Whats the topic for today?
The heart and what sorts of things can go wrong with it
Are animal hearts the same as human hearts?
Not all animals but all mammals have the same basic heart design of four chambers with valves between the chambers and also valves at the outlets.
What do the valves do?
Basically the heart is like a mechanical pump.The valves are one way valves that ensure the blood only flows in a forwards direction.
What happens if the valves wear out?
You get back flow of blood just like in a leaking mechanical pump. If the valves leak the blood simply flows backwards and forwards between the heart chambers rather than circulating around the body.
Presumably that is bad news?
Yes. Without an efficient flow of blood the supply of oxygen and nutrients to the rest of the body would be reduced.
Can valves be replaced?
They certainly can in humans but that technology is not yet available in vet clinics.
So is there any other treatment apart from surgery?
Yes there are very effective medicines that help increase the efficiency of the heart so that it can cope with leaking valves. Some medicines reduce the back pressure on the heart so that it doesn’t need to work as hard to keep the blood moving forwards. Other medicines increase the hearts ability to pump harder so that more blood is pumped forwards with each heart beat.
What other things can go wrong with the heart apart from leaking valves?
Theres such a long list it would be impossible to mention them all but apart from the valves you can get diseases of the heart muscle. In some diseases the heart muscle becomes very thickened and in others it becomes thin and flabby. We also see tumours of the heart and also diseases that affect the heart rate and rhythm.
It must be quite complicated working out what is wrong with the heart?
Yes it can be but fortunately we have the help of lots of technical equipment.
What sorts of things have you got?
Well the humble stethoscope is still the first thing we use. We use that to listen to the flow of blood through the heart and to listen to the heart rate and rhythm. The stethoscope can only detect certain types of heart problems.
So what else can you use?
Chest xrays are what we do next. This is to look at the size and shape of the heart and to see if we can see any changes in the lungs that would suggest heart disease. Again xrays don’t show everything.
So what next?
We are fortunate to have an ultrasound machine and this is really useful for hearts. We are able to use it to look at blood flow through the heart and to measure the thickness of the heart muscle. We can use it to look at the heart valves too.
Is there any other technical wizardry you use
We do have an ECG machine and that is specifically used for looking for heart arythmias which is a change in the pattern of the heart beat.
All this sounds very clever but what should people look out for if they are concerned about their own pets hearts.
It depends on the species of animal and also the type of heart disease. But in general the pet will have slowed down a lot and may have laboured breathing particularly after exercising. Dogs may develop a cough which is typically worse in the evenings. Cats tend not to cough and often the first sign is struggling to breath. With severe heart problems the pet may have regular periods of collapsing or fitting.
So slowing down and increased breathing or coughing should prompt a visit to the Vet?
Yes, the sooner we detect heart problems the more likely we will be able to do something about it.
And todays question?
How many chambers does a cats heart have (four)