Lectures

ECG Tracing: Normal Intervals – Electrocardiogram

by Thad Wilson, PhD
(1)

Questions about the lecture
My Notes
  • Required.
Save Cancel
    Learning Material 2
    • PDF
      Slides Electrocardiogram CardiacPhysiology.pdf
    • PDF
      Download Lecture Overview
    Report mistake
    Transcript
    So, now, let’s put some numbers to these. So, you could actually measure someone's P wave, their PR interval, their QRS complex, and even their QT interval and know what's normal. Because if you know what's normal, then you can see what pathology might occur if they’re outside these normal ranges. The P wave needs to be somewhere between about 0.08 to 0.1 second. The PR interval, this is very important, needs to be between 0.12 and 0.2 seconds. The QRS complex, we went through earlier, 0.06 to 0.1 second. And finally, the QT interval is a little bit more varied. The QT interval is very dependent upon someone's heart rate. So, you measure your R-R interval and that's part of the equation to calculate what's normal for a QT interval. So, the QT interval is usually less than 0.44 seconds, but it's dependent on heart rate. And so, with a really high heart rate, you have to adjust that number. A very low heart rate, you have to adjust that number. QT intervals are very important for a disease known as sudden cardiac death, in which a person can die, and if you have a prolonged or long QT interval, it is a set up or potentially part of that pathology Okay, so we have the three standard limb leads, 1, 2 and 3. Standard limb lead 1 is taking a picture across the heart n this direction. So, for taking a picture across, we know we have to have two poles. In the right side, we’re going to have a negative pole and the left side we’re going to have a positive pole. This picture then is taken in this direction. Standard limb lead 2 goes from a negative pole on this side to a positive pole down...

    About the Lecture

    The lecture ECG Tracing: Normal Intervals – Electrocardiogram by Thad Wilson, PhD is from the course Cardiac Physiology.


    Included Quiz Questions

    1. Lead II
    2. Lead I
    3. aVR
    4. aVL

    Author of lecture ECG Tracing: Normal Intervals – Electrocardiogram

     Thad Wilson, PhD

    Thad Wilson, PhD


    Customer reviews

    (1)
    4,0 of 5 stars
    5 Stars
    0
    4 Stars
    1
    3 Stars
    0
    2 Stars
    0
    1  Star
    0
     
    Good but there can be improvement
    By Melissa T. on 08. January 2017 for ECG Tracing: Normal Intervals – Electrocardiogram

    Generally good lecture but there are tons of typos everywhere on the slides for cardiac physiology and I'm pretty sure he misspeaks occasionally. Make sure you use another resource to fact check