Arrhythmia Information & Pictures : OmniMedicalSearch.com

Arrhythmia, or dysrhythmia, is any irregularity in the heart rate or rhythm which can lead to insufficient pumping of blood. This can mean your heart pumps blood too slow, fast, or in an irregular pattern. When the heart beats faster than normal, it is called tachycardia. When the heart beats too slowly, it is called bradycardia.

Some arrhythmias are not life threatening and temporary. Arrhythmia can be caused by: strong emotions, exercise, Coronary Artery Disease (CAD), electrolyte (i.e., Sodium or Potassium) imbalances in the blood, changes in the heart muscle, injury from heart attack, and in the healing process after heart surgery (1).

Arrhythmias that are more serious contribute to about 500,000 deaths in the US annually. About 330,000 people die annually in the US due to ventricular fibrillation, a type of arrhythmia. Other types of arrhythmias lead to strokes, and formation of blood clots. Approximately 4 million Americans suffer from recurrent arrhythmias, and 850,000 are hospitalized annually for arrhythmia (1,2,3).

Before discussing the various types of arrhythmias, it is important to understand the heart’s complicated electrical system. Every heartbeat sends an electrical signal from the top of the heart to the bottom - causing the heart to contract and pump blood. This process repeats with each new heartbeat.

Every electrical signal of a heart begins in a group of cells called sinus node or sinoatrial (SA) node, which is located in the right atrium (i.e., upper right chamber of the heart). The two upper chambers of the heart are the left atrium and right atrium, and the two lower chambers are called the left ventricle and right ventricle. Each electrical signal travels through special pathways to the right and left atrias causing them to contract and pump blood into the two ventricles. This electrical signal travels further down to another group of cells called the atrioventricular (AV) node, located between the atria and the ventricles, and slows down a bit permitting the ventricles to fill up with blood.

From the AV node, the electrical signal then progresses along a pathway called the bundle of His dividing into right and left bundle branches - causing the ventricles to contract and pump blood to lungs and rest of the body. The ventricles then relax and the process of heartbeat starts all over again in the SA node. (4)

Conditions & Diseases: Cardiovascular System

Arrhythmia

Introduction & Overview