Summary about Disease
Supraventricular tachycardia (SVT) is a type of abnormally fast heart rate that originates from above the ventricles (the lower chambers of the heart). It involves the upper chambers (atria) or the atrioventricular (AV) node. The AV node acts as an electrical relay station between the atria and ventricles. SVT is characterized by a sudden onset and termination of rapid heartbeats, often significantly faster than the normal resting heart rate. While SVT can be frightening, it's usually not life-threatening, especially in individuals with otherwise healthy hearts.
Symptoms
Symptoms of SVT can vary from person to person and depend on the heart rate and duration of the episode. Common symptoms include:
A racing or pounding heartbeat (palpitations)
Dizziness or lightheadedness
Shortness of breath
Chest tightness or discomfort
Sweating
Anxiety
Fainting (syncope) or near-fainting
Fatigue
Causes
SVT is often caused by abnormal electrical pathways in the heart that create a "short circuit," leading to rapid and repetitive signaling. Some common causes and triggers include:
Re-entry circuits: These are the most common cause, where electrical signals travel in a loop within the heart.
AV nodal reentrant tachycardia (AVNRT): A specific type of re-entry circuit within the AV node.
Accessory pathways: Extra electrical connections between the atria and ventricles (e.g., Wolff-Parkinson-White syndrome).
Underlying heart conditions: Such as coronary artery disease, heart failure, or congenital heart defects.
Stimulants: Caffeine, alcohol, nicotine, and some medications.
Stress and anxiety
Thyroid problems
Electrolyte imbalances
Dehydration
Sometimes, the cause is unknown (idiopathic).
Medicine Used
4. Medicine used Medications used to treat or manage SVT include:
Adenosine: Often the first-line drug to stop an acute SVT episode. It temporarily blocks electrical signals in the AV node.
Calcium channel blockers (e.g., Verapamil, Diltiazem): Slow down the heart rate by affecting the AV node.
Beta-blockers (e.g., Metoprolol, Atenolol): Slow down the heart rate and reduce the force of heart contractions.
Antiarrhythmic drugs (e.g., Flecainide, Propafenone, Amiodarone): Help to prevent SVT episodes by regulating the heart's electrical activity. Digoxin may also be used in some cases.
Is Communicable
No, Supraventricular Tachycardia (SVT) is not communicable. It is not an infectious disease and cannot be spread from person to person.
Precautions
While you cannot prevent SVT in all cases, some precautions may help reduce the frequency or severity of episodes:
Avoid triggers: Identify and avoid potential triggers like excessive caffeine, alcohol, nicotine, and stress.
Maintain a healthy lifestyle: Eat a balanced diet, exercise regularly (with your doctor's approval), and get enough sleep.
Manage underlying conditions: Control conditions like high blood pressure, thyroid problems, and heart disease.
Stay hydrated: Drink plenty of fluids, especially during exercise or hot weather.
Learn vagal maneuvers: Practice techniques like the Valsalva maneuver (bearing down as if having a bowel movement), coughing, or applying ice to your face to try to slow your heart rate during an episode. Discuss these with your doctor first.
Take medications as prescribed: If you are prescribed medications for SVT, take them as directed.
Regular check-ups: Schedule regular appointments with your doctor to monitor your heart health.
How long does an outbreak last?
SVT episodes are not considered "outbreaks." Individual episodes can last from a few seconds to several hours. The duration varies depending on the underlying cause and individual factors. Some people experience infrequent, short episodes, while others have more frequent or prolonged episodes.
How is it diagnosed?
SVT is diagnosed through a combination of:
Medical history and physical exam: Your doctor will ask about your symptoms, medical history, and risk factors.
Electrocardiogram (ECG or EKG): This test records the electrical activity of your heart and can identify SVT during an episode.
Holter monitor: A portable ECG that records your heart's electrical activity over 24-48 hours or longer to detect infrequent episodes.
Event monitor: A device you wear for weeks or months to record your heart's activity when you experience symptoms.
Electrophysiologic study (EPS): An invasive procedure where catheters are inserted into blood vessels and guided to the heart to map the electrical pathways and induce SVT. This helps determine the cause and best treatment option.
Timeline of Symptoms
9. Timeline of symptoms The onset of SVT symptoms is typically sudden and abrupt. A typical timeline might look like this:
Sudden onset: A feeling of a racing or pounding heart develops quickly.
Rapid heartbeat: The heart rate increases significantly, often to 150-250 beats per minute or higher.
Associated symptoms: Dizziness, shortness of breath, chest discomfort, or anxiety may develop along with the rapid heart rate.
Duration: The episode lasts from a few seconds to several hours.
Resolution: The heart rate returns to normal, either spontaneously or with treatment. Symptoms subside.
Important Considerations
Seek medical attention: If you experience symptoms of SVT, it's important to see a doctor to get a diagnosis and treatment plan.
Underlying heart conditions: SVT can be more serious in people with underlying heart conditions.
Treatment options: Treatment options range from vagal maneuvers and medications to more invasive procedures like catheter ablation.
Catheter ablation: This procedure uses radiofrequency energy to destroy the abnormal electrical pathways causing SVT and can be curative in many cases.
Individualized care: The best treatment approach depends on the frequency and severity of episodes, underlying health conditions, and individual preferences.