An ECG (electrocardiogram) is a test that records the electrical activity of your heart, including the rate and rhythm. It's usually quick and painless.
ElectroCardioGram
You'll usually have an ECG (electrocardiogram) if
a doctor or healthcare professional thinks you're having
symptoms of
· a heart attack
· coronary heart disease
· problems with how quickly or regularly your heart beats
(arrhythmia) You also may have an ECG
· if you've been diagnosed with a heart condition or
another condition that affects how well your heart works
· before and while taking certain medicines
ARRHYTHMIA
The term "arrhythmia" refers to any problem in the rate or rhythm of a person’s heartbeat.
During an arrhythmia, the electrical impulses may be too fast,
too slow or erratic causing an irregular heartbeat.