Electrocardiogram is used today worldwide as a relatively simple method for diagnosing heart disease.
Electrocardiogram is a simple, painless test that records the electrical activity of the heart. To understand this test, it’s important to know how the heart works. With each heartbeat, an electrical signal (or a wave) is transmitted from the top of the heart to the base (generated by special cells in the upper right upper chamber of the heart). As it advances, the signal causes the heart to contract and pump blood, the process repeating itself with every heartbeat; the electrical signals of the heart set the pace of the heart beats. Right and left atriums or upper chambers create a wave called “P wave” (following a straight line when the electrical impulse goes to the base cells), and left and right ventricles or lower chambers create the next wave called “QRS complex“; final wave or “T wave” and represents electric return to a resting phase for ventricles.
An electrocardiogram may show:
- evidence of volume increase of the heart
- signs of insufficient blood flow to the heart
- signs of new or old heart lesions (infarcts)
- heart rhythm problems (arrhythmias)
- changes in electrical activity caused by electrolyte imbalance