Supraventricular tachycardia (SVT), also referred to as paroxysmal SVT or PSVT, is a type of abnormal heart rhythm (arrhythmia) in which the heart beats too fast. When the heart beats too fast, it may not function effectively, resulting in less oxygen-rich blood reaching the tissues throughout the body. SVT often starts and ends suddenly, and may not be associated with any symptoms. However, many people do experience symptoms as a result of SVT, including palpitations (rapid, noticeable heartbeats), dizziness, fainting, shortness of breath and chest pain (angina).
In most cases, SVT occurs because of a malfunction of the heart’s electrical system. The heart is made up of two upper chambers (atria) and two lower chambers (ventricles). In a normal heartbeat, an electrical impulse originates from an area in the right atrium called the sinus node. This impulse travels first to the atria, causing them to contract and pump blood into the ventricles. The electrical impulse then continues along its circuit to the atrioventricular (AV) node, where it pauses to allow the ventricles to fill with blood. Finally, the impulse reaches the ventricles, signaling them to contract and pump blood out to the lungs and the body. In SVT, the electrical malfunction occurs at some point before the electrical signal reaches the ventricles.
Common types of SVT include:
- Atrial fibrillation (A-fib) is a type of tachycardia that occurs when multiple circuits of disorganized electrical activity in the atria replace the organized electrical activity that is normally generated by the heart. The result is fibrillation (quivering) of the atria instead of regular heartbeats.
- Atrioventricular (AV) node re-entry tachycardia (AVNRT) is the most common form of SVT. Patients with this arrhythmia do not have structural problems with their heart, but have two pathways that can channel impulses to and from the AV node. Under certain conditions, usually following a premature beat, these pathways can form an electrical circuit, which starts a rapid heart rhythm.
- Wolff-Parkinson-White syndrome (WPW) is an arrhythmia caused by an extra electrical pathway from the atria to the ventricles. Although some people with WPW do not have any symptoms, others experience palpitations, dizziness and angina. Rarely, WPW can be life threatening.
SVT often first occurs in children and young adults. Many controllable factors can increase the risk of SVT episodes, including stress and anxiety, certain medications, excessive alcohol or caffeine consumption, smoking and the use of illegal stimulants such as cocaine.
Otherwise healthy individuals experiencing SVT without significant symptoms may not require any treatment. However, if you have an underlying related health condition or significant symptoms, treatment may be necessary. This may take the form of medication therapy, pacemaker implantation or cardiac ablation, in which radiofrequency energy is used to destroy very tiny areas of tissue that give rise to abnormal electrical signals.
Emory’s Arrhythmia treatment program is one of the most comprehensive and innovative clinics for heart rhythm disorders in the country. In addition to offering state-of-the-art care for the full range of heart rhythm disorders, we also operate heart rhythm screening clinics at a number of locations throughout the Atlanta area. If you have experienced an irregular heartbeat, palpitations, a racing heartbeat or other troubling heart irregularities, we recommend that you schedule an appointment with one of our specialty-trained nurse practitioners, who will begin a comprehensive screening evaluation to determine whether you need follow-up care with an electrophysiologist.
About Dr. DeLurgio
David DeLurgio, MD , is a professor of medicine at Emory University School of Medicine and director of Electrophysiology at Emory Saint Joseph’s Hospital. Dr. DeLurgio earned his medical degree from the University of California Los Angeles School of Medicine, where he also completed his residency and fellowship training. He joined Emory Healthcare in 1996 and served as the director of the Arrhythmia Center and Electrophysiology Lab at Emory University Hospital Midtown before relocating to Emory Saint Joseph’s Hospital.
About Emory’s Arrhythmia Center
Emory’s Arrhythmia Center is one of the most comprehensive and innovative clinics for heart rhythm disorders in the country. Our electrophysiologists have been pioneers in shaping treatment options for patients with arrhythmias such as atrial fibrillation, as well as for those with congestive heart disease. Our specialized electrophysiology (EP) labs host state-of-the-art equipment, including computerized three-dimensional mapping systems to assist with the ablation of complex arrhythmias, and an excimer laser system to perform pacemaker and defibrillator lead extractions.
Patients with devices, whether implanted at Emory or elsewhere, have access to Emory’s comprehensive follow-up care. Patients benefit from remote monitoring, quarterly atrial fibrillation support groups and 24-hour implantable cardiac device (ICD) and pacemaker monitoring services. Inpatient telemetry and coronary care units, as well as outpatient care and educational support of patients with pacemakers and ICDs, complete Emory’s comprehensive range of arrhythmia treatments and services.