The heart of a healthy adult beats within the range of 60-100 times per minute at rest. This rate is controlled by electrical signals within the heart. An abnormally high pulse rate above 100 beats per minute is also called tachycardia, and it occurs when the heart tissues produce electrical signals rapidly, affecting the upper or lower chamber of the heart, or both.
Tachycardia, or rapid heart rate, may produce either a regular or an irregular rhythm in the heart. At extremely rapid rates, the heart may not be able to pump oxygen-rich blood efficiently to the rest of the body, and may cause symptoms as well as complications.
There are many factors that can cause it. In healthy people, most reasons for having rapid pulses are temporary, although a few other factors may increase one's pulse rate for longer periods.
Rapid heart rates reduce the ability of the heart to pump out blood efficiently to the vital organs like the brain. This deprives the organs of oxygen-rich blood, which can cause the symptoms like dizziness, lightheadedness, fainting spells, palpitations, chest pains, and shortness of breath. Some people, however, do not experience symptoms, especially when tachycardia is temporary or short-lived. In those with underlying medical conditions, tachycardia may be detected during a physical examination or after doing a test called electrocardiogram.
Having chronically rapid pulses may result in complications that depend on the severity of the existing condition and the duration of the tachycardia. These complications may include formation of blood clots leading to stroke or heart attack, heart failure, frequent fainting spells or worst of all, sudden death.
Some stimuli or underlying conditions increase one's risk of having rapid pulse rates, and these are factors that usually put a strain on the heart. These include the heavy use of tobacco, caffeine, alcohol, or recreational drugs, stress and anxiety, high blood pressure, and heart disease.
Other inherent factors that could increase the risk of rapid pulse rates include aging and family history of tachycardia.
The goals of treatment for tachycardia are to stop a fast pulse rate when it occurs, to prevent future occurrences, and to reduce complications.
Fast heartbeats may be self-limiting, but you may be able to slow down your heart rate by using simple vagal maneuvers which can help regulate tachycardia. These can be done by coughing forcefully, bearing down (like when you are constipated) or by simply placing an ice pack on the face.
You may also need medically prescribed medications to stop fast heartbeats, and these include oral anti-arrhythmic drugs like propafenone (Rythmol) or flecainide (Tambocor). If you are brought to the hospital, other anti-arrhythmic drugs may be injected to restore your normal heart rate. In serious cases, a cardioversion may be required, which involves the delivery of a shock wave to the heart using electrical currents.
Future occurrences of tachycardia may be prevented by using different methods, such as the use of anti-arrhythmic medications which may be taken in combination with other heart medications like channel blockers (such as diltiazem and verapamil) or beta blockers (such as metoprolol and esmolol).
When medications fail to prevent further episodes, other means may be employed, such as catheter ablation, pacemaker implantation, or cardioverter-defibrillator implantation (in severe cases). Other people may need an open heart surgery to destroy or interrupt abnormal electrical pathways that cause life threatening tachycardia.
To prevent the formation of blood clots that may lead to stroke or heart attack, doctors may prescribe medications like blood thinners such as dabigatran and warfarin. Aside from these, the underlying conditions such as heart disease or overactive thyroid gland must be treated to prevent future episodes and possible complications.