When we are sitting quietly, we are not usually aware of our heart beating. Occasionally, we can hear or feel our normal heartbeat, for example when lying on our left side. When we exercise, our heart beats faster and more vigorously. We are not usually concerned or even aware of this as we know that is perfectly normal and the strong fast beats go back to normal on resting.
Palpitations are a disagreeable awareness of your heartbeat. Your heartbeat does not have to have changed in rhythm, speed or forcefulness – you just need to have become aware of it and be disturbed by the feeling.
However, often the reason you start noticing your heartbeat is because it has changed in either rhythm, speed or forcefulness.
Many people have a heart that occasionally changes rhythm or speed and they are blissfully unaware of this. Your heart has plenty of reserves and can change up and down a gear or have regular hiccoughs in its rhythm without affecting how well it works overall.
Occasionally people feel a buzzing, pulsation or movement in their chest that they call palpitations but is not actually related to the heartbeat.
Psychology plays a large part in how sensitive a person is to their heartbeat. If you are worried about your health, especially if it is about heart disease, you may be far more aware of any change to your heartbeat than you would normally be.
Once you notice palpitations, and especially if you are concerned about them, your brain becomes hyper-vigilant and you tend to notice your heartbeat even more.
What causes palpitations?
Most palpitations are benign – that is they are not dangerous or a sign of anything wrong with the heart. For many people, if they have a recording of their heartbeat during palpitations, it will actually show that there is no change in the speed or rhythm of their heart. One of the commonest causes of palpitations is just becoming aware of a normal heartbeat. Often stress plays a part and learning that the heart is normal when you feel palpitations can help relieve anxiety.
What are other possible causes of palpitations?
Ectopics (also known as extrasystole) are a heartbeat that started a little before it was meant to. If this is triggered by the top chambers of the heart, it is called a supraventricular ectopic or atrial extrasystole. If it comes from the bottom chambers it is called a ventricular ectopic or ventricular extrasystole.
Often the ectopic results in a single weak heartbeat that can be hard to feel. Since the ectopic was early, the time before the next beat is longer than normal. Therefore, there appears to be a longer gap between the beats. If you don’t feel the weak ectopic, you might just feel the pause – in effect, your heart feels as though it missed or skipped a beat.
The beat after an ectopic often feels very forceful as the longer gap means the heart has filled up with a bit more blood than normal before beating. If you have ectopics, it might feel as though your heart misses a beat and then has a strong beat.
Sometimes ectopics can come in groups where every second or third beat is an extra one.
Ectopics are usually entirely benign and many normal people have them without even noticing them. If you have a very high number of ectopics recorded over 24 hours, this could be a sign of heart disease and you would need further review by a cardiologist.
Supraventricular tachycardia (SVT)
This is a common rhythm problem where the heart suddenly jumps into a very fast rhythm – often twice or even three time’s normal speed. It will then suddenly jump back to normal. This rhythm is common in all ages but more so in young people. It is usually caused by various forms of short-circuiting between the top and bottom chambers of the heart. When the heart is beating fast from an SVT, it is regular. It can sometimes cause chest pain, breathlessness or dizziness.
Atrial Fibrillation or Flutter (AF)
These rhythm problems become commoner as you get older but can occasionally be seen in young people. The top chambers of the heart stop beating regularly and the rhythm is often more chaotic. Some people develop this rhythm and are unaware of it. Others can have short spells of atrial fibrillation and feel very debilitated with chest pain, breathlessness or fatigue.
The speed of the heartbeat is usually determined by special cells in the top right chamber of the heart – your own pacemaker. Sometimes this pacemaker just runs slow. There are special fibres that travel down the heart to coordinate the top and bottom chambers so that they beat one after the other. If these fibres become damaged, the signal may not get through reliably and the heart can suddenly drop to a dangerously slow speed. When this happens, usually you will feel the beats are slow and may be more forceful.
Ventricular tachycardia (VT)
This is a rare rhythm problem where the bottom chambers of the heart trip into a fast, regular rhythm. It is more common in hearts that have been damaged after a heart attack but can occasionally be seen in a heart that appears to be otherwise normal. Ventricular tachycardia can be dangerous or even life-threatening and you should be reviewed by a cardiologist. There are some forms that are benign, but you may need several tests to prove this.
Dr Harkness is an expert cardiologist and highly-experienced in using CT coronary scans and advanced echocardiography to identify if there are any irregularities in the heart. Do not hesitate to book an appointment if you have any concerns.