Normal, fast or irregular heart rate: when should you see a doctor?

Your heart changes pace all day long, and that is normal: it speeds up when you climb the stairs, slows down while you sleep and sometimes races with emotion. Yet many people worry about a fast pulse, a beat that seems to be missing or an alert from their watch. Here are the useful benchmarks to tell what is normal from what deserves medical advice.

What is a normal heart rate?

At rest, an adult's heart usually beats between 60 and 100 times per minute. The figure varies from one person to another and with the time of day.

• In trained athletes, a resting pulse around 50, sometimes lower, is common and harmless.
• During sleep, the heart rate slows down naturally.
• During exercise it can rise well above 100: that is the heart's normal response.
• In children the rate is higher than in adults and gradually decreases with age.

How to take your pulse properly

For the reading to mean something, take it at rest, after sitting for at least five minutes, and away from coffee or a cigarette.

• Place your index and middle fingers on the inside of your wrist, below the base of the thumb, or on the side of your neck.
• Count the beats for 30 seconds and multiply by two.
• If the rhythm feels irregular, count over a full minute.
• Write down the number, the time and how you felt: these notes help the doctor a great deal.

Smartwatches and electronic blood pressure monitors give a useful indication, but their reading can be wrong when the rhythm is irregular.

The 2024 European guidelines are clear: a watch that measures the pulse using light can raise an alert, but it does not make the diagnosis. An electrocardiogram tracing, recorded at the practice or with a device able to record an ECG, is needed to confirm atrial fibrillation.

A heart that beats too fast: tachycardia

Tachycardia means a heart rate above 100 beats per minute at rest. In the vast majority of cases, the cause is ordinary and temporary.

• Stress, anxiety or a strong emotion.
• Fever, dehydration or an infection.
• Coffee, strong tea, energy drinks or tobacco.
• Anaemia or an excess of thyroid hormones.
• Some medicines, such as decongestants or asthma treatments.

Less often, the speeding up comes from an electrical disorder of the heart itself. A rhythm that starts and stops suddenly for no reason, or that stays fast at rest for several minutes, should be checked by a doctor.

A heart that beats too slowly: bradycardia

Below 60 beats per minute, it is called bradycardia. In athletes or during sleep, this is often normal. It becomes a concern when it comes with unusual tiredness, dizziness, breathlessness or fainting spells. It may then reflect a disorder of the heart's electrical conduction, or the effect of medicines that slow the heart rate.

An irregular rhythm: extrasystoles and atrial fibrillation

The feeling of a skipped beat followed by a stronger one is very common. Most often these are extrasystoles, premature beats that are usually harmless and are brought on by tiredness, stress or caffeine.

A completely chaotic pulse with no regularity at all, on the other hand, suggests atrial fibrillation. This rhythm disorder becomes more common with age and can go unnoticed. It needs to be diagnosed, because it increases the risk of stroke. Only an electrocardiogram can confirm it.

The risk is far from theoretical: atrial fibrillation makes a stroke about five times more likely, because blood pools in the atria and can form a clot there. Anticoagulant treatment, discussed with the cardiologist, greatly reduces this risk.

Read also: preventing stroke and screening for carotid stenosis

Palpitations: when to see a doctor?

Palpitations means feeling your heart beat too fast, too hard or irregularly. When they are isolated, brief and come with no other symptom, they are rarely serious. Do book an appointment, however, if:

• they come back often or last several minutes;
• your resting pulse stays above 100 or below 50 for no clear reason;
• they occur during exercise rather than at rest;
• you already have a heart condition, a diseased valve or a history of heart surgery;
• a member of your family died suddenly before the age of 50.

Cardiology consultation in Tangier: heart check-up, review of your tests and a second opinion

Signs that require calling emergency services

Do not wait: call 141 (SAMU) or 15 (Civil Protection) immediately if an abnormal heart rhythm comes with any of these signs:

• pain or tightness in the chest;
• severe or sudden breathlessness;
• fainting, loss of consciousness or the feeling that you are about to pass out;
• confusion, weakness on one side of the body or difficulty speaking.

Do not drive yourself to the hospital.

Read also: the signs of a cardiac emergency

In children, different benchmarks

A child's heart beats faster than an adult's, and the younger the child, the faster it beats. A figure that would be worrying in a parent can therefore be perfectly normal in an infant. Some signs, however, call for specialist advice:

• a baby who gets out of breath or sweats during feeds;
• poor weight gain;
• lips or nails that turn blue;
• fainting or loss of consciousness during exercise;
• a heart murmur that the paediatrician wants to have investigated.

Dr Tber performs heart surgery in children as well as adults, in coordination with the paediatrician and the cardiologist who follow your child.

The tests that explain what is going on

When the heart rhythm is disturbed, the assessment is simple and painless in most cases.

• The electrocardiogram, which records the heart's electrical activity in a few minutes.
• The Holter monitor, a small device worn for 24 to 48 hours to catch a disorder that comes and goes.
• The heart ultrasound, to check the valves and the strength of the heart muscle.
• A blood test, in particular for the thyroid, anaemia and mineral salts.
• Sometimes an exercise test, if the symptoms appear during activity.

When the heart rhythm leads to the surgeon

Most rhythm disorders are treated with medicines or with a procedure performed by the cardiologist. Surgical advice is mainly considered when the arrhythmia is linked to a valve disease, a heart malformation or another planned heart operation. The rhythm treatment can then sometimes be combined with the surgery.

Conversely, heart surgery can itself trigger a temporary rhythm disorder: after bypass surgery, about one patient in three develops atrial fibrillation in the following days. It is expected, monitored and treated during the hospital stay.

Read also: aortic stenosis, when is surgery needed

Are you feeling palpitations, or is your pulse worrying you? Dr Tber's practice in Tangier reviews your test results and guides you, even when the answer lies with another specialist.

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This article gives general guidance and does not replace a medical consultation.

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