What is ECG test?

Frequently Asked Questions:

What is ECG used for?

An electrocardiogram (ECG) is a medical test that measures the electrical activity generated by the heart as it contracts to diagnose cardiac abnormalities. An ECG can reveal a variety of cardiac disorders, such as a rapid, slow, or irregular heart rhythm, a heart defect, coronary artery disease, heart valve disease, or an enlarged heart.

Understanding the test results of ECG Test

If the test is normal, your heart should beat at a consistent rate of 60 to 100 bpm. P waves, a marker of atrial excitement, should be looked for while evaluating the heart rhythm. The ECG exhibits sinus rhythm when every P wave is followed by a QRS complex. Sinus arrhythmia is most likely present if the P waves are irregular.

Men and women had different ECG normal ranges:

Why do I need ECG?

An ECG may be recommended by your doctor to monitor your following health conditions of heart:

• Diagnosis of an irregular heartbeat (arrhythmias)
• Determine whether your heart's chambers have any structural issues.
• Examine the results of any previous cardiac surgery.
• To check whether you have coronary artery disease.

What happens during ECG?

During an ECG test, Lead cables tie-up to 12 sensors (electrodes) will be connected to your chest and limbs. Electrodes are adhesive patches that connect to a monitor through cables. Natural electrical impulses help maintain blood flowing properly by coordinating contractions in different areas of the heart. Thus, the heart's electrical activity is recorded, analysed and printed. Your doctor will interpret the results to see whether it is normal or abnormal.

How to calculate heart rate from ECG?

There are two ways to estimate the heart rate from ECG

1. Estimation method 
   • Draw two lines on the ECG trace
   • Count the number of QRS complexes between the two lines
   • Multiply your answer by 10, provide you with the total number of heartbeats in one minute
   • Remember that this treatment is especially useful for irregular heart rhythms.
2. Mathematical method
   • Count the space between each QRS complex
   • Multiply with 40ms gives you the cycle length
   • The heart rate in beats per minute (bpm) is figured out by dividing the cycle length by 60,000.

What shouldn't you do before an ECG?

A typical ECG requires no extra preparation. Inform your physician about taking any medications or supplements. These can have a significant impact on the outcome of your test. 

You won't be able to do much to prepare for echocardiography. You may go about your daily routine on the day of the surgery because it is non-invasive. As a result, you can wash and have breakfast or lunch before the exam.

On the day of the test, avoid using oily or greasy skin creams or lotions. They obstruct the electrode-to-skin contact.

Because electrodes must be put directly on the legs, avoid wearing full-length hosiery.

Wear a shirt that can be readily removed so that the leads may be placed on your chest.

What does an ECG test detect?

An electrocardiogram (ECG or EKG) is used to detect heart rate and rhythm. This test can frequently reveal heart illness, cardiomyopathy, a heart attack, coronary heart disease, an enlarged heart, or irregular cardiac rhythms that could lead to heart failure. The X-ray of the chest is used to determine whether the heart is enlarged and the lungs are fluid-filled.

Can you have a normal ECG but still have heart problems?

Yes, some individuals with cardiac illness may have a normal ECG reading. Although an ECG is quite accurate in detecting many heart problems, it may not always detect all disorders.  An abnormal reading may not always imply a cardiac problem. As a result, in addition to the ECG, you may also require one or more further tests.

What do you wear for an ECG test?

The Cardiac physiologist will instruct you to remove your top garments for an ECG test and lie down on the bed. Instead, you'll be given a gown to wear. Sticky ECG electrodes will be placed on your chest. The probe must be wrapped in a particular lubricating gel to achieve a clear picture of signals. Clothing can interfere with ECG readings, therefore you may be requested to undress before the test.

Does anxiety affect ECG?

Anxiety may be linked to specific ECG abnormalities, including T-wave inversion, whether it is due to short-term test nerves or a persistent ailment. Stress affects components of the signal-averaged ECG in the atrium.  ST flatness is the most frequent ECG alteration seen with anxiety. These alterations point to pathways via which frequent stresses might cause arrhythmia.

Reach us! Get a medical opinion on the uses, side effects, and precautions of ECG (Electrocardiogram) by consulting our specialists at Yashoda Hospitals.