Fatigue

What heart related fatigue tends to feel like

Everybody feels tired sometimes. The kind of tiredness that interests a cardiologist is different. It is persistent, it does not lift after a good night's sleep or a quiet weekend, and it starts to change what you are able to do in an ordinary day.

When the heart is not working efficiently, the body may not receive the oxygen and nutrients it needs. Over time that shows up as a drop in energy rather than as anything dramatic. Dr Jogiya's experience is that when fatigue is linked to the heart it tends to follow a gradual but noticeable decline, and people usually notice it in activity before they notice it at rest.

One of the patterns he sees frequently is that people normalise this. They put it down to ageing, to work or to a busy family life, and they quietly reduce what they do without ever registering the decision. Symptoms are often subtle. There may be no obvious chest pain at all, just a sense that everyday activities have become more demanding.

• A persistent lack of energy
• Reduced ability to exercise or carry out daily tasks
• Feeling unusually tired after minimal effort
• Fatigue that does not improve with rest

Most fatigue is not coming from the heart

Fatigue is a non-specific symptom, which means it can be linked to many different conditions. A common mistake is to assume that all fatigue must point to something serious. In reality, lifestyle factors are often the underlying cause, and the explanations below turn out to be the right ones more often than a heart problem does.

Sleep is worth singling out, because quality matters as much as quantity and broken sleep can leave someone tired despite spending long enough in bed. Obstructive sleep apnoea causes repeated interruptions in breathing during sleep, which drops oxygen levels and fragments sleep, and daytime fatigue is one of its common signs alongside loud snoring, waking unrefreshed and morning headaches. It is frequently underdiagnosed, and many people are unaware they have it until a partner notices. It matters to the heart as well, because untreated sleep apnoea is associated with high blood pressure, atrial fibrillation and heart failure.

None of this means the tiredness is imaginary, or that it should be ignored. It means the first job is to work out which of the many possible causes is yours, and several of the most common ones are found on a blood test rather than a heart scan. What changes the calculation is persistence. When fatigue is ongoing, unexplained or getting worse, it is worth considering all the possible causes, including the heart.

• Poor sleep, including sleep that is broken rather than simply short
• Obstructive sleep apnoea, particularly alongside heavy snoring or waking unrefreshed
• Stress or anxiety
• Nutritional deficiencies, including anaemia
• Thyroid problems, particularly an underactive thyroid
• Infections

When fatigue may be coming from the heart

The heart's job is to pump oxygen rich blood around the body. When that process is affected, muscles and organs do not get the energy they need. There are four broad reasons this happens. The heart muscle may be weakened, blood flow may be reduced, the rhythm may be irregular, or the heart may struggle to meet the increased demand of activity.

Heart failure is the clearest example. The heart is not pumping as effectively as it should, so the body receives less oxygen, particularly during physical activity. Fatigue often arrives alongside breathlessness or swelling in the legs.

Heart rhythm disorders affect how well the heart fills and pumps blood. In atrial fibrillation the heart is not beating in a coordinated way, so it does not fill and pump as well as it should. A rhythm that runs too slowly, as in heart block or sick sinus syndrome, causes the same shortfall from the opposite direction, because a slow rhythm reduces the amount of blood reaching the brain and other organs. In practice, patients often attribute this tiredness to ageing or lifestyle when the underlying issue is a rhythm disturbance.

Coronary artery disease can cause fatigue when narrowed arteries limit the oxygen reaching the heart muscle, and some people notice reduced stamina rather than any typical chest discomfort. Valve problems, such as aortic valve disease or mitral valve disease, make the heart work harder to maintain circulation, which can lead to fatigue over time. Conditions affecting the heart muscle itself, including cardiomyopathy and ventricular hypertrophy, can show up as fatigue or reduced stamina. Low blood pressure belongs on the list too, usually with dizziness or light-headedness alongside the tiredness.

• Heart failure
• Atrial fibrillation and other heart rhythm disorders
• Heart block, sick sinus syndrome and tachy brady syndrome, where the rhythm runs too slowly or swings between fast and slow
• Coronary artery disease and angina
• Valve disease, including aortic valve disease and mitral valve disease
• Cardiomyopathy and ventricular hypertrophy
• Low blood pressure

The symptoms that change the picture

Fatigue on its own is a weak signal. Fatigue with company is a much stronger one. When tiredness turns up alongside breathlessness, dizziness or palpitations, the likelihood that the heart is involved goes up.

Taken individually these things are easy to explain away. Mild breathlessness on the stairs, a little less energy than last year, an ankle that looks puffier by the evening. Together they point somewhere, and that combination is worth describing in full when you see someone rather than mentioning only the symptom that bothers you most.

It is also worth saying that heart symptoms in women are more likely to be missed, delayed or put down to something else. Research has shown women are around 50 per cent more likely to be initially misdiagnosed after a heart attack. Unusual fatigue that has crept up over weeks or months and is out of keeping with normal life is one of the presentations most often overlooked.

• Breathlessness, particularly during activity that used to feel easy
• Waking at night short of breath, or needing extra pillows to sleep
• Swelling in the ankles, legs or abdomen
• Palpitations, or a heartbeat that feels irregular
• Dizziness, light-headedness or fainting
• Chest discomfort of any kind, including pressure, tightness or burning

When to arrange an assessment rather than wait

There are situations where fatigue should be looked at rather than lived with. Dr Jogiya recommends seeking advice when fatigue persists despite adequate rest, when it comes with breathlessness or chest discomfort, when it limits your normal daily activities, when it is associated with dizziness or fainting, or when it has developed without a clear explanation.

Fainting deserves its own line. Any unexplained fainting, or dizziness that keeps returning, should be assessed by a doctor rather than waited out, and fainting that happens during exercise is always taken seriously and should always be investigated promptly.

What actually tends to happen is that people adapt to their symptoms gradually. They reduce their activity levels without realising that their energy has declined, so the change never announces itself. That is why fatigue is worth raising even when it feels too vague to bring up.

If you have already been told your symptoms are unlikely to be cardiac and something still does not feel right, that is a reasonable thing to have looked at properly. Early assessment allows any underlying issue to be identified before it progresses, and where nothing cardiac is found it sends the search somewhere more productive.

• Fatigue that persists despite adequate rest
• Fatigue accompanied by breathlessness or chest discomfort
• Fatigue that limits your normal daily activities
• Fatigue associated with dizziness or fainting
• Fainting during exercise, or fainting that keeps happening without a clear explanation
• Fatigue that has developed without a clear explanation

What Dr Jogiya would do about it

The approach is usually straightforward. It begins with a detailed discussion of your symptoms and your medical history, because the pattern of the tiredness, when it began and what makes it worse often narrows things down before any test is arranged. Heavy snoring and poor sleep are worth mentioning at that appointment, because they point somewhere specific.

From there, a small number of tests answer most of the question. A 12 lead ECG looks at the electrical conduction of the heart. Blood tests check for anaemia, thyroid function and other conditions, which is how many of the non cardiac causes are found or ruled out. An echocardiogram is an ultrasound scan that looks at the structure and function of the heart, including the valves and chambers. Exercise testing looks at how the heart responds to activity and exertion.

Where a rhythm problem is suspected and the symptoms come and go, Dr Jogiya will usually arrange an ECG monitor, which records the heart's electrical conduction over a longer duration, from 24 hours to 14 days. An intermittent problem rarely shows itself during a short recording. Where the heart muscle needs looking at in greater depth, a cardiac MRI can be arranged, which is Dr Jogiya's own research field.

These investigations exist as much to rule the heart out as to rule it in. For many people the useful outcome is a clear answer that the heart is working normally. Where something is found, identifying it early means treatment can begin sooner and there are usually more options available.

Alongside whatever the cause turns out to be, regular physical activity within comfortable limits, good sleep habits, a balanced diet, managing stress and staying hydrated all support energy levels and general cardiovascular health. They are not a substitute for assessment when symptoms are persistent. This page is general information about fatigue and is not individual medical advice, so please speak to your GP or a cardiologist about your own symptoms.

• 12 lead ECG
• Blood tests, including anaemia and thyroid function
• Echocardiogram
• ECG monitor, from 24 hours up to 14 days
• Exercise tolerance test
• Cardiac MRI where the heart muscle needs assessing in greater depth