Arrhythmias are abnormal heart rhythms that are produced when the natural electrical conduction system of the heart malfunctions. Not all arrhythmias pose health risks. For instance, a temporary arrhythmia caused by alcohol, caffeine, or insomnia is not usually a cause for concern.
Arrhythmias are generally classified into two groups:
(1) Bradycardia: An abnormally slow heart rhythm
(2) Tachycardia: An abnormally fast heart rhythm
Patients with Bradycardia generally have a heart rate of only about 40 to 60 beats per minute. They tend to experience fatigue, dizziness, and episodes of fainting as their hearts do not pump enough blood to supply their brains and other vital organs with sufficient oxygen.
In contrast, patients with Tachycardia have abnormally rapid heart rhythms, usually of more than 100 beats per minute. The main symptoms of this condition are similar to those associated with Bradycardia.
Tachycardia occurs when the atria becomes enlarged by hypertension, inflamed, or damaged by coronary heart disease. If left untreated, the victim may suffer a stroke.
Tachycardia may also occur in the ventricles, which is more dangerous. When the ventricles beat too rapidly, the heart is incapable of filling with blood in between beats, causing blood pressure to drop. Ventricular Tachycardia may worsen and turn into ventricular fibrillation, a potentially fatal condition in which the ventricles merely quiver and do not pump any blood at all. If untreated, ventricular fibrillation will lead to immediate loss of consciousness and death. Arrhythmias can result from a variety of causes and has a strong association with other cardiovascular conditions such as high blood pressure, heart failure, heart valve diseases and coronary artery disease.