Paroxysmal supraventricular tachycardia (PSVT) is a type of supraventricular tachycardia, named for its intermittent episodes of abrupt onset and termination. Often people have no symptoms. Otherwise symptoms may include

palpitations Palpitations are perceived abnormalities of the heartbeat characterized by awareness of cardiac muscle contractions in the chest, which is further characterized by the hard, fast and/or irregular beatings of the heart. Symptoms include a rapi ...

, increased heart rate, feeling lightheaded, sweating,

shortness of breath Shortness of breath (SOB), also medically known as dyspnea (in AmE) or dyspnoea (in BrE), is an uncomfortable feeling of not being able to breathe well enough. The American Thoracic Society defines it as "a subjective experience of breathing di ...

, and

chest pain Chest pain is pain or discomfort in the chest, typically the front of the chest. It may be described as sharp, dull, pressure, heaviness or squeezing. Associated symptoms may include pain in the shoulder, arm, upper abdomen, or jaw, along with ...

. The cause is not known. Risk factors include alcohol,

caffeine Caffeine is a central nervous system (CNS) stimulant of the methylxanthine class. It is mainly used recreationally as a cognitive enhancer, increasing alertness and attentional performance. Caffeine acts by blocking binding of adenosine t ...

, nicotine,

psychological stress In psychology, stress is a feeling of emotional strain and pressure. Stress is a type of psychological pain. Small amounts of stress may be beneficial, as it can improve athletic performance, motivation and reaction to the environment. Excess ...

, and Wolff-Parkinson-White syndrome, which often is inherited. The underlying mechanism typically involves an accessory pathway that results in re-entry. Diagnosis is typically by an electrocardiogram (ECG) which shows narrow QRS complexes and a fast heart rhythm typically between 150 and 240

beats per minute Beat, beats or beating may refer to: Common uses * Patrol, or beat, a group of personnel assigned to monitor a specific area ** Beat (police), the territory that a police officer patrols ** Gay beat, an area frequented by gay men * Battery ( ...

. Vagal maneuvers, such as the

Valsalva maneuver The Valsalva maneuver is performed by a forceful attempt of exhalation against a closed airway, usually done by closing one's mouth and pinching one's nose shut while expelling air out as if blowing up a balloon. Variations of the maneuver can ...

, are often used as the initial treatment. If not effective and the person has a normal

blood pressure Blood pressure (BP) is the pressure of circulating blood against the walls of blood vessels. Most of this pressure results from the heart pumping blood through the circulatory system. When used without qualification, the term "blood pressur ...

the medication

adenosine Adenosine (symbol A) is an organic compound that occurs widely in nature in the form of diverse derivatives. The molecule consists of an adenine attached to a ribose via a β-N9-glycosidic bond. Adenosine is one of the four nucleoside buildin ...

may be tried. If adenosine is not effective a calcium channel blocker or

beta blocker Beta blockers, also spelled β-blockers, are a class of medications that are predominantly used to manage abnormal heart rhythms, and to protect the heart from a second heart attack after a first heart attack ( secondary prevention). They are ...

may be used. Otherwise synchronized cardioversion is the treatment. Future episodes can be prevented by

catheter ablation Catheter ablation is a procedure used to remove or terminate a faulty electrical pathway from sections of the heart of those who are prone to developing cardiac arrhythmias such as atrial fibrillation, atrial flutter and Wolff-Parkinson-White syn ...

. About 2.3 per 1000 people have paroxysmal supraventricular tachycardia. Problems typically begin in those 12 to 45 years old. Women are more often affected than men. Outcomes are generally good in those who otherwise have a normal

heart The heart is a muscular organ found in most animals. This organ pumps blood through the blood vessels of the circulatory system. The pumped blood carries oxygen and nutrients to the body, while carrying metabolic waste such as carbon diox ...

. An ultrasound of the heart may be done to rule out underlying heart problems.

Signs and symptoms

Symptoms may include

, feeling faint, sweating,

, and

. Episodes start and end suddenly.

Types

* AV nodal re-entrant tachycardia (AVNRT) makes up 56% of cases *

Atrioventricular reentrant tachycardia Atrioventricular reentrant tachycardia (AVRT), or atrioventricular reciprocating tachycardia, is a type of abnormal fast heart rhythm and is classified as a type of supraventricular tachycardia (SVT). AVRT is most commonly associated with Wol ...

(AVRT) makes up 27% of cases ** Wolff-Parkinson-White syndrome * Paroxysmal atrial tachycardia makes up 17% of cases

Treatment

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

Physical maneuvers

A number of physical maneuvers increase the resistance of the AV node to transmit impulses (AV nodal block), principally through activation of the

parasympathetic nervous system The parasympathetic nervous system (PSNS) is one of the three divisions of the autonomic nervous system, the others being the sympathetic nervous system and the enteric nervous system. The enteric nervous system is sometimes considered part ...

, conducted to the heart by the

vagus nerve The vagus nerve, also known as the tenth cranial nerve, cranial nerve X, or simply CN X, is a cranial nerve that interfaces with the parasympathetic control of the heart, lungs, and digestive tract. It comprises two nerves—the left and rig ...

. These manipulations are collectively referred to as vagal maneuvers. The

should be the first vagal maneuver tried and works by increasing intra-thoracic pressure and affecting baroreceptors (pressure sensors) within the arch of the

aorta The aorta ( ) is the main and largest artery in the human body, originating from the left ventricle of the heart and extending down to the abdomen, where it splits into two smaller arteries (the common iliac arteries). The aorta distributes ...

. It is carried out by asking the patient to hold his/her breath while trying to exhale forcibly as if straining during a bowel movement. Holding the nose and exhaling against the obstruction has a similar effect. Pressing down gently on the top of closed eyes may also bring heartbeat back to normal rhythm for some people with atrial or supraventricular tachycardia (SVT). This is known as the oculocardiac reflex.

Medications

Adenosine Adenosine (symbol A) is an organic compound that occurs widely in nature in the form of diverse derivatives. The molecule consists of an adenine attached to a ribose via a β-N9-glycosidic bond. Adenosine is one of the four nucleoside buildin ...

, an ultra-short-acting AV nodal blocking agent, is indicated if vagal maneuvers are not effective. If unsuccessful or the PSVT recurs

diltiazem Diltiazem, sold under the brand name Cardizem among others, is a calcium channel blocker medication used to treat high blood pressure, angina, and certain heart arrhythmias. It may also be used in hyperthyroidism if beta blockers cannot be ...

verapamil Verapamil, sold under various trade names, is a calcium channel blocker medication used for the treatment of high blood pressure, angina (chest pain from not enough blood flow to the heart), and supraventricular tachycardia. It may also be ...

are recommended.

may be safely used during pregnancy. SVT that does not involve the AV node may respond to other anti-arrhythmic drugs such as

sotalol Sotalol, sold under the brand name Betapace among others, is a medication used to treat and prevent abnormal heart rhythms. It is only recommended in those with significant abnormal heart rhythms due to potentially serious side effects. Evidence ...

amiodarone Amiodarone is an antiarrhythmic medication used to treat and prevent a number of types of cardiac dysrhythmias. This includes ventricular tachycardia (VT), ventricular fibrillation (VF), and wide complex tachycardia, as well as atrial fibrill ...

Cardioversion

If the person is hemodynamically unstable or other treatments have not been effective, synchronized electrical cardioversion may be used. In children this is often done with a dose of 0.5 to 1 J/Kg.

References

External links

{{Medical resources , DiseasesDB = , ICD10 = {{ICD10, I, 47, 1, i, 30 , ICD9 = {{ICD9, 427.0 , ICDO = , OMIM = , MedlinePlus = , eMedicineSubj = , eMedicineTopic = , MeshID = D013617 Wikipedia medicine articles ready to translate Cardiac arrhythmia Wikipedia emergency medicine articles ready to translate