Supraventricular tachycardia, or SVT, is an abnormally fast heartbeat that occurs suddenly. It is triggered in the atria, or upper chambers, of the heart. People with SVT feel as if their heart is pounding out of their chest. Cardiac arrhythmias refer to a host of conditions characterized by an irregular heartbeat.
Identification
The heart has a built-in electrical system with special pacemaker cells that produce electrical impulses.These cells send an electrical current down pathways to the heart muscle. When the current happen at the right time, a normal heart rate and rhythm is produced. When the current starts at the wrong time, in the wrong place or goes in the wrong direction, an abnormal heart rhythm occurs. SVT occurs when the current flows in a circle instead of a line. SVT will cause rapid heart rates of 160 to 180 beats per minute in adults, more than 180 beats per minute in children and more than 220 in infants.
Causes and Risks
SVT can be triggered from physical or psychological stress. Some people have recurrent episodes of SVT from an abnormal development in the electrical pathways at birth. In otherwise healthy people, SVT requires very little medical treatment; however, older adults with underlying heart disease may be predisposed to heart failure or heart attacks due to SVT.
Symptoms
Adults and children with SVT will most often complain of palpitations, chest pain and shortness of breath. Fainting and dizziness are also common clinical symptoms associated with SVT. Infants may present with poor feeding, irritability and vomiting, and may have rapid breathing and pale skin.
Treatment
SVT may be managed with simple measures like bearing down as if having a bowel movement. Some individuals will require medications such as beta-blockers, calcium channel blockers and antiarrhythmic agents, or drugs that regulate hearth rhythms. If the SVT cannot be managed with medication alone, a procedure call a radiofrequency catheter ablation may be preformed by a specialist. This procedure uses radio waves to eliminate the abnormal electrical pathway. SVT is diagnosed by an electrocardiogram.
Expert Insight
Anyone experiencing signs and symptoms of SVT should notify a doctor, who may direct the sufferer to be seen in the emergency department. Signs and symptoms of SVT should not be ignored, as the condition can be fatal.
References
- "Emergency Nursing Core Curriculum"; Saunders; 2007
- "Advanced Cardiac Life Support"; American Heart Association; 2006
- "Pediatric Advanced Life Support"; American Heart Association; 2006
