https://ecgvn.com/en/tags/pr-interval/ Recent content in Pr Interval on ECG Library – LITFL Basics Hugo en-us Thu, 04 Feb 2021 00:00:00 +0000 https://ecgvn.com/en/posts/pr-interval/ Thu, 04 Feb 2021 00:00:00 +0000 https://ecgvn.com/en/posts/pr-interval/ <p><a href="https://litfl.com/ecg-library/basics/">↪  ECG Basics Homepage</a></p> <h4 id="pr-interval">PR Interval</h4> <p>The <strong>PR interval</strong> is the time from the onset of the P wave to the start of the QRS complex. It reflects conduction through the AV node.</p> <ul> <li>The normal PR interval is between 120 – 200 ms (0.12-0.20s) in duration (three to five small squares).</li> <li>If the PR interval is &gt; 200 ms, <a href="https://litfl.com/first-degree-heart-block-ecg-library/">first degree heart block</a> is said to be present.</li> <li>PR interval &lt; 120 ms suggests <a href="https://litfl.com/pre-excitation-syndromes-ecg-library/">pre-excitation</a> (the presence of an accessory pathway between the atria and ventricles) or <strong>AV nodal (junctional) rhythm</strong>.</li> </ul> <p><a href="https://litfl.com/wp-content/uploads/2018/10/ECG-waves-segments-and-intervals-LITFL-ECG-library-3.jpg"><img alt="ECG basics: waves, segments and intervals LITFL ECG library" loading="lazy" src="https://litfl.com/wp-content/uploads/2018/10/ECG-waves-segments-and-intervals-LITFL-ECG-library-3.jpg"></a></p>