Atrial tachycardia

Atrial Tachycardia

Atrial tachycardia is a type of supraventricular tachycardia.

Atrial tachycardia is a type of supraventricular tachycardia that originates in the atria of the heart. It is characterized by a rapid heart rate that exceeds the normal resting rate, typically over 100 beats per minute. This condition can occur in individuals with or without structural heart disease and can be paroxysmal or sustained.

Pathophysiology

Atrial tachycardia results from abnormal electrical activity in the atria. This can be due to enhanced automaticity, triggered activity, or reentrant circuits. In enhanced automaticity, certain atrial cells spontaneously depolarize at a faster rate than the sinoatrial node, leading to a rapid heart rate. Triggered activity involves afterdepolarizations that reach threshold and cause premature atrial contractions. Reentrant circuits occur when there is a loop of electrical activity within the atria, causing repeated activation of the atrial tissue.

Clinical Presentation

Patients with atrial tachycardia may experience symptoms such as palpitations, dizziness, shortness of breath, and chest pain. In some cases, atrial tachycardia can lead to heart failure or syncope if the heart rate is excessively high or if the patient has underlying heart disease.

Diagnosis

Electrocardiogram showing atrial tachycardia.

The diagnosis of atrial tachycardia is typically made using an electrocardiogram (ECG). The ECG will show a rapid atrial rate with abnormal P wave morphology, which differs from the normal sinus rhythm. Additional diagnostic tools may include Holter monitoring, event monitors, and electrophysiological studies to determine the mechanism and origin of the tachycardia.

Treatment

Treatment of atrial tachycardia depends on the underlying cause and the severity of symptoms. Options include:

• Medications: Antiarrhythmic drugs such as beta-blockers, calcium channel blockers, and class I or III antiarrhythmics can be used to control the heart rate or restore normal rhythm.
• Catheter Ablation: This procedure involves the use of radiofrequency energy to destroy the abnormal tissue causing the tachycardia.
• Lifestyle Modifications: Avoiding triggers such as caffeine, alcohol, and stress can help reduce episodes of atrial tachycardia.

Prognosis

The prognosis for patients with atrial tachycardia varies depending on the presence of underlying heart disease and the effectiveness of treatment. Many patients can achieve good control of their symptoms with appropriate therapy.

Related Pages

• Atrial fibrillation
• Supraventricular tachycardia
• Electrophysiology