick your neck out. Who knows, but the patient did say it was a 'murmur' in his first post......

Chrisy. Load of gobblydegook eh? I guess you want to know what it means.

Well, coffee just kicking in, so lets try.

Cardiac output (CO, the amount of blood your heart pumps per minute) is calculated by

CO = SV x HR

where

SV = Stroke Volume, how much blood pumped out each time your heart beats
HR = Heart Rate.

Simple stuff eh?

For the mythical normal man
HR = 70 per min
SV = 70ml
That gives a cardiac output of approx 5 litres/min and that is what is needed to keep all your cells alive.

Now, you have a HR of 45. To get a cardiac output of 5 litres per min you need to up your stroke volume to approx 110ml per beat. So you need a larger ventrical volume to fill with blood. That is the 'increase in the left ventricular endiastolic volume' the cardiologist mentions.

Now, a clever chap called Starling discovered that if you increase the size of your resting ventricles (which the echo shows you have), your heart muscles will contract harder when they come around to pumping. So it would not be surprising if they get a little thicker. And it seems there is an area of your heart which is a little thicker, but no big deal.

So we can explain everything and it's all well and good. The trabeculation bit just means he has looked for specific type of thickening and it isn't there. So no problem.

As you appear to be healthy, probably a lot healthier than most of us, the 'out of range' findings can be explained. That's all that really matters and you should get a class 1, but we knew that already

Edit: Coffee fully kicked in now, so can see what I missed, how does this all fit with the murmur?

Well, we surmised you are ejecting 110ml of blood instead of 70 ml of blood. The arteries and valves don't stretch so easily, so the cross section area this blood has to pass through stays the same. So more blood per beat going though the same sized hole, hardly surprising you might get a little extra noise generated.

Last edited by slim_slag; 7th Jul 2007 at 10:34.
slim_slag is offline