Waves, intervals and segments of the EKG


waves intervals 300x175 Waves, intervals and segments of the EKG

In essence the electrocardiogram is a drawing of the hearts electrical activity. The waves and segments of the EKG are therefore best understood in connection with the electrical conduction system of the heart. Here is a short overview:

  • The P wave represents the depolarisation of the atria.

p wave Waves, intervals and segments of the EKG

  • The PQ interval represents the AV conduction (however including atrial conduction) and is measured from the beginning of the P wave to the beginning of the QRS complex.

pq interval Waves, intervals and segments of the EKG

  • The QRS complex represents the depolarization of the ventricles beginning with the septum (the Q wave correspond to septum depolarization) and ending with the ventricular walls.

qrs complex Waves, intervals and segments of the EKG

  • The ST segment starts from the end of the QRS complex and ends at the beginning of the T wave. The ventricles are fully depolarized.

st segment Waves, intervals and segments of the EKG

  • The T wave represents ventricular repolarization. The QT interval (the T wave included) represents the duration of the ventricular systole.

t wave Waves, intervals and segments of the EKG

  • The U wave represents late ventricular repolarization (may not be visible).

u wave Waves, intervals and segments of the EKG

The normal values of the PQ interval, the QRS complex and the corrected QT interval (QTc) are:normal values Waves, intervals and segments of the EKG

– Mathias

{ 8 comments… read them below or add one }

Sharon Grooms August 22, 2011 at 2:31 pm

Absolutely a marvelous review and a great adjunct as a teaching tool for our office.

mimine November 27, 2011 at 3:52 pm

It was a very detailed review. I really have a good grip of the EKG now.

Juanita January 28, 2012 at 11:20 am

Good explanation thank you

Lisa Marie April 2, 2012 at 12:57 am

I have a test tomorrow on EKG and this helped out a lot!! Thank you!!

Skunk Rabbit April 27, 2012 at 11:57 pm

Great review of basic EKG. So helpful.

Penny Minnick May 31, 2012 at 4:24 pm

I am preparing for my state test. Great refresher information.

G September 26, 2012 at 7:54 pm

Great review!! Thank you!!

dawn bartell December 2, 2012 at 9:59 pm

why are leads placed on a fleshy part of the limb

Leave a Comment