Supraventricular Tachycardia (SVT)
What is Supraventricular Tachycardia?
Supraventricular Tachycardia (SVT) is an abnormally fast heart rhythm resulting from abnormal electrical fibers in the heart. When a patient develops SVT they often suffer from palpitations, dizziness or even fainting. Although these symptoms are disturbing, SVT is generally not life-threatening.
There are 3 common types of SVT. They are atrio-ventricular nodal reentrant tachycardia (AVNRT), atrio-ventricular reciprocating tachycardia (AVRT), and atrial tachycardia (AT). The diagnosis is made with an EKG or an event monitor. The treatment may include medications or even ablation. Ablation is usually curative.
What are the symptoms when a person has supraventricular tachycardia?
Supraventricular tachycardia may suddenly occur and suddenly pass with stretches of normal heart rates in between. Episodes can last a few minutes to a few days. Some people don’t experience any symptoms.
This condition becomes a problem if it happens frequently and is ongoing. This is especially true if you have heart damage or other medical problems. Some symptoms, such as shortness of breath, may be related to other serious health conditions.
These are typical signs of SVT:
- Rapid heartbeat
- Shortness of breath
- Fluttering in the chest
- A pounding sensation in the neck
- Fainting or near fainting
different types of supraventricular tachycardia
There are three main types of supraventricular tachycardia:
- Atrioventricular nodal reentrant tachycardia (AVNRT) — This is the most common form of SVT and occurs in males and females of any age. It is more likely to afflict young women.
- Atrioventricular reciprocating tachycardia (AVRT) — This is the second most common form of SVT, usually afflicting younger people.
- Atrial tachycardia — This form is more common in patients who have heart disease. Atrial tachycardia, unlike the other two forms, does not involve the AV node.
There are other forms of SVT, although they are less common:
- Sinus tachycardia
- Inappropriate sinus tachycardia
- Multifocal atrial tachycardia
- Nonparoxysmal junctional tachycardia
What are the risk factors for a person to develop supraventricular tachycardia?
Supraventricular tachycardia is the most common type of arrhythmia in infants and children. It is also much more prevalent in pregnant women. Here are all the factors that increase a person’s likelihood of developing supraventricular tachycardia:
- Coronary artery disease, other heart problems, and previous heart surgery — If you have heart damage, such as narrowed heart arteries, abnormal valves, heart failure, or other issues, this increases your risk.
- Age — Some types of SVT are more common in people middle-aged and older.
- Congenital heart disease — People born with a heart abnormality have a higher risk of rhythm issues.
- Overactive or underactive thyroid
- Anxiety or emotional stress
- Drugs and supplements, usually cold, allergy, and asthma drugs
- Physical fatigue
- Obstructive sleep apnea
- Smoking and illegal drugs such as cocaine and amphetamines
How can Premier Cardiology diagnose supraventricular tachycardia?
Dr. Ahuja specializes in supraventricular tachycardia and he will likely be your lead physician. To diagnose SVT, Dr. Ahuja will first conduct a physical examination and review of your symptoms. From there he will likely order any of these heart-monitoring tests:
- Electrocardiogram — In an ECG, sensors are attached to your chest to detect electrical activity in your heart. Timing and duration of each electrical pulse are measured.
- Holter monitor — This is a portable ECG that you wear for a day or more and it records your heart’s activity.
- Event monitor — You keep your event monitor available, attaching it and pressing a button when you have symptoms.
- Echocardiogram — A hand-held transducer placed on your chest uses sound waves to produce images of your heart’s size, structure, and motion.
- Implantable loop recorder — This device is implanted under the skin on your chest and it detects abnormal heart rhythms.
If these tests don’t find your arrhythmia, Dr. Ahuja may order other tests such as stress tests to try and trigger an SVT episode.
Is there any way I can prevent supraventricular tachycardia?
Things such as being overly fatigued or drinking too much coffee can trigger this heart condition. If you’ve had an episode, you can try to prevent future episodes with these actions:
- Get more exercise
- Eat a heart-healthy diet
- Don’t smoke
- Stay at a healthy weight
- Limit alcohol consumption
- Reduce stress in your life
- Get enough sleep
- Be cautious with over-the-counter allergy and cold or cough medications
- Don’t use stimulant drugs such as cocaine
How is supraventricular tachycardia treated?
Most patients with supraventricular tachycardia don’t require treatment, but if you have prolonged or frequent episodes treatment will likely be necessary. At Premier Cardiology, Dr. Ahuja may use these methods:
- Catheter ablation — Dr. Ahuja threads a catheter through a blood vessel to your heart. Electrodes on the catheter tip then deliver heat, extreme cold, or radiofrequency energy to the heart to damage a small spot of tissue and create an electrical block along the path that is causing your irregular electrical signals.
- Medications — We may prescribe medications that either control your heart rate or restore normal rhythm.
- Carotid sinus massage — Gentle pressure is applied on the neck at the spot where the carotid artery splits into two branches. This can release certain chemicals that slow the heart rate.
- Cardioversion — A shock is delivered to your heart through paddles or patches on the chest. This shock can return the electrical impulses to normal.
- Vegal maneuvers — Certain actions can be done on your part during an episode, such as holding your breath and straining, dunking your face in ice water, or coughing. These affect the nervous system that controls your heartbeat, the vagus nerves, and this can slow your heart rate.
What is An ablation?
Catheter ablation is a procedure where Dr. Ahuja uses heat to remove the abnormal electrical cells in your heart that are causing your SVT. The procedure is relatively safe and highly effective (almost always curative). Dr. Ahuja will discuss the risks, benefits, and alternatives of using medications versus ablation for your specific type of SVT.
You must have been fasting that day, and Dr. Ahuja will review pre-operative instructions and medications with you before the procedure. The ablation takes place in a special room called an electrophysiology (EP) lab while you are mildly sedated. The room is similar to an operating room. Nurses and anesthesiology will introduce themselves, and prep you for the procedure. After your groin area is prepared and cleaned under sterile conditions, mild conscious sedation and local anesthesia will be given near the groin area. Dr. Ahuja will insert 3-4 small wires called catheters through the veins in your groins, and pass them into different chambers of your heart. These catheters will both send and record electric signals to and from the heart and record its electrical activity.
Then, Dr. Ahuja uses these signals to figure out where an arrhythmia is coming from so he knows where to perform the ablation in the heart. Rarely the ablation is not performed because your specific arrhythmia may be better treated with medications or may be coming from critical areas of the heart where ablation would be considered “risky.” After the procedure begins, it usually lasts about two hours.
Recovery from surgery is relatively quick. Almost all patients can go home the next morning after spending one night in the hospital for observation. Dr. Ahuja reviews all post-operative instructions and appointments after the procedure.