Electrocardiography (EKG)

Overview

An electrocardiogram or Electrocardiography (EKG or ECG) is a test that determines the electrical activity of the heartbeat. With every beat, an electrical impulse (or “wave”) flows through the heart. This wave allows the muscles to squeeze and pump blood from the heart. A normal heartbeat on EKG displays the timing of the top and lower chambers. This test is used to check for cardiac disease symptoms as well as a routine check-up to record the ticker’s electrical activity through little electrode patches attached to your chest, arms, and legs. EKGs are quick, painless, and safe procedures.

Why do doctors recommend this procedure?

An EKG may be recommended by the heart specialist (cardiologist) or your primary physician who thinks you might have a problem with your heart. An EKG provides two significant types of information. First, by measuring the time intervals on the EKG, a doctor can determine the time taken for the electric impulse to pass through the heart’s chambers. This time determines whether the electrical activity is regular or slow, fast or irregular. Second, by measuring the electrical activity extent passing through the heart muscle, a cardiologist can estimate if cardiac parts are enlarged or overworked. With this test, the doctor can:

• Check heart rhythm
• See if there is a poor blood flow to your heart muscle (ischemia)
• Identify a heart attack
• Check abnormal things like thickened heart muscle
• Detect any significant electrolyte abnormalities, like high potassium or high or low calcium.

What are the different types of EKG?

There are three main types of EKG, as follows –

1. Resting EKG – This is performed when you are in the lying down position. It is a traditional EKG wherein you must visit the hospital, a lab or a diagnostic imaging center to carry out the testing. Once the procedure is completed, you can return home and carry out your activities as usual.
2. Stress or Exercise EKG – This is performed while you are using an exercise bike or treadmill or have an injection of a pharmaceutical agent that increases the heart rate. It allows the doctor to check how far any stimulus can stimulate your heart and its subsequent response. Typically, the test begins with graded exercises and gets more difficult as you go further.
3. Ambulatory EKG – This method allows monitoring of your heart for 1 to 2 days at home. The electrodes connect to a small portable machine worn typically at your waist. This method is preferred when your heart’s rhythm only shows abnormalities occasionally. The electrodes are connected to their appropriate positions, and you can carry out your activities as usual, except showering. After a couple of days, when the machine is removed, the doctor can review your EKG reports and check the risk factors for your heart.

How should I prepare?

You are advised to take care of the following preparatory measures before EKG:

• Avoid oily skin creams and lotions the day of the test since they can keep the electrodes from contacting your skin.
• Avoid full-length hosiery since electrodes need to be placed directly on your legs.
• Wear a loose shirt that you can remove easily to put the leads on your chest.
• You can eat normally before the test.

What happens during an  EKG?

There are several ways an EKG can be carried out. Usually, the test involves attaching several small and sticky sensors called electrodes to your arms, legs, and chest. Wires connect these to an ECG recording machine.

With each beat, the electrical impulse (or “wave”) travels through the heart. This wave allows the muscles to squeeze and pump blood from the heart. A normal heartbeat on EKG will show the timing of the upper and lower chambers. The right and left atria form the first wave called a “P wave,” followed by a flat line when the impulse travels to the lower chambers. The right and left bottom chambers or ventricles make the next wave called a “QRS complex.” The final wave or “T wave” represents electrical recovery or return to a resting state for the ventricles.

What am I likely to experience during and after the procedure?

The technologist will fix ten electrodes with adhesive pads to the skin of your chest, arms, and legs. Men may need to shave their chest to ensure the adhesive pads connect properly. During the test, you’ll lie flat while a computer creates a graph of the electrical impulses that move through your heart. This procedure is called a “resting” EKG, although the same test may be used to check your heart while you exercise.

Report to your doctor if you develop any signs or symptoms similar to what you had before the EKG (for instance, chest pain, shortness of breath, dizziness, or fainting). The test itself typically only lasts a few minutes, and you should be able to resume your normal activities as usual.