Supraventricular Tachycardia

Supraventricular tachycardia (SVT) is a problem with your heart's rhythm, causing it to beat too fast or erratically. This fast heartbeat affects the top chambers of your heart. It's sometimes called a paroxysmal supraventricular tachycardia because it can come and go.

A normal heart beats between 60 and 100 times a minute. With SVT, the heartbeat speeds up to between 150 and 220 beats per minute, though it can sometimes go even faster or slower.

Most people with SVT don't need treatment. If treatment is needed, it might involve simple actions like changing positions, or taking medication. Sometimes, a heart procedure or a device to regulate your heartbeat is necessary.

SVT is categorized into several types:

• Atrioventricular nodal reentrant tachycardia (AVNRT): This is the most common type of SVT. It happens when electrical signals in the heart get stuck in a loop in the heart's connecting area.

• Atrioventricular reciprocating tachycardia (AVRT): This is another fairly common type, often seen in younger people. It's similar to AVNRT but involves a different part of the electrical pathway.

• Atrial tachycardia: This type is more often found in people with existing heart problems. The problem with this type happens in the top chambers (atria) of the heart and doesn't involve the connecting area (AV node).

There are other less common types of SVT, including:

• Sinus nodal reentrant tachycardia (SNRT): This involves a loop in the heart's natural pacemaker.

• Inappropriate sinus tachycardia (IST): The heart's natural pacemaker beats too quickly, even when it shouldn't.

• Multifocal atrial tachycardia (MAT): This is when different parts of the upper chambers (atria) are beating too fast in an uncoordinated way.

• Junctional ectopic tachycardia (JET): The electrical signals originate from an area other than the usual pacemaker or connecting area.

• Nonparoxysmal junctional tachycardia (NPJT): The fast heartbeat is continuous, not coming and going.

Understanding the specific type of SVT can help doctors choose the best treatment plan.

Supraventricular tachycardia (SVT) is a condition where your heart beats much faster than normal. This rapid heartbeat, usually between 150 and 220 beats per minute (instead of the normal 60-100 beats per minute), can last from a few minutes to several days. The fast beating often starts and stops suddenly.

Common Symptoms of SVT:

• Palpitations: A feeling of pounding or fluttering in your chest.
• Neck pounding: A noticeable pounding sensation in your neck.
• Chest pain: Pain in your chest.
• Fainting or near-fainting: Losing consciousness or feeling very lightheaded.
• Lightheadedness or dizziness: Feeling unsteady or confused.
• Shortness of breath: Difficulty breathing.
• Sweating: Excessive sweating.
• Weakness or tiredness: Feeling unusually weak or exhausted.

Important Note: Some people with SVT don't experience any noticeable symptoms. In babies and young children, the symptoms might be less obvious and could include:

• Sweating
• Poor feeding
• Changes in skin color
• Fast pulse

When to See a Doctor:

If you have any of these symptoms, especially if they are new or persist, it's crucial to contact a healthcare professional. This is especially important for infants and young children.

When to Call 911 or Emergency Services:

While SVT isn't usually life-threatening on its own, a very fast and irregular heartbeat can sometimes lead to a sudden stop in your heart's activity, called sudden cardiac arrest. This is a serious medical emergency. You should call 911 or your local emergency number if:

• You experience a sudden, very fast heartbeat for the first time.
• An irregular heartbeat lasts for more than a few seconds.
• A fast heartbeat occurs with any of these symptoms:
  • Chest pain
  • Dizziness
  • Shortness of breath
  • Weakness

Important Considerations: Symptoms of SVT could be related to other serious health issues. It's essential to seek prompt medical attention if you have concerns.

Fast heartbeats, called supraventricular tachycardia (SVT), are usually not dangerous on their own, unless you already have a heart problem. However, a very fast, irregular heartbeat can sometimes become so severe that it stops the heart completely. This is called sudden cardiac arrest.

If you experience a fast heartbeat for the first time, or if an irregular heartbeat lasts more than a few seconds, contact a healthcare professional. This is important, as symptoms of SVT can be connected to other, more serious health issues.

Seek immediate medical attention (call 911 or your local emergency number) if you have a fast heartbeat that lasts for more than a few minutes, or if the fast heartbeat comes along with:

• Pain in your chest
• Feeling dizzy or lightheaded
• Trouble breathing
• Feeling weak or tired

Supraventricular tachycardia (SVT) happens when the heart's electrical signals get messed up. Your heart's rhythm is controlled by electrical signals. These signals tell your heart when to beat.

In SVT, something goes wrong with these signals, causing the heart to beat too fast and too early in the upper chambers (called the atria). This rapid heartbeat prevents the heart from filling properly with blood, which can lead to symptoms like lightheadedness or dizziness.

Imagine your heart like a well-oiled machine. A tiny group of cells, called the sinus node, is like the starting mechanism. It sends out an electrical signal that travels through the top chambers (atria). This signal then slows down at a special spot called the AV node before traveling to the lower chambers (ventricles) to make them pump blood.

SVT is essentially an unusually fast and sometimes irregular heartbeat. It happens when faulty electrical signals trigger a series of early beats in the heart's upper chambers.

To understand SVT, it helps to know how a normal heartbeat works. The heart has four chambers: two smaller, upper chambers called atria, and two larger, lower chambers called ventricles. A group of cells in the upper right chamber, called the sinus node, is the heart's natural pacemaker. It creates the electrical signals that start each heartbeat.

These signals travel across the atria. Then, they reach another group of cells called the AV node, where the signals are slowed down. After that, the signals go to the ventricles, causing them to contract and pump blood.

In a healthy heart, this process happens smoothly. A resting heart usually beats between 60 and 100 times a minute. But in SVT, the heart beats much faster, often between 150 and 220 times per minute. This rapid beating can be uncomfortable and even dangerous if it continues for too long.

Rapid heartbeat problems (supraventricular tachycardia, or SVT) are a common issue in babies and kids. Women, especially during pregnancy, are also more likely to experience them.

Several factors can raise the chances of getting SVT. 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 effectively, is another risk factor. A birth defect in the heart, called a congenital heart defect, also raises the risk. Having had heart surgery in the past can also be a contributing factor.

• Other health issues: Obstructive sleep apnea, a sleep disorder where breathing is interrupted, can increase the risk of SVT. Problems with the thyroid gland, uncontrolled diabetes, and certain medications can also play a role. Some medications used to treat asthma, allergies, and colds might increase the risk.

• Lifestyle factors: Stressful situations can make SVT more likely. Drinking too much caffeine or alcohol (defined as 14 or more drinks a week for men, and 7 or more drinks a week for women) can also elevate the risk. Smoking and using nicotine products, and using stimulant drugs like cocaine and methamphetamine, can also increase the likelihood of experiencing this rapid heartbeat.

In short, a variety of factors can contribute to SVT, including pre-existing heart conditions, certain medical treatments, and lifestyle choices.

A rapid heartbeat can sometimes mean the heart isn't pumping enough blood to the rest of the body. This lack of blood flow can deprive organs and tissues of the oxygen they need to function properly.

If a person experiences frequent episodes of a rapid heartbeat called supraventricular tachycardia (SVT) without treatment, their heart may gradually weaken over time. This is particularly important to note if they also have other health problems. A weakened heart can eventually lead to heart failure, where the heart struggles to pump enough blood throughout the body.

A very fast or severe episode of SVT can lead to fainting, or a complete stopping of the heart's function, a condition known as sudden cardiac arrest. This is a serious medical emergency.

Lifestyle changes that help control supraventricular tachycardia (SVT) can also help prevent future episodes. Here are some helpful tips:

Maintain a Healthy Heart: A heart-healthy lifestyle is key. This means eating foods that are good for your heart, like fruits, vegetables, and whole grains. It also means avoiding smoking and getting regular physical activity. Exercise helps your heart stay strong and healthy, and it can also help manage stress. Stress can sometimes trigger SVT episodes. Finding healthy ways to manage stress, such as meditation or yoga, can also be beneficial.

Limit Caffeine: While moderate amounts of caffeine usually aren't a problem for most people with SVT, large amounts can sometimes trigger episodes. It's best to limit your intake of caffeinated drinks like coffee, tea, and soda.

Be Mindful of Medications: Some medications, even over-the-counter ones, contain stimulants that can trigger SVT. Always talk to your doctor or pharmacist about any medications you're taking, including those you buy without a prescription. If you have a history of SVT, it's important to discuss any new medications with your doctor before starting them. They can help you determine if the medication is safe for you and whether it might increase your risk of SVT episodes.

Diagnosing Supraventricular Tachycardia (SVT)

Doctors use several tests to figure out if someone has SVT, a condition where the heart beats too fast. These tests help pinpoint the cause and find the best treatment.

Basic Tests:

• Blood tests: Doctors might take a blood sample to check for other possible reasons for a fast heartbeat, like problems with the thyroid gland.

• Electrocardiogram (ECG or EKG): This simple test records the electrical activity of the heart. Small, sticky pads (electrodes) are placed on your chest, sometimes on your arms or legs. The ECG shows how quickly or slowly your heart is beating. Even some smartwatches can do ECGs, so ask your doctor if this is an option.

• Holter monitor: This portable ECG machine records your heart's activity for a day or two while you go about your normal daily routine. It can detect irregular heartbeats that might not show up in a regular ECG.

• Event recorder: Similar to a Holter monitor, but it only records your heart's activity for short periods when you're having symptoms. You press a button when you feel the fast heartbeat. This device is usually worn for about a month. Some newer models automatically record irregular heartbeats.

• Implantable loop recorder: This device is placed under the skin and continuously records your heart's activity for up to three years. It's like a permanent event recorder. This helps doctors understand how your heart beats during everyday activities.

• Echocardiogram: This test uses sound waves to create pictures of your heart. It shows how blood flows through your heart chambers and valves. Doctors can see if there are any problems in the heart's structure that might be contributing to the fast heartbeat.

More Advanced Tests:

• Exercise stress test: Sometimes, exercise can trigger or worsen SVT. During this test, you walk or cycle on a machine while your heart is monitored. This helps see how your heart reacts to physical activity. If you can't exercise, medicine may be given to increase your heart rate, mimicking exercise. An echocardiogram might also be done during the stress test.

• Electrophysiology (EP) study: This test helps pinpoint where the abnormal electrical signals causing the fast heartbeat originate in the heart. A doctor inserts thin, flexible tubes (catheters) through a blood vessel, usually in the groin, and guides them to different parts of the heart. Sensors at the ends of the catheters record the heart's electrical signals. This test is often used to diagnose specific types of fast heartbeats and irregular rhythms.

These tests help doctors understand the cause of your SVT and develop the best treatment plan. Different tests are used depending on the individual circumstances.