What is paroxysmal atrial tachycardia?
Paroxysmal atrial tachycardia is a type of arrhythmia, or irregular heartbeat. Paroxysmal means that the episode of arrhythmia begins and ends abruptly. Atrial means that arrhythmia starts in the upper chambers of the heart (atria). Tachycardia means that the heart is beating abnormally fast. Paroxysmal atrial tachycardia (PAT) is also known as paroxysmal supraventricular tachycardia (PSVT).
Other types of tachycardia that start in the atria include:
PAT can cause an adult’s heart rate to increase from between 60 and 100 beats per minute (bpm) to between 130 and 230 bpm. Infants and children normally have higher heart rates than adults — between 100 and 130 bpm. When an infant or child has PAT, their heart rate will be greater than 220 bpm. PAT is the most common form of tachycardia in infants and children.
In most cases this condition isn’t life-threatening, but it can be uncomfortable. In rare cases, some people with Wolff-Parkinson-White syndrome may develop a rapid heart rate that is life-threatening.
PAT occurs when electrical signals starting in the heart’s atria fire irregularly. This affects the electrical signals transmitted from the sinoatrial node, which is your heart’s natural pacemaker. Your heart rate will speed up. This prevents your heart from having enough time to fill with blood before pumping blood out to the rest of the body. As a result, your body may not receive enough blood or oxygen.
Women are at a higher risk for PAT than men. Your emotional health can also affect your risk for PAT.
If you’re physically exhausted or have anxiety you’re at high risk for the condition. Your risk for PAT also goes up if you drink excessive amounts of caffeine or drink alcohol daily.
Having other heart issues such as a history of heart attacks or mitral valve disease may increase your risk. Children who have congenital heart disease are at a high risk for PAT.
Some people don’t experience symptoms of PAT, while others may notice:
- palpitations, or an increased heart rate
- angina, or pains in the chest
In rare cases, PAT may cause:
- cardiac arrest
Your doctor may recommend an electrocardiogram (ECG) to help diagnose PAT. An ECG measures the electrical activity in your heart. Your doctor will ask you to lie down and will then attach some electrodes to your chest, arms, and legs. You will need to remain still and hold your breath for a few seconds. It’s important to stay still and relaxed. Even a slight movement can affect the results.
The electrodes on your chest, arms, and legs attach to wires that send your heart’s electrical activity to a machine that prints them out as a series of wavy lines. Your doctor will examine this data to determine if your heart rate is higher than normal or has an irregular rhythm.
You may also undergo this test while doing light exercise to measure the changes in your heart under stress. Your doctor may also want to test your blood pressure.
It can be difficult to catch your episode of PAT, so your doctor may also want to have you wear a Holter monitor. Your doctor will apply two or three electrodes to your chest, like the ECG. You will wear the device for 24 to 48 hours (or longer) while you do your normal daily activities, and then return it to the doctor. The device will record any fast heartbeats that occur while you are wearing it.
Most people with PAT don’t need treatment for their condition. Your doctor may recommend treatment or medications if your episodes occur often or last for a considerable length of time.
Vagal maneuvers slow your heart rate by stimulating your vagus nerve. Your doctor may suggest using one of the following vagal maneuvers during an episode of PAT:
- carotid sinus massage, or applying gentle pressure to your neck where your carotid artery branches
- applying gentle pressure to closed eyelids
- valsalva maneuver, or pressing your nostrils together while exhaling through your nose
- dive reflex, or immersing your face or body in cool water
If you often experience episodes of PAT and the maneuvers outlined above don’t restore your normal heart rate, your doctor may prescribe medication. These medications can include flecainide (Tambocor) or propafenone (Rythmol). They’re available in a few forms. Your doctor may give you an injection in their office or a pill that you can take during an episode of PAT.
Your doctor may recommend that you reduce your intake of caffeine and alcohol, and stop or reduce use of tobacco. They’ll also want to ensure that you’re getting plenty of rest.
In rare and extreme cases, your doctor may suggest catheter ablation. This is a nonsurgical procedure that removes tissue in the area of the heart that’s causing the increased heart rate.
During the procedure, your doctor will place a catheter against the trigger area. They will send radio-frequency energy through the catheter to produce enough heat to destroy the precise trigger area.
Complications of PAT vary with the rate and duration of the abnormally fast heartbeat. Complications also vary based on whether you have an underlying heart condition.
Some people with PAT may be at risk for blood clots that could result in a heart attack or stroke. In those cases, doctors usually prescribe medications such as dabigatran (Pradaxa) or warfarin (Coumadin). These medications thin the blood and reduce the risk for blood clots. In rare cases, complications may include congestive heart failure and cardiomyopathy.
The best way to prevent PAT is to avoid smoking, and limit drinking alcohol and caffeinated beverages. Getting regular exercise and plenty of rest is also advised. Maintaining a healthy diet and lifestyle and keeping your weight in a healthy range can also significantly reduce your risk of PAT.
PAT is not a life-threatening condition. The periods of sudden rapid heartbeat are more uncomfortable than they are dangerous. The outlook for someone who has PAT is generally positive.