Supraventricular tachycardia is a faster-than-normal heartbeat. This type of heart rhythm disorder is dangerous, because it can cause sudden cardiac arrest.
Normally, the heart beats about 60–100 beats/minute. However, in people with supraventricular tachycardia, the heart rate can reach 150–220 beats / minute. If not treated immediately, this condition can inhibit blood flow throughout the body.
Types of Supraventricular Tachycardia
Some types of supraventricular tachycardia and their ECG features:
- Atrioventricular nodal reentrant tachycardia (AVNRT): presence of pre-excitation features or Wolff-Parkinson-White syndrome (WPW)
- Atrioventricular reciprocating tachycardia (AVRT): short RP intervals, with varying P wave time and morphology. P waves generally appear after QRS complexes and can be obscured by T waves.
- Abnormal sinus tachycardia: the rate of sinus waves increases (>100 beats/minute) persistently/without any obvious stimulation or no physiological response.
- Atrial tachycardia, which consists of:
- Focal atrial tachycardia: atrial heart rate between 120-300 beats per minute.
- Multifocal atrial tachycardia: shows the presence of at least 3 P. wave morphology
- Macro reentrant atrial flutter (typical atrial flutter): sawtooth appearance.
- Junctional tachycardia: P waves are retrograde because the waves originate from an abnormal point in the atrioventricular (junctional rhythm)
- Accessory pathway-mediated reentrant tachycardia (Mahim’s tachycardia): left bundle branch block (LBBB) features with normal PR intervals
- Paroxysmal supraventricular tachycardia (PSVT): supraventricular tachycardia of sudden onset. A normal wave image appears, followed by an SVT image 
Supraventricular Tachycardia Causes
Supraventricular tachycardia is caused by a disturbance in the heart’s electrical pacemaker system. This condition causes the heart to beat so fast that it does not have time to fill with blood before contracting again. Disruptions to the electric system can be caused by:
- Heart disease
- Heart failure
- Wolf-Parkinson-White Syndrome
- Drug abuse, such as coca**ine or amphetamines.
In addition, there are several factors that are thought to increase a person’s risk of supraventricular tachycardia, namely:
- History of chronic lung disease
- Heart disease
- Have had heart surgery
- Congenital heart disease
- Sleep apnea
- Smo**king habits
- Thyroid disease
- Excessive consumption of caffeinated and alco**holic beverages
- Use of medications, such as asthma, allergies, or the flu medications.
Supraventricular Tachycardia Symptoms
Supraventricular tachycardia symptoms generally arise and disappear suddenly. This condition can also occur several times every day, but it can also arise very rarely, for example once a year. Symptoms can last for a few minutes, but can also persist for up to several hours.
In most cases of SVT, the patient is in the age range of 25 to 40 years. Supraventricular tachycardia is characterized by a faster than normal frequency of heart rate, which is about 140 to 250 times per minute (normal heart rate 60 to 100 times per minute). Symptoms that can be experienced by people, including:
- Heart palpitations.
- Shortness of breath.
- Chest pain.
- The pulse on the neck throbbed violently.
- Feeling exhausted.
- Head dizziness, or feeling floating.
In people with SVT who already have heart problems before, symptoms are felt more severely compared to people who do not have a history of heart problems.
Supraventricular Tachycardia Treatment
When experiencing SVT, the heart beats fast until it can cause a lack of blood supply throughout the body. You are also at risk of experiencing some symptoms such as heart palpitations, sweating, dizziness to fainting.
To overcome the heart that beats fast due to SVT, you can do some simple ways with the valsava maneuver. This technique is a certain way of breathing that increases the pressure in the chest. The valsalva technique is performed by taking a deep breath and holding your breath for about 10 seconds.
Imagine that the muscles of the chest and abdomen become tight and pressing, as if trying to defecate. Take a breath forcefully, then exhale quickly.
If these simple steps do not work, immediately consult a doctor to get proper medical treatment.
- Page, R.L., et al., 2015 ACC/AHA/HRS Guideline for the Management of Adult Patients With Supraventricular Tachycardia. A Report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines and the Heart Rhythm Society, 2016. 67(13): p. e27-e115.
- Image: James Heilman, MD, CC BY-SA 3.0 https://creativecommons.org/licenses/by-sa/3.0, via Wikimedia Commons
- Video: UIChildrens