https://ecgvn.com/en/tags/fascicular-block/ Recent content in Fascicular Block on ECG Library – LITFL Basics Hugo en-us Tue, 08 Oct 2024 00:00:00 +0000 https://ecgvn.com/en/posts/ecg-conduction-blocks/ Tue, 08 Oct 2024 00:00:00 +0000 https://ecgvn.com/en/posts/ecg-conduction-blocks/ <p>ECG Library summary of the different types of conduction disturbance, with links to read more about each type of conduction block</p> <hr> <h4 id="conduction-blocks">Conduction Blocks</h4> <h5 id="first-degree-block">First-degree block</h5> <ul> <li><a href="https://litfl.com/first-degree-heart-block-ecg-library/">First-degree block</a> PR interval &gt;200 msec (1 large square)</li> </ul> <hr> <h5 id="second-degree-block">Second-degree block</h5> <ul> <li><a href="https://litfl.com/av-block-2nd-degree-mobitz-i-wenckebach-phenomenon/">Mobitz Type I (Wenckebach Block)</a>: progressive prolongation of the PR interval before the missed QRS complex</li> <li><a href="https://litfl.com/av-block-2nd-degree-mobitz-ii-hay-block/">Mobitz Type II (Hay Block)</a>: absence of progressive prolongation of the PR interval before the missed QRS complex</li> <li><a href="https://litfl.com/av-block-2nd-degree-fixed-ratio-blocks/">Fixed ratio blocks (e.g. 2:1, 3:1)</a>: constant relationship between P waves and QRS complexes (e.g. 2:1 = 2 P waves for each QRS complex).</li> <li><a href="https://litfl.com/av-block-2nd-degree-high-grade-av-block/">High grade AV block</a>: 2nd degree AV block with a high P:QRS ratio, producing a very slow ventricular rate</li> </ul> <hr> <h5 id="third-degree-block">Third-degree block</h5> <ul> <li><a href="https://litfl.com/av-block-3rd-degree-complete-heart-block/">Third-degree block</a>: absence of any relationship between P waves of sinus origin and QRS complexes (AV dissociation)</li> </ul> <hr> <h4 id="fascicular-blocks">Fascicular Blocks</h4> <h5 id="left-anteriorfascicular-block-lafb"><a href="https://litfl.com/left-anterior-fascicular-block-lafb-ecg-library/">Left anterior</a><a href="https://litfl.com/left-anterior-fascicular-block-lafb-ecg-library/">fascicular</a> <a href="https://litfl.com/left-anterior-fascicular-block-lafb-ecg-library/">block (LAFB)</a></h5> <ul> <li>Left axis deviation</li> <li>qR complexes in leads I, aVL</li> <li>rS complexes in leads II, III, aVF</li> <li>Prolonged R wave peak time in aVL &gt; 45ms</li> </ul> <hr> <h5 id="left-posterior-fascicular-block-lpfb"><a href="https://litfl.com/left-posterior-fascicular-block-lpfb-ecg-library/">Left posterior fascicular block (LPFB)</a></h5> <ul> <li>Right axis deviation</li> <li>rS complexes in leads I, aVL</li> <li>qR complexes in leads II, III, aVF</li> <li>Prolonged R wave peak time in aVF</li> </ul> <hr> <h5 id="right-bundle-branch-block"><a href="https://litfl.com/right-bundle-branch-block-rbbb-ecg-library/">Right bundle branch block</a></h5> <ul> <li>QRS &gt; 120 ms</li> <li>Dominant R wave in V1</li> <li>RSR’ pattern (“M”) in V1 with wide, slurred S wave (“W”) in V6 (=<strong>M</strong>a<strong>RR</strong>o<strong>W</strong>)</li> </ul> <hr> <h5 id="left-bundle-branch-block"><a href="https://litfl.com/left-bundle-branch-block-lbbb-ecg-library/">Left bundle branch block</a></h5> <ul> <li>QRS &gt; 120 ms</li> <li>Dominant S wave in V1</li> <li>Deep S wave (“W”) in V1 with broad R wave (“M”) in V6 (=<strong>W</strong>i<strong>LL</strong>ia<strong>M</strong>)</li> </ul> <hr> <h5 id="bifascicular-block"><a href="https://litfl.com/bifascicular-block-ecg-library/">Bifascicular block</a></h5> <ul> <li><a href="https://litfl.com/right-bundle-branch-block-rbbb-ecg-library/">RBBB</a> plus either <a href="https://litfl.com/left-anterior-fascicular-block-lafb-ecg-library/">LAFB</a> or <a href="https://litfl.com/left-posterior-fascicular-block-lpfb-ecg-library/">LPFB</a></li> </ul> <hr> <h5 id="trifascicular-block"><a href="https://litfl.com/trifascicular-block-ecg-library/">Trifascicular block</a></h5> <ul> <li><a href="https://litfl.com/bifascicular-block-ecg-library/">Bifascicular block</a> plus 3rd degree AV block</li> </ul> <hr> <h5 id="interventricular-conduction-disturbance"><a href="https://litfl.com/interventricular-conduction-delay-qrs-widening/">Interventricular conduction disturbance</a></h5> <ul> <li>QRS &gt; 100 ms, not due to LBBB or RBBB. Most important causes are <a href="https://litfl.com/hyperkalaemia-ecg-library/">hyperkalaemia</a> or <a href="https://litfl.com/tricyclic-overdose-sodium-channel-blocker-toxicity/">tricyclic antidepressant poisoning</a></li> </ul> <hr> <h5 id="advanced-reading">Advanced Reading</h5> <p>Online</p>