Supraventricular Tachycardia

Overview

Supraventricular tachycardia (SVT) is a type of irregularly fast or erratic heartbeat (arrhythmia) that originates from the heart's upper chambers. It is also known as paroxysmal supraventricular tachycardia. The typical heart rate is around 60 to 100 beats per minute, and a heart rate above 100 beats per minute is considered tachycardia. During an episode of SVT, the heart beats at a rate of 150 to 220 beats per minute, but can sometimes beat faster or slower. SVT is usually not a serious condition and doesn't require activity restrictions or treatment for most people. However, some individuals may need lifestyle changes, medications, or heart procedures to manage symptoms and control rapid heartbeats.

Understanding the disease

Symptoms

The main symptom of supraventricular tachycardia (SVT) is a very fast heartbeat (100 beats a minute or more) that may last for a few minutes to a few days. Additional symptoms may include palpitations, chest pain, neck pounding, fatigue, shortness of breath, lightheadedness or dizziness, sweating, and fainting (syncope) or near fainting. Some people with SVT have no signs or symptoms. If you have an episode of SVT that lasts for more than a few minutes or if you have an episode with chest pain, shortness of breath, weakness, or dizziness, you should call 911 or your local emergency number.

Risk Factors

The risk factors for developing supraventricular tachycardia (SVT) include:

1. Age: Some types of SVT are more common in people who are middle-aged or older.
2. Congenital heart disease: A heart problem present at birth (congenital heart defect) may cause irregular heartbeats such as SVT.
3. Thyroid disease: Having an overactive or underactive thyroid gland can increase the risk of supraventricular tachycardia.
4. Diabetes: The risk of developing heart disease and high blood pressure greatly increases with uncontrolled diabetes.
5. Obstructive sleep apnea: This disorder, in which breathing is interrupted during sleep, can increase the risk of supraventricular tachycardia.
6. Nicotine and illegal drug use: Nicotine and illegal drugs, such as amphetamines and cocaine, may trigger an episode of supraventricular tachycardia. It's important to note that SVT can occur in anyone, regardless of these risk factors.

Development

Supraventricular tachycardia (SVT) develops due to faulty electrical connections in the heart, specifically in the upper chambers (atria). In most cases, the heart signaling process goes smoothly, resulting in a resting heart rate of 60 to 100 beats per minute. However, when there are faulty electrical connections, it causes a series of early beats in the atria, leading to a rapid heart rate. The heart doesn't have enough time to fill with blood before the chambers contract, which can result in symptoms like lightheadedness or dizziness due to insufficient blood and oxygen supply to the brain.

Assessment and Diagnosis

Triage

You should see a doctor if supraventricular tachycardia (SVT) is suspected, especially if you have an episode of a very fast heartbeat for the first time or if an irregular heartbeat lasts longer than a few seconds. Additionally, consult a healthcare provider if you experience any of the following symptoms: chest pain, shortness of breath, weakness, dizziness, sweating, or fainting (syncope) or near fainting. In infants and very young children, signs and symptoms of SVT may be difficult to identify, so it's essential to consult a healthcare provider if you notice any of the listed symptoms or if the child seems pale, poorly fed, or lethargic.

Diagnosis

To diagnose supraventricular tachycardia (SVT), a health care provider will examine you and ask questions about your symptoms and medical history. Blood tests are usually done to check for conditions that can cause similar symptoms, such as thyroid disease. The health care provider may also perform tests such as an electrocardiogram (ECG) or a Holter monitor to evaluate the heart and diagnose SVT. An ECG measures the electrical activity of the heart, while a Holter monitor is a portable ECG device that can be worn for a day or more to record the heart's activity during daily activities.

Management and Treatment

Complications

Potential complications of supraventricular tachycardia (SVT) include:

1. Frequent fainting spells or unconsciousness: The rapid heart rate caused by SVT can reduce the flow of blood to the brain, leading to fainting or unconsciousness.
2. Heart failure: The continuous and rapid beating of the heart can cause it to work harder than normal, potentially leading to heart failure over time.
3. Sudden death caused by cardiac arrest: If the heart rate is not restored to a normal rhythm quickly, it can lead to sudden cardiac arrest, which can be fatal.
4. Ventricular fibrillation: A life-threatening condition where the lower heart chambers contract in a rapid and uncoordinated manner, potentially causing sudden cardiac arrest. Remember that not all people with SVT experience complications, and the severity of complications can vary from person to person. It is essential to work closely with a healthcare provider to manage and treat SVT effectively.

Prevention

supraventricular tachycardia (SVT) can be prevented to some extent. Taking certain precautions and making lifestyle changes can help reduce the risk of experiencing an episode of SVT. Key steps to prevent SVT include:

1. Identify and avoid triggers: Keeping a diary can help you identify triggers such as caffeine, nicotine, and certain medications. Once identified, you can avoid these triggers to reduce the risk of an SVT episode.
2. Maintain a healthy heart: A healthy heart is less likely to experience arrhythmias. To maintain a healthy heart, follow a heart-healthy diet, exercise regularly, maintain a healthy weight, and manage stress.
3. Manage existing medical conditions: If you have other medical conditions like obstructive sleep apnea or heart disease, it is essential to manage them effectively to reduce the risk of SVT episodes.
4. Use medications with caution: Be aware of the side effects of medications, including stimulants that could trigger a rapid heartbeat. Consult with your healthcare provider about any concerns you may have about your medications.
5. Seek prompt medical attention: If you experience symptoms of SVT, such as a rapid heartbeat, palpitations, or shortness of breath, seek prompt medical attention to prevent complications. Remember that not all cases of SVT can be prevented, and each person's situation may be different. It is essential to work closely with your healthcare provider to develop an appropriate prevention plan based on your specific needs.

Treatment

The treatments for supraventricular tachycardia (SVT) vary depending on the type and severity of the condition. Treatment options may include:

1. Lifestyle changes: Maintaining a heart-healthy lifestyle can help prevent SVT episodes. This includes eating a healthy diet, not smoking, getting regular exercise, managing stress, and avoiding stimulants like caffeine and alcohol.
2. Medications: Several medications can be used to treat SVT, including anti-arrhythmic drugs to control or prevent rapid heartbeats, and beta-blockers to help manage symptoms like palpitations and chest pain.
3. Cardioversion: This is a medical procedure that uses electric shocks to restore a normal heart rhythm. It may be used for people experiencing a life-threatening or severely disabling SVT episode.
4. Catheter ablation: This minimally invasive procedure involves inserting a thin tube through a blood vessel and using heat, cold, or radiofrequency energy to destroy the specific heart tissue causing the abnormal heartbeat.
5. Surgery: In rare cases, surgery may be required to treat SVT, typically in cases where other treatments have been unsuccessful or when a person has a pre-existing heart condition that increases their risk of complications. It is important to consult with a healthcare professional to determine the most appropriate treatment for your specific case of supraventricular tachycardia.

Preparing for medical consultation

To prepare for an appointment for supraventricular tachycardia, you should:

1. Make a list: Prepare a list of any symptoms you are experiencing, including those that may seem unrelated to heart arrhythmia. Also, include key personal information, such as a family history of heart disease, stroke, high blood pressure, or diabetes, as well as any major stresses or recent life changes.
2. Medications: Create a list of all medications, including vitamins or supplements that you are taking.
3. Bring a family member or friend: Consider bringing a family member or friend with you to the appointment. They can help remember important information and provide support.
4. Write down questions: Prepare a list of questions to ask your health care provider, such as questions about the most likely cause of your symptoms, appropriate treatment, lifestyle changes, and follow-up care.
5. Be aware of pre-appointment restrictions: Inquire about any pre-appointment restrictions, such as dietary restrictions if your doctor orders any blood tests. By being prepared and actively participating in your appointment, you can ensure that you receive the most accurate and helpful information for managing your supraventricular tachycardia.