In order for the heart to beat properly, the signal must follow an exact course throughout the heart. An arrhythmia is an irregular heartbeat. Almost all heart muscle is capable of acting like the pacemaker. The incidence of arrhythmias increases with age, occurring most frequently in middle-aged adults. People with a history of heart disease, blood chemistry imbalances and some metabolic diseases are at a greater risk for the development of and complications associated with arrhythmias.
Stress can also trigger an arrhythmia.
However, often there is no obvious cause to an arrhythmia. Occasionally the heart rate fluctuates between a rapid and slow heart rate. This can cause the heart rate to increase. The heart tremors rather than beats. Premature heart beat arising from the ventricles cause the heart to pause somewhat before the next regular heartbeat.