Supraventricular tachycardia (supraventricular tachycardia/SVT) is a type of heart rhythm disorder, in which the heart beats faster than normal, which originates from electrical impulses in the atria or atria (spaces above the heart chambers or ventricles), namely the AV node.
SVT occurs when the electrical impulses that regulate the heartbeat don't work normally. As a result, the heart beats so fast that the heart muscle cannot relax between contractions. When this condition occurs, the heart's ventricles cannot contract strongly so they cannot meet the needs of the blood supply needed by the body, including the brain. This condition can make the sufferer feel dizzy or faint.
Supraventricular tachycardia can occur at any age. Most sufferers experience only occasional SVT, and can live a normal life. However, this condition can cause problems when symptoms persist, especially in patients who have previously had problems with the heart.
Supraventricular Tachycardia Symptoms
Supraventricular tachycardia is characterized by a heart rate that is faster than normal.
with the following characteristics:
- Symptoms often start and end suddenly.
- Occurs several times each day or once a year.
- Lasts for a few minutes, although sometimes it can last up to several hours.
- It can happen at any age. Most sufferers experience symptoms of SVT at the age of about 25 to 40 years.
Meanwhile, other symptoms that SVT shows are:
- Dizziness or dizziness.
- Sweating.
- The pulse in his neck was throbbing.
- Faint.
- Chest pain.
- Hard to breathe.
- Feeling exhausted.
- SVT heart rate can reach 140 to 250 beats per minute, which is very high when compared to a normal heart rate of 60-100 beats per minute.
Symptoms in people with SVT with pre-existing heart disease will be more uncomfortable than in people without heart problems. Meanwhile, in some patients, SVT does not show any symptoms at all.
Symptoms of SVT in children are indicated by:
- Pale skin.
- Heart rate exceeding 200 beats per minute.
- Sweating.
Causes of Supraventricular Tachycardia
Supraventricular tachycardia (SVT) occurs when the electrical system that regulates heart rhythm in the body is disturbed. Heart rhythm is regulated by the natural pacemaker (sinus node) located in the right atrium. These nodes produce electrical impulses that start each heartbeat. From the sinus node, impulses pass through the atria causing the atrial muscles to contract, thereby pumping blood into the ventricles of the heart. Next, the node arrives at a group of cells called the atrioventricular (AV) node, which is the single pathway of electrical signals from the atria to the ventricles. This AV node slows down electrical signals to the ventricles, so that the ventricles fill with blood before contracting and pumping blood to the lungs or the rest of the body, as a result of these electrical signals.
When there is a disturbance in the AV node, the heart beats very fast, so that the heart does not have time to fill with blood before contracting again. As a result, other organs, such as the brain, do not get an adequate supply of blood or oxygen.
Of the many types of supraventricular tachycardia, the three most common are:
- Atrioventricular nodal reentrant tachycardia (AVNRT). This type can occur at any age, but is more common in young women. In this condition, these cells near the AV node do not transmit electrical signals properly, but instead create circular signals that cause additional beats.
- Atrioventricular reciprocating tachycardia (AVR). This type is most commonly found in adolescents. Normally, one signal sent by the sinus node ends after passing through all the chambers in the heart. In AVRT, however, the signal loops back to the AV node after passing through the ventricles causing an additional beat.
- Atrial tachycardia. In this condition, in addition to the sinus node, there are other nodes that send electrical impulses causing additional beats. This condition is generally experienced by people with heart or lung disease.
Several factors can also increase a person's risk of developing SVT, including:
- Have heart disease or have had heart surgery. Heart disease can be in the form of coronary heart disease, heart valve disease, cardiomyopathy, and congenital heart disease.
- Suffering from other medical conditions, such as thyroid hormone disorders, diabetes, and sleep apnea.
- Physical exhaustion.
- Experiencing anxiety or stress.
- Abusing drugs or smoking.
- Infants, children, and women (especially pregnant women).
- Take medications and supplements. Several types of drugs and supplements can trigger SVT, including: digoxin for heart failure, theophylline for asthma, and decongestant and anti-allergic drugs for colds (ephedrine, pesudophedrine, phenylephrine).
- Consuming too much caffeine or alcohol.
Supraventricular Tachycardia Diagnosis
After knowing the symptoms experienced by the patient and their medical history, the cardiologist can perform a physical examination. The physical examination includes measuring body temperature and blood pressure, checking the condition of the heart and lungs with a stethoscope, and feeling the condition of the thyroid gland in the neck,
To ensure that the arrhythmia experienced is SVT and to find out the conditions that trigger the patient to experience SVT, the doctor needs to perform a series of supporting tests, which include:
- Electrocardiography, to see the electrical activity of the heart.
- Echocardiography, to show the size, structure, and movement of the heart.
- Holter monitoring, used for a full day to record the electrical activity of the heart during routine activities.
- implantable loop recorder, is a device that is placed under the skin in the chest area, to detect abnormal heart rhythms.
If the test results do not show the patient has an arrhythmia, the doctor may perform other tests, including:
- pressure test (stress test). In this test, the patient is asked to exercise on a stationary bicycle or a bicycle treadmill to see the electrical activity of the heart when it is under pressure.
- Electrophysiological tests and mapping. In this test, the doctor inserts a catheter containing electrodes into a blood vessel in the heart. Once placed, the electrodes can map the spread of electrical impulses throughout the heart.
- Tilted table test. This test is performed for SVT patients who have fainted. In this test, the patient is asked to lie down on a table, and their blood pressure and heart rate are measured. After that, the table will be tilted so that it is as if the patient is standing to see how the heart and nervous system respond to the change in position.
- Cardiac catheterization. This test is done if the pressure test shows abnormal results, while the patient has chest pain, shortness of breath, or fainting. Cardiac catheterization is performed under local anesthesia to identify problems with the heart valves or coronary arteries.
In addition to a series of tests to determine the cause of SVT, blood and urine tests will also need to be done. A blood test is done to check for thyroid disease or heart muscle damage, while a urine test can identify if the SVT is caused by drugs.
Supraventricular Tachycardia Treatment
The focus of treatment for supraventricular tachycardia (SVT) is to lower the heart rate and correct abnormal electrical circuits. Most cases of SVT that occur only occasionally do not require treatment. However, there are some measures that can stop the SVT attack. These efforts are in the form of:
- Cold water technique. Place your face in a bowl of cold water and ice, and hold your breath for a few seconds.
- Valsalva maneuver. Hold your breath, keep your mouth shut, close your nose tight, and blow quickly. The movement affects the nervous system that controls the heart rate, so the heart rate can be slower.
Medical treatment is done if supraventricular tachycardia occurs repeatedly or prolonged. Treatment actions taken by doctors, among others:
- Giving heart rhythm medication, to control SVT until the heart rate returns to normal. Consumption of this drug should be in accordance with the doctor's recommendations to minimize side effects.
- This method provides an electric shock effect on the heart which can affect the electrical impulses in the heart so that the heartbeat returns to normal.
- Ablation through cardiac catheterization. In this procedure, electrodes on a catheter are inserted through the blood vessels of the heart. These electrodes with radio waves can damage or dilate heart tissue, and create electrical blocks along the electrical pathways that cause SVT.
- Insertion of a pacemaker. This device is placed under the skin near the neck bone, to emit electrical impulses to stimulate the heart rate to return to normal.
For people with tachycardia caused by other conditions, such as coronary heart disease, hyperthyroidism, or lung disease, these conditions need to be treated before SVT is treated.
Supraventricular Tachycardia Complications
Complications can occur if recurrent supraventricular tachycardia is not treated completely. Among them are decreased consciousness, a weaker heart, to heart failure.
Supraventricular Tachycardia Prevention
Prevention of attacks of supraventricular tachycardia (SVT) can be done by avoiding the trigger if it is known. In addition, lifestyle changes can also reduce the likelihood of SVT attacks, including:
- Implement a healthy diet.
- Make sure you get enough rest.
- Reducing caffeine or alcohol consumption.
- Quit smoking.
- Be careful when taking drugs that can trigger an accelerated heart rate. For example, over-the-counter medicines for coughs and colds can trigger an accelerated heart rate. In addition, cocaine abuse or methamphetamine can also cause SVT.
- Maintain ideal body weight.
- Manage stress well.