paroxysmal atrial tachycardia

Paroxysmal Atrial Tachycardia

Definition

A period of very rapid and regular heart beats that begins and ends abruptly. The heart rate is usually between 160 and 200 beats per minute. This condition is also known as paroxysmal supraventricular tachycardia.

Description

The term paroxysmal means that the event begins suddenly, without warning and ends abruptly. Atrial tachycardia means that the upper chambers of the heart are beating abnormally fast. Paroxysmal atrial tachycardia can occur without any heart disease being present. It is usually more annoying than dangerous.

Causes and symptoms

Paroxysmal atrial tachycardia may be caused by several different things. The fast rate may be triggered by a premature atrial beat that sends an impulse along an abnormal electrical path to the ventricles. Other causes stem from anxiety, stimulants, overactive thyroid, and in some women, the onset of menstruation.Though seldom life-threatening, paroxysmal atrial tachycardia produces annoying symptoms which can include lightheadedness, chest pain, palpitations, anxiety, sweating, and shortness of breath.

Diagnosis

Diagnosis is not always easy, because the event is usually over by the time the patient sees a doctor. A careful description of the episode will aid the doctor in his diagnosis. If the rapid heart rate is still occurring, an electrocardiograph (ECG) will show the condition. If the event is over, physicians often recommend a period of ambulatory electrocardiographic monitoring (called Holter monitoring) to confirm the diagnosis.

Treatment

The doctor may suggest that during an episode of paroxysmal atrial tachycardia the following practice may help. Briefly hold the nose and mouth closed and breathe out, or by bearing down, as though straining at a bowel movement. The doctor may try to stop the episode by gently massaging an area in the neck called the carotid sinus.If these conservative measures do not work, an injection of the drug verapamil or adenosine should stop the episode quickly.In rare cases, the drugs do not work and electrical shock (cardioversion) may be necessary, particularly if serious symptoms are also present with the tachycardia.

Prognosis

Paroxysmal atrial tachycardia is not a disease, and is seldom life-threatening. The episodes are usually more unpleasant than they are dangerous, and the prognosis is generally good.

Prevention

Frequent episodes are usually cause for medication. In rare cases, the doctor may recommend a procedure called catheter ablation, which will remove (or ablate) the precise area of the heart responsible for triggering the fast heart rate.In a catheter ablation procedure, the doctor will place a special catheter against the area of the heart responsible for the problem. Radio-frequency energy is then passed to the tip of the catheter, so that it heats up and destroys the target area. Catheter ablation is considered a non-surgical technique.

Key terms

Premature atrial beat — A beat that occurs before it would normally be expected.Supraventricular — A term for an event that occurs in the upper chambers (atria) of the heart.

Resources

Organizations

American Heart Association. 7320 Greenville Ave., Dallas, TX 75231. (214) 373-6300. http://www.americanheart.org.

tachycardia

[tak″e-kahr´de-ah] abnormally rapid heart rate, usually taken to be over 100 beats per minute. adj., adj tachycar´diac.

A, Sinus tachycardia; B, Ventricular tachycardia. From Chernecky, 2001.antidromic circus movement tachycardia a supraventricular tachycardia supported by a circuit" >reentry circuit that uses the atrioventricular node in the retrograde direction and an pathway" >accessory pathway in the anterograde direction; this produces a broad QRS rhythm indistinguishable from ventricular tachycardia. Such a tachycardia may also use two pathways" >accessory pathways (one anterograde and one retrograde) and not involve the AV node at all.atrial tachycardia a rapid heart rate, between 140 and 250 beats per minute, with the ectopic focus in the atria and with no participation by the atrioventricular node or the sinoatrial node. It is recognizable on the electrocardiogram because the P wave precedes the QRS complex, as opposed to being merged with it or following it. This condition is usually associated with block" >atrioventricular block or digitalis toxicity.benign ventricular tachycardia tachycardia originating in the ventricles, not associated with structural heart disease or significant hemodynamic symptoms.bidirectional ventricular tachycardia (bifascicular ventricular tachycardia) a ventricular arrhythmia characterized by heart rates of 90 to 160 beats per minute, alternating right and left deviation" >axis deviation, ectopic focus that alternates between the anterior superior and posterior inferior fascicles, and a right bundle branch block pattern in lead V₁; seen in digitalis toxicity and other conditions.chaotic atrial tachycardia an ectopic atrial tachycardia due to multifocal activity, characterized by at least three different shapes of P waves on the electrocardiogram; often associated with chronic obstructive lung disease.circus movement tachycardia (CMT) a circuit" >reentry circuit that uses an pathway" >accessory pathway or pathways; there are two subtypes, antidromic and orthodromic circus movement tachycardia.ectopic tachycardia rapid heart action in response to impulses arising outside the sinoatrial node.junctional tachycardia rhythm at the rate of 100 to 140 beats per minute that arises in response to impulses originating in the atrioventricular junction, i.e., the atrioventricular node. It is often seen with digitalis toxicity and is due to triggered activity, but it may also be due to altered automaticity. In the case of digitalis toxicity, the term may be used to encompass the entire span of junctional rates with this condition, i.e., approximately 70 to 140 beats per minute.monomorphic ventricular tachycardia a type that has a uniform beat-to-beat QRS morphology.nonsustained ventricular tachycardia a type that terminates spontaneously within 30 seconds and does not lead to hemodynamic collapse.orthodromic circus movement tachycardia a supraventricular tachycardia supported by a circuit" >reentry circuit that uses the atrioventricular node in the anterograde direction and an pathway" >accessory pathway in the retrograde direction, producing a narrow QRS complex.orthostatic tachycardia disproportionate rapidity of the heart rate on arising from a reclining to a standing position.paroxysmal tachycardia rapid heart action that starts and stops abruptly.paroxysmal atrial tachycardia paroxysmal supraventricular tachycardia.paroxysmal supraventricular tachycardia (PSVT) a narrow QRS tachycardia that begins and ends abruptly; it may be terminated with a vagal maneuver. It has two common mechanisms, atrioventricular nodal reentry and movement" >circus movement that uses the atrioventricular node anterogradely and an pathway" >accessory pathway retrogradely. On the electrocardiogram it is characterized by abrupt onset, and mechanisms are differentiated by the relation of the P wave to the QRS complex.polymorphic ventricular tachycardia a type that has a constantly, and sometimes subtly, changing beat-to-beat QRS configuration.potentially malignant ventricular tachycardia a type that is not associated with structural heart disease or hemodynamically important cardiac symptoms but is sometimes associated with left ventricular dysfunction.sinus tachycardia (ST) a rapid rhythm originating in the sinoatrial node with a rate of usually 100 to 160 beats per minute; conduction through the ventricles is normal. During exercise or stress this is normal, but if it occurs during rest it is abnormal.supraventricular tachycardia a combination of junctional tachycardia and atrial tachycardia.sustained ventricular tachycardia tachycardia that lasts more than 30 seconds and leads to hemodynamic collapse.ventricular tachycardia an abnormally rapid ventricular rhythm with aberrant ventricular excitation, characterized by at least three consecutive complexes" >ventricular complexes of more than 100 beats per minute. It is generated within the ventricle and is most often associated with dissociation" >atrioventricular dissociation.

paroxysmal atrial tachycardia

Paroxysmal supraventricular tachycardia, see there.

单词	paroxysmal atrial tachycardia
释义	DictionarySeetachycardia paroxysmal atrial tachycardia Paroxysmal Atrial Tachycardia Definition A period of very rapid and regular heart beats that begins and ends abruptly. The heart rate is usually between 160 and 200 beats per minute. This condition is also known as paroxysmal supraventricular tachycardia. Description The term paroxysmal means that the event begins suddenly, without warning and ends abruptly. Atrial tachycardia means that the upper chambers of the heart are beating abnormally fast. Paroxysmal atrial tachycardia can occur without any heart disease being present. It is usually more annoying than dangerous. Causes and symptoms Paroxysmal atrial tachycardia may be caused by several different things. The fast rate may be triggered by a premature atrial beat that sends an impulse along an abnormal electrical path to the ventricles. Other causes stem from anxiety, stimulants, overactive thyroid, and in some women, the onset of menstruation.Though seldom life-threatening, paroxysmal atrial tachycardia produces annoying symptoms which can include lightheadedness, chest pain, palpitations, anxiety, sweating, and shortness of breath. Diagnosis Diagnosis is not always easy, because the event is usually over by the time the patient sees a doctor. A careful description of the episode will aid the doctor in his diagnosis. If the rapid heart rate is still occurring, an electrocardiograph (ECG) will show the condition. If the event is over, physicians often recommend a period of ambulatory electrocardiographic monitoring (called Holter monitoring) to confirm the diagnosis. Treatment The doctor may suggest that during an episode of paroxysmal atrial tachycardia the following practice may help. Briefly hold the nose and mouth closed and breathe out, or by bearing down, as though straining at a bowel movement. The doctor may try to stop the episode by gently massaging an area in the neck called the carotid sinus.If these conservative measures do not work, an injection of the drug verapamil or adenosine should stop the episode quickly.In rare cases, the drugs do not work and electrical shock (cardioversion) may be necessary, particularly if serious symptoms are also present with the tachycardia. Prognosis Paroxysmal atrial tachycardia is not a disease, and is seldom life-threatening. The episodes are usually more unpleasant than they are dangerous, and the prognosis is generally good. Prevention Frequent episodes are usually cause for medication. In rare cases, the doctor may recommend a procedure called catheter ablation, which will remove (or ablate) the precise area of the heart responsible for triggering the fast heart rate.In a catheter ablation procedure, the doctor will place a special catheter against the area of the heart responsible for the problem. Radio-frequency energy is then passed to the tip of the catheter, so that it heats up and destroys the target area. Catheter ablation is considered a non-surgical technique. Key terms Premature atrial beat — A beat that occurs before it would normally be expected.Supraventricular — A term for an event that occurs in the upper chambers (atria) of the heart. Resources Organizations American Heart Association. 7320 Greenville Ave., Dallas, TX 75231. (214) 373-6300. http://www.americanheart.org. tachycardia [tak″e-kahr´de-ah] abnormally rapid heart rate, usually taken to be over 100 beats per minute. adj., adj tachycar´diac.A, Sinus tachycardia; B, Ventricular tachycardia. From Chernecky, 2001.antidromic circus movement tachycardia a supraventricular tachycardia supported by a circuit" >reentry circuit that uses the atrioventricular node in the retrograde direction and an pathway" >accessory pathway in the anterograde direction; this produces a broad QRS rhythm indistinguishable from ventricular tachycardia. Such a tachycardia may also use two pathways" >accessory pathways (one anterograde and one retrograde) and not involve the AV node at all.atrial tachycardia a rapid heart rate, between 140 and 250 beats per minute, with the ectopic focus in the atria and with no participation by the atrioventricular node or the sinoatrial node. It is recognizable on the electrocardiogram because the P wave precedes the QRS complex, as opposed to being merged with it or following it. This condition is usually associated with block" >atrioventricular block or digitalis toxicity.benign ventricular tachycardia tachycardia originating in the ventricles, not associated with structural heart disease or significant hemodynamic symptoms.bidirectional ventricular tachycardia (bifascicular ventricular tachycardia) a ventricular arrhythmia characterized by heart rates of 90 to 160 beats per minute, alternating right and left deviation" >axis deviation, ectopic focus that alternates between the anterior superior and posterior inferior fascicles, and a right bundle branch block pattern in lead V₁; seen in digitalis toxicity and other conditions.chaotic atrial tachycardia an ectopic atrial tachycardia due to multifocal activity, characterized by at least three different shapes of P waves on the electrocardiogram; often associated with chronic obstructive lung disease.circus movement tachycardia (CMT) a circuit" >reentry circuit that uses an pathway" >accessory pathway or pathways; there are two subtypes, antidromic and orthodromic circus movement tachycardia.ectopic tachycardia rapid heart action in response to impulses arising outside the sinoatrial node.junctional tachycardia rhythm at the rate of 100 to 140 beats per minute that arises in response to impulses originating in the atrioventricular junction, i.e., the atrioventricular node. It is often seen with digitalis toxicity and is due to triggered activity, but it may also be due to altered automaticity. In the case of digitalis toxicity, the term may be used to encompass the entire span of junctional rates with this condition, i.e., approximately 70 to 140 beats per minute.monomorphic ventricular tachycardia a type that has a uniform beat-to-beat QRS morphology.nonsustained ventricular tachycardia a type that terminates spontaneously within 30 seconds and does not lead to hemodynamic collapse.orthodromic circus movement tachycardia a supraventricular tachycardia supported by a circuit" >reentry circuit that uses the atrioventricular node in the anterograde direction and an pathway" >accessory pathway in the retrograde direction, producing a narrow QRS complex.orthostatic tachycardia disproportionate rapidity of the heart rate on arising from a reclining to a standing position.paroxysmal tachycardia rapid heart action that starts and stops abruptly.paroxysmal atrial tachycardia paroxysmal supraventricular tachycardia.paroxysmal supraventricular tachycardia (PSVT) a narrow QRS tachycardia that begins and ends abruptly; it may be terminated with a vagal maneuver. It has two common mechanisms, atrioventricular nodal reentry and movement" >circus movement that uses the atrioventricular node anterogradely and an pathway" >accessory pathway retrogradely. On the electrocardiogram it is characterized by abrupt onset, and mechanisms are differentiated by the relation of the P wave to the QRS complex.polymorphic ventricular tachycardia a type that has a constantly, and sometimes subtly, changing beat-to-beat QRS configuration.potentially malignant ventricular tachycardia a type that is not associated with structural heart disease or hemodynamically important cardiac symptoms but is sometimes associated with left ventricular dysfunction.sinus tachycardia (ST) a rapid rhythm originating in the sinoatrial node with a rate of usually 100 to 160 beats per minute; conduction through the ventricles is normal. During exercise or stress this is normal, but if it occurs during rest it is abnormal.supraventricular tachycardia a combination of junctional tachycardia and atrial tachycardia.sustained ventricular tachycardia tachycardia that lasts more than 30 seconds and leads to hemodynamic collapse.ventricular tachycardia an abnormally rapid ventricular rhythm with aberrant ventricular excitation, characterized by at least three consecutive complexes" >ventricular complexes of more than 100 beats per minute. It is generated within the ventricle and is most often associated with dissociation" >atrioventricular dissociation. paroxysmal atrial tachycardia Paroxysmal supraventricular tachycardia, see there. AcronymsSeePAT
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