How to tell if your breathlessness is being caused by a heart problem

Breathlessness is a very common symptom and may be caused by underlying heart disease. Apart from heart disease, breathlessness can be caused by several other conditions. These include being unfit, being overweight, and even just getting older. Other important causes include anemia and lung disease.

In this article, I will discuss how you can work out if the breathlessness could be caused by underlying heart problems.

Breathlessness caused by heart disease is usually worse on exertion than it is at rest. If your breathlessness is worse at rest than it is on exercise then it is highly unlikely that it is due to an underlying heart condition. Heart disease is significantly more prevalent in older patients than in younger patients unless there is a history of congenital heart disease.

Common heart conditions which can cause breathlessness include:

1. Heart failure or cardiomyopathy

Heart failure is a rather negative term and is probably more accurately described as heart insufficiency. The heart is responsible for pumping oxygen rich blood to all the vital organs. If the heart is weak, it may be still be able to pump adequate amounts of oxygen rich blood to the rest of the body but if the demands are increased by exercise then the heart is unable to get enough blood around and this manifests as breathlessness, exercise intolerance and fatigue. When the patient stops exercising, the demands on the heart  get less, supply matches demand and the symptoms resolve. It is not uncommon to heart failure to be accompanied with worsening leg swelling and sometimes even breathlessness when the patient bends over to pick something up or when the patient lies flat in bed.

Common causes of heart failure include previous heart attacks, a virus causing the heart to weaken and excessive alcohol intake causing heart muscle dysfunction.

2. Heart valve disease

The heart has 4 valves which allow the passage of blood through the heart and out of the heart. Often, as a consequence of aging or due to infections such as rheumatic fever, the heart valves can get affected and can become abnormally narrowed or even start leaking back. The end product of valve disease is that it becomes more difficult the heart to pump out adequate amounts of blood even though the heart muscle is strong.

3. Angina

The heart muscle needs blood to contract adequately. The blood is supplied to the heart muscle by  blood vessels known as the coronary arteries. With age and additional comorbidities such as diabetes and high blood pressure, the coronary arteries can become diseased and can progressively narrow. This results in less blood getting to the heart muscle especially during exercise and therefore the heart muscle is not able to contract as well on exercise and this in turn can manifest with breathless. Usually the breathlessness is accompanied by a sensation of chest tightness or constriction. This sensation is called angina. In diabetics in particular, the breathlessness may be the only symptom of angina.

4. Heart rhythm disturbances

If there is an electrical abnormality of the heart then the heart can go into fast heart rhythms. When the heart goes very fast, it does not get enough time to fill with as much blood and therefore less blood is ejected with each heart beat and this can also cause breathlessness. Usually patients will complain of symptoms of palpitations or a fast heart rate which will accompany breathlessness.

I would recommend the following tests to ensure that your breathless is not being caused by an underlying heart disease.

1. Blood tests: I think it is vital to have a blood test to check the full blood count and urea and electrolyes. This is to look for the presence or absence of anemia and also to ensure there are no major elecrolyte abnormalities. Another blood test that can be useful is called BNP. Patients with heart failure usually have very high BNP levels but although a  normal BNP level makes heart failure unlikely, it does not definitively exclude the diagnosis.

2. ECG: A simple 12 lead ECG can be very useful to look for a heart rhythm disturbance or even prexisting heart disease and should be done in every patient.

3. ECHO: This is the definitive test to assess the function of the heart valves and the heart muscle. If the echo is normal then you can exclude heart muscle weakness or significant heart valve disease.

4. Exercise test: As heart related breathlessness is usually worse on exercise, it makes sense to study the heart during exercise. This is also an excellent way to asess if the coronary arteries are supplying the heart muscle with blood during times of stress. If there is a shortage of blood supply, the ECG during exercise may become abnormal and the patient may also manifest with chest discomfort.

5. Lung function tests: Lung disease can often cause breathlessness and lung function tests can help identify underlying lung disease.