What is atrial tachycardia?
Atrial tachycardia (AT) is a type of abnormal heart rhythm or arrhythmia. It happens when the electrical signal that controls the heartbeat starts from an unusual location in the upper chambers (atria) and rapidly recurrences, causing the atria to beat too quickly.
What happens during atrial tachycardia?
A normal heartbeat begins with an electrical instinct from the sinus node, a single point in the heart’s right atrium (right upper chamber). Throughout atrial tachycardia, an electrical impulse outside the sinus node fires repeatedly, often due to a short circuit – a circular electrical pathway. Electricity circles the atria, again and again, causing the upper chambers to agreement more than 100 times per minute. (A normal heart rate is between 60 and 100 beats per minute.) The rapid heart contractions prevent the chambers from filling completely between beats.
An arrhythmia placed in the upper chambers of the heart is called supraventricular tachycardia (SVT) – accurately, fast “heartbeat above the ventricles” (lower chambers). Atrial tachycardia usually occurs for brief periods and starts and stops spontaneously. That’s called paroxysmal AT. If it continues, it is called persistent AT.
Causes of atrial tachycardia
Atrial tachycardia happens most often in elderly patients and those with other types of heart disease, although it occasionally seems in children, younger people, and people with healthy hearts. Causes include:
- A “stretched” atrium as a result of high blood pressure (hypertension) or cardiomyopathy
- A previous heart attack
- Excessive use of alcohol, cocaine, and other stimulants
- An “irritable focus,” when cells outside the sinus node automatically start to generate an electrical impulse on their own
- Sometimes atrial tachycardia is idiopathic, which means that doctors cannot find a specific cause
Symptoms of atrial tachycardia
Atrial tachycardia can cause the following symptoms:
- Pressure or pain in the chest
- Fainting, also known as syncope or near syncope
- Lightheadedness or dizziness
- Palpitations, which may jump, flap, or pound in the chest
- Difficulty breathing
It is important to note that some children may not know how to describe what they feel during a period of atrial tachycardia. They may have trouble custody up with other children or realize that they are having “incantations” and want to sit and rest. Occasionally a child does not experience any symptoms at all.
Diagnosis of atrial tachycardia
The tests and procedures used to diagnose atrial tachycardia may include:
- Blood tests to check thyroid function, heart disease, or other conditions that can trigger atrial tachycardia
- Electrocardiogram (ECG) to measure the electrical activity of your heart and measure the time and duration of each beat
- Holter monitor, which is a transportable ECG device designed to record your heart activity as you go about your routine
- Echocardiogram, which uses sound waves to produce pictures of the size, structure, and movement of your heart
Your doctor may also try to trigger an episode with other tests, which may include:
- A stress test, which is usually done on a treadmill or stationary bike while monitoring heart activity
- Electrophysiological testing and plotting, which allows your doctor to see the precise location of the arrhythmia
Treatment for atrial tachycardia
Treatment of atrial tachycardia depends on the harshness of the condition and the factors that trigger it. In addition to managing any underlying conditions that may trigger your atrial tachycardia, your doctor may recommend or test:
- Vagal maneuvers: You may be able to temporarily lower your heart rate by using particular maneuvers including holding your breath and straining, dipping your face in ice water, or coughing.
- Medicines: Your doctor may suggest intravenous or oral medications to control your heart rate or restore a normal heart rhythm.
- Cardioversion: If your arrhythmia (irregular heartbeat) does not respond to vagal maneuvers or medication, and if there is no identifiable and treatable condition that triggers it, your doctor may use electrical cardioversion. In the procedure, a shock is delivered to the heart through paddles or patches on the chest. The present affects the electrical impulses in your heart and can restore a normal rhythm.
- Catheter ablation. In some cases, your physician may recommend tube ablation. For this procedure, your doctor inserts one or more catheters through the blood vessels to the heart. The electrodes on the catheter tips can use heat, extreme cold, or radiofrequency energy to damage (remove) a small part of the heart tissue and create an electrical jam along the pathway that is causing the arrhythmia.
- If you experience common episodes of atrial tachycardia and all other treatment options are vain, your doctor may suggest implantation of a small device called a pacemaker to deliver electrical impulses that kindle your heart to beat at a normal rate. For people with AT, this procedure is usually shadowed by the ablation of the AV node.
Incessant (prolonged) atrial tachycardia can lead to cardiomyopathy (a weakening of the heart muscle) and heart failure. This type of cardiomyopathy is often reversible if the atrial tachycardia can be controlled.