Paroxysmal atrial tachycardia is a type of arrhythmia (irregular heartbeat). Paroxysmal means that the episode of arrhythmia begins and ends abruptly. Atrial means that arrhythmia starts in the atria or upper chambers of your heart. 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 atrial fibrillation, atrial flutter, and Wolff-Parkinson-White syndrome.
PAT can cause an adult’s heart rate to increase from between 60 and 100 beats per minute to between 130 and 230 beats per minute. Infants and children normally have higher heart rates than adults, with between 100 and 130 beats per minute. When an infant or child has PAT, their heart rate will be greater than 220 beats per minute. PAT is the most common form of tachycardia in infants and children.
In most cases this condition isn’t life-threatening. However, it’s uncomfortable and can be alarming. In rare instances, some people with Wolff-Parkinson-White syndrome may develop an extremely rapid heart rate that is life-threatening.
PAT occurs when electrical signals starting in the heart’s upper chambers (atria) fire irregularly. This affects the electrical signals transmitted from the sinoatrial node, which is your heart’s natural pacemaker. This speeds up your heart rate and prevents your heart from having enough time to fill with blood before pumping blood out to the rest of the body. This means that your body may not receive enough blood or oxygen.
Women are at a higher risk for PAT than men.
Your emotional health can affect your risk for PAT. If you’re physically exhausted or have anxiety, then you’re at high risk for the condition. In addition, if you drink excessive amounts of caffeine or drink alcohol daily, your risk for PAT goes up.
Having other heart issues such as a history of heart attacks or mitral valve disease may increase your risk. Children suffering from congenital heart disease are at a high risk for PAT.
Some people don’t experience signs or symptoms of PAT, while others may notice:
- palpitations (increased heart rate)
- angina (pains in the chest)
In rare cases, PAT may cause:
- cardiac arrest
Your doctor may recommend an electrocardiogram (ECG) test to help diagnose PAT. An ECG test measures the electrical activity in your heart. Your doctor will ask you to lie down and will then attach a number of electrodes to your chest, arms, and legs. You will need to remain still and hold your breath for just a few seconds. It’s important to try to stay still and relaxed, as even a slight movement can affect the results.
The electrodes attach to wires that transmit 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 you have a heart rate that’s higher than normal or has an irregular rhythm.
You may also undergo this test during a period of light exercise or activity 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. Two or three electrodes will be applied to your chest, similar to the ECG. You will wear the device for 24 to 48 hours (or more) while you do your normal daily activities, and then return it to the doctor. The device will record any fast heartbeats that may occur during the time you are wearing it.
Most people with PAT don’t ever require treatment for their condition. However, your doctor may recommend treatment or medications if your episodes occur frequently or last for a considerable length of time.
Vagal maneuvers stimulate your vagus nerve to slow your heart rate. Your doctor may suggest using one of the following vagal maneuvers during an episode of PAT:
- carotid sinus massage (applying gentle pressure to your neck where your carotid artery branches)
- applying gentle pressure to the closed eyelids
- valsalva maneuver (pressing your nostrils together while exhaling through your nose)
- dive reflex (suddenly immersing your face or body in cool water)
If you frequently experience episodes of PAT and the maneuvers outlined above don’t restore your normal heart rate, your doctor may prescribe medication. Your doctor may give you an injection of flecainide (Tambocor) or propafenone (Rythmol) to slow your heart rate. Your doctor may also prescribe one of those medications in pill form that you can take during a future episode of PAT.
Your doctor may recommend that you reduce your intake of caffeine and alcohol, and stop or reduce your 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 heart 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 transmit 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 a stroke. In those cases, doctors usually prescribe medications like dabigatran (Pradaxa) or warfarin (Coumadin), which 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. By maintaining a healthy diet and lifestyle and keeping your weight in a healthy range, you can also significantly reduce your risk of PAT.
PAT is not a life-threatening condition. The periods of sudden rapid heartbeat are much more uncomfortable than they are dangerous. The outlook for someone who has PAT is generally positive.