Sometimes referred to as cardiac arrhythmia, cardiac dysrhythmia is the accurate medical term for an irregular or abnormal heart rate. Cardiac dysrhythmia occurs when the average adult heart rate falls below or rises above the normal range of 60 to 100 beats per minute. Cardiac dysrhythmia can be life threatening.

When the heart rate drops below 60 beats per minute, this condition is known as bradycardia. Bradycardia is generally not a life threatening form of cardiac dysrhythmia, but it can cause aggravating symptoms. If symptoms of bradycardia are persistent, it may be treated by implanting a pacemaker.

The opposite spectrum of cardiac dysrhythmia is when the heart rate rises above 100 beats per minute. This condition is called tachycardia. Tachycardia occurs when the electrical impulses controlling the heartbeat become abnormally fast. Exercise, stress, adrenaline, and stimulant sources such as caffeine can cause tachycardia. Generally, tachycardia is not life threatening unless it becomes so fast it causes blood pressure to drop and interferes with the pumping action of the heart.

Fibrillation is a form of cardiac dysrhythmia that can be fatal. It occurs when the heart begins a quivering rhythm rather than the normal, healthy pumping rhythm of the heart. Fibrillation can effect the atrium or the ventricle. Atrial fibrillation is an irregular quivering of the upper chambers of the heart and can indicate a problem with the heart. Though atrial fibrillation is not necessarily immediately life threatening, the condition should be evaluated by a physician.

Ventricular fibrillation affects the lower chambers of the heart. This form of cardiac dysrhythmia poses an immediate risk of death, as the heart stops pumping blood effectively. Ventricular fibrillation is a form of cardiac arrest and is always a medical emergency that responds only to cardiopulmonary resuscitation (CPR) and defibrillation to restore the heart to more normal pumping.

Though some forms of cardiac dysrhythmia are not emergency situations, any form of cardiac dysrhythmia requires medical attention. Even dysrhythmias that are not emergency situations can be indicators of a more serious underlying cause and should be evaluated by a physician. Symptoms can often be felt through a change in heart rate or pulse, and dysrhythmia can sometimes be discovered during routine physical examines, but the only way to determine a specific diagnosis and assessment of heart rhythm is with an electrocardiogram (ECG or EKG).