What is supraventricular tachycardia. How is SVT diagnosed. What are the common symptoms of SVT. What causes supraventricular tachycardia. How is SVT treated. Can SVT be prevented. Who is at risk for developing SVT.

Understanding Supraventricular Tachycardia: An Overview

Supraventricular tachycardia (SVT) is a type of heart rhythm disorder characterized by an abnormally fast heartbeat originating from the upper chambers of the heart. This condition can significantly impact a person’s quality of life and, in some cases, lead to more serious complications. In this comprehensive article, we’ll explore the intricacies of SVT, its symptoms, causes, and various treatment options.

SVT is defined as a dysrhythmia that originates at or above the atrioventricular (AV) node. It typically presents with a narrow complex on an electrocardiogram (QRS < 120 milliseconds) and a heart rate exceeding 100 beats per minute (bpm). One common subtype of SVT is atrioventricular nodal reentrant tachycardia (AVNRT), also known as paroxysmal SVT, which often manifests with a ventricular rhythm of around 160 bpm.

The Epidemiology of Supraventricular Tachycardia

SVT affects a significant portion of the population, with varying prevalence across different demographic groups. The incidence of atrioventricular nodal reentrant tachycardia is approximately 35 per 10,000 person-years, or 2.29 per 1000 persons. This makes it the most common non-sinus tachydysrhythmia in young adults.

Interestingly, certain groups are more susceptible to developing SVT:

• Women have a two times higher risk of developing paroxysmal SVT compared to men.
• Older individuals have a five times higher risk compared to younger people.
• SVT is the most common symptomatic dysrhythmia in infants and children.
• Children with congenital heart disease are at increased risk for SVT.

In children younger than 12 years old, an accessory atrioventricular pathway causing reentry tachycardia is the most common cause of SVT.

Pathophysiology: How SVT Affects the Heart

To understand SVT, it’s crucial to grasp the normal electrical conduction through the heart. The process begins at the sinoatrial (SA) node, which acts as the heart’s natural pacemaker. From there, the electrical signal travels through the atrial tissue to the atrioventricular (AV) node.

At the AV node, a critical delay of approximately 100 milliseconds occurs. This pause allows the atria to contract and empty before ventricular contraction. After passing through the AV node, the electrical signal continues through the His-Purkinje system, distributing to the left and right bundles, and ultimately to the myocardium of the ventricles.

In SVT, this normal conduction pattern is disrupted. The most common mechanism is an orthodromic reentry phenomenon, where:

1. Normal anterograde electrical conduction occurs from the atria to the AV node to the ventricles.
2. Retrograde conduction then occurs via an accessory pathway from the ventricles back to the atria.

This creates a circular electrical pattern that can sustain itself, leading to the rapid heart rate characteristic of SVT.

Recognizing the Symptoms of Supraventricular Tachycardia

SVT can manifest with a variety of symptoms, ranging from mild discomfort to more severe presentations. Common symptoms include:

• Anxiety
• Palpitations
• Chest discomfort
• Lightheadedness
• Syncope (fainting)
• Dyspnea (shortness of breath)

In more severe cases, patients may present with:

• Shock
• Hypotension
• Signs of heart failure
• Exercise intolerance

It’s important to note that some individuals may be asymptomatic, with the tachycardia discovered incidentally during routine screening, such as at pharmacies or through fitness trackers.

The onset of SVT is typically abrupt and can be triggered by various factors, including physical activity or emotional stress. This sudden onset is a key characteristic that distinguishes SVT from other forms of tachycardia.

Diagnosing Supraventricular Tachycardia

Accurate diagnosis of SVT is crucial for appropriate management. The primary diagnostic tool for SVT is the electrocardiogram (ECG). Characteristic ECG findings in SVT include:

• Narrow complex, regular tachycardia
• Heart rate typically between 180 to 220 beats per minute
• Absence of detectable P waves in most cases

If P waves are detectable, other conditions such as sinus tachycardia, atrial fibrillation, or atrial flutter should be considered as potential diagnoses.

Physical examination of a patient with SVT may be relatively unremarkable, especially in those with good cardiovascular reserve. However, patients beginning to decompensate may show signs of congestive heart failure, such as:

• Bibasilar crackles in the lungs
• Presence of a third heart sound (S3)
• Jugular venous distention

Treatment Approaches for Supraventricular Tachycardia

The management of SVT involves both acute treatment to terminate the episode and long-term strategies to prevent recurrence. Treatment options include:

Acute Management

• Vagal maneuvers: Simple techniques like the Valsalva maneuver or carotid sinus massage can be attempted first.
• Pharmacological interventions: Medications such as adenosine, beta-blockers, or calcium channel blockers may be used to terminate the SVT episode.
• Electrical cardioversion: In hemodynamically unstable patients, synchronized cardioversion may be necessary.

Long-term Management

• Chronic medication: Beta-blockers or calcium channel blockers may be prescribed for long-term prevention.
• Catheter ablation: This minimally invasive procedure can eliminate the abnormal electrical pathway causing SVT.
• Lifestyle modifications: Avoiding triggers like caffeine, alcohol, and stress can help reduce SVT episodes.

The choice of treatment depends on the frequency and severity of episodes, patient preferences, and any underlying cardiac conditions.

Prevention Strategies and Risk Factors for SVT

While not all cases of SVT can be prevented, certain strategies can help reduce the risk of episodes or their frequency:

• Avoiding known triggers such as caffeine, alcohol, and nicotine
• Managing stress through relaxation techniques or counseling
• Maintaining a healthy lifestyle with regular exercise and a balanced diet
• Adhering to prescribed medications and treatment plans

Understanding the risk factors for SVT can also help in its management. Key risk factors include:

• Age: Both the very young and older adults are at increased risk
• Gender: Women are more susceptible than men
• Congenital heart defects
• Family history of SVT or other arrhythmias
• Certain medical conditions, such as thyroid disorders or lung diseases

The Role of Interprofessional Care in SVT Management

Effective management of SVT often requires a coordinated effort from an interprofessional healthcare team. This team may include:

• Cardiologists specializing in electrophysiology
• Emergency medicine physicians for acute management
• Primary care providers for ongoing care and monitoring
• Nurses trained in cardiac care
• Pharmacists to assist with medication management

The collaboration of these professionals ensures comprehensive care, from accurate diagnosis to effective treatment and long-term management. Regular communication among team members is crucial for optimizing patient outcomes and quality of life.

In conclusion, supraventricular tachycardia is a complex cardiac condition that requires thorough understanding and careful management. By recognizing its symptoms, understanding its mechanisms, and implementing appropriate treatment strategies, healthcare providers can significantly improve the lives of those affected by SVT. As research in this field continues to advance, we can expect even more refined and effective approaches to managing this common arrhythmia.

Supraventricular Tachycardia – StatPearls – NCBI Bookshelf

Continuing Education Activity

Supraventricular tachycardia (SVT) is a dysrhythmia originating at or above the atrioventricular (AV) node and is defined by a narrow complex (QRS &lt; 120 milliseconds) at a rate &gt; 100 beats per minute (bpm). Atrioventricular nodal reentrant tachycardia (AVNRT), also known as paroxysmal SVT, is defined as intermittent SVT without provoking factors, and typically presents with a ventricular rhythm of 160 bpm. This activity describes the cause, pathophysiology, and presentation of SVT and stresses the importance of an interprofessional team in its management.

Objectives:

• Describe the pathophysiology of SVT.

• Outline the presentation of a patient with SVT.

• Summarize the treatment options for SVT.

• Review the importance of improving care coordination among interprofessional team members to improve outcomes for patients affected by SVT.

Access free multiple choice questions on this topic.

Introduction

Supraventricular tachycardia (SVT) is a dysrhythmia originating at or above the atrioventricular (AV) node and is defined by a narrow complex (QRS < 120 milliseconds) at a rate > 100 beats per minute (bpm). 

Atrioventricular nodal reentrant tachycardia (AVNRT), also known as paroxysmal SVT, is defined as intermittent SVT without provoking factors, and typically presents with a ventricular rhythm of 160 bpm. [1][2][3]

Etiology

The differential diagnosis includes sinus tachycardia, atrial tachycardia, junctional tachycardia, atrial fibrillation, atrial flutter, or multi atrial tachycardia.

In patients susceptible to SVT, medications, caffeine, alcohol, physical or emotional stress, or cigarette smoking can trigger SVT.[4][5]

Epidemiology

The incidence of atrioventricular nodal reentrant tachycardia is 35 per 10,000 person-years or 2.29 per 1000 persons and is the most common non-sinus tachydysrhythmia in young adults. Women have two times higher risk of developing paroxysmal SVT in comparison to men, and older individuals have five times higher compared to a younger person. 

SVT is the most common symptomatic dysrhythmia in infants in children. Children with congenital heart disease are it increased risk for SVT. In children younger than 12 years old, an accessory atrioventricular pathway causing reentry tachycardia is the most common cause of SVT. [6][7]

Pathophysiology

The electrical conduction through the heart starts at the sinoatrial (SA), which then travels to the surrounding atrial tissue to the atrioventricular (AV) node. At the AV node, the electrical signal is delayed for approximately 100 milliseconds. Once through the AV node, the electrical signal travels through the His-Purkinje system, which distributes the electrical signal to the left and right bundles, and ultimately to the myocardium of the ventricles. The pause at the AV node allows the atria to contract and empty before ventricular contraction.

The most common cause of SVT is an orthodromic reentry phenomenon, which occurs when the tachycardia is secondary to normal anterograde electrical conduction from the atria to the AV node to the ventricles, with retrograde conduction via an accessory pathway from the ventricles back to the atrial.

A narrow QRS complex (< 120 milliseconds) indicates the ventricles are being activated superior to the His bundle via the usual pathway through the His-Purkinje system. This implies that the arrhythmia originates from the sinoatrial (SA) node, the atrial myometrium, the AV node, or within the His bundle. 

In the rarer antidromic conduction, conduction passes from the atria to the ventricles via the accessory pathway, then returns retrograde through the AV node to the atria. [8]

History and Physical

Patients typically present with anxiety, palpitations, chest discomfort, lightheadedness, syncope, or dyspnea. In some cases, a patient may present with shock, hypotension, signs of heart failure, lightheadedness, or exercise intolerance. Some may present without symptoms, and the tachycardia is discovered during routine screening, for example, at pharmacies or with fitness trackers. The onset is typically abrupt and can be triggered by stress secondary to physical activity or emotional stress.

Physical exam, aside from tachycardia, is typically normal in a patient with good cardiovascular reserve. Patients beginning to decompensated may show signs of congestive heart failure, (bibasilar crackles, a third heart sound (S3), or jugular venous distention).

Evaluation

The first test to evaluate for SVT is to obtain an ECG.  [9][10][11]

ECG characteristic includes a narrow complex, regular tachycardia with a rate of approximately 180 to 220 beats per minute. P waves are not detectable. If P waves are detectable, consider sinus tachycardia or atrial fibrillation or flutter as a potential etiology.

The remainder of the evaluation is focused on trying to isolate a cause of SVT, for example, electrolyte abnormalities, anemia, or hyperthyroidism. Consider checking a digoxin level of patients using that drug, as SVT can be secondary to supratherapeutic digoxin concentrations.

Treatment / Management

Once an SVT is identified, the next objective is to assess for hemodynamic instability. Signs of hemodynamic instability include hypotension, hypoxia, shortness of breath, chest pain, shock, evidence of poor end-organ perfusion, or altered mental status.[12][13]

If a patient is unstable, consider immediate synchronized cardioversion. It is important that the defibrillator is placed in a sync mode, typically indicated by a marker on the defibrillator screen noting each QRS complex. This mode allows the defibrillator to deliver the shock synchronized with the QRS complex, to prevent the shock from being delivered during the T-wave, while the heart is depolarized. The R on T phenomenon can cause polymorphic ventricular tachycardia. In adults, the starting dose for synchronized cardioversion is 100 joules to 200 joules and can be increased in a stepwise fashion if unsuccessful at lower doses. In children, the first dose for cardioversion is 0.5 J/kg to 1 J/kg and can be doubled to 2 J/kg on subsequent attempts.

In a stable patient, attempted vagal maneuvers while preparing for chemical cardioversion, including the Valsalva maneuver and carotid massage. Both of these act to stimulate the parasympathetic system. This slows impulse formation at the sinus node, slows conduction velocity at the AV node, lengthens the AV node refractory period, and decreases ventricular inotropy.

The Valsalva maneuver is performed expiring against a closed glottis, and needs to be held for 10 seconds to 15 seconds. Patients can achieve this by bearing down as if they are going to have a bowel movement. Younger children can blow out through a syringe or straw. In infants and toddlers, ice packs applied to the face can cause a similar vagal reaction. Although ocular pressure can cause a vagal reaction, it is not recommended as it can lead to a ruptured globe if excessive force is used.

Carotid massage involves placing the patient in a supine position with the neck extended, and applying pressure to one carotid sinus for approximately 10 seconds. Carotid massage is contraindicated in patients with carotid bruit, or who have had a prior transient ischemic attack or cerebral vascular accident in the last three months. Carotid massage is not indicated in children or infants.

The REVERT trial demonstrated that a modified Valsalva maneuver, with the traditional Valsalva maneuver being held for 60 seconds at a 45 degree recumbent position, then being switched to a recumbent position with the legs held at 45 degrees angle for 15 seconds, was more efficacious than the standard Valsalva maneuver. [14]

If vagal maneuvers are ineffective, treat with adenosine. Adenosine is rapidly metabolized in the periphery, and therefore must be given as a rapid push through a large, ideally peripheral, intravenous route. The initial dose is 6 mg intravenously (IV) (pediatric dose 0.1 mg/kg, maximum dose 6 mg). If the initial dose is ineffective, adenosine may be dosed again at 12 mg IVP (pediatric dose 0.2 mg/kg, maximum dose 12 mg). The second dose of adenosine 12 mg IVP may be repeated one additional time if there is no effect. Each dose of adenosine needs to be flushed rapidly with 10 mL to 20 mL normal saline. Often two person administration, with one person administering the adenosine at a proximal IV port, and a second person flushing the IV line via a distal port immediately after adenosine administration, is required to adequate flush in the adenosine.

Consider reducing the adenosine dose to 3 mg IVP if the patient is currently receiving carbamazepine or dipyridamole, is the recipient of a heart transplant, or adenosine is being given through a central line.

In the event of a patient with a misinterpreted rhythm, the administration of adenosine can help slow down the heart rate long enough to determine if the cause of the patient’s tachycardia is due to a different narrow complex tachycardia (e.g., atrial fibrillation or atrial flutter). 

If adenosine fails, second line medications include diltiazem (0.25 mg/kg IV loading dose followed by 5mg/hr to 15 mg/hr infusion), esmolol (0.5 mg/kg IV loading dose, then 0. 5 mg/kg/min up to 0.2 mg/kg/min, will need to repeat bolus for every up-titration), or metoprolol (2.5 mg to 5 mg IV every two to five minutes, not to exceed 15 mg over 10 to 15 minutes). 

These measures still prove ineffective, overdrive pacing, or pacing the heart at a faster rate than its native rhythm, can help discontinue SVT. However, there is an increased risk of ventricular tachycardia or fibrillation, and therefore should be used with caution and with cardioversion immediately available.

Patients with recurrent SVT without a pre-excitation syndrome may require long-term maintenance with oral beta-blockers or calcium to maintain sinus rhythm. They may also require radio-frequency ablation if an accessory pathway is identifiable. Patients should be counseled on how to perform vagal maneuvers on their own for long-term management of recurrent SVT. [2][15]

Differential Diagnosis

Complications

Complications are either related to the medications or radiofrequency ablation. Since the latter is an invasive procedure the following complications may occur:

• Hematoma

• Pseudoaneurysm of the artery

• Bleeding

• Myocardial infarction

• Heart block and the need for a pacemaker

• Stroke

• Death

Pearls and Other Issues

Wolff-Parkinson-White (WPW) syndrome is an example of an accessory pathway syndrome, characterized by a short PR interval (< 120 ms), a prolonged QRS (> 100 ms), and a delta wave (a slurred upstroke to the QRS complex). Patients with WPW can occasionally present with an antidromic reentry tachycardia, in which the accessory pathway is the anterograde limb, and the AV node is the retrograde pathway. These typically present with a wide complex, regular, and extremely rapid tachycardia. In these cases, AV nodal blocking agents like adenosine are contraindicated because they can allow unopposed retrograde conduction through the accessory pathway, leading to ventricular tachycardia or fibrillation. Procainamide (15 mg/kg to 18 mg/kg loading dose, 1 mg/min to 4 mg/min maintenance infusion) is the first-line treatment of this tachydysrhythmia, followed by amiodarone (150 mg over 10 minutes, followed by 360 mg over six hours, then 540 mg over 18 hrs). For ventricular rates greater than 250 bpm, consider synchronized cardioversion at 100 J  to 200 J.

Enhancing Healthcare Team Outcomes

Paroxysmal SVT is usually managed by an interprofessional team of healthcare workers dedicated to cardiac arrhythmias. Since these arrhythmias cannot be prevented, the focus is on treatment. Besides the cardiologist, the role of the nurse and pharmacist is indispensable. The patient should be educated about this arrhythmia and the potential risk of sudden death if left untreated. For patients with SVT managed with medications, the pharmacist should assist the team by educating the patient on potential adverse effects, drug interactions and the need for close follow-up. The patient should also be educated on the option of radiofrequency ablation, which has a much higher success rate compared to medications. [16](Level II)

Outcomes

For the most part, patients with paroxysmal SVT have a good outcome with treatment. However, a small number of patients with WPW do have a tiny risk of sudden death. In patients with SVT arising due to a structural defect in the heart, the prognosis depends on the severity of the defect, but in healthy people with no structural defects, the prognosis is excellent. Pregnant women who develop SVT do have a slightly higher risk of death if there is an unrepaired heart defect. [17][18][19](Level V)

Review Questions

• Access free multiple choice questions on this topic.

• Comment on this article.

Figure

Lead II (2) Supraventricular tachycardia SVT. Contributed by Wikimedia Commons, James Heilman, MD (Public Domain-Self)

Figure

A graphical representation of the Electrical conduction system of the heart showing the Sinoatrial node, Atrioventricular node, Bundle of His, Purkinje fibers, and Bachmann’s bundle. Contributed by Wikimedia Commons (Public Domain)

Figure

This is a recording of the termination of a supraventricular tachycardia at about 130/min. which terminates and leaves a pause and then sinus bradycardia. This is a from of “tachy/brady” syndrome where a tachycardia is followed by a bradycardia. Contributed (more…)

References

1.

Karmegeraj B, Namdeo S, Sudhakar A, Krishnan V, Kunjukutty R, Vaidyanathan B. Clinical presentation, management, and postnatal outcomes of fetal tachyarrhythmias: A 10-year single-center experience. Ann Pediatr Cardiol. 2018 Jan-Apr;11(1):34-39. [PMC free article: PMC5803975] [PubMed: 29440828]

2.

Brubaker S, Long B, Koyfman A. Alternative Treatment Options for Atrioventricular-Nodal-Reentry Tachycardia: An Emergency Medicine Review. J Emerg Med. 2018 Feb;54(2):198-206. [PubMed: 29239759]

3.

Lundqvist CB, Potpara TS, Malmborg H. Supraventricular Arrhythmias in Patients with Adult Congenital Heart Disease. Arrhythm Electrophysiol Rev. 2017 Jun;6(2):42-49. [PMC free article: PMC5517371] [PubMed: 28835834]

4.

Massari F, Scicchitano P, Potenza A, Sassara M, Sanasi M, Liccese M, Ciccone MM, Caldarola P. Supraventricular tachycardia, pregnancy, and water: A new insight in lifesaving treatment of rhythm disorders. Ann Noninvasive Electrocardiol. 2018 May;23(3):e12490. [PMC free article: PMC6931545] [PubMed: 28833859]

5.

Corwin DJ, Scarfone RJ. Supraventricular Tachycardia Associated With Severe Anemia. Pediatr Emerg Care. 2018 Apr;34(4):e75-e78. [PubMed: 28376069]

6.

Khurshid S, Choi SH, Weng LC, Wang EY, Trinquart L, Benjamin EJ, Ellinor PT, Lubitz SA. Frequency of Cardiac Rhythm Abnormalities in a Half Million Adults. Circ Arrhythm Electrophysiol. 2018 Jul;11(7):e006273. [PMC free article: PMC6051725] [PubMed: 29954742]

7.

Amara W, Montagnier C, Cheggour S, Boursier M, Gully C, Barnay C, Georger F, Deplagne A, Fromentin S, Mlotek M, Lazarus A, Taïeb J. , SETAM Investigators. Early Detection and Treatment of Atrial Arrhythmias Alleviates the Arrhythmic Burden in Paced Patients: The SETAM Study. Pacing Clin Electrophysiol. 2017 May;40(5):527-536. [PubMed: 28244117]

8.

Ho RT. A narrow complex tachycardia with atrioventricular dissociation: What is the mechanism? Heart Rhythm. 2017 Oct;14(10):1570-1573. [PubMed: 28965610]

9.

Tabing A, Harrell TE, Romero S, Francisco G. Supraventricular tachycardia diagnosed by smartphone ECG. BMJ Case Rep. 2017 Sep 11;2017 [PMC free article: PMC5612203] [PubMed: 28899884]

10.

L’Italien K, Conlon S, Kertesz N, Bezold L, Kamp A. Usefulness of Echocardiography in Children with New-Onset Supraventricular Tachycardia. J Am Soc Echocardiogr. 2018 Oct;31(10):1146-1150. [PubMed: 30076010]

11.

Jain D, Nigam P, Indurkar M, Chiramkara R. Clinical Significance of the Forsaken aVR in Evaluation of Tachyarrhythmias: A Reminder. J Clin Diagn Res. 2017 Jun;11(6):OM01-OM04. [PMC free article: PMC5535428] [PubMed: 28764236]

12.

Chung R, Wazni O, Dresing T, Chung M, Saliba W, Lindsay B, Tchou P. Clinical presentation of ventricular-Hisian and ventricular-nodal accessory pathways. Heart Rhythm. 2019 Mar;16(3):369-377. [PubMed: 30103070]

13.

Voerman JJ, Hoffe ME, Surka S, Alves PM. In-Flight Management of a Supraventricular Tachycardia Using Telemedicine. Aerosp Med Hum Perform. 2018 Jul 01;89(7):657-660. [PubMed: 29921358]

14.

Appelboam A, Reuben A, Mann C, Gagg J, Ewings P, Barton A, Lobban T, Dayer M, Vickery J, Benger J., REVERT trial collaborators. Postural modification to the standard Valsalva manoeuvre for emergency treatment of supraventricular tachycardias (REVERT): a randomised controlled trial. Lancet. 2015 Oct 31;386(10005):1747-53. [PubMed: 26314489]

15.

Mironov NY, Golitsyn SP. [Overwiew of New Clinical Guidelines for the Diagnosis and Treatment of Supraventricular Tachycardias (2015) of the American College of Cardiology/American Heart Association/Society for Heart Rhythm Disturbances (ACC/AHA/HRS)]. Kardiologiia. 2016 Jul;56(7):84-90. [PubMed: 28290912]

16.

Ordonez RV. Monitoring the patient with supraventricular dysrhythmias. Nurs Clin North Am. 1987 Mar;22(1):49-59. [PubMed: 3644291]

17.

Balli S, Kucuk M, Orhan Bulut M, Kemal Yucel I, Celebi A. Transcatheter Cryoablation Procedures without Fluoroscopy in Pediatric Patients with Atrioventricular Nodal Reentrant Tachycardia: A Single-Center Experience. Acta Cardiol Sin. 2018 Jul;34(4):337-343. [PMC free article: PMC6066944] [PubMed: 30065572]

18.

Alsaied T, Baskar S, Fares M, Alahdab F, Czosek RJ, Murad MH, Prokop LJ, Divanovic AA. First-Line Antiarrhythmic Transplacental Treatment for Fetal Tachyarrhythmia: A Systematic Review and Meta-Analysis. J Am Heart Assoc. 2017 Dec 15;6(12) [PMC free article: PMC5779032] [PubMed: 29246961]

19.

Upadhyay S, Marie Valente A, Triedman JK, Walsh EP. Catheter ablation for atrioventricular nodal reentrant tachycardia in patients with congenital heart disease. Heart Rhythm. 2016 Jun;13(6):1228-37. [PubMed: 26804568]

Disclosure: Laryssa Patti declares no relevant financial relationships with ineligible companies.

Disclosure: John Ashurst declares no relevant financial relationships with ineligible companies.

How it affects the heart

Supraventricular tachycardia (SVT) is a heart rhythm disorder that originates in the heart’s upper chambers, called the atria. There are several types of SVT. The condition is not usually life threatening, although it can be. Often, people with SVT may experience discomfort and require treatment.

The most common type of SVT is atrioventricular node reentrant tachycardia (AVNRT), affecting 0.23% of people.

The primary symptom of SVT is a rapid heartbeat. SVT can cause the heart to beat so quickly that it does not have enough time to fill with blood between beats. This can reduce blood flow to the body and, in severe cases, lead to fainting or a heart attack.

Keep reading to learn more about how SVT can affect the heart, the symptoms it can cause, and how doctors might treat the condition.

SVT is a heart rhythm disorder or arrhythmia affecting the atria, the top chambers of the heart. The condition can cause people to have episodes of a very fast heart rate.

The typical adult heart rate is 60–100 beats per minute (bpm). In an SVT episode, the heart rate goes over 100 bpm and may even reach 220 bpm or higher.

How does the heart beat?

The heart has four chambers. The two upper ones are the atria and the two lower ones are the ventricles. People refer to the sinoatrial (SA) node, which is in the right atrium, as the pacemaker.

In a typical heartbeat, the electrical signal that controls heart rate begins in the SA node. The signal travels through the atria to the atrioventricular (AV) node in the lower right atrium. From there, it passes into the ventricles, allowing them to contract and pump blood.

In people with SVT, the electrical signal that initiates the heartbeat comes from somewhere above the ventricle other than the SA node. As a result, the heart rate accelerates, shortening the time the ventricles have to fill with blood. This prevents the heart from pumping blood efficiently to the body.

These episodes of abnormal heart rhythm may last for just a few seconds or go on for several hours. They can also occur often or only once in a while.

Learn more about the structure and function of the heart.

Types of SVT include:

• AVNRT: This is the most common type of SVT, accounting for around two-thirds of cases. It happens when the electrical signal travels in a circle, passing through the AV node twice.
• Atrioventricular reciprocating tachycardia: This is another common type of SVT that occurs when a second connection between the upper and lower chambers exists. The electrical impulses then move more quickly.
• Atrial fibrillation (A-fib): The most common type of heart arrhythmia, A-fib will affect more than 12 million people in the United States by 2030, according to estimates. In A-fib, the beating in the atria is irregular, the heart can race, and there can be a higher risk of clots leading to stroke.
• Atrial flutter (AFL): With AFL, the atria beat abnormally fast, up to 300 bpm, but the ventricle usually has a regular pattern and conducts at half or another fraction of the rate of the atria. AFL creates a distinct “saw tooth” pattern on an electrocardiogram (ECG), a test doctors use to diagnose arrhythmias.
• Paroxysmal SVT: These are SVT episodes that occur intermittently and usually self-terminate.
• Atrial tachycardia: With this kind of SVT, the electrical signal originates from somewhere other than the SA node.

There is often no specific cause of SVT.

Some people have atypical electrical pathways in their hearts from birth. Other times, SVT can develop later in life because of certain triggers, including:

• stress
• stimulant medications
• caffeine
• thyroid disease
• alcohol
• cigarette smoking
• electrolyte abnormalities
• a pulmonary embolism
• infection

The symptoms a person with SVT may experience can depend on how quickly their heart is beating.

They may include:

• palpitations
• lightheadedness
• sweating
• shortness of breath
• chest pain
• fainting

Doctors begin by taking a medical history to help diagnose SVT heart problems. They may ask about symptoms and any family history of heart conditions. They may also check for a pulse in the neck arteries.

Next, they will perform a physical exam, listen to the heart with a stethoscope, and check for abnormal heart sounds. They may also check the thyroid gland in the neck.

Imaging tests, such as a chest X-ray or echocardiogram, can be useful to detect the cause of heart problems. A doctor may also use cardiac MRI in rare cases.

ECG

If doctors suspect SVT, they will likely order an ECG test.

During an ECG, the doctor places sticky electrodes on the chest. The electrodes connect to an ECG machine, which measures the heart’s electrical activity and produces a readout on paper.

A doctor may also provide an ECG device for the person to wear at home. This may be a small Holter monitor to record the heart’s electrical activity for 24 hours or up to 2 weeks.

Alternatively, it may be a wearable event monitor that the individual wears for as long as needed until an episode of SVT happens. An implantable loop recorder is a small monitor that a doctor will fit under a person’s skin to record their heart rhythm for up to 3 years.

If the ECG shows SVT, a doctor may recommend an electrophysiology study to determine the type and cause. This test takes place in the hospital and requires sedation. During the study, doctors insert catheters through the veins in the leg and thread them to the heart. Then, they use electrical signals to stimulate the heart and record the electrical activity on an ECG.

Learn more about abnormal ECG results here.

The goal of treatment for SVT is to slow the heart rate and restore a normal heart rhythm. Treatment options may include medications and surgery. The treatment course may depend on:

• the type of SVT
• the frequency of SVT episodes
• the severity and duration of symptoms — people often require no treatment if their symptoms are mild

Brief episodes of SVT

A person can use vagal maneuvers, such as bearing or squeezing down, coughing, or holding their breath, to slow the electrical impulses in the heart.

A doctor may prescribe medications, such as beta-blockers, for a person to take as needed for SVT episodes. These drugs also slow the electrical impulses in the heart.

If the SVT does not resolve, people should visit the emergency room. A doctor may recommend a medication called adenosine or another called verapamil to help the heart beat correctly.

In rare cases, an individual may need an electrical shock to return the heart to a typical rhythm.

Long-term treatment

If someone experiences SVT episodes often, a doctor may prescribe daily medication to prevent them. Beta-blockers and verapamil are common choices. These drugs help slow down the heart’s electrical impulses. Antiarrhythmic medications that are more effective than beta-blockers include flecainide and sotalol.

Doctors may recommend ablation therapy if medications do not work or are unsuitable. With ablation, a doctor uses heat, cold, or radiofrequency waves to destroy the electrical pathway in the heart that is causing SVT.

Ablation is usually successful in treating specific forms of SVT. However, it has some rare but serious risks.

SVT can be unpredictable and can occur without warning. One way to help manage the condition is to avoid triggers. These may include:

• alcohol
• cigarettes
• caffeine
• drugs such as cocaine and methamphetamine
• herbal supplements

It is also important for people to get regular sleep and share any new symptoms with their doctor.

They should consider attending regular checkups and should not use any new medications or supplements without talking with a doctor first.

Generally, SVT is not life threatening, and most people have good outcomes with treatment. The outlook is excellent in healthy people with no structural defects of the heart.

However, in some cases, SVT may lead to complications, including:

• hematoma
• bleeding
• heart attack
• heart block and the need for a pacemaker
• stroke

In some instances, the condition can even be fatal.

SVT is a type of abnormal heart rhythm that happens when electrical signals make the heart beat too fast. It can cause a racing heart, chest pain, and shortness of breath.

SVT is not typically life threatening, but it can sometimes cause complications. Prompt treatment with medications and surgery can help alleviate the symptoms. People who notice any changes in their heart health should talk with their doctors about any issues they are experiencing.

Supraventricular tachycardia (SVT) | First Clinical Medical Center

Supraventricular tachycardia (SVT) is a condition in which the heart suddenly begins to beat much faster than normal. It is usually not serious, but some people may need treatment.

Causes of supraventricular tachycardia (SVT)

SVT occurs when the electrical system that controls the heart’s rhythm is not working properly.

This causes the heart to suddenly start beating much faster. Then it can slow down dramatically.

The normal resting heart rate is 60-100 beats per minute (bpm). But in SVT, the heart rate suddenly rises above 100 beats per minute. This can happen when you are resting or exercising.

Supraventricular tachycardia (SVT) symptoms

Supraventricular tachycardia means that your heart suddenly starts beating faster.

This is:

• usually lasts a few minutes but can sometimes last several hours
• may occur several times a day or once a year – it depends on the situation
• may be triggered by fatigue, caffeine, alcohol or drugs – but often no obvious cause
• can occur at any age, but often first begins in children and young adults—many people have their first symptoms between the ages of 25 and 40.

You may not have any other symptoms, but sometimes people with this condition also:

• experiencing chest pain
• feel weak, short of breath or dizzy
• feeling tired
• feeling unwell or sick

Important tip: see your doctor if you have a fast heartbeat.

It is important to get tested. You may need a test, such as an electrocardiogram (ECG), to find out what’s going on.

Call an ambulance immediately if:

• you are diagnosed with SVT and the attack lasts more than 30 minutes
• you have sudden shortness of breath with chest pain

You need to go to the hospital immediately for treatment.

What you can do to help with supraventricular tachycardia (SVT)

If your SVT attacks last only a few minutes and don’t bother you, you may not need treatment.

Disease Prevention

You can make lifestyle changes to reduce the chance of seizures, such as:

• reduce the amount of caffeine or alcohol you drink
• stop or reduce smoking
• make sure you get enough rest.

Your doctor can also give you some simple methods to help stop seizures when they happen.

Treatment of supraventricular tachycardia (SVT) in hospital

Supraventricular tachycardia is rarely life threatening. But you may need treatment in the hospital if you continue to have prolonged seizures.

This may include:

• medicines to treat SVT attacks – pills or by vein
• cardioversion – a small electric shock to the heart to help it return to a normal rhythm
• catheter ablation, a procedure in which thin tubes are inserted through a vein or artery into the heart to correct an electrical problem; in most patients, this solves the problem permanently.

How to diagnose supraventricular tachycardia (SVT)

How to diagnose supraventricular tachycardia (SVT) – advice from a cardiologist

Recording 24/7

Find the center and
write down for diagnostics

+7(812)209-29-49

• home
• org/ListItem”>
  Supraventricular tachycardia

Quick navigation

Supraventricular tachycardia (SVT) is a condition in which a person’s heart suddenly begins to beat much faster than normal. Diagnosis and treatment of supraventricular tachycardia is performed by a cardiologist.

Causes of supraventricular tachycardia

Supraventricular tachycardia is a common type of arrhythmia. It often begins for the first time in people between the ages of 25 and 40. The main features of this type of arrhythmia is a sharp increase in heart rate and the preservation of a pathological rhythm for a certain period of time. Normal resting heart rate is between 60 and 90 beats per minute. But in SVT, the heart rate suddenly exceeds 100 beats per minute.

Symptoms of supraventricular tachycardia

• palpitations usually last a few minutes but can sometimes last several hours
• palpitations may occur several times a day
• arrhythmias may be triggered by fatigue, caffeine, alcohol, or drugs, but there is often no obvious trigger
• have chest pain
• have weakness, shortness of breath or dizziness
• there is a feeling of nausea.

Diagnosis of supraventricular tachycardia

The patient should have an electrocardiogram (ECG) to evaluate the state of the heart rhythms. According to the results of the diagnosis, it may be necessary to consult a cardiologist.

Treatment

If SVT episodes last only a few minutes, the patient may not need treatment. A person can make lifestyle changes to reduce the chance of episodes, for example:

• reducing the amount of caffeine or alcohol consumed
• smoking cessation or reduction.

Treatment by a cardiologist may include:

• drugs to control SVT episodes
• cardioversion
• catheter ablation.

Author: Telegina Natalya Dmitrievna

Specialization: Therapist

Where does the appointment: MRI Center and Clinic RIORIT

Share:

The best specialists in St. Petersburg with a rating of 4.

5+

Teslya Olga Vladimirovna

Specialization: Ultrasound doctor, Cardiologist, Functional diagnostics doctor

Medical experience: since 1998

Place of admission: ID-Clinic Infectious Diseases Clinic, EXPERT Gastro-Hepatocenter, Center for the Prevention and Control of AIDS and Infectious Diseases

Bortulev Sergey Alexandrovich

Specialization: Therapist, Cardiologist, Doctor of Functional Diagnostics

Medical experience: since 2006

Where does the appointment: ID-Clinic Infectious Diseases Clinic

Kolesnikova Tamara Nikolaevna

Specialization: Therapist, Cardiologist, Occupational Pathologist

Medical experience: since 2009

Where does the reception: LDC Svetlana, Center Almazov Parkhomenko

Bezrukov Yuri Nikolaevich

Specialization: Therapist, Gastroenterologist, Cardiologist

Medical experience: since 1990

Where does the reception: LDC Svetlana

Slesareva Ekaterina Gennadievna

Specialization: Therapist, Ultrasound Doctor, Cardiologist, Allergist, Immunologist, Physiotherapist

Medical experience: since 2009

Where does the reception: MC Baltmed Ozerki, City Hospital No. 40 Kurortny District

Nurgazizova Albina Kamilievna

Specialization: Therapist, Ultrasound doctor, Cardiologist, Functional diagnostics doctor

Medical experience: since 2012

Where does the reception: MC Baltmed Ozerki, Clinic Medpomoshch 24

Kuznetsova Olga Nikolaevna

Specialization: Cardiologist, Doctor of Functional Diagnostics

Medical experience: since 2007

Where does the reception: MC Baltmed Ozerki

Chuldum Saglay Saluuevna

Specialization: Therapist, Cardiologist

Medical experience: since 2018

Where does the reception: MC Baltmed Ozerki

Pushkareva (Vinogradova) Irina Alekseevna

Specialization: Cardiologist, Pediatrician

Medical experience: since 2009

Place of admission: MC Baltmed Ozerki, Clinical Hospital No. 31, Medswiss Gakkelevskaya

Pesotskaya Oksana Vladimirovna

Specialization: Therapist, Gastroenterologist, Cardiologist, General Practitioner

Medical experience: from 1991 years old

Where does the reception: MC Baltmed Ozerki

Semyonova Irina Nikolaevna

Specialization: Cardiologist, Doctor of Functional Diagnostics

Medical experience: since 1990

Where does the reception: MC Baltmed Ozerki

Karpova Anna Aleksandrovna

Specialization: Therapist, Gastroenterologist, Cardiologist

Medical experience: since 1999

Where does the reception: MC Baltmed Ozerki

Bernhardt Edward Robertovich

Specialization: Cardiologist

Medical experience: since 1995

Where does the reception: MC Baltmed Ozerki

Ivanova Olga Viktorovna

Specialization: Therapist, Cardiologist

Medical experience: since 2009

Where does the reception: MC Baltmed Ozerki

Sakhartov Dmitry Borisovich

Specialization: Therapist, Cardiologist, Doctor of Functional Diagnostics

Medical experience: since 1999

Where does the reception: MC Medicenter, City Pokrovskaya Hospital

Abdrakhmanova Sultanpashsha

Specialization: Cardiologist, Doctor of Functional Diagnostics

Medical experience: since 2020

Where does the reception: MC Medicenter, VMT Pirogova Fontanka

Ablikova Marina Petrovna

Specialization: Therapist, Cardiologist, General Practitioner

Medical experience: since 2008

Where does the reception: MC Medicenter, Medicus Koroleva

Tajibaev Pulod Jahongirovich

Specialization: Cardiologist, Doctor of Functional Diagnostics

Medical experience: since 2005

Where does the reception: MC Medpomoshch 24 Zanevsky

Maslova Julia Vladimirovna

Specialization: Cardiologist

Medical experience: since 1993

Where does the reception: MC Medpomoshch 24 Balkansky, Polyclinic Almazov on Akkuratova

Levin Vladimir Mikhailovich

Specialization: Therapist, Cardiologist

Medical experience: since 2012

Where does the reception: MC Medpomoshch 24 Balkan

Krivonosov Denis Sergeevich

Specialization: Cardiologist

Medical experience: since 2005

Where does the reception: MC March

Rishko Irina Gennadievna

Specialization: Therapist, Cardiologist

Medical experience: since 1989

Where does the reception: MC Energo Kyiv, Polyclinic No. 1 of the Russian Academy of Sciences (RAS)

Taran Andrey Dmitrievich

Specialization: Cardiologist, Somnologist

Medical experience: since 2001

Where does the reception: MC Energo Kyiv

Golikova Rimma Vladimirovna

Specialization: Therapist, Cardiologist

Medical experience: since 1985

Where does the reception: MC Energy of Health, Clinic of Faculty Therapy of the First Med

Kogai Sergey Valerievich

Specialization: Therapist, Cardiologist

Medical experience: since 2016

Where does the appointment: MC Long Vita, Gatchina Clinical Interdistrict Hospital, MC Polis on Danube

Sitnikov Anton Alexandrovich

Specialization: Therapist, Gastroenterologist, Cardiologist

Medical experience: since 2016

Where does the reception: SM-Clinic on Udarnikov, Trauma Center on Kolomyazhsky

Chizhova Svetlana Nikolaevna

Specialization: Therapist, Gastroenterologist, Hepatologist, Cardiologist

Medical experience: from 1980 years old

Where does the reception: SM-Clinic on the Danube, Omega Medical Center

Dolzhenkova Irina Nikolaevna

Specialization: Ultrasound doctor, Gynecologist, Cardiologist

Medical experience: since 1990

Where does the appointment: SM-Clinic on Vyborgsky, First Family Clinic of St. Petersburg on Kolomyazhsky

Baidina Valentina Alexandrovna

Specialization: Therapist, Cardiologist

Medical experience: since 1999

Where does the reception: SM-Clinic on Malaya Balkanskaya

Bogomolov Sergey Nikolaevich

Specialization: Therapist, Cardiologist, Somnologist

Medical experience: since 1998

Where does the appointment: SM-Clinic on Udarnikov, Clinic and Department of Propaedeutics of Internal Diseases of the Military Medical Academy

Buryanova Natalya Pavlovna

Specialization: Therapist, Cardiologist

Medical experience: since 2000

Where does the reception: SM-Clinic on Vyborgsky

Zavyalov Vasily Vasilyevich

Specialization: Therapist, Cardiologist

Medical experience: since 2002

Where does the reception: SM-Clinic on Vyborgsky

Shcheglova Raisa Aleksandrovna

Specialization: Cardiologist, Rheumatologist

Medical experience: since 1994

Where does the reception: SM-Clinic on Vyborgsky

Aibash Faisal

Specialization: Cardiologist

Medical experience: since 2011

Where does the reception: SM-Clinic on Malaya Balkanskaya

Binatova Natalya Yurievna

Specialization: Cardiologist

Medical experience: since 1992

Where does the reception: SM-Clinic on Marshal Zakharov

Bozhenko Sergey Antonovich

Specialization: Cardiologist

Medical experience: since 1988

Where does the reception: SM-Clinic on Udarnikov

Bredikhin Dmitry Anatolyevich

Specialization: Cardiologist

Medical experience: since 2005

Where does the reception: SM-Clinic on Marshal Zakharov

Butch Anna Valentinovna

Specialization: Cardiologist

Medical experience: since 2009

Where does the appointment: SM-Clinic on Vyborgsky, Polyclinic Almazov on Akkuratova

Danilova Irina Vitalievna

Specialization: Therapist, Cardiologist

Medical experience: since 1994

Where does the appointment: SM-Clinic on the Danube, City Polyclinic No. 109

Dudetsky Andrey Sergeevich

Specialization: Therapist, Ultrasound Doctor, Cardiologist, Somnologist

Medical experience: since 2012

Where does the reception: SM-Clinic on Danube

Dumcheva Tatyana Alexandrovna

Specialization: Therapist, Cardiologist

Medical experience: since 2014

Where does the reception: SM-Clinic on Malaya Balkanskaya

Ivanova Olga Yurievna

Specialization: Cardiologist

Medical experience: since 2013

Where does the reception: SM-Clinic on Danube

Kiselev Alexey Alexandrovich

Specialization: Cardiologist, Nephrologist

Medical experience: since 2007

Where does the reception: SM-Clinic on Udarnikov

Lyukina Maria Yurievna

Specialization: Cardiologist, Nephrologist

Medical experience: since 2016

Where does the reception: SM-Clinic on Udarnikov

Murtazina Rimma Rashidovna

Specialization: Therapist, Cardiologist

Medical experience: since 2007

Where does the reception: SM-Clinic on Marshal Zakharov

Nazarova Elena Eduardovna

Specialization: Therapist, Cardiologist

Medical experience: since 2008

Where does the reception: SM-Clinic on Marshal Zakharov

Privalova Svetlana Olegovna

Specialization: Therapist, Cardiologist

Medical experience: since 2011

Where does the reception: SM-Clinic on Danube

Rzayeva Kular Mammadovna

Specialization: Cardiologist

Medical experience: since 2015

Where does the reception: SM-Clinic on Vyborgsky

Torchinskaya Elena Vladimirovna

Specialization: Cardiologist

Medical experience: since 2000

Where does the reception: SM-Clinic on Vyborgsky

Kazachenko Alexander Alexandrovich

Specialization: Therapist, Cardiologist, Somnologist

Medical experience: since 2003

Where does the reception: SM-Clinic on Udarnikov

Meshcheryakova Irina Fedorovna

Specialization: Cardiologist, Pediatrician

Medical experience: since 1999

Where does the reception: SM-Clinic on Udarnikov

Nikitin Ilya Valentinovich

Specialization: Therapist, Gastroenterologist, Cardiologist, Nutritionist

Medical experience: since 1996

Where does the appointment: Dr. Pel’s Clinic

Petrov Alexander Nikolaevich

Specialization: Cardiologist

Medical experience: since 1989

Where does he receive: Clinic of Dr. Pel, Road Clinical Hospital of JSC Russian Railways, Tikhvin Central District Hospital on Karl Marx

Kudryashova Maria Yurievna

Specialization: Cardiologist, Pediatrician, Doctor of functional diagnostics

Medical experience: since 1990

Where does the appointment: Dr. Pel’s Clinic, MEDA Clinic, Children’s Clinic No. 39

Literature:

1. Ardashev V.N., Ardashev A.V., Steklov V.I., Treatment of cardiac arrhythmias.- M.: Medpraktika, 2005. 228 p.
2. Boitsov S.A., Grishaev C.JL, Tishchenko O.L. A new method for describing the results of spectral-temporal mapping of ECG BP and assessing its diagnostic capabilities // Bulletin of Arrhythmology 1999; M: 25-29.
3. Bockeria L.A., Golukhova E.Z., Ivanitsky A.V. Functional diagnostics in cardiology. Volume 12005 p. 228 242.
4. Ivanov GG, Grachev SV, Syrkin AL High resolution electrocardiography. M. 2003. S. 13 64.
5. Kushakovsky M.S. Heart arrhythmias // St. Petersburg. “Foliant”.-1998. pp. 438-441.
6. Sokolov S.F., Golitsin S.P. Supraventricular tachycardia: mechanisms, diagnosis and treatment. Cardiology 1982, II, p. 112-117.

Latest diagnostic articles

Atrial fibrillation

Atrial fibrillation (alternatively called atrial fibrillation) is a condition in which the heart beats abnormally fast. Usually significantly more than 100 beats per minute (often 140 beats per minute or more).

Read more

Cardiac arrhythmias

Arrhythmias are problems with the heart rhythm. The rhythm of the human heart is controlled by electrical signals. An arrhythmia is a heart rhythm disorder that causes the heart to beat too slowly, too fast, or irregularly. These deviations range from a minor inconvenience or discomfort to a condition with a direct threat to a person’s life.