Diagnosis
To diagnose atrioventricular nodal reentry tachycardia (AVNRT), a healthcare professional examines you and asks questions about your symptoms and medical history. The healthcare professional listens to your heart and lungs using a stethoscope.
Tests are often done to check heart health.
Tests
Tests used to diagnose atrioventricular nodal reentry tachycardia (AVNRT) may include:
- Blood tests. Blood tests can check for thyroid disease and other conditions that can cause an irregular heartbeat.
- Electrocardiogram (ECG or EKG). This simple test checks the electrical activity of the heart. It shows how fast or slow the heart is beating.
- Holter monitor. This portable ECG device is worn for a day or more to record the heart's activity during daily activities. A Holter monitor can find irregular or fast heartbeats that don’t show up on a regular electrocardiogram.
- Echocardiogram. Sound waves create pictures of the beating heart. An echocardiogram shows the heart's size and how blood flows through the heart.
- Exercise stress tests. These tests often involve walking on a treadmill or riding a stationary bike while the heart activity is watched. Exercise tests show how the heart reacts to physical activity. If you can't exercise, you might get medicines that affect the heart like exercise does.
- Electrophysiological study. Also called an EP study, this test can show where in the heart the irregular heartbeat starts. During this test, a doctor guides one or more flexible tubes through a blood vessel, usually in the groin, to various areas in the heart. Sensors on the tips of the tubes record the heart's electrical signals.
Treatment
Most people with atrioventricular nodal reentry tachycardia (AVNRT) don't need treatment. But if the fast heartbeat happens often or lasts a long time, treatment may be needed.
Treatment for AVNRT may include:
- Vagal maneuvers. Simple but specific actions such as coughing, bearing down as if passing stool, gently massaging the main artery in the neck or putting an ice pack on the face can help slow down the heart rate. These actions affect the vagus nerve, which helps control the heartbeat.
- Medicines. If the fast heartbeat happens frequently, your healthcare professional may prescribe medicines to slow or control your heart rate.
- Cardioversion. Paddles or patches on the chest are used to electrically shock the heart and help reset the heart rhythm. Cardioversion is typically used when vagal maneuvers and medicines don't work.
- Catheter ablation. This treatment may be suggested if medicines don't work or if their side effects are too bothersome. A doctor inserts a thin, flexible tube called a catheter through a blood vessel, usually in the groin, and guides it to the heart. Sensors on the tip of the catheter use heat or cold energy to create tiny scars in the heart. The scars block irregular electrical signals and restore a typical heartbeat.
Preparing for your appointment
If you have a very fast heartbeat that often starts and ends suddenly, make an appointment for a health checkup. If a fast heartbeat lasts more than a few minutes, get medical care right away.
You may see a doctor trained in heart conditions, called a cardiologist. You also might see a doctor trained in heart rhythm disorders, called an electrophysiologist.
Appointments can be short, so it's good to be prepared. Here's some information to help you get ready for your visit.
What you can do
When you make the appointment, find out if there's anything you need to do in advance. For example, you may be told not to eat or drink before some tests.
Make a list to share with your healthcare team. Your list should include:
- Any symptoms, including those that may seem unrelated to your heart.
- Important personal information, including any major stresses or big life changes.
- All medicines you take. Write down any vitamins, supplements and medicines bought with and without a prescription. Include the doses.
- Questions to ask your care team.
For atrioventricular nodal reentry tachycardia (AVNRT), some questions to ask your healthcare professional include:
- What is causing my rapid heart rate?
- What tests do I need?
- What treatment is right for me?
- What are the risks of AVNRT?
- How often do I need checkups?
- How do other conditions I have or medicines I take affect my heartbeat?
- Do I need to change my activities or what I eat and drink?
- Do you have information I can take home with me? What websites do you suggest?
Don't hesitate to ask any other questions.
What to expect from your doctor
Your healthcare team is likely to ask you many questions. Being ready to answer them can save time to talk about any other concerns. Your care team may ask:
- When did your symptoms start?
- How often do you have a fast heartbeat?
- How long does it last?
- Does anything make your symptoms worse?
- Does anyone in your family have a fast heartbeat or other heart condition?
- Has anyone in your family ever died suddenly or had sudden cardiac arrest?
- Have you ever smoked, or do you smoke now?
- Do you use alcohol or caffeine? If so, how much and how often?
- What medicines are you taking?
- Do you have health issues such as high blood pressure, high cholesterol, diabetes or another condition that could affect your heart?