Tachycardia
Tachycardia Causes
An increase in sympathetic nervous system stimulation can lead the heart rate to increase, both by the direct action of sympathetic nerve fibers on the heart and by causing the endocrine system to release hormones such as epinephrine (adrenaline), which have a similar effect. Increased sympathetic stimulation is generally due to physical or psychological stress (the so-called "fight or flight" response), but can also be induced by stimulants such as amphetamines.
Tachycardia Definition
A heart rate over 100 beats a minute is known as tachycardia. Some tachycardias are relatively benign and need no treatment, but others can be life-threatening.
Tachycardia Diagnosis
Tests that monitor the heart rate -- such as electrocardiogram (ECG), holter monitor, and event monitor -- can help in diagnosing tachycardia.
Tachycardia Symptoms and Signs
Some symptoms include: dizzines, shortness of breath, lightheadness, rapid heartbeat, heart palpitation, chest pain, blackouts, visual problems, and fainting (syncope).
Tachycardia Treatment
Treatment of tachycardia is typically directed at chemical conversion (with antiarrhythmics), electrical conversion (giving external shocks to convert the heart to a normal rhythm) or use of drugs to simply control heart rate (for example as in atrial fibrillation).
Drugs used for treatment of Tachycardia
Betapace
Cordarone
Toprol XL