The heart is a pump with four chambers comprised of right and left atria at the top and ventricles at the bottom. In order for the chambers to pump in the right order the sequence of contraction needs to allow the blood to flow in the correct pathway. The electrical circuits within the heart form a network of fast signals to coordinate this process; however every cell in the heart also has electrical properties therefore can generate extra or ectopic beats. The rate at which the heart beats is also determined by the needs of the body. For instance if we need to run, the muscles require a greater supply of blood carrying oxygen and the heart rate will pump faster; when we sleep the opposite is true. Therefore the heart rate is also influenced by the autonomic nervous system which predominantly regulates bodily functions without you having to think about them.
This means that palpitations can be due to:
- An awareness of an appropriately raised heart beat in which the electrical conduction within the heart is normal. This is not due to an abnormality of the heart and is secondary to another cause.
- A short circuit within the conduction pathway which predisposes you to abnormal fast heart rhythms, also known as tachycardia. If these arise from the top two chambers of the heart then they are referred to as a supraventricular tachycardia (SVT). If they arise from the bottom chambers of the heart they are referred to as a ventricular tachycardia (VT).
- Extra beats from heart cells which are not part of the normal conduction sequence of the heart. This often referred to as ectopic beats.
Are palpitations common?
The symptoms of palpitation are very common and in most case entirely benign in nature, however they can also be associated with more serious heart conditions
How do I tell whether the palpitations are serious?
If your palpitations are associated with other symptoms such as chest pain, breathlessness or blacking out, then they may be more serious and you should seek some medical advice. Also if you already have previous heart problems, such as prior heart attacks then palpitations could be a cause for concern. Some heart rhythm conditions are inherited so a family history of arrhythmia, unexplained black outs and unexplained sudden death may be relevant. Some drugs such as certain antibiotics and others used to treat psychiatric illness may alter the electrical conduction pattern of the heart and make dangerous heart rhythms more likely. This is especially the case in individuals that have an inherited susceptibility to this type of problem (long QT syndrome).
How do I find out whether my palpitations are a cause for concern?
Once you book your consultation with Wiltshire cardiology, we will discuss the nature of your symptoms, take a thorough history and if, this is a face to face consultation, conduct a detailed cardiovascular examination. We will also undertake a 12 lead ECG if you have not already had a recent one by your GP. The definitive diagnosis of palpitations is made by having a recording of your heart when you are experiencing the symptoms. These tests include: 24 or longer hour tapes, Cardiac memo, Alivecor recorder and implantable loop recorder. The frequency of your symptoms will determine which of these tests is better for you. We may also undertake an ultrasound of your heart or echocardiogram in order to determine whether there is any structural abnormality of the heart that would put you at higher risk of arrhythmia.
Will I always need so many other tests?
At Wilshire cardiology we are used to seeing people with palpitations and are experienced at trying to determine which are potentially serious. Therefore we will take the time to explain to you the nature of your symptoms and in some cases no further tests may be needed. If we do recommend further tests then we will explain which is better suited for obtaining the answers for you.
What if my palpitations are not due to a problem with the heart rhythm?
If there is no abnormality with the heart rhythm then that is reassuring and the cause may be due other physical or mental health reasons.
In some people there is an abnormal response of the autonomic nervous system (ANS) which regulates bodily functions without you having to think about them. In normal circumstances, when we stand up from lying down, gravity will cause blood to pool lower in the body, potentially reducing the blood supply to the heart and brain. Of course that does not happen because the ANS regulates our blood pressure and heart rate to compensate for the changes associated with posture. However problems with the ANS can cause an abnormally high heart rate especially with standing and this is known as postural orthostatic tachycardia or (POTS).
What happens if my palpitations are due to a heart rhythm problem (arrhythmia)?
Rhythm problems that arise from the top chambers of the heart or supraventricular tachycardias (SVT) are not life threatening and treatment is predominantly focused on improving your symptoms. The most common of these is Atrial fibrillation which is an irregular heartbeat. The other types of SVT are usually due to short circuits within the conduction system of the heart or between the upper and lower chambers of the heart. Depending on your symptoms and the type of short circuit you may not need any regular treatment. In the majority tablets can control the symptoms but sometimes an electrophysiological study of the heart is needed to diagnose and potentially get rid of the short circuit, known as ablation.
Some short circuits or potential substrates for dangerous rhythms can be diagnosed from the 12 lead ECG. These are inherited conditions and include: 1) short circuits between the upper and lower chambers of the heart also known as “pre-excitation” or “Wolf – Parkinson- White syndrome”. 2) Problems with the re-setting of the electrical signal known as long QT syndrome.
Rhythm disturbances that arise from the lower chambers of the heart (ventricular tachycardia) can be more serious and are usually associated with scarring of the heart muscle, structural abnormalities of the heart, prior heart attacks and previous cardiac surgery. They can also be associated with inherited disorders of the electrical channels, the muscle structure or the cell connections within the heart. These types of rhythm disturbance can lead to a cardiac arrest and sudden death. The treatment of these involves tablets but also may require the fitting of an internal cardiac defibrillator (ICD).
Should I be worried about ectopic beats?
Ectopic beats can arise from any part of the heart and in most cases are not causes for concern. If they are very frequent and associated with structural heart abnormalities then treatment may be needed. If they are causing very troublesome symptoms then we can recommend some tablets such as betablockers which may help alleviate the symptoms. Very rarely frequent ectopic beats arising from a localised area in the ventricles can lead to deterioration in the heart function and so getting rid of them with an ablation may be helpful.