Atrial tachycardia is an uncommon form of SVT characterized by paroxysms or bursts of rapid, regular arrhythmia due to focal atrial impulses originating outside of the normal sinus node. Common sites include the tricuspid annulus, the crista terminalis of the right atrium and the coronary sinus.
During an atrial tachycardia episode, the heart rate increases to more than 100 beats per minute before returning to a normal heart rate of around 60 to 80 beats per minute. An episode may start slowly or abruptly. Atrial tachycardia can cause light-headedness, dizziness and sometimes, fainting.
Multifocal atrial tachycardia is a particular subtype seen in patients with severe COPD and characterized by varying P wave morphology (by definition, three or more foci) and markedly irregular PP intervals. The rate is usually between 100 beats/min and 140 beats/min, and it is often confused for atrial fibrillation. Solitary atrial premature beats
What are the symptoms of atrial tachycardia?
Atrial tachycardia can happen without symptoms, especially when it happens only for short periods. When it does cause symptoms in adults, these commonly include:
- Heart palpitations.
- Dizziness and lightheadedness.
- Fainting or passing out.
- Chest pain (angina).
- Shortness of breath.
In infants and children, atrial tachycardia tends to cause the following symptoms:
- Feeding problems.
- Rapid breathing.
Tests and procedures used to diagnose atrial tachycardia may include:
- Blood tests to check thyroid function, heart disease or other conditions that may trigger atrial tachycardia
- Electrocardiogram (ECG) to measure the electrical activity of your heart and measure the timing and duration of each heartbeat
- Holter monitor, which is a portable ECG device designed to record your heart’s activity as you go about your routine
- Echocardiogram, which uses sound waves to produce images of your heart’s size, structure and motion
Your doctor might also try to trigger an episode with other tests, which may include:
- Stress test, which is typically done on a treadmill or stationary bicycle while your heart activity is monitored
- Electrophysiological (EP) study and cardiac mapping, which allows your doctor to see the precise location of the irregular heartbeat (arrhythmia)
Initial management of atrial tachycardia is similar to other types of PSVT; however, vagal maneuvers and intravenous adenosine are generally less effective. Intravenous beta-blockers or calcium channel blockers can be given in the hemodynamically stable patient with a change to oral formulations for long-term managment. Antiarrhythmic medications or catheter ablation should be considered in patients who continue to have symptomatic episodes. Long-term anticoagulation is not indicated in the absence of coexistant atrial fibrillation or atrial flutter.
For patients with multifocal atrial tachycardia, treatment of the underlying condition (eg, COPD) is paramount; verapamil, 240–480 mg orally daily in divided doses may be effective in some patients.