Any irregularity in your heart's natural rhythm is called an arrhythmia. Almost everyone's heart skips or flutters at one time or another, and these mild, one-time palpitations are harmless. But there are about 4 million Americans who have recurrent arrhythmias, and these people should be under the care of a doctor.
Arrhythmias can be divided into two categories:
- Ventricular - Ventricular arrhythmias happen in the heart's two lower chambers, called the ventricles.
- Supraventricular - Supraventricular arrhythmias happen in the structures above the ventricles, mainly the atria, which are the heart's two upper chambers.
Arrhythmias are further defined by the speed of the heartbeats.
A very slow heart rate, called bradycardia, means the heart rate is less than 60 beats per minute. Tachycardia is a very fast heart rate, meaning the heart beats faster than 100 beats per minute. Atrial fibrillation results from a very rapid and uncoordinated contraction of the top chambers of the heart. Atrial fibrillation puts patients at risk for stroke. Ventricular fibrillation results from rapid and chaotic quivering of the lower chambers and unless promptly corrected, it leads to instant sudden death.
Many factors can cause your heart to beat irregularly, for example, Wolfe-Parkinson-White Syndrome or Supraventricular Tachycardia. Some people are born with arrhythmias, meaning the condition is congenital. Some medical conditions, including many types of heart disease and high blood pressure may be responsible for arrhythmias. Also, stress, caffeine, smoking, alcohol, and some over-the-counter cough and cold medicines can affect the pattern of your heartbeat.
Symptoms of a heart arrhythmia depend on the health of your heart and the type of arrhythmia. Symptoms also depend on how severe the arrhythmia is, how often it happens, and how long it lasts. Some arrhythmias do not produce any warning signs.
