Supraventricular Tachycardia

The three common types of supraventricular tachycardia are

• Atrioventricular Nodal Reentrant Tachycardia (AVNRT): This is the most common type of Supraventricular tachycardia. It is caused due to the extra pathway called the reentrant circuit located near the atrioventricular node that makes the heart beat faster. It is most common in young women but can affect anyone.

• Atrioventricular Reciprocating Tachycardia (AVRT): It is a rhythm problem in the heart that makes the heart beat faster. It is caused due to an extra connection between the upper and lower chambers. It commonly occurs in children or teenagers.

• Atrial Tachycardia: It refers to a faster heartbeat that commonly occurs in people with heart disease. It may also occur in people who had heart surgery or are pregnant. It is triggered by infections, medications, or alcohol.

SVT refers to the heart suddenly beating faster; its symptoms include:

• Rapid heartbeat for several minutes
• Pounding in the chest
• Weakness and tiredness
• Dizziness
• Shortness of breath and sweating
• Fatigue

Symptoms in young children are very difficult to identify. They include sweating, poor food intake, rapid pulse, or pale skin. Supraventricular tachycardia is not life-threatening. If a person has heart problems, an episode of supraventricular tachycardia can cause cardiac arrest or unconsciousness.

Consult the doctor if the episode lasts for a long duration or if the patient experiences the given symptoms.

An electric system controls the heart rhythm. If this electrical system doesn't function properly, it can lead to Supraventricular tachycardia. This suddenly makes the heart beat faster. Supraventricular tachycardia episodes can be caused by triggers such as exercise stress or lack of sleep.

Other factors that may cause supraventricular tachycardia episodes are

• Heart disease
• Heart failure
• Other heart problems such as Wolff Parkinson White syndrome
• Too much alcohol intake or smoking
• Drug abuse
• Chronic lung disease
• Pregnancy 
• Medications

Diagnosis for supraventricular tachycardia includes a physical examination, questions about current symptoms, and medical history.

Supraventricular tachycardia can be diagnosed using the following tests:

• Electrocardiogram: ECG refers to recording the electrical activity of the heart. This test measures the duration and timing of each electrical phase in a heartbeat. The test shows how fast or slow the heart beats.

• Blood tests: A blood test can be recommended when the symptoms indicate health problems such as thyroid disease.

• Holter Monitor: This test is a portable ECG device that can be worn for a full day to record heart activity throughout the day, monitoring daily activity.

• Echocardiogram: This test uses sound waves to create an image of the heart in motion. The image provides details about the heart and its valves.

• Loop recorder: Implantable loop recorder is a device that detects the heart's irregular rhythms. It is implanted under the skin of the chest.

• Exercise stress test: Supraventricular tachycardia can be triggered by stress and exercise. The person is asked to walk on a treadmill or a stationary bicycle to monitor their heart's activity. 

• Electrophysiological study: In this test, a thin, flexible tube or tube is inserted through a blood vessel and attached to various parts of the heart. The sensors on the tips of the catheter record the heart's electrical patterns. The study helps the doctor to see the electrical signals through each heartbeat.
• Tilt table test: This test is considered if a person has experienced fainting. In this test, a person's heart rate and blood pressure and monitored while the person lies flat on the table. The table is then tilted to observe how the heart and the nervous system respond to the sudden change in angle.

If the episodes of Supraventricular tachycardia last for only a few minutes, the treatment may not be needed. It can be easily controlled. The most common treatments for the condition include

• Medicine: Medicine to control the episodes in the form of tablets or injected through a vein.

• Catheter ablation: Treatment in which thin tubes are inserted through a vein into the heart to correct the supraventricular tachycardia problem using an electrical system. This method permanently treats the disease.

• Carotid sinus massage: In this treatment, the doctor applies gentle pressure where the carotid artery splits into two branches in the neck. This massage helps the body to release chemicals that slow down the heartbeat.

• Pacemaker: This treatment uses a small implantable device to stimulate the heart to beat at a normal rate. The device is implanted inside the skin near the collarbone using minor surgery. The device is connected to the heart using a wire.
• Cardioversion: In this treatment, small electric shocks are given to the heart to bring the rhythm back to normal.

Supraventricular tachycardia is common in infants, children, and young adults. Other factors that may increase the risk include

• Age: Few types of supraventricular tachycardia are common in children, young adults, and middle-aged people.
• Thyroid disease: An overactive or underactive thyroid gland or thyroid disease can increase the risk of supraventricular tachycardia.

• Sleep apnoea: Obstructive sleep apnoea refers to interrupted breathing during sleep; this condition can increase the risk of supraventricular tachycardia.

• Drugs: Abuse of illegal drugs such as cocaine or amphetamines can trigger an episode.

An episode of supraventricular tachycardia can be controlled or prevented by avoiding its triggers. Taking a few precautionary steps can help to reduce the chances of having the episodes.

• Limit the intake of caffeine and alcohol
• Stop smoking
• Get enough rest and sleep
• Monitor the use of medications
• Exercise regularly

A person experiencing this condition can lead a normal life by taking a few precautions. In normal cases, it is easily curable and may not lead to any major health conditions.

Supraventricular tachycardia after major exercise or physical activity is normal and does not need any treatment. If the condition lasts longer than normal, it may cause problems.