From the Guidelines
Atrial tachycardia and premature atrial complexes are abnormal heart rhythms originating in the atria, with atrial tachycardia being a rapid heart rate, typically exceeding 100 beats per minute, due to an abnormal electrical impulse in the atria, as defined in the 2015 ACC/AHA/HRS guideline for the management of adult patients with supraventricular tachycardia 1.
Key Characteristics
- Atrial tachycardia can be further classified into:
- Focal atrial tachycardia, which arises from a localized atrial site, characterized by regular, organized atrial activity with discrete P waves and typically an isoelectric segment between P waves 1
- Multifocal atrial tachycardia, which is an irregular supraventricular tachycardia characterized by ≥3 distinct P-wave morphologies and/or patterns of atrial activation at different rates 1
- Premature atrial complexes, on the other hand, are early electrical impulses originating in the atria that disrupt the normal heart rhythm, often felt as skipped beats or palpitations
Management
In terms of management, for symptomatic atrial tachycardia, treatment may involve medications such as:
- Beta blockers like metoprolol, starting at a dose of 25-50 mg orally twice a day
- Calcium channel blockers like diltiazem, starting at a dose of 30-60 mg orally three times a day For premature atrial complexes, treatment is often not necessary, but if symptoms are bothersome, medications like beta blockers may be used. In some cases, anti-arrhythmic medications like flecainide, at a dose of 50-100 mg orally twice a day, may be prescribed for both conditions, as discussed in the context of supraventricular tachycardia management 1. It is essential to consult a healthcare provider for proper diagnosis and treatment, as the management plan should be individualized based on the patient's specific condition and medical history.
From the Research
Definition and Characteristics
- Atrial tachycardia refers to a type of abnormal heart rhythm, or arrhythmia, that originates in the atria 2.
- Premature atrial complexes (PACs), also known as atrial premature depolarizations (APD) or atrial ectopics, are supraventricular beats that arise from a focus other than the sinus node 3.
- PACs are characterized by prematurity and distinct P wave morphology on an electrocardiogram (ECG) 3.
Clinical Significance
- PACs are a common finding on Holter ECG monitoring and can be innocent in individuals with a normal heart, but may also be a harbinger of more serious atrial tachyarrhythmias in patients with heart disease 3.
- Frequent premature atrial contractions have been associated with a higher risk of incident atrial fibrillation, stroke, and all-cause mortality 4.
- Atrial tachycardias, including atrial flutter and atrial fibrillation, are sustained atrial tachycardias that can be caused by reentry, increased automaticity, or triggered activity 2.
Diagnosis and Mechanism
- ECG is fundamental in the diagnosis of atrial fibrillation and can help identify the site of origin of focal atrial tachycardias and the mechanism of these arrhythmias 2.
- The response to premature atrial complexes during tachycardia can differentiate atrioventricular nodal re-entrant tachycardia (AVNRT) from focal junctional tachycardia (JT) 5.
- A two-for-one response to premature atrial complexes can occur in AVNRT and is not diagnostic of JT 5.