The Pulse

Written by Cardiologists Dr Joe Morton & Dr Bhupesh Pathik

The pulse rate is one of our bodies’ four “vital signs”. Along with the blood pressure, temperature and respiratory or breathing rate, the pulse is a key indicator of a persons’ health. In simple terms the pulse rate is telling us how fast or slow our heart is beating. Most people are unaware of what their resting heart rate is at any given time. Try it now: Stop what you are doing, stand or sit quietly and see if you can feel your heart beating …Good luck!

Most people cannot feel their heartbeat and so we do the next best thing – we measure our pulse. The pulse is what we feel with our fingertips as a wave of blood passes through an artery. The pulsing sensation is the transmission of the heartbeat to our fingertips through an artery carrying blood away from the heart.

How do I measure the pulse?

Prepare to measure the pulse by sitting quietly.

The pulse can be felt by carefully laying two or three fingertips over any artery, but the commonest sites are at our wrist or on the side of our neck.

Use the fleshy pulp of your middle two or three fingertips and do not press too hard. The pulse can be extremely hard to feel if too much force is applied with the fingers. Try to avoid using your thumb to feel the pulse.

Measuring your pulse from your wrist (radial artery) is best felt just below the base of the thumb, where a wristwatch band would sit. The fingers should fall into the groove between the bony outside of the wrist (radius bone) and cable like tendons passing over the front of the wrist.

The carotid pulse is felt in the groove on the side of the neck between the larynx and the long cord-like, sternocleidomastoid muscle. It may be uncomfortable to feel and it is very important not to push hard or to push on both sides of the neck. With practice it can be easy to feel but I would suggest you ask a health professional to demonstrate feeling the carotid pulse before trying it on yourself.

Once you can feel the pulse count how many pulsations there are in a minute and that is the pulse rate. Most people will measure for fifteen or thirty seconds and then multiply by four or two, respectively. For example, I measured 20 pulsations in 15 seconds over my radial pulse, so my pulse rate is 80beats per minute (bpm).

If there is no artery, then the pulse disappears. A common magician’s trick is to squeeze a concealed ball under the armpit to block the blood supply to the wrist and make the radial pulse magically disappear! If you are delivering first aid at the scene of an injury or trauma then failing to feel a pulse on an injured limb may indicate profoundly serious vascular trauma.

What is considered a normal pulse?

There is tremendous variability in the resting pulse rate:

• For adults and children aged 10 years and older the resting heart rate is usually between 50 and 110bpm.
• Children aged one year to ten years of age may have a normal resting heart rate ranging from 60-140bpm.
• Infants under the age of 12 months of age may have very fast resting pulse rates of well over 100bpm (100-160bpm)

Our maximum heart rates at peak exercise is easily calculated as 220 minus our age. The pulse rate is a “vital sign” and changes with our blood pressure, our temperature, our breathing rate, and our level of alertness. It usually drops lower while we sleep. It goes up and down during the day. A normal healthy 40-year-old may have an average heart rate of 80 bpm during the day with a range from 40 overnight to 180bpm with peak exercise. The range described above is taken from our resting pulse while sitting, standing, or lying quietly.

Fast and slow pulse

Measuring the pulse may help measure fitness. Endurance exercise leads to a slower pulse over time. The pulse rate may rise slower with exercise and return more quickly to baseline. Wearable technologies may help better define these measurements.

In individuals where fitness is not a factor, a slow pulse (bradycardia – heart rate less than 55bpm) may be a sign of disease in the heart’s electrical conducting system. If you are feeling dizzy and/or lightheaded, then identifying a slow pulse should initiate a medical evaluation with your general practitioner.

Having a fast-resting pulse (tachycardia, heart rate greater than 100bpm) may be normal or may be a sign of illness including infection, fever, overactive thyroid disease, low blood pressure or a true arrhythmia (abnormal heart rhythm). If you have a tachycardia and feel unwell than please seek medical attention.

Regular vs. irregular pulse

“Doctor I am missing heart beats!” - This is a common finding when people have what is referred to, as ectopic beats. These are extra beats that our heart may have. Ectopic beats may be from the top chambers of the heart (atrial ectopic beats), or the bottom chambers of the heart (ventricular ectopic beats). The ectopic beat occurs close after the normal beats and are also described as premature beats. The ectopic beats may not create their own pulsation of blood that our fingers can feel and because of this, the pulse may apparently “skip” or “miss” a beat. For example, an individual with an actual heart rate of 80 bpm may record a radial pulse of 40 bpm. If every second beat is an ectopic beat (bigeminy),there would be 40 normal beats and 40 premature ectopic beats that do not produce a pulse.

Atrial fibrillation

Atrial fibrillation is an arrhythmia caused by chaotic electrical activity in the top chambers of the heart (the atria). The pulse becomes very irregular. It may be slow and irregular or fast and irregular. The diagnosis is confirmed by having an electrocardiogram (ECG). Atrial fibrillation may cause palpitations but unfortunately, many times the person cannot feel the palpitations. Instead they may experience breathlessness, dizziness, fatigue, or chest pain. Even more concerning is that many patients who have atrial fibrillation are asymptomatic. Atrial fibrillation is a major cause of stroke in our society. Atrial fibrillation is more common in patients with a history of high blood pressure or previous heart disease but can occur in otherwise healthy adults. Atrial fibrillation becomes more common as we get older. Atrial fibrillation may come and go (paroxysmal) or be persistent or even permanent.

Measuring the pulse to detect Atrial fibrillation

Checking our pulse each day might help detect asymptomatic atrial fibrillation. If we check our pulse each day for a minute and detect an irregular pattern, your general practitioner can evaluate if further investigation is required. There are many effective treatments available for atrial fibrillation including medications to prevent stroke (anticoagulants) and procedures to eradicate the arrhythmia (catheter ablation).

Palpitations

Remember I said earlier that most people cannot feel their heartbeat? Well of course sometimes we can feel our heartbeat and we call that sensation of being aware of our own heartbeat “palpitations”. Almost all of us have felt our heart pounding in our chest during or after exercise, when we are frightened, if we are angry or emotionally worked up or if we are nervous. For example, imagine you are sitting on the couch at night watching a scary movie and suddenly there is a bang at the window! I bet most of us would jump in fright and feel our hearts beating out of our chest! That is normal and is our own heart beating fast and forcefully in response to a sudden fright.

We call that sinus tachycardia - a fast but normal heartbeat. Most of us are particularly good at recognising the palpitations associated with an appropriate sinus tachycardia. For example, we have been exercising hard, about to make an important speech, make a marriage proposal, or ask our boss for a raise! At other times we recognise that “palpitations”, or an awareness of our heartbeat is not normal. These palpitations often come on suddenly, may be very fast, may be regular or irregular and last either seconds, or minutes or hours. If someone is experiencing these types of palpitations, they should see their general practitioner for an assessment of their heart. Palpitations may indicate an abnormal heart rhythm (arrhythmia). Arrhythmias are treatable and many are curable. Very brief palpitations that last only a second and feel like a lurch or jump in the chest are often due to extra or ectopic beats. These ectopic beats can be very annoying for some people.

Use of technology to check the pulse

In recent years, we have seen new technologies that allow the pulse to measured using smartwatches and smartphones (iPhone and Android). These new technologies may help improve the detection of abnormal heart rhythms. Some new technologies include:

Smartwatches

• Smartwatches available in Australia are able to detect your pulse rate and see if your heart is beating too fast, too slow or at a normal pace.
• Some watches such as the Apple watch can detect abnormal heart rhythms that should be investigated to rule our conditions such as atrial fibrillation.
• Currently, smartwatches available in Australia are unable to generate an electrocardiograph (ECG)

Apps

This technology is often used in heart research studies or when recommended by a cardiologist who specialises in heart rhythm disorders (electrophysiologist).

• A smartphone ECG App used with a sensor, can generate an ECG
• With the app open, the user places their fingers on the sensor (as pictured) for 30 seconds
• The ECG is generated immediately and this can then be sent to a doctor electronically for review.
• Abnormal heart rhythms such as atrial fibrillation can be detected by this app.

In Summary - The Pulse and Our Health

Understanding what the pulse is and knowing how to measure and record it is a powerful and simple tool to provide an indicator of our health. It can be confusing to give a single “ideal” pulse rate but there are some important key points. If you feel unwell and the pulse is slow (less than 50bpm) or fast (greater than 100bpm), then seek medical attention. If the pulse is irregular, then regardless of whether you feel unwell or not it should be evaluated further by your general practitioner.