Atrial tachycardia is a fast heartbeat, called an arrhythmia. It's a type of supraventricular tachycardia (SVT).

During an atrial tachycardia episode, the heart beats more than 100 times a minute. Then it returns to a heart rate of around 60 to 80 beats a minute. An episode may start slowly or it may start suddenly and quickly. It can cause a pounding or racing heartbeat, light-headedness, dizziness, and fainting.

Atrial tachycardia is common. It may occur in people who have had heart surgery or who are pregnant. Infections, stimulant medicines or alcohol use may trigger it.

Tests and procedures used to diagnose atrial tachycardia may include:

• Blood tests. Blood tests are done to check for thyroid disorders, heart disease or other conditions that can affect the heartbeat.
• Electrocardiogram (ECG or EKG). This quick test measures the electrical activity of the heart. It can show how fast or how slow the heart is beating.
• Holter monitor. This device is worn for a day or more to record the heart's activity during daily activities.
• Echocardiogram. Also called a heart ultrasound, this test uses sound waves to take pictures of the beating heart. It shows the heart's size and structure.

Other tests may be done to try to trigger an episode of atrial tachycardia. They can give more information about the heart.

• Stress test. During a stress test, the heart's activity is watched while you ride on a stationary bicycle or walk on a treadmill. If you can't exercise, you may be given medicine that affects the heart in a way that's similar to exercise.
• Electrophysiological (EP) study and cardiac mapping. This test is done in a hospital. It shows how electrical signals spread through the heart during each heartbeat.

Treatment of atrial tachycardia depends on what causes it and how severe it is. Treatment may include:

• Vagal maneuvers. Simple but specific actions such as coughing, putting an ice pack on the face or pushing down as if having a bowel movement can help slow down the heart rate. These actions affect the vagus nerve, which helps control the heartbeat.
• Medicines. Medicines may be given to control the heart rate and reset the heart rhythm. Some medicines may need to be given by IV.
• Cardioversion. Paddles or patches on the chest are used to give an electrical shock to the heart. The shock affects the heart's signals. It can reset the heart rate. This treatment may be done if atrial tachycardia doesn't get better with vagal maneuvers or medicine.
• Catheter ablation. A doctor guides a thin, flexible tube through a blood vessel, usually in the groin, and up to the heart. Sometimes more than one catheter is used. Sensors on the tip of the catheter use heat energy, called radiofrequency energy, to create tiny scars in the heart. The scar tissue permanently blocks faulty electrical signals. This restores a regular heartbeat.
• Pacemaker.This small device may be needed if other treatments for atrial tachycardia don't work. It's surgically placed under the skin in the chest area. When the pacemaker finds an irregular heartbeat, it sends an electrical signal that helps correct the heart's rhythm. For people with atrial tachycardia, this treatment is typically done with a procedure called ablation of the AV node.