The heart is made up of four chambers, two upper (the atria) and two lower (the ventricles). The rhythmic contractions of these chambers are responsible for efficient flow of blood, and therefore the delivery of oxygen, around the body. Ensuring these contractions in the heart are on time is the sinoatrial node (SA node); think of this a pacemaker for the heart.
Tachycardia is a form of abnormal heartbeat in which the heart beats faster than usual. Commonly, people with tachycardia do not experience many restrictions to daily life. However, tachycardia can cause discomfort such as dizziness and shortness of breath.
There are many different types of tachycardia but the wider term of supraventricular tachycardia (SVT) relates to impulses that originate above the ventricle. The most common of these tachycardias are sinus tachycardia (caused by work, exercise etc.), atrial flutters/fibrillations and paroxysmal SVT (PSVT). PSVT is the condition discussed most when SVTs are mentioned due to the sudden onset. These occur when the the electrical impulses from the SA node are abnormal, causing the heart to beat quicker.
This can result in the chambers being in a constant state of contraction and, therefore, they do not have the ability to fill with blood at their maximum capacity. In turn, this leads to a reduction in blood, and therefore oxygen, delivery around the body.
As with many conditions, symptoms differ depending on the individual and whether they have a history of medical issues. Sometimes with SVT there are no symptoms at all. However, when symptoms do arise, they can can last anywhere from 30 seconds to a couple of days.
Whilst experiencing SVT, some of the symptoms are…
Loss of breath
Use of illegal stimulants, caffeine and alcohol can also be responsible for SVT and, therefore, those diagnosed will be advised to avoid these.
If symptoms become bothersome and contribute to generally feeling unwell, individuals should seek a doctor’s advice immediately.
There are home remedies which individuals can do to help halt SVT when an episode starts.
The valsalva manoeuvre - Whilst holding your nose, with your mouth and eyes shut, exhale like you are inflating a balloon for 10 - 15 seconds.
Cold water immersion - Fill a bowl with ice cold water, hold your breath and submerge your face in the water for 5 -10 seconds.
Did you know? The valsalva manoeuvre was named after a 17th century Italian doctor, Antonio Maria Valsalva.
Before a doctor can diagnose SVT, they will check symptoms and do a thorough examination. This usually involves a blood pressure test and a listen to the heartbeat, using a stethoscope.
Another means of testing for SVT is a electrocardiogram (ECG). An ECG is a test to show whether the electric activity in your heart is normal or not. This can be done in a GP surgery and is painless. Other means of treatments are drugs, a cardioversion (a small electric shock on the heart, resetting the rhythm back to normal) and a catheter ablation (tubes inserted through veins which lead to the heart which stop abnormal electrical signals by creating scar tissue at the site of irregular activity.)
If individuals don’t suffer from other heart disorders, SVT is rarely life threatening. However, the best way of avoiding it is to maintain a healthy diet, undertake regular exercise and avoid smoking and heavy drinking.
This article is intended to inform and give insight but not treat, diagnose or replace the advice of a doctor. Always seek medical advice with any questions regarding a medical condition.