What is Paroxysmal Atrial Tachycardia?
Atrial tachycardia is a type of heart condition, specifically a supraventricular tachycardia (SVT), which is usually observed in people with heart abnormalities. However, it can also occur in perfectly healthy hearts. Unlike other SVTs, atrial tachycardia doesn’t rely on the area connecting the heart’s upper and lower chambers, or additional transfer routes to start or sustain itself.
Typically for most SVTs, atrial tachycardia displays a narrow QRS complex tachycardia, with the QRS complex being a pattern on a heart monitor. Specifically, a narrow complex tachycardia is when the QRS pattern lasts less than 120 milliseconds. This brief duration indicates quick activation of the lower chambers of the heart (the ventricles), showing that the irregular heartbeat starts above these ventricles.
In atrial tachycardia, heart rates can vary greatly, typically falling between 100-250 beats per minute. The heart rhythms are usually regular, though irregularities can occur. The form and variability of P waves, another pattern on heart monitors, can help identify where the irregular heartbeat originates. It can begin in various areas within the heart, including the top chambers (left or right atrium), the superior vena cava (a large vein carrying blood to the heart), or less common places like the hepatic veins (veins from the liver) and the noncoronary aortic cusp (part of the aorta, the main artery).
Understanding the basic structure of the heart is crucial to recognizing where reentry (when the electric signal circles back around through the heart) can occur. The openings of the vena cava, a vein carrying blood into the heart, the coronary sinus, the heart’s main vein, and the pulmonary veins, veins carrying oxygenated blood, are commonly involved sites.
What Causes Paroxysmal Atrial Tachycardia?
Atrial tachycardia, a type of heart rhythm disorder, can occur in people with both normal and abnormal heart structures. The details and types of this condition can actually change based on the individual’s heart structure. For example, a form of atrial tachycardia known as reentrant occurs in hearts that allow the electrical impulses to travel in circuits, commonly around areas like the openings to the large veins (vena cava), coronary sinus, and lung veins (pulmonary veins).
Atrial tachycardia can also occur as a response to different triggering events or conditions. Things like low oxygen in the body (hypoxia), hormone (catecholamine) release, drinking alcohol, using drugs, or even just exercising can trigger this heart condition. A version of atrial tachycardia can also be unintentionally caused by medical procedures. This happens most commonly after heart procedures that use heat to destroy problematic heart tissue (ablation), particularly when there are gaps left in the places where tissue was destroyed.
Risk Factors and Frequency for Paroxysmal Atrial Tachycardia
Atrial tachycardia is a less common type of rapid heart rate issue, known as SVT, making up 5-15% of all diagnosed SVTs. It can happen to anyone, regardless of their age, race, or ethnicity. However, it’s usually more common in older people and those with certain risk factors.
Signs and Symptoms of Paroxysmal Atrial Tachycardia
Atrial tachycardia is a condition that affects the heart’s rhythm. Some people who have this condition may not experience any symptoms and only discover they have it after a routine heart test. Others may feel symptoms such as dizziness, heart palpitations, shortness of breath, feeling lightheaded, or experiencing chest pain. Sometimes, atrial tachycardia might be a sign of another underlying health problem. For instance, 60% of people with a type of atrial tachycardia called ‘multifocal atrial tachycardia’ also have a lung condition called chronic obstructive pulmonary disease.
When a doctor sees a patient with atrial tachycardia, they’ll need to take a detailed medical history. This includes asking about any past heart surgeries or procedures, family history of heart conditions, and sudden death. They also need to know about current medications and any non-prescription drugs, including illicit drugs and alcohol use. Exposure to certain environments or substances at work also need to be considered.
A detailed physical examination is also necessary to look for other potential causes. The doctor will check vital signs to see if the patient’s overall health is stable. Tests like an electrocardiogram (EKG) and an echocardiogram can help to identify the cause of the abnormal heart rhythm and to detect any structural problems in the heart.
Testing for Paroxysmal Atrial Tachycardia
If you’re experiencing atrial tachycardia (an abnormal heart rhythm), your doctor will first conduct an EKG (electrocardiogram), which is a test that records your heart’s electrical activity. If you’ve had one before, they’ll compare your current EKG with the previous one to see what changes have occurred. The EKG helps your doctor figure out the specific type of atrial tachycardia you might have and can even suggest where the abnormal rhythm is starting in your heart.
Positive or biphasic P waves in a certain lead (aVL) on your EKG can suggest the abnormal rhythm is originating from the right side of your heart. Similarly, positive P waves in another lead (V1) might point to the abnormal rhythm starting from the left side of your heart.
After your EKG, your doctor will run some basic lab tests. These tests can help identify any potential underlying health issues that could be causing your heart’s abnormal rhythm. Your doctor might also perform an echocardiogram, a type of ultrasound that uses sound waves to create detailed images of your heart. This test can reveal any structural issues in your heart that could be causing your atrial tachycardia.
If the atrial tachycardia doesn’t appear to be caused by any underlying or structural issues — what doctors call ‘primary’ atrial tachycardia — your doctor may decide to map out your heart’s electrical activity. This detailed study can illustrate where your abnormal rhythm is starting from within your heart. This information is important if you decide to undergo heart ablation, a procedure where doctors make small burns on your heart to interrupt the signals causing your abnormal rhythm.
Another approach, often used in patients with unpredictable episodes of atrial tachycardia, is home monitoring. This involves wearing a portable device that records your heart’s activity for 24-hour periods. This method can be helpful for catching your abnormal heart rhythm in progress, especially if you’re experiencing symptoms but all your office tests, including the EKG and lab tests, appear normal. The recordings from the monitor can provide your doctor with valuable information to help determine the cause of your abnormal heart rhythm.
Treatment Options for Paroxysmal Atrial Tachycardia
When a patient has rapid heartbeats in the upper chambers of the heart, a condition known as atrial tachycardia, the first step in deciding the treatment is to assess the stability of the patient’s heart blood flow, also known as hemodynamic stability. According to guidelines from major heart health organizations including the American College of Cardiology, the American Heart Association, and the Heart Rhythm Society, the first line of treatment for a patient whose heart blood flow is unstable is a medication given through an IV known as Adenosine. If Adenosine doesn’t work or can’t be used for some reason (like if an IV can’t be inserted), the next step might be a procedure called synchronized cardioversion that uses electrical shocks to restore a normal rhythm. Adenosine is also the first step in treating patients with sudden episodes of atrial tachycardia.
If the patient’s heart blood flow is stable, the first line of treatment could be IV medications like beta-blockers, Diltiazem, or Verapamil. If these don’t work, the doctor might try other IV medications like amiodarone or ibutilide.
In managing atrial tachycardia over the long term, beta-blockers, diltiazem, and verapamil can also be taken in pill forms. In patients who don’t have abnormalities in the structure of their heart or disease in the arteries supplying the heart, medicines like flecainide or propafenone can also be used. Other options might include long-term use of medications like amiodarone or sotalol. Digitalis is another drug option for managing atrial tachycardia over the long term. While too much of this drug can cause atrial tachycardia, with the right dose, it can help manage the condition.
If the atrial tachycardia doesn’t respond to drugs or is hard to control with them, cardioversion might be used. There’s also another non-drug treatment for hard-to-treat cases, called radiofrequency catheter ablation. This procedure uses heat to destroy the part of the heart tissue causing the abnormal rhythm. Experienced doctors have seen good success rates with this procedure, typically higher than 90%, with complications around 1%.
What else can Paroxysmal Atrial Tachycardia be?
When a patient shows signs of atrial tachycardia, which is a fast heart rhythm, medical professionals need to consider other conditions that may cause similar symptoms. To accurately identify the heart rhythm, a 12 lead EKG, a form of heart monitor, will need to be performed. Furthermore, a thorough medical assessment is necessary to determine if the rapid heart rhythm is a side effect of another illness.
These are several conditions that can cause similar symptoms:
- Sinus tachycardia (another type of fast heart rhythm)
- Atrial fibrillation (irregular heart rhythm)
- Atrial flutter (another irregular heart rhythm)
- Ventricular tachycardia (fast rhythm starting in the lower chambers of the heart)
- Torsades de Pointes (specific type of abnormal heart rhythm)
- Hyperthyroidism (overactive thyroid gland)
- Anemic state (low red blood cells or hemoglobin)
What to expect with Paroxysmal Atrial Tachycardia
Atrial tachycardia, a condition where your heart beats faster than usual, is not typically a threat to your life. However, you should make some lifestyle changes to lower the chance of it happening again, especially if it was brought on by certain triggers. You’d be better off avoiding caffeine, alcohol, and situations that cause stress or anxiety. Also, it’s crucial to have healthy, regular sleep routines.
If left unchecked, prolonged atrial tachycardia could lead to long-term heart issues, like changes to the heart’s structure (cardiac remodeling). It usually becomes harder to manage the longer the heart stays in this irregular rhythm. Therefore, it’s really important to address the irregular heartbeat or underlying issue as soon as possible.
Possible Complications When Diagnosed with Paroxysmal Atrial Tachycardia
Atrial tachycardia, a type of heart rhythm disorder, may not directly cause many problems, but its treatment can lead to various complications. If you have this condition for a long time, it can change the structure of your heart leading to heart failure.
One common treatment, cardiac ablation, carries risks such as bleeding where the doctor inserted the devices. In some cases, the heart can be physically damaged, leading to damaged blood vessels, valves, or potentially piercing the heart wall. Moreover, a scary risk is that the ablation could trigger another heart rhythm disorder, making the patient’s condition unstable. Sometimes, if the regular heart rhythm pathway is severely damaged, a pacemaker may be needed to manage the new heart rhythm disorder.
Medications used to treat atrial tachycardia may also have side effects, and there can be issues if it’s contraindicated for the patient. Another treatment, cardioversion, comes with its own potential problems. These can go from minor skin burns to severe heart rhythm disorders, and in worst circumstances, a state where the heart doesn’t beat at all.
Common complications of atrial tachycardia and its treatments include:
- Heart structure changes leading to heart failure
- Bleeding from the site of ablation
- Physical damage to the heart
- Creation of new heart rhythm disorder
- Potential need for a pacemaker
- Side effects from medications
- Complications from cardioversion, ranging from minor skin burns to severe heart rhythm disorders
- The heart stopping to beat (asystole)
Preventing Paroxysmal Atrial Tachycardia
Atrial tachycardia is a condition caused by an issue within the heart’s conduction system, the part of the heart that coordinates the heartbeat. Essentially, it makes the heart beat faster than normal. Whether someone with atrial tachycardia would feel any symptoms can differ, but some people do report feeling heart palpitations, dizziness, or faintness, and they may even pass out. If you have been feeling any of these symptoms continuously, it’s recommended you seek medical help.
Doctors use various types of tests to diagnose atrial tachycardia. One of these tests is an EKG, or an electrocardiogram, that helps to monitor the heart’s rhythm. For a more extended evaluation of the heart’s activity, tools like a Holter monitor or a loop recorder might be used. They record the heart’s rhythm over a longer period, providing doctors with more detailed information.
There are different treatments available for atrial tachycardia. Medication can be prescribed to either slow down the heart rate or adjust the uneven rhythm. There’s also a method called cardioversion, where an electrical shock is used to reset the heart’s rhythm to normal. Sometimes, a procedure called ablation is used. In this process, the part of the heart that’s sending out the abnormal signals is heated until it’s no longer functional, preventing further fast heartbeats.
