The heart generates electrical impulses within itself. These impulses make the heart beat.
This electrical activity is recorded with the help of an electrocardiogram (ECG or EKG). Each heart beat starts with an electrical impulse, which makes the heart contract. The activity of the heart contract. The activity of the heart during each beat is recorded on ECG paper. This is the ‘ECG’.
ECG tells us how much damage the heart has suffered as a result of a heart attack.
It also tells us about past events like heart attacks and irregular rate and rhythms (called arrhythmia). High blood Pressure or heart failure may lead to an enlargement of the heart. The ECG detects such changes. The ECG also gives an idea about Valve defects and Congenital Heart Diseases. Effects of drugs on the heart and any changes in blood chemistry are reflected in the ECG tracing.
The ECG changes in the first few hours of a heart attack are so important that heart attack patients are continuously under observation on the ECG monitor. It is only after the ECG and blood tests show stabilization of the heart. That the doctor declares the patient to be out of the simplest and cheapest tests available, and provides the maximum helps in the diagnosis of heart disease.