Atrioventricular Nodal Reentry Tachycardia (Avnrt)

AVNRT, or atrioventricular nodal reentry tachycardia, is a common type of irregular heartbeat, also known as an arrhythmia. It's the most frequent kind of fast heartbeat that originates above the lower chambers of the heart (supraventricular tachycardia).

People with AVNRT experience a rapid heartbeat that often starts and stops abruptly. This means the heart beats much faster than normal, typically over 100 times per minute. This rapid rhythm is caused by a problem with the electrical signals that tell the heart to beat. Imagine the heart's natural pacemaker is sending out extra signals, causing the heart to beat too quickly.

While AVNRT is sometimes more common in young women, it can affect anyone at any age. Sometimes, AVNRT doesn't cause any problems and doesn't need treatment. However, if symptoms are bothersome, treatment options may include lifestyle changes, like specific exercises or breathing techniques, medications to slow the heart rate, or a procedure to correct the electrical problem in the heart.

A common problem affecting the heart is called atrioventricular nodal reentry tachycardia (AVNRT). In this condition, the heart beats much faster than normal. The heart rate can speed up to between 120 and 280 beats per minute. This rapid heartbeat often begins unexpectedly.

AVNRT doesn't always cause noticeable problems. However, when symptoms do appear, they might include:

• A feeling of a strong, fast beat in your chest or neck. This is often described as a pounding sensation.
• A noticeable thumping or fluttering heartbeat, which is sometimes called palpitations.
• Feeling dizzy or lightheaded.
• Shortness of breath, making it hard to catch your breath.
• Sweating.
• Feeling weak or extremely tired.
• Passing out or nearly passing out.

In children, the symptoms of AVNRT can be less severe. For example, children might experience sweating, have trouble eating or feeding, notice changes in their skin color (such as paleness or bluish tint), and have a fast heartbeat. These symptoms can vary and are less dramatic than in adults.

If you notice your heartbeat changing unexpectedly, schedule a check-up with a doctor.

It's also important to take an infant or child to a doctor right away if you see any of these signs:

• A rapid heartbeat
• Excessive sweating without a clear cause
• Changes in how the child eats or drinks
• Changes in the child's skin color

In urgent situations, call 911 or your local emergency number if you have a very fast heartbeat that lasts for several minutes or if it's accompanied by these symptoms:

• Chest pain
• Feeling dizzy or lightheaded
• Trouble breathing
• Feeling weak or faint

These symptoms could be a sign of something serious, so getting prompt medical attention is crucial.

AVNRT, or atrioventricular nodal reentry tachycardia, is a heart problem caused by a glitch in the heart's electrical system. The heart's electrical signals normally follow a specific route to make the heart beat. In AVNRT, an extra electrical pathway forms, creating a loop that makes the heart beat too quickly. This extra pathway, sometimes called a "re-entry circuit," causes the heart to beat irregularly and not pump blood efficiently.

Doctors don't fully understand why some people develop this extra pathway. Possible reasons might include changes in the heart's structure or other underlying conditions. The extra electrical pathway is what leads to the rapid heart rate in AVNRT.

Atrial-ventricular nodal reentry tachycardia (AVNRT) is a heart rhythm problem that's more common in young women, but anyone can develop it.

Several factors can make a person more likely to get AVNRT. These include:

• Heart problems: Conditions like coronary artery disease (problems with the blood vessels supplying the heart), heart valve disease, and other heart conditions can increase the risk. Heart failure, where the heart struggles to pump blood efficiently, is another risk factor. Congenital heart defects, which are heart problems present at birth, also make a person more susceptible.

• Past surgeries and health issues: Previous surgeries on the heart, lungs, or throat can increase risk. Obstructive sleep apnea, where breathing is interrupted during sleep, can also play a role. Problems with the thyroid gland and lung diseases like chronic obstructive pulmonary disease (COPD) are other factors that might be linked to a higher risk of AVNRT. Uncontrolled diabetes can also increase the risk.

• Lifestyle choices and medications: Stressful emotions can affect heart rhythm. Caffeine, excessive alcohol consumption (defined as 15 or more drinks per week for men and 8 or more for women), smoking, and nicotine use can also elevate risk. Stimulant drugs, including cocaine and methamphetamine, are particularly risky.

• Certain Medications: Some medications, such as those used to treat asthma, allergies, and colds, might increase the likelihood of developing AVNRT. It's important to talk to your doctor about any concerns you have regarding your medications and heart health.

It's important to remember that these are just some factors that might increase the risk of AVNRT. If you have concerns about your heart health, talk to your doctor.

Atrial Ventricular Nodal Reentrant Tachycardia (AVNRT) is a heart condition that can cause a rapid heartbeat. While usually not life-threatening, there are potential problems:

• Making existing heart problems worse: If you already have heart conditions like heart failure or coronary artery disease, AVNRT can make them more difficult to manage. This is because the rapid heartbeat can strain the heart muscle and increase the workload on the heart.

• Sudden cardiac arrest: In rare cases, AVNRT can lead to a complete stopping of the heart's activity, called sudden cardiac arrest. This is a serious emergency requiring immediate medical attention. The rapid heartbeat can disrupt the heart's normal electrical signals, potentially leading to a complete halt in pumping blood.

Doctors diagnose atrioventricular nodal reentry tachycardia (AVNRT) by first talking to you about your symptoms and medical history. They also listen to your heart and lungs with a stethoscope.

To get a clearer picture of your heart health, several tests might be needed.

These tests can help identify AVNRT:

• Blood tests: These tests can check for problems like thyroid issues, which can sometimes cause a fast or irregular heartbeat. They can also look for other medical conditions that might be related.

• Electrocardiogram (ECG or EKG): This common test measures the electrical signals that make your heart beat. It shows how quickly or slowly your heart is working. This is a basic test to start with.

• Holter monitor: A small, portable ECG machine that you wear for a day or more. This records your heart's activity throughout your daily life, including when you're resting and moving around. It can pick up irregular or fast heartbeats that might not show up on a regular ECG.

• Echocardiogram: This test uses sound waves to create images of your heart as it beats. It shows the size of your heart and how blood is flowing through it. This helps doctors see the structure and function of your heart.

• Exercise stress tests: These tests often involve walking on a treadmill or riding a stationary bike while your heart activity is monitored. This shows how your heart responds to physical activity. If you can't exercise, medication might be used to simulate the effects of exercise on your heart.

• Electrophysiological study (EP study): This test helps pinpoint where the irregular heartbeat originates within your heart. During the EP study, a doctor inserts thin, flexible tubes (catheters) into a blood vessel, usually in your groin, and guides them to different parts of your heart. Sensors at the tips of these catheters record the heart's electrical signals. This detailed test helps pinpoint the exact location of the problem.

Supraventricular tachycardia (SVT) is a condition where your heart beats too fast and irregularly. This happens because of problems with the electrical signals that control your heartbeat. These signals start in the top chambers of your heart and cause a series of extra, early beats.

Many people with a type of SVT called atrioventricular nodal reentry tachycardia (AVNRT) don't need any treatment. Their heart rate might speed up occasionally, but it doesn't cause significant problems. However, if the fast heartbeat happens often, lasts a long time, or makes you feel unwell, treatment might be necessary.

If treatment is needed, there are several options:

• Simple Actions (Vagal Maneuvers): Certain actions can help slow your heart rate. These include:

  • Coughing: A forceful cough can sometimes help.
  • Bearing Down: Trying to have a bowel movement, but not actually going, can also work.
  • Neck Massage: Gently massaging the main artery in your neck can affect the vagus nerve, which controls your heartbeat.
  • Ice on Face: Placing an ice pack on your face can also help. These actions all stimulate the vagus nerve, which helps regulate your heart rate.

• Medication: If the fast heartbeat happens frequently, a doctor might prescribe medicine to help slow down or control your heart rate. These medications work by affecting the electrical signals in your heart.

• Cardioversion: In some cases, a cardioversion procedure is used. This involves using small paddles or patches placed on your chest to deliver a controlled electric shock to your heart. This shock can help reset the heart's rhythm. Cardioversion is usually considered only after other methods, like vagal maneuvers and medications, haven't been successful.