ECG Guru - Instructor Resources - Wrong machine interpretation https://www.ecgguru.com/ecg/wrong-machine-interpretation en Right Bundle Branch Block With Machine Interpretation Error https://www.ecgguru.com/ecg/right-bundle-branch-block-machine-interpretation-error <div class="field field-name-field-ecg field-type-image field-label-hidden"><div class="field-items"><div class="field-item even"><a href="/ecg/right-bundle-branch-block-machine-interpretation-error"><img typeof="foaf:Image" src="https://www.ecgguru.com/sites/default/files/RB110.jpg" width="1800" height="713" alt="" /></a></div></div></div><div class="field field-name-field-ecg-interpretation field-type-text-long field-label-hidden"><div class="field-items"><div class="field-item even"><p class="MsoNormal">Today’s ECG is from a 74-year-old man for whom we have no clinical information.&nbsp; It shows a “classic” right bundle branch block.&nbsp; It also shows an example of the ECG machine getting some of the interpretation wrong.&nbsp; An early mistake in the interpretative algorithm caused a cascade of inaccuracies.</p><p class="MsoNormal"><strong>REVIEW of RIGHT BUNDLE BRANCH BLOCK ECG CRITERIA</strong></p><p class="MsoNormal" style="margin-bottom: .0001pt;">&nbsp;&nbsp;&nbsp;&nbsp; *&nbsp;&nbsp; Supraventricular rhythm</p><p class="MsoNormal" style="margin-bottom: .0001pt;">&nbsp;&nbsp;&nbsp;&nbsp; *&nbsp;&nbsp; QRS .12 seconds (120 ms) in width</p><p class="MsoNormal" style="margin-bottom: .0001pt;">&nbsp;&nbsp;&nbsp;&nbsp; *&nbsp;&nbsp; rSR’ pattern in V<sub>1</sub></p><p class="MsoNormal" style="margin-bottom: .0001pt;">&nbsp;&nbsp;&nbsp;&nbsp; *&nbsp;&nbsp; Small, wide S wave in Leads I and V<sub>6</sub></p><p class="MsoNormal" style="margin-bottom: .0001pt;">In right bundle branch block, the initial part of each QRS complex represents the depolarization of the septum and left ventricle.&nbsp; The right ventricle depolarizes late, and is represented by a terminal wave at the end of each QRS.&nbsp; In V<sub>1</sub>, that terminal wave is the R’ and in I and V<sub>6</sub> it is the small S wave.<span style="font-size: 8pt;">&nbsp;</span></p><p class="MsoNormal" style="margin-bottom: .0001pt;"><strong>MACHINE MISTAKES&nbsp; </strong>The first mistake the machine made was in measuring the QRS width. The machine says the QRS is .096 seconds (96 ms).&nbsp; It is actually about .16 - .18 seconds.&nbsp; Look at the second QRS in V<sub>1</sub>, and you will see that it extends almost the full width of a wide block (.20 sec).&nbsp; It is apparent that the machine measured only the left ventricular portion of the QRS complex. Because of this error, the right bundle branch block was not noted.<span style="font-size: 8pt;">&nbsp;</span></p><p class="MsoNormal" style="margin-bottom: .0001pt;">The mistake in measuring the QRS complex resulted in the machine misinterpreting the terminal wave as the ST segment.&nbsp; This resulted in notations in capital letters warning of ST elevation and presence of myocardial ischemia.&nbsp; The j points are actually at the baseline in all leads, indicating NO ST elevation.<span style="font-size: 13.008px;">&nbsp;</span></p><p class="MsoNormal" style="margin-bottom: .0001pt;"><strong>ST and T WAVE CHARACTERISTICS OF RBBB&nbsp; </strong>Typically, in RBBB, the T wave will be opposite in direction from the terminal (RV) deflection.&nbsp; So, when there is an R’, there will be T wave inversion.&nbsp; The j point of the ST segment will not be altered, as the ST segment reflects what is happening in the LEFT VENTRICLE, which is depolarizing normally.&nbsp; That means that an acute ST elevation M.I. will look the same in RBBB as it does without BBB.<span style="font-size: 13.008px;">&nbsp;</span></p><p class="MsoNormal" style="margin-bottom: .0001pt;"><strong>OTHER FINDINGS&nbsp; </strong>With the artifact, and the lack of “small blocks” marked on the ECG paper, it is difficult to say for certain what the P wave width and voltage is, but it is suggestive of P mitrale, &nbsp;or left atrial enlargement.&nbsp; There is a first-degree AV block, with a PR interval of .24 seconds.&nbsp; The axis is slightly leftward, but criteria for left anterior fascicular block are not met.&nbsp; And there is low voltage in precordial leads, and inferior leads.&nbsp; Clinical correlation, including the body size of the patient, would be needed to determine the significance of these abnormalities.<span style="font-size: 13.008px;">&nbsp;</span></p><p>&nbsp;</p><p class="MsoNormal" style="margin-bottom: .0001pt;">The ECG machine’s interpretation can be very helpful.&nbsp; At times, it will remind us to look for something we have forgotten to consider.&nbsp; However, it should never be used exclusively for ECG interpretation. There are many mistakes made by interpretative algorithms, and there is no clinical correlation used except for age and gender.</p></div></div></div><div class="field field-name-field-rate-this-content field-type-fivestar field-label-above"><div class="field-label">Rate this content:&nbsp;</div><div class="field-items"><div class="field-item even"><form class="fivestar-widget" action="/taxonomy/term/716/feed" method="post" id="fivestar-custom-widget" accept-charset="UTF-8"><div><div class="clearfix fivestar-average-text fivestar-average-stars fivestar-form-item fivestar-hearts"><div class="form-item form-type-fivestar form-item-vote"> <div class="form-item form-type-select form-item-vote"> <select id="edit-vote--2" name="vote" class="form-select"><option value="-">Select rating</option><option value="20">Give Right Bundle Branch Block With Machine Interpretation Error 1/5</option><option value="40">Give Right Bundle Branch Block With Machine Interpretation Error 2/5</option><option value="60">Give Right Bundle Branch Block With Machine Interpretation Error 3/5</option><option value="80" selected="selected">Give Right Bundle Branch Block With Machine Interpretation Error 4/5</option><option value="100">Give Right Bundle Branch Block With Machine Interpretation Error 5/5</option></select> <div class="description"><div class="fivestar-summary fivestar-summary-average-count"><span class="average-rating">Average: <span >4</span></span> <span class="total-votes">(<span >3</span> votes)</span></div></div> </div> </div> </div><input class="fivestar-submit form-submit" type="submit" id="edit-fivestar-submit" name="op" value="Rate" /><input type="hidden" name="form_build_id" value="form-iDWHpxO55IoQ-OGph3intopBli-3zKmk4NHSCPUg_qg" /> <input type="hidden" name="form_id" value="fivestar_custom_widget" /> </div></form></div></div></div><div class="field field-name-field-taxonomy field-type-taxonomy-term-reference field-label-above"><div class="field-label">Related Terms:&nbsp;</div><div class="field-items"><div class="field-item even"><a href="/ecg/right-bundle-branch-block-1" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">Right bundle branch block</a></div><div class="field-item odd"><a href="/ecg/rbbb" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">RBBB</a></div><div class="field-item even"><a href="/ecg/wrong-machine-interpretation" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">Wrong machine interpretation</a></div></div></div><ul class="links inline"><li class="addtoany first last"><span><span class="a2a_kit a2a_target addtoany_list" id="da2a_1"> <a class="a2a_dd addtoany_share_save" href="https://www.addtoany.com/share#url=https%3A%2F%2Fwww.ecgguru.com%2Fecg%2Fright-bundle-branch-block-machine-interpretation-error&amp;title=Right%20Bundle%20Branch%20Block%20With%20Machine%20Interpretation%20Error"><img src="/sites/all/modules/addtoany/images/share_save_256_24.png" width="256" height="24" alt="Share"/></a> </span> <script type="text/javascript"> <!--//--><![CDATA[//><!-- if(window.da2a)da2a.script_load(); //--><!]]> </script></span></li> </ul> Tue, 19 Sep 2017 20:33:34 +0000 Dawn 739 at https://www.ecgguru.com https://www.ecgguru.com/ecg/right-bundle-branch-block-machine-interpretation-error#comments