Heart murmurs in adults – part 2

If your heart is making unusual noises, how do doctors find the source of the problem? Are these heart murmurs serious? Expert cardiologist Dr Allan Harkness talks tests and treatment in part 2 of his piece on heart murmurs.

What tests help in heart murmurs?

You might need further tests to determine the cause of the heart murmur and decide if it is serious. These tests can be very simple (feeling your pulse) or very complex (having an MRI).

Your pulse

If you have an irregular pulse, you might have a condition called atrial fibrillation. This is more common if you have a leaky mitral valve or heart failure. Atrial fibrillation can be a sign that the valve is very leaky and needs to be repaired or replaced.

Your pulse may also feel different if you have a damaged aortic valve – it may appear weak if the valve is severely narrowed and it may feel bounding if the valve is very leaky.

Your blood pressure

Your blood pressure gives an indication of the strength of each heart beat and will be altered if you have a narrowed or leaky aortic valve.

Electrocardiogram (ECG)

This may detect, or confirm, that you have atrial fibrillation. It may also show signs that you have had a heart attack, which can sometimes cause a leaky mitral valve. If the heart has been working extra hard to pump blood through a narrow aortic valve, it becomes more muscular and that change can show up on the ECG. Hypertrophic cardiomyopathy can also show similar signs on an ECG.

Chest x-ray

If your heart is struggling then fluid can build up in or around the lungs. This can be seen on a chest x-ray. If you have a heart murmur and fluid in or around your lungs, it is possible you may need an operation on your heart valve.

Leaky heart valves can cause no symptoms for many years even if the leak is quite significant. This gradually puts strain on the heart by dilating the chamber the blood is leaking into. This may show up on a chest x-ray as an enlarged heart.

Echocardiogram

This is the most useful test for determining why you have a murmur and working out how bad any valve problem is. An echocardiogram takes pictures of your heart as it is pumping and can show each valve opening and closing.

Special measurements can show if the valves are narrow or leaking and can estimate how badly they are damaged.

The echocardiogram will also show if problems with your valve are associated with any other heart conditions, such as heart failure caused by a heart attack.

Cardiac MRI

Cardiac MRI can provide similar information to an echocardiogram. The images of the valves are not quite so sharp but this test is very good at measuring how badly a valve is leaking or narrowed. It is also very good at indicating how well a heart is working and whether operations on the heart are likely to restore the heart to full working order.

Cardiac catheterisation

Before we had echocardiograms, cardiologists had to rely on cardiac catheterisation. This was both technically challenging and carried some risk – for instance of causing a stroke. Modern echocardiograms and cardiac MRI have meant cardiac catheterisation is very rarely done to just measure valve function.

If the echocardiogram or MRI suggests you need to have a valve repaired or replaced, this will mean you will likely need open heart surgery. Before such an operation, the surgeon will want to know that your coronary arteries are normal as he can perform a bypass at the same time if required.

Therefore, most adults have a coronary angiogram before heart surgery. Cardiac CT coronary angiography is sometimes all that is required, especially if you are young and unlikely to have coronary artery disease. Otherwise a standard coronary angiogram will be needed.

Are heart murmurs serious?

Innocent murmurs are not serious and don’t need any follow-up. Sometimes they can disappear and then reappear later. They are a bit more common in pregnancy but any murmur in pregnancy should be investigated to ensure there are no signs of valve disease.

Leaky heart valves often cause no symptoms and many adults, and a very large number of elderly people, have leaky heart valves that are causing them no problems. Your cardiologist will be able to tell you whether the leak is important enough to need follow up or an operation. Often, you may just need an annual review and occasionally a repeat echocardiogram.

Narrowed heart valves generally get worse over time so most patients with this form of valve disease needs to be followed up.

The decision to move forward with a repair or replacement of a heart valve can be very complicated. Factors your cardiologist will take into consideration are:

• Symptoms of breathlessness, fatigue, chest pain or dizziness
• Signs your heart is struggling

Even if your heart is working well, and you have no apparent symptoms, there are some circumstances where you may still be recommended to have valve surgery. Your cardiologist would explain why such preventative surgery may be required.

Valve surgery has become a common operation for heart surgeons and the techniques are now very advanced with low risk. This means we are now considering valve surgery on very elderly patients who may have other health problems. Newer techniques, such as TAVI, can allow a valve to be replaced without surgery.

For more of Dr Harkness' expert insight on this topic, read part one of this series on heart murmurs. To schedule an appointment with Dr Harkness, visit his Top Doctors profile.