It's with you your entire life, yet you probably don't notice it much: your heartbeat. When normal, the heartbeat is nice and regular, and has just the right rate. But when things aren't quite right -- when the heartbeat is too fast or too slow, or just too irregular -- it's known as a cardiac arrhythmia (heart rhythm problem), which is among the most common of the heart disorders.
Most people, in fact, have occasional cardiac arrhythmias. The significance of cardiac arrhythmias can vary tremendously. Many arrhythmias are completely benign and inconsequential, while others are extremely dangerous and life-threatening. Here you will find an overview on heart rhythm problems, including the types of heart arrhythmias, the symptoms they cause, how they are evaluated, and how they are treated.
The Basics: The Heart's Normal Electrical System
You might find it useful to begin with a review of the normal electrical system of the heart, which regulates the heart rate and heart rhythm.
The Various Types of Cardiac Arrhythmias
While there are many types of cardiac arrhythmias, they can be divided into four general groups, which you can read about here:
- "extra" heart beats, known as premature atrial complexes (PACs) or premature ventricular complexes (PVCs)
- bradycardias, or arrhythmias that make the heart rhythm too slow
- tachycardias, or arrhythmias that make the heart rhythm too fast. One of the most common tachyarrhythmias is atrial fibrillation.
- disorders affecting the bundle branches, referred to as bundle branch block, or BBB. While BBB is not strictly a cardiac arrhythmia (since it's not really the heart rhythm, but instead the pattern of conduction of the electrical signal that is disordered in BBB), cardiologists usually lump it in with the heart rhythm disturbances, so we will do the same.
Symptoms of Cardiac Arrhythmias
Despite the fact that there are many different cardiac arrhythmias, the symptoms caused by these arrhythmias generally fall into only four major categories. Follow the links to learn more about these symptoms, and what kinds of arrhythmias may cause them.
Diagnosing and Evaluating Cardiac Arrhythmias
Diagnosing a heart rhythm problem generally requires "capturing" its electrical signal on an electrocardiogram (ECG). Read here about diagnosing cardiac arrhythmias.
Treating Cardiac Arrhythmias
Just as there are many types of heart rhythm problems, many treatment options are available. Deciding which treatment to use for which arrhythmia can be challenging even for cardiologists. The most common options for treating cardiac arrhythmias include:

