Abnormal heart rhythms - getting to the heart of the matter
You're lying in bed trying to drift off to sleep and suddenly your heart starts thumping away nineteen to the dozen. Should you panic? Usually not, but it's worth checking with your doctor if your symptoms 'tick any of the boxes' below.
Palpitations is the medical name for feeling your heart beating. When you're out and about, you rarely notice your heart, even though it beats, on average, 55-80 times a minute every hour of every day of your life. But once you notice your heart beating it can be hard to ignore. What's more, if you notice your heart beating and it makes you anxious, your body will immediately produce adrenaline - the 'fight or flight' hormone that helps you cope in an emergency. One of its many effects? A speeding up of your heart rate. If your heart wasn't really pumping before you panicked, it is now - a vicious cycle sets in.
Lots of my patients talk about palpitations when they mean their heart is beating in a way that's not normal for them. It may be faster than usual; it may feel as if it's beating harder than normal, or fluttering; or it may be irregular.
Sinus tachycardia is one of the most common findings among patients of mine who come in with palpitations. This means a normal rhythm but a fast rate, so technically it's not an abnormal heart rhythm. Common causes include:
- Large amounts of coffee
- Medicines including over-the-counter cold remedies or frequent doses of asthma 'reliever' inhalers
- Anxiety. A very frequent cause of this type of palpitation, it's more common when you're at rest or in bed
- Overactive thyroid. Other symptoms include losing weight, feeling anxious, getting diarrhoea or feeling the heat.
Extra systoles are occasional extra beats with a regular background rhythm. These extra beats are more common at rest and tend to disappear with any exertion. It's worth seeing your GP if you get them regularly, but you're unlikely to need any treatment.
Supraventricular tachycardia (SVT) causes an extremely fast, regular beat of 150 beats a minute or more. A condition of the 'youngsters' among us, it's common in young adulthood. It can be associated with breathlessness, chest tightness and dizziness and can last anything from minutes to hours, so can be scary. It's always worth checking with your doctor if you get these symptoms. Some people don't need treatment and others can control episodes by taking a tablet just when the rapid heartbeat starts. Occasionally, though, depending on the cause of the SVTs, surgery to cure the problem may be recommended.
Heart block can cause a very slow but regular heart rate, with your heart beating at only 40 beats a minute or even less. Symptoms relate to lack of oxygen to the body because your heart isn't beating fast enough, and include shortness of breath, tiredness and feeling faint or light-headed. There are different degrees of heart block and the condition may not need treating. Other causes of slow heart rate include taking beta-blocker tablets and being very fit.
Atrial fibrillation (AF) causes an 'irregularly irregular' heart rhythm and usually a fast heart rate. It gets more common with age and may affect up to 1.2 million people in the UK. Breathlessness, dizziness and angina may accompany your palpitations, but you may get no symptoms at all. It's very important to have your condition monitored even if you feel well, because without treatment AF greatly increases your risk of stroke.
It's worth remembering that the vast majority of people who go to see their GP with palpitations are given the all clear. We live in a stressful world, and very often a fast heart rate is just your body trying to cope. So, unless you have any of the 'red flags' in this blog or the attached links, you can probably relax - it just might help!