Dr Boon Lim is a renowned cardiologist and expert in the diagnosis and treatment of arrhythmias. He recently presented at the 2018 Heart Rhythm Congress in Birmingham, which is the largest meeting of heart rhythm specialists in the UK. Here he presented on several topics, including the fascinating link between arrhythmia (specifically ectopic beats) and anxiety.
How can arrhythmias cause anxiety?
The heart is made up of four chambers – the right and left atria and the right and left ventricles. High up in the right atrium we have the sinus node (also known as the sinoatrial (SA) node), which is responsible for the start of all heart activity.
What happens when our heart rate increases (too fast)?
When we are faced with stress or an impending threat, which in its most primal form might have been a sabre-toothed cat, we react with a fight or flight response, activating the autonomic nervous system. Both reactions bring about an increase in adrenaline, in turn increasing our heart rate.
To put this into context of this day and age, whilst we are not facing encounters with dangerous animals, we do face other mental stressors, such as forgetting to buy your mother-in-law a birthday gift or running late for an important meeting! Although we know that these do not pose the same level of threat as a sabre-toothed cat, our heart does not know the difference.
Therefore, the response is the same – adrenaline kicks in, increasing both the sinus node rate (chronotropy) and strength of cardiac contraction (inotropy), which can be discerned as a palpitations.
An example of an atrial ectopic beat (red arrow) seen on an electrocardiogram (ECG) rhythm strip:
An example of a ventricular ectopic beat (blue arrow) seen on an electrocardiogram (ECG) rhythm strip:
Patients experience this as a strong, forceful and rapid heartbeat that is often misconstrued as a heart rhythm abnormality. We experience the same response when exercising, but in this context it does not cause us concern as we recognise that it is a natural response to adrenaline. Hence, when we experience this sensation without physical exertion, many of us feel concerned about our cardiac health.
What happens when our heart rate is too slow?
On the flipside, sometimes our heart rate can be too slow (bradycardia). This might be because of progressive scarring in the electrical system of the heart, which is a problem that does require intervention, such as a pacemaker. This problem may cause dizziness and fainting in the patient. A slow heart might also result from an individual being extremely physically fit. For example, a resting night time heart rate of 35 beats per minute in a triathlete might be entirely normal for that person, so long as they are not experiencing symptoms of fainting or dizziness.
What are ectopic beats?
The sinus node is our heart’s natural pacemaker. It works continuously, providing approximately 100,000 beats per day, slowing down at night and being faster when required in the daytime. The heart is also created with what we describe as ‘back-up’ pacemaker cells which are what cause ectopic beats. These cells can occur in places other than the sinus node and can trigger single jumps in heartbeat, distinct from a stress response or exercise. This is what an ectopic beat is. They can occur in the top chambers (atria) or the bottom chambers (ventricles), and we are able to detect where in the heart they come from using an ECG (electrocardiogram).
Hence, ectopic beats are a series of extra beats and they are a diagnosis and not a symptom, whereas palpitations are a patient’s description of their symptoms. Ectopic beats may or may not be associated with symptoms and equally palpitations may or may not be associated with ectopic beats.
So, how does anxiety fit into all of this?
Arrhythmias are heart rhythm abnormalities and come in the form of:
- Ectopic beats
- Atrial fibrillation
- Atrial flutter
- Supraventricular tachycardia
- Ventricular arrhythmia
All these heart rhythm abnormalities can be triggered by activation of the autonomic nervous system.
A feeling of anxiety can be triggered by a single ectopic beat, for example, initiating the fight or flight response, in turn increasing levels of adrenaline which can give you more palpitations. Hence, adrenaline can induce arrhythmias, in turn increasing your anxiety because the arrhythmia is perceived as something to fear, and so on and so forth. Here we describe a vicious cycle that can be a challenge for cardiologists to manage.
Can anxiety contribute to arrhythmias?
Yes. As described above, when we are stressed or anxious our heart perceives this as an impending threat, triggering our fight or flight response in which adrenaline is released, which can trigger arrhythmia, in turn triggering an additional release of adrenaline.
What tools can be used to investigate palpitations and to diagnose arrhythmias?
- ECG (electrocardiogram)
- Prolonged heart rate monitoring (24-hour, 48-hour Holter monitoring)
- 7-day event recorder (also known as a 7 day ECG)
- Implantable loop recorder
- Self-monitoring smart devices (e.g. the Kardia mobile)
- Tilt test
- Treadmill test
What strategies can a patient adopt to help themselves?
This will depend entirely on what the diagnosis is. If your palpitations are due to benign ectopic beats, confirmed by your cardiologist, then usually no medical treatment is needed and you will be reassured of this. However, you may continue to experience significant symptoms and it may be worth engaging in a form of relaxation therapy which you are comfortable with. This could include:
- Deep breathing exercises
- Visualisation therapy
- Seeing a psychologist to develop care strategies to deal with the symptoms as they arrive.
What support and treatment can a cardiologist provide?
A cardiologist can provide the following support, depending on the diagnosis:
- If a heart rhythm abnormality is detected, your cardiologist can recommend a specific treatment, which may include drug therapy or catheter ablation.
- If your palpitations are due to benign ectopic beats, then the simple reassurance from your cardiologist of a benign and safe diagnosis usually goes a long way in alleviating symptoms.
If you are concerned about your cardiac health, make an appointment with an expert.