As a cardiologist I see a large number of patients who suffer from palpitations or rapid heart beat. Often this is eventually diagnosed as being related to anxiety. However I have also diagnosed a number of different heart rhythm problems (called arrhythmia) causing these symptoms. One of these is supraventricular tachycardia, also known as âSVTâ for short.
What is supraventricular tachycardia?
Supraventricular tachycardia is a heart rhythm problem that can present as very rapid heart palpitations. While it is not a dangerous condition it can cause a great deal of discomfort for the sufferer. Supraventricular tachycardia occurs due to a short circuit in the heart causing a very fast heartbeat from time to time. It can develop at any age but usually affects younger people under the age of 40. Symptoms of sudden onset of a rapid heartbeat (palpitations) can develop without warning. Accompanying symptoms of chest tightness and dizziness/lightheadedness may also occur. If it feels as if your heart is beating extremely rapidly like machine gun fire, or as if you have suddenly had a fright (without actually being frightened) it is possible you may be suffering from supraventricular tachycardia.
The important thing to understand about this heart condition, and something that your cardiologist should also tell you, is that it is not dangerous. It will certainly make you feel unwell and cause a great deal of distress but it is a benign arrhythmia. 1 in 4 people have a short circuit within their heart that can potentially develop into this condition, but very few actually do develop into this. The reasons for this are not clear.
If you think you have SVT then it is vital to get an ECG done at the time you are having palpitations. That is the only way to make a diagnosis. Sometimes this can be done by attending Accident and Emergency and having an ECG in the emergency room. Many paramedics have a portable ECG machine and can arrange this if they are called during one of these episodes. Most of the time further investigations are necessary to make a diagnosis. When I see a patient with palpitations I take a detailed history of their symptoms â what the palpitations feel like, how often they occur, how long they last and if anything brings them on. A 12 lead ECG is an important test to conduct during an initial consultation because this may provide clues to the underlying cause. Conditions such as Wolff-Parkison-White syndrome (an inherited condition with an electrical short circuit within the heart) can be diagnosed with an ECG. An echocardiogram (heart ultrasound) is also useful to confirm that the heart is structurally normal. Ultimately ambulatory (portable) ECG monitoring may be necessary to make the diagnosis.
Once the diagnosis is made what can your cardiologist do to treat this? There are a number of treatment options and ultimately the choice is made as a result of collaboration between the cardiologist and the patient. If the symptoms are very infrequent, such as occurring every few months, then doing nothing is a reasonable option. As long as the echocardiogram is normal and the symptoms are not causing too much discomfort or causing the patient to faint or pass out it is perfectly acceptable to treat this conservatively.
Another option is drug treatment and a number of medications have been used to successfully treat supraventricular tachycardia. Beta-blockers can be effective but may have side effects such as tiredness, cold hands and feet or erectile problems in men. Flecainide is another alternative that can also work for some patients. It is not safe to use in patients with pre-existing coronary artery disease or heart failure and it can cause side effects such as headaches, rashes and bowel disturbance. Calcium channel blockers such as Verapamil are also sometimes used. These can also cause bowel disturbance and dizziness or light-headedness.
Drug treatment is not a permanent cure and some patients do not like the idea of taking regular medication for the rest of their lives, particularly for a benign condition. Radiofrequency ablation or catheter ablation is therefore another treatment option available. This is an invasive procedure with some small risks but offers the potential for a permanent cure for symptoms. Not every cardiologist is capable of performing this procedure â a patient will need to get the help of an electrophysiologist. The procedure involves passing a wire from the vein in the leg into the heart and using tiny electrical impulses to identify the short circuit in the heart. Once identified a small burn is applied to the short circuit to remove it. The procedure carries a small risk of injury to the artery or vein in the leg and a very small risk of requiring a pacemaker.
If you are a patient suffering from palpitations and think you might have supraventricular tachycardia it might be worth contacting a cardiologist and getting this assessed in more detail.
