In most cases, if you experience short episodes of supraventricular tachycardia (SVT) with no symptoms, your health care professional may recommend no therapy. However, if you do have symptoms, frequent episodes, or both, then you will likely require treatment.
Common symptoms are palpations, dizziness, chest pain, and feeling like you are about to faint. Treatment for SVT includes drug therapies and catheter ablation. What type of therapy is best for you depends on the type of SVT you have, how often it occurs, and the degree and length of symptoms. The goal is to prevent these abnormal heart rhythms and to limit your symptoms.
Sudden, Short Episode of SVT
The initial treatment for a sudden episode of SVT is vagal maneuvers, such as bearing down, coughing, or holding your breath. These actions can slow the electrical impulses in your heart and may stop the SVT. Sometimes, your health care professional also may prescribe medications such as beta-blockers to be taken as needed during these sudden, short episodes.
If the SVT episode continues, you should go to the emergency room. There, you might be given a medicine called adenosine, which also slows the electrical impulses in the heart, or another medicine called verapamil. In rare cases, you might require an electrical shock to get your heart back into a normal rhythm.
Long-Term SVT Treatment
You and your health care team will consider many factors — including your values and the type of SVT you have — when deciding what treatment is right for you. You should be actively involved in making the decision between medical therapy and ablation therapy. Each type of SVT responds differently to medical therapy, and has different risks and success rates with ablation. Also, the risk of side effects from drug therapy should be weighed against the risks and benefits of ablation.
Drug Therapy: Patients are prescribed daily medications to help prevent SVT episodes from occurring or to slow heart rates during SVT episodes. Commonly prescribed medications are beta-blockers, verapamil, and digoxin. Occasionally, other medications called antiarrhythmic drugs (such as amiodarone or sotalol) may be given to prevent SVT episodes from occurring.
Ablation Therapy: Ablation can be considered as a primary, first-line therapy for certain types of SVT, and it may also be considered if you often have symptoms with medical therapy. During an ablation, a small tube called a catheter is placed through a vein typically in your leg, then guided to your heart. An electrical study is done to find the area in your heart causing the electrical problems that trigger SVT. Your doctor then destroys this area either by burning or freezing that part of the heart.
Ablation is very successful in treating specific forms of SVT. However, ablation therapy does have some rare, but serious procedural risks. Be sure to talk about the procedure and its risks with your physician. Together with your health care team, you will find a treatment that is right for you.
Exams and Tests
To find out whether you have supraventricular tachycardia (SVT), your health care professional will ask you questions about your symptoms and do a physical exam. These questions might include:
- What, if anything, triggers your fast heart rate (exercise, stress, caffeine)?
- What symptoms do you feel? Do they come on slowly or quickly? How long do they last?
- Do your heartbeats feel regular or uneven?
- Does anyone in your family have heart problems?
During the physical exam, your health care professional will listen to your heart and lungs. He or she will also feel your thyroid gland on your neck. Other tests may include blood tests and an echocardiogram (an ultrasound that shows pictures of the heart in motion).
Your health care professional will do a test called an electrocardiogram (ECG). During an ECG, sticky patches (electrodes) are placed on your chest. Each electrode has a wire that goes to the ECG machine so it can record your heart’s electrical activity over several minutes. If you are in SVT, the machine will be able to measure it.
If you do not have an episode of SVT during your health visit, you may be given an electrocardiogram that you can wear at home. You may be asked to wear:
- A Holter monitor. This is a small ECG that records your heart’s electrical activity for 24 hours.
- An event monitor. You can wear this for longer than a Holter monitor and press a button when you feel symptoms. The monitor will record details for the next few minutes while you’re feeling the fast heart rate. You may be asked to wear this for days or weeks depending on how frequently you have symptoms.
If you’re ECG shows SVT, your health care professional may want to perform an electrophysiology study to determine what type of SVT you have and what is causing it. This test is performed in the hospital. You will be sedated and wires are passed through your veins into your heart. Your doctor can look at different sections of your heart and see how they are sending electrical signals.