Palpitations – common, mostly safe, but know the red flags

Palpitations are an awareness of your heart beat. The heart beats approximately 90,000 times per day and generally people cannot feel this occurring. There are circumstances where you are more likely to be aware of your heart beat, particularly when the heart is beating more vigorously such as during exercise or when you are stressed or frightened. In these circumstances it is normal to feel a more vigorous and faster pulsation. 

Athletes can sometimes become aware of their heart beating due to the combination of heart enlargement and low body fat. The heart enlargement is a normal response to physical training and fitness and results in more blood being pumped with every heart beat (called ‘stroke volume’). Although the heart and blood vessels do not have any sensory nerve fibres to detect this increased amount of blood pumped with every beat, the surrounding tissues that are ‘pushed’ by the heart and blood vessels do have sensory nerves and thus you may feel your pulse.  Athletes may report an awareness of their heart beating whilst resting quietly and particularly when lying on their left side because in this position the heart lies up against the chest wall.  Sometimes, athletes will become more aware of this as they become fitter and less so when they decondition.  This is all safe and healthy.

We as doctors become more concerned when there is an awareness of a sudden change in heart rhythm. You may feel this as extra heart beats, skipped heart beats or sudden periods of very fast heart beats.

Ectopic heart beats

By far the most common cause of palpitations are due to ‘ectopic beats’.  Normally the heart rate is generated by specialised pacemaker cells and the electric current travels down specialised conduction tissue like electrical wires within the heart. However, every single cell within the heart has the capacity to generate its own electricity and start a new heart beat.  This is important because if the ‘wires’ in the heart become damaged there is a need for a ‘back-up’ or ‘escape’ rhythm to keep you alive.  Indeed, the scene where the beating heart is extracted from some poor man’s chest in Indiana Jones is in fact real physiology!  A side effect of this important back-up mechanism is that you can have little patches of overly exuberant cells that fire off more frequently than they should. When a cell fires off (depolarises) the electric current travels through the heart to cause the heart to beat.  These heart beats occurring from cells other than the normal pathway are called ‘ectopic beats’. They are very common. Approximately 2% of the population have frequent extra heart beats.  For reasons that we do not understand, some people feel every single beat and find them very bothersome whilst other people do not feel them at all.  Often people do not feel the extra beats but rather feel a pause that occurs after the extra beat.  This is called a ‘compensatory pause’ and feels like the heart misses a beat, often followed by a much stronger beat as the heart resumes its normal rhythm.

Ectopic heart beats can occur in two settings.  Most commonly they occur with no clear reason in someone with a normal heart.  It seems that they may be more common in athletes although the data on this is not 100% clear.  Ectopics occurring in someone with a normal heart (including in athletes with healthy heart enlargement due to exercise) is a very safe condition.  It is very important that the cardiologist does tests to make sure that your heart is normal. In the likely case that it is then you can be reassured that you are safe and well.

The other setting is ectopics in someone with heart disease. If you have ectopics, your cardiologist will do some tests to make sure that there is not an underlying problem with the heart because ectopics can be stimulated by scar or inflammation in the heart and in someone with heart problems (previous heart attack, heart muscle weakness or heart muscle inflammation) then the ectopics need to be taken more seriously.

In the vast majority of the population, including athletes, ectopics are common and safe.

Sustained arrhythmias

The other type of palpitations that athletes report is when they feel their heart rate suddenly jump.  This may feel like a rapid heart thumping that may feel regular or jumping all over the place.  It may be captured as a sudden increase in heart rate on a heart rate monitor or activity device.

As a cardiologist, symptoms such as these are always taken seriously and warrant further investigation. Often, the symptoms are suggestive of a heart rhythm abnormality but the majority of these are benign (safe) arrhythmias that can be effectively treated.  However, occasionally these symptoms can be the first sign of a serious heart condition.

The general approach when the cardiologist suspects a heart rhythm disorder is to try and document the heart rhythm when the palpitations are occurring. There are several ways in which this can be done. Traditionally we have used devices such as a wearable electrocardiogram (often called a ‘Holter monitor’) that continuously detects the electrical pattern from the heart for 24 or 48 hours. The problem with this strategy is that you may not experience palpitations at the time of wearing the monitor.  In fact, I often joke about these monitors being our most effective treatment as it seems that patients never get the symptoms when you want them to! Alternatively, we may perform an exercise test with ECG monitoring.  A recent advance in hand-held ECG monitoring has proved very useful.  A number of companies make devices that you can simply place your fingers on when you get palpitations and it will record an ECG. Some of the watchmakers and activity devices also provide capabilities for recording ECGs.  These ECGs are less ‘complete’ than that obtained from a Holter monitor but they have the massive advantage of being available whenever the symptoms occur.  I have diagnosed many patient’s heart rhythm disorders in this way.

Although most often palpitations are not associated with a serious heart problem, there are some ‘red flag’ symptoms that should be taken very seriously and should be reported to your doctor very promptly. These include:

-        Any palpitations associated with collapse or a feeling like you might pass out

-        Any palpitations associated with shortness of breath or sudden exercise intolerance

-        Any palpitations associated with chest pain

-        Any palpitations if you have a family history of family members collapsing or dying at an early age, or of unexplained car accidents or drowing.

If in doubt, be sure to seek medical advice. Palpitations are common symptoms and something that your family doctor and cardiologist can easily work through.  It is better to be reassured than ride along with question marks in your head!

Hear more about palpitations in our podcast with Mat Hayman.