The human heart is not all about muscles and blood supply, as most discussions around heart would like to believe.

It is primarily more to do with the heartbeat. The muscular action and flow of blood which keeps the heart in a working condition is an intricate network of electrical conduction system. It is this electrical system which passes electrical impulses through the heart causing it to beat. This essentially means that the electrical system causes the heart to contract by pumping the blood throughout the body and to lungs. The coordination of rhythmic contractions of heart muscles through electrical signals causes your heart to beat.

Issue with electrical system of the heart is much more critical in nature. In case of any malfunction of the conduction system, the heart can stop beating, instantly triggering a cardiac arrest which is almost instantaneously fatal, leaving seconds to recuperate a victim through defibrillation, which is kick-starting the heart with electric shock.

Worst of all, issues with malfunctioning of heart beats are largely asymptomatic, go on without suspicion and difficult to diagnose. Therefore, accurate reading of heart rhythms is essential and which is why doctors prescribe electrocardiogram (ECG).

Recording Electrical Activity of Heart

electrical activity of the heart is recorded by electrocardiogram, which includes heart rhythm, heart rate, and shows if there are any changes in the heart due to hypertension or previous heart attack or any genetic malfunction. It is the basic level of testing which provides the doctor with the window to your heart’s activities,” said Dr. Vanita Arora of Max Super Speciality Hospital.

An ECG is usually prescribed if there is some existing heart condition that merits testing. Otherwise, a doctor may suspect conduction issues in your heart, especially if you are complaining of arrhythmias, and may want to read your heart rhythm for further diagnosis.

Reading the Heart Rhythm Right

According to Dr. Sanjay Mittal of Columbia Asia Hospital, Ghaziabad, it is important to note that even in the state of rest, there is significant variation in flow of current and electric conduction system of the heart.

“Superficially, the heart may seem to be beating in sync but ECG tries to capture the subtle fluctuations in the cardiac rhythm. Studying ECG strips correctly needs years of experience, as multiple factors are involved and the conduction process of heart in itself has many aspects to it. Drawing correlations to family history, medical history of the patient, risk factors of heart diseases, and other aspects are done to draw a clinical assessment. Therefore, it is advisable to consult an expert or senior cardiologist,” said Dr. Sanjay Mittal.

He further said that while conducting ECG, the machine analyses both depolarisation and repolarisation flow of 12 different ways which are examined closely by an expert. Misreading of any of the 12 leads can lead to incomplete or different interpretation.