Lead II electrocardiogram Strip showing SVT

A supraventricular tachycardia (SVT) is a tachycardia or rapid rhythm of the heart in which the origin of the electrical signal is either the atria or the AV node. These rhythms, by definition, are either initiated or maintained by the atria or the AV node. This is in contrast to the deadlier ventricular tachycardias, which are rapid rhythms that originate from the ventricles of the heart, that is, below the atria or AV node. The International Statistical Classification of Diseases and Related Health Problems (most commonly known by the abbreviation ICD) provides codes to classify diseases and a wide variety of signs, symptoms, abnormal findings, complaints, social circumstances and external causes of injury or disease. ... The International Statistical Classification of Diseases and Related Health Problems 10th Revision (ICD-10) is a coding of diseases and signs, symptoms, abnormal findings, complaints, social circumstances and external causes of injury or diseases, as classified by the World Health Organization (WHO). ... // I00-I99 - Diseases of the circulatory system (I00-I02) Acute rheumatic fever (I00) Rheumatic fever without mention of heart involvement (I01) Rheumatic fever with heart involvement (I02) Rheumatic chorea (I05-I09) Chronic rheumatic heart diseases (I05) Rheumatic mitral valve diseases (I050) Mitral stenosis (I051) Rheumatic mitral insufficiency (I06) Rheumatic aortic... The International Statistical Classification of Diseases and Related Health Problems (most commonly known by the abbreviation ICD) provides codes to classify diseases and a wide variety of signs, symptoms, abnormal findings, complaints, social circumstances and external causes of injury or disease. ... The following is a list of codes for International Statistical Classification of Diseases and Related Health Problems. ... Medical Subject Headings (MeSH) is a huge controlled vocabulary (or metadata system) for the purpose of indexing journal articles and books in the life sciences. ... Image File history File links Size of this preview: 800 × 199 pixelsFull resolution‎ (1,592 × 396 pixels, file size: 180 KB, MIME type: image/jpeg) File historyClick on a date/time to view the file as it appeared at that time. ... Image File history File links Size of this preview: 800 × 199 pixelsFull resolution‎ (1,592 × 396 pixels, file size: 180 KB, MIME type: image/jpeg) File historyClick on a date/time to view the file as it appeared at that time. ... “QRS” redirects here. ... This article or section does not cite any references or sources. ... The heart and lungs, from an older edition of Grays Anatomy. ... In anatomy, the atrium (plural: atria) is the blood collection chamber of a heart. ... The atrioventricular node (abbreviated AV node) is the tissue between the atria and the ventricles of the heart, which conducts the normal electrical impulse from the atria to the ventricles. ... Ventricular tachycardia (V-tach or VT) is a fast rhythm that originates in one of the ventricles of the heart. ...

Symptoms

Symptoms can come on suddenly and may go away without treatment. They can last a few minutes or as long as 1-2 days. The rapid beating of the heart during SVT can make the heart a less effective pump so that the cardiac output is decreased and the blood pressure drops. The following symptoms are typical with a rapid pulse of 140-250 beats per minute:

• Palpitations - The sensation of the heart racing, fluttering or pounding strongly in the chest or the carotid arteries
• Dizziness, or light-headedness (near-faint), or fainting
• Shortness of breath
• Anxiety
• Chest pain or sensation of tightness
• Weakness in legs
• numbness in limbs

A palpitation is an abnormal, rapid beating of the heart, brought on by overexertion, disease or drugs. ... The carotid artery is a major artery of the head and neck that supplies blood to the head and neck. ... Many different terms are often used to describe what is collectively known as dizziness. ... Anxiety is a physiological state characterized by cognitive, somatic, emotional, and behavioral components[1]. These components combine to create the feelings that we typically recognize as anger and known as fear, apprehension, or worry. ... In medicine, chest pain is a symptom of a number of conditions and is generally considered a medical emergency, unless the patient is a known angina pectoris sufferer and the symptoms are familiar (appearing at exertion and resolving at rest, known as stable angina). When the chest pain is not... Weakness can mean: The opposite of strength Weakness (medical) This is a disambiguation page — a navigational aid which lists pages that might otherwise share the same title. ...

Terminology

The term supraventricular tachycardia is often used differently in different settings. Properly, it refers to any tachycardia that is not ventricular in origin. This definition includes sinus tachycardia. Often, however, in a clinical setting, it is used loosely as a synonym for paroxysmal supraventricular tachycardia (PSVT), which refers to those SVTs that have a sudden, almost immediate onset. A person experiencing PSVT may see their heart rate go from 90 to 180 beats per minute instantaneously. Because sinus tachycardias (and some other SVTs) have a gradual (i.e. non-immediate) onset, they are excluded from the PSVT category. PSVTs are usually AV nodal reentrant tachycardias. Sinus tachycardia is a rhythm with elevated rate of impulses originating from the SA node, defined as a rate greater than 100 beats/min in an average adult. ... AV nodal reentrant tachycardia (AVNRT) is a type of reentrant tachycardia (fast rhythm) of the heart. ...

Types of SVTs

The following are types of supraventricular tachycardias, each with a different mechanism of impulse maintenance:

SVTs from a SINOATRIAL source:

• Sinus tachycardia
• Inappropriate sinus tachycardia
• Sinoatrial node reentrant tachycardia (SANRT)

SVTs from an ATRIAL source: Sinus tachycardia is a rhythm with elevated rate of impulses originating from the SA node, defined as a rate greater than 100 beats/min in an average adult. ... Inappropriate sinus tachycardia (IST) is an uncommon type of cardiac arrhythmia, within the category of supraventricular tachycardia (SVT). ...

• (Unifocal) Atrial tachycardia (AT)
• Multifocal atrial tachycardia (MAT)
• Atrial fibrillation with a rapid ventricular response
• Atrial flutter with a rapid ventricular response

SVTs from an ATRIOVENTRICULAR source: Multifocal atrial tachycardia is a cardiac arrhythmia, specifically a type of supraventricular tachycardia. ... Atrial fibrillation (AF or afib) is a cardiac arrhythmia (abnormal heart rhythm) that involves the two upper chambers (atria) of the heart. ... Atrial flutter is an abnormal fast heart rhythm that occurs in the atria of the heart. ...

• AV nodal reentrant tachycardia (AVNRT)
• AV reentrant tachycardia (AVRT)
• Junctional ectopic tachycardia

AV nodal reentrant tachycardia (AVNRT) is a type of reentrant tachycardia (fast rhythm) of the heart. ... This article or section cites very few or no references or sources. ...

Diagnosis

Holter monitor-Imaging with start (red arrow) and end (blue arrow) of a SV-tachycardia with a pulse frequency of about 128/min.

Most supraventricular tachycardias have a narrow QRS complex on EKG, but it is important to realise that supraventricular tachycardia with aberrant conduction (SVTAC) can produce a wide-complex tachycardia that may mimic ventricular tachycardia (VT). In the clinical setting, it is important to determine whether a wide-complex tachycardia is an SVT or a ventricular tachycardia, since they are treated differently. Ventricular tachycardia has to be treated appropriately, since it can quickly degenerate to ventricular fibrillation and death. A number of different algorithms have been devised to determine whether a wide complex tachycardia is supraventricular or ventricular in origin.^[1] In general, a history of structural heart disease dramatically increases the likelihood that the tachycardia is ventricular in origin. Image File history File links Metadata Size of this preview: 800 × 207 pixelsFull resolution‎ (1,532 × 396 pixels, file size: 366 KB, MIME type: image/jpeg) File historyClick on a date/time to view the file as it appeared at that time. ... Image File history File links Metadata Size of this preview: 800 × 207 pixelsFull resolution‎ (1,532 × 396 pixels, file size: 366 KB, MIME type: image/jpeg) File historyClick on a date/time to view the file as it appeared at that time. ... Holter monitor In medicine, a Holter monitor (also called an ambulatory electrocardiography device), named after its inventor, Dr. Norman J. Holter, is a portable device for continuously monitoring the electrical activity of the heart for 24 hours or more. ... ECG may also refer to the East Coast Greenway Lead II An Electrocardiogram (ECG or EKG, abbreviated from the German Elektrokardiogramm) is a graphic produced by an electrocardiograph, which records the electrical voltage in the heart in the form of a continuous strip graph. ... Ventricular tachycardia (V-tach or VT) is a fast rhythm that originates in one of the ventricles of the heart. ... Ventricular fibrillation (V-fib or VF) is a cardiac condition which consists of a lack of coordination of the contraction of the muscle tissue of the large chambers of the heart that eventually leads to the heart stopping altogether. ... For other uses, see Death (disambiguation). ... Flowcharts are often used to graphically represent algorithms. ...

The individual subtypes of SVT can be distinguished from each other by certain physiological and electrical characteristics, many of which present in the patient's EKG.

• Sinus tachycardia is considered "appropriate" when a reasonable stimulus, such as the catecholamine surge associated with fright, stress, or physical activity, provokes the tachycardia. It is distinguished by a presentation identical to a normal sinus rhythm except for its fast rate (>100 beats per minute in adults).
• Sinoatrial node reentrant tachycardia (SANRT) is caused by a reentry circuit localised to the SA node, resulting in a normal-morphology p-wave that falls before a regular, narrow QRS complex. It is therefore impossible to distinguish on the EKG from ordinary sinus tachycardia. It may however be distinguished by its prompt response to Vagal manouvres.
• (Unifocal) Atrial tachycardia is tachycardia resultant from one ectopic foci within the atria, distinguished by a consistent p-wave of abnormal morphology that fall before a narrow, regular QRS complex.
• Multifocal atrial tachycardia (MAT) is tachycardia resultant from at least three ectopic foci within the atria, distinguished by p-waves of at least three different morphologies that all fall before irregular, narrow QRS complexes.
• Atrial fibrillation is not, in itself, a tachycardia, but when it is associated with a rapid ventricular response greater than 100 beats per minute, it becomes a tachycardia. A-fib is characteristically an "irregularly irregular rhythm" both in its atrial and ventricular depolarizations. It is distinguished by fibrillatory p-waves that, at some point in their chaos, stimulate a response from the ventricles in the form of irregular, narrow QRS complexes.
• Atrial flutter, is caused by a re-entry rhythm in the atria, with a regular rate of about 300 beats per minute. On the EKG, this appears as a line of "sawtooth" p-waves. The AV node will not usually conduct such a fast rate, and so the P:QRS usually involves a 2:1 or 4:1 block pattern, (though rarely 3:1, and sometimes 1:1 in setting of class IC anti-arrhythmic drug use). Because the ratio of P to QRS is usually consistent, A-flutter is often regular in comparison to its irregular counterpart, A-fib. Atrial Flutter is also not necessarily a tachycardia unless the AV node permits a ventricular response greater than 100 beats per minute.
• AV nodal reentrant tachycardia (AVNRT) is also sometimes referred to as a junctional reciprocating tachycardia. It involves a reentry circuit forming just next to or within the AV node itself. The circuit most often involves two tiny pathways one faster than the other, within the AV node. Because the AV node is immediately between the atria and the ventricle, the re-entry circuit often stimulates both, meaning that a retrogradely conducted p-wave is buried within or occurs just after the regular, narrow QRS complexes.
• Atrioventricular reentrant tachycardia (AVRT) also results from a reentry circuit, although one physically much larger than AVNRT. One portion of the circuit is usually the AV node, and the other, an abnormal accessory pathway from the atria to the ventricle. Wolff-Parkinson-White syndrome is a relatively common abnormality with an accessory pathway, the Bundle of Kent crossing the A-V valvular ring.
  • In orthodromic AVRT, atrial impulses are conducted down through the AV node and retrogradely re-enter the atrium via the accessory pathway. A distinguishing characteristic of orthodromic AVRT can therefore be a p-wave that follows each of its regular, narrow QRS complexes, due to retrograde conduction.
  • In antidromic AVRT, atrial impulses are conducted down through the accessory pathway and re-enter the atrium retrogradely via the AV node. Because the accessory pathway initiates conduction in the ventricles outside of the bundle of His, the QRS complex in antidromic AVRT is often wider than usual, with a delta wave.
• Finally, Junctional Ectopic Tachycardia or JET is a rare tachycardia caused by increased automaticity of the AV node itself initiating frequent heart beats. On the EKG, junctional tachycardia often presents with abnormal morphology p-waves that may fall anywhere in relation to a regular, narrow QRS complex.

Sinus tachycardia is a rhythm with elevated rate of impulses originating from the SA node, defined as a rate greater than 100 beats/min in an average adult. ... tyrosine is the precursor of catecholamines epinephrine norepinephrine dopamine Synthesis Catecholamines are chemical compounds derived from the amino acid tyrosine containing catechol and amine groups. ... The normal electrical conduction in the heart allows the impulse that is generated by the SA node of the heart to be propagated to (and stimulate) the myocardium (muscle of the heart). ... Cardiac arrhythmia is any of a group of conditions in which the electrical activity of the heart is irregular or is faster or slower than normal. ... Lead II electrocardiogram Strip showing SVT A supraventricular tachycardia (SVT) is a tachycardia or rapid rhythm of the heart in which the origin of the electrical signal is either the atria or the AV node. ... Multifocal atrial tachycardia is a cardiac arrhythmia, specifically a type of supraventricular tachycardia. ... Atrial fibrillation (AF or afib) is a cardiac arrhythmia (abnormal heart rhythm) that involves the two upper chambers (atria) of the heart. ... Atrial flutter is an abnormal fast heart rhythm that occurs in the atria of the heart. ... AV nodal reentrant tachycardia (AVNRT) is a type of reentrant tachycardia (fast rhythm) of the heart. ... This article or section cites very few or no references or sources. ... Wolff-Parkinson-White syndrome (WPW) is a syndrome of pre-excitation of the ventricles of the heart due to an accessory pathway known as the Bundle of Kent. ... Bundle of Kent is an extra or accessory conduction pathway between the atria and ventricles in the heart. ... Wolff-Parkinson-White syndrome (WPW) is a syndrome of pre-excitation of the ventricles of the heart due to an accessory pathway known as the Bundle of Kent. ... Cardiac arrhythmia is any of a group of conditions in which the electrical activity of the heart is irregular or is faster or slower than normal. ...

Acute Treatment

In general, SVT is not life threatening, but episodes should be treated or prevented. While some treatment modalities can be applied to all SVTs with impunity, there are specific therapies available to cure some of the different sub-types. Cure requires intimate knowledge of how and where the arrhythmia is initiated and propagated.

The SVTs can be separated into two groups, based on whether they involve the AV node for impulse maintenance or not. Those that involve the AV node can be terminated by slowing conduction through the AV node. Those that do not involve the AV node will not usually be stopped by AV nodal blocking manoevres. These manoevres are still useful however, as transient AV block will often unmask the underlying rhythm abnormality.

AV nodal blocking can be achieved in at least three different ways:

Physical manoeuvres

A number of physical maneuvers cause increased AV nodal block, principally through activation of the parasympathetic nervous system, conducted to the heart by the Vagus nerve. These manipulations are therefore collectively referred to as Vagal Maneuvers.

The best recognised of these is the Valsalva maneuver, which increases intra-thoracic pressure and affects baro-receptors (pressure sensors) within the arch of the aorta. This can be achieved by asking the patient to hold their breath and "bear down" as if straining to pass a bowel motion, or less embarrassingly, by getting them to hold their nose and blow out against it. Plunging the face into, or just drinking a glass of ice cold water is also often effective. Firmly pressing the bulb at the top of one of the carotid arteries in the neck (carotid sinus massage, stimulating carotid baro-receptors) is also effective, but not recommended for those without adequate medical training. A Valsalva maneuver is any attempted exhalation against a closed glottis or against a closed mouth and nose. ... The aorta (generally pronounced [eɪˈɔːtə] or ay-orta) is the largest artery in the human body, originating from the left ventricle of the heart and bringing oxygenated blood to all parts of the body in the systemic circulation. ...

Drug Treatment

Another modality involves treatment with medications. Prehospital care providers and hospital clinicians might administer Adenosine, an ultra short acting AV nodal blocking agent. If this works, followup therapy with Diltiazem, Verapamil or Metoprolol may be indicated. SVT that does NOT involve the AV node may respond to other anti-arrhythmic drugs such as Sotalol or Amiodarone. Adenosine is a nucleoside composed of adenine attached to a ribose (ribofuranose) moiety via a β-N9-glycosidic bond. ... Diltiazem is a member of the group of drugs known as Benzothiapines , which are a class of calcium channel blockers, used in the treatment of hypertension, angina pectoris, and some types of arrhythmia. ... Verapamil (brand names: Isoptin®, Verelan®, Calan®) is a medical drug that acts as an L-type calcium channel blocker. ... “Minax” redirects here. ... Sotalol is a drug used in individuals with rhythm disturbances (cardiac arrhythmias) of the heart. ... Amiodarone belongs to a class of drugs called Vaughan-Williams Class III antiarrhythmic agent. ...

In pregnancy, Metoprolol is the treatment of choice as recommended by the American Heart Association. “Minax” redirects here. ... The American Heart Association (AHA) is a non-profit organization in the United States that fosters appropriate cardiac care in an effort to reduce disability and deaths caused by cardiovascular disease and stroke American Stroke Association Web site. ...

Electrical Cardioversion

If physical maneuvers or drugs do not work, or if the patient is extremely unstable, a DC shock delivered to the chest (synchronized cardioversion) may also be used, and is almost always effective. Through electricity or drug therapy, cardioversion converts heart arrhythmias to normal rhythms. ...

Prevention & Cure

Once the acute episode has been terminated, ongoing treatment may be indicated to prevent a recurrence of the arrhythmia. Patients who have a single isolated episode, or infrequent and minimally symptomatic episodes usually do not warrant any treatment except observation.

Patiets who have more frequent or disabling symptoms from their episodes generally warrant some form of preventative therapy. A variety of drugs including simple AV nodal blocking agents like beta-blockers [[1]]and verapamil, as well as anti-arrhythmics may be used, usually with good effect, although the risks of these therapies need to be weighed against the potential benefits. Beta blockers or beta-adrenergic blocking agents are a class of drugs used to treat a variety of cardiovascular conditions and some other diseases. ...

For tachycardia caused by a re-entrant pathway, radiofrequency ablation is probably the best option. This is a low risk procedure that uses a catheter inside the heart to deliver radiofrequency energy to locate and destroy the abnormal electrical pathways. Ablation has been shown to be highly effective: up to 99% effective in eliminating AVNRT. Similar high rates of success are achieved with radiofrequency ablation in eliminating AVRT and typical Atrial Flutter. Radiofrequency ablation (RFA) uses radiofrequency energy to destroy abnormal electrical pathways in heart tissue. ...

Notable cases

After being successfully diagnosed and treated, Bobby Julich went on to place third in the 1998 Tour de France and win a Bronze Medal in the 2004 Summer Olympics.^[2] Tony Blair, former PM of the UK, was operated for SVT. Robert Julich,[1] most commonly referred to as Bobby Julich, (born on November 18, 1971, in Corpus Christi, Texas) is an American professional road bicycle racer who currently rides for Team CSC in the UCI ProTour racing series. ... The 1998 Tour de France was marred by doping scandals throughout, starting with the arrest of Willy Voet a soigneur in the French Festina team. ... The ceremony for the lighting of the flame is arranged as a pagan pageant, with priestesses dancing. ... For other people of the same name, see Tony Blair (disambiguation) Anthony Charles Lynton Blair (born May 6, 1953)[1] is the Prime Minister of the United Kingdom, First Lord of the Treasury, Minister for the Civil Service, Leader of the Labour Party, and Member of Parliament for the constituency...

See also

• Tachycardia
• AV nodal reentrant tachycardia (AVNRT)
• AV reentrant tachycardia (AVRT)
• Inappropriate Sinus Tachycardia
• Ashman phenomenon

This article or section does not cite any references or sources. ... AV nodal reentrant tachycardia (AVNRT) is a type of reentrant tachycardia (fast rhythm) of the heart. ... This article or section cites very few or no references or sources. ... Inappropriate sinus tachycardia (IST) is an uncommon type of cardiac arrhythmia, within the category of supraventricular tachycardia (SVT). ... The Ashman phenomenon, also known as Ashman beats, describes a particular type of wide complex tachycardia (fast rhythm of the heart) that is often seen in atrial fibrillation. ...

References

External links

• Supraventricular Tachycardia information from Seattle Children's Hospital Heart Center