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Understanding the electrocardiogram


The graphic shows a first electrical wave as the electricity moves through the right and left upper chambers of your heart. 

Eincoming wave: the "complex QRS"


Final wave: the "T wave"


The EKG, or electrocardiogram, is the graphic representation of the heart's electrical activity. It can detect certain cardiovascular pathologies. 

With each heartbeat, an electrical wave runs through your heart. This wave causes your heart to contract and blood to pump. 

The gold standard ECG records 12 leads (or roads) of the heart. This configuration is known as hijacking D1

What professionals look for in the EKG chart

A normal heartbeat on the EKG chart will show the time it takes for the electrical wave to travel through your heart. There are 3 distinct patterns:

First wave: The "wave P"

This second pattern shows the electrical energy moving through the right and left lower chambers. 

The final wave represents electrical recovery or a return to resting state for the ventricles. 

By measuring the time intervals on an EKG, doctors can tell if this movement of electricity is too slow, normal, too fast, or even irregular.

What conditions can electrocardiogram devices detect?

EKGs can detect a range of conditions, from angina to serious heart attacks. ECG devices focus on detecting atrial fibrillation. If you think you are having a heart attack, contact emergency services. 

Results you might see:


  • Normal sinus rhythm



  • A sinus rhythm means that your heart is beating in an even pattern.

  • Atrial Fibrillation

  • Atrial fibrillation occurs when the heart's two upper chambers move erratically instead of pumping normally.

  • The wave P on the ECG it disappears and is replaced by a neural baseline. The complex QRS occurs at "irregularly irregular" intervals.

An ambiguous result means that the record cannot be classified. This can happen for many reasons. Heart rate is low: the heart rate received cannot be classified as a recording. To achieve a full resolution, the heart rate must be above 50 bpm during recording. The heart rate is high: a full diagnosis is not possible for a heart rate above 100 bpm.To achieve a full resolution, the heart rate must be below 100 bpm during recording.


Signs of another arrhythmia: an unclear signal may be explained by the presence of an arrhythmia other than atrial fibrillation or a bundle branch block.



The signal is too noisy: there is too much interference to classify the recording. Place your hand on a table or on your thigh, relax, do not talk or move during the recording. See the Best Practices section to learn the right gestures to adopt and those to avoid. If you think you may be having a heart attack (myocardial infarction) or have a medical emergency, call emergency services. 

*With information from

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