ECG Guru - Instructor Resources - Paced rhythm https://www.ecgguru.com/ecg/paced-rhythm en Ask The Expert https://www.ecgguru.com/expert-review/ask-expert-12 <div class="field field-name-body field-type-text-with-summary field-label-hidden"><div class="field-items"><div class="field-item even" property="content:encoded"><p class="MsoNormal" style="line-height: 15pt; background-image: initial; background-position: initial; background-size: initial; background-repeat: initial; background-attachment: initial; background-origin: initial; background-clip: initial;"><strong><span style="font-size: 12pt; font-family: 'Lucida Sans Unicode', sans-serif; border-width: 1pt; border-style: none; border-color: windowtext; padding: 0in;">Today’s expert is Dr. Jerry W. Jones, MD, FACEP, FAAEM</span></strong></p><p class="MsoNormal" style="line-height: 15pt; background-image: initial; background-position: initial; background-size: initial; background-repeat: initial; background-attachment: initial; background-origin: initial; background-clip: initial;"><span style="font-size: 9pt; font-family: Verdana, sans-serif; border-width: 1pt; border-style: none; border-color: windowtext; padding: 0in;">Jerry W. Jones, MD FACEP FAAEM is a diplomate of the American Board of Emergency Medicine who has practiced internal medicine and emergency medicine for 35 years. <img src="/sites/default/files/headshot_0.jpg" alt="Dr. Jerry Jones" width="96" height="100" style="float: right;" />Dr. Jones has been on the teaching faculties of the University of Oklahoma and The University of Texas Medical Branch in Galveston. He is a published author who has also been featured in the New York Times and the Annals of Emergency Medicine for his work in the developing field of telemedicine. He is also a Fellow of the American College of Emergency Physicians and a Fellow of the American Academy of Emergency Medicine and, in addition, a member of the European Society of Emergency Medicine.&nbsp;</span></p><p>&nbsp;<span style="font-size: 9pt; font-family: Verdana, sans-serif; border-width: 1pt; border-style: none; border-color: windowtext; padding: 0in;">Dr. Jones is the CEO of</span><a style="font-size: 13.008px;" title="Medicus of Houston Website" href="http://www.medicusofhouston.com/"><span style="font-size: 9pt; font-family: inherit, serif; color: #0062a0; border-width: 1pt; border-style: none; border-color: windowtext; padding: 0in;">&nbsp;Medicus of Houston</span></a><span style="font-size: 9pt; font-family: Verdana, sans-serif; border-width: 1pt; border-style: none; border-color: windowtext; padding: 0in;">&nbsp;and the principal instructor for the Advanced ECG Interpretation Boot Camp and the Advanced Dysrhythmia Boot Camp.</span><span style="font-size: 10pt; font-family: 'Lucida Sans Unicode', sans-serif; border-width: 1pt; border-style: none; border-color: windowtext; padding: 0in;">&nbsp;</span></p><p class="MsoNormal" style="line-height: 15pt; background-image: initial; background-position: initial; background-size: initial; background-repeat: initial; background-attachment: initial; background-origin: initial; background-clip: initial;"><span style="font-size: 20pt; line-height: 107%; color: #00b050;"><br /></span></p><p class="MsoNormal" style="line-height: 15pt; background-image: initial; background-position: initial; background-size: initial; background-repeat: initial; background-attachment: initial; background-origin: initial; background-clip: initial;"><span style="font-size: 20pt; line-height: 107%; color: #00b050;">Question:&nbsp;&nbsp; </span><span style="font-size: 16pt; line-height: 107%; color: #00b050;">What is the cause of an apparent right bundle branch block pattern in a paced rhythm?</span></p><p class="MsoNormal" style="line-height: 15pt; background-image: initial; background-position: initial; background-size: initial; background-repeat: initial; background-attachment: initial; background-origin: initial; background-clip: initial;"><span style="font-size: 16pt; line-height: 107%; color: #00b050;">Answer: &nbsp;</span><strong style="text-align: center; font-size: 13.008px;"><span style="font-size: 20.0pt; line-height: 107%;">Is There a Pacemaker Wire Problem… or Not?</span></strong></p><p class="MsoNormal">&nbsp;<span style="font-size: 13.008px;">During one of my orientations as a young internal medicine house officer, the cardiologist lectured to us on the essentials of how to check pacemakers. Since none of us had any ECG interpretation background our comprehension was less than sterling. But I remember him stressing the point that a properly paced pacemaker lead would result in a left bundle branch block pattern on the ECG. A right bundle branch block pattern in V1, on the other hand, meant that the pacemaker wire had inadvertently wandered into the left ventricle – a highly undesirable situation.</span><span style="font-size: 13.008px;">&nbsp;</span></p><p class="MsoNormal">“Not to worry,” he said. “Such things rarely happen and you will probably retire before seeing such a thing!” That evening I saw my first pacemaker 12-lead ECG with a right bundle branch block pattern in V1. Fate wasted no time with me.</p><p class="MsoNormal">I ordered a 3-view chest x-ray and as far as I could see, the wire looked like it was in the right ventricle where it was supposed to be. I called the cardiologist on-call who happened to be in the hospital at the time and he dropped by the ward. Back then, we didn’t have ultrasound or echo available. But he, too, was convinced the pacemaker wire was in the right ventricle. It really was and so I still hadn’t seen a RBBB pattern due to a pacer wire in the left ventricle. I still haven’t, but I have seen a number of pacemaker ECGs with a RBBB pattern in V1.</p><p class="MsoNormal">How do we know if such a finding represents a real left ventricular pacer wire or a pseudo-malplacement?</p><p class="MsoNormal">First, just be aware that a wire that really IS in the left ventricle is going to present with a RBBB pattern in V1. It will NOT ever present with a LBBB pattern. However, a wire that has been correctly placed in the RIGHT ventricle can – from time to time – present with a RBBB pattern in V1. In my years as an attending in the emergency department, I saw this seven or eight times.</p><p class="MsoNormal">Second, the axis of the pseudo-malplacement tends to demonstrate a significant left axis deviation, between -30 ° and&nbsp;&nbsp; &nbsp;-90 °. Since the right ventricle is activated first, the vector finishes by pointing up and to the left. If the wire were actually located in the left ventricle, the mean frontal axis would be to the right of +90 °</p><p class="MsoNormal">Third, when we look in the precordial leads, we know that Leads V1 and V2 overlie the right ventricle and leads V5 and V6 overlie the left ventricle. Leads V3 and V4 are in between. If the pacemaker wire is in the right ventricle, whatever is causing it to have an RBBB pattern in V1 will disappear before V3. A pacemaker wire in the right ventricle will show a LBBB pattern (QS) by Lead V3. If the wire is truly in the left ventricle, the RBBB pattern will extend to V3 and usually beyond. So a quick check is this: if you see a RBBB pattern in V1 in a pacemaker patient, look at V3. If the RBBB pattern is in V3 also, the wire is truly in the left ventricle. If V3 has a predominately negative QRS (QS), the wire is safely in the right ventricle where it is supposed to be.<span style="font-size: 13.008px;">&nbsp;</span></p><p class="MsoNormal">A fourth check is to look for an S wave in Lead I. Remember: one of the most characteristic features of RBBB is that slurred S wave in Lead I (as well as the other left-sided leads). If the ECG shows an RBBB pattern in V1 and an S wave is present in Lead I, then that is most likely a real RBBB pattern and the wire has somehow made its way into the left ventricle.</p><p class="MsoNormal"><img src="/sites/default/files/Pseudo-Malplacement%20of%20Pacemaker%20Wire_0.jpg" alt="Pseudo Malplacement of Pacemaker Wire" title="Pseudo Malplacement of Pacemaker Wire" width="976" height="759" /></p><p class="MsoNormal" style="line-height: 15pt; background-image: initial; background-position: initial; background-size: initial; background-repeat: initial; background-attachment: initial; background-origin: initial; background-clip: initial;"><span style="font-size: 10pt; font-family: 'Lucida Sans Unicode', sans-serif; border-width: 1pt; border-style: none; border-color: windowtext; padding: 0in;"><br /></span></p></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/pacemaker" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">Pacemaker</a></div><div class="field-item odd"><a href="/ecg/paced-rhythm" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">Paced rhythm</a></div><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/pacemaker-wire-pseudo-malplacement" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">Pacemaker wire pseudo malplacement</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%2Fexpert-review%2Fask-expert-12&amp;title=Ask%20The%20Expert"><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 18:57:01 +0000 Dawn 738 at https://www.ecgguru.com https://www.ecgguru.com/expert-review/ask-expert-12#comments Paced Rhythm Following AV Node Ablation https://www.ecgguru.com/ecg/paced-rhythm-following-av-node-ablation <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/paced-rhythm-following-av-node-ablation"><img typeof="foaf:Image" src="https://www.ecgguru.com/sites/default/files/PM%20110%20AV%20Pacing%20post%20AVN%20ablation.jpg" width="1800" height="912" 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">This ECG is taken from a woman who had suffered for several years with intractable intermittent atrial fibrillation. She had tolerated medications poorly, and several attempts at electric cardioversion had resulted in only temporary relief. Ultimately, she chose to undergo AV node ablation.&nbsp; In the electrophysiology lab, her AV node was destroyed, preventing the atrial fib impulses from penetrating into the ventricles.&nbsp; This resulted in a “man-made” complete AV block.&nbsp; A pacemaker was implanted in the EP lab.&nbsp; When she is in atrial fibrillation, the fibrillatory waves of the atria INHIBIT the atrial pacing electrode from firing, so she has no paced P waves at that time.&nbsp; The right ventricular pacing electrode functions without inhibition, and makes a wide QRS complex with a leftward axis deviation (normal for RV pacing).<span style="font-size: 13.008px; line-height: 1.538em;">&nbsp;</span></p><p class="MsoNormal">In this ECG, we see the patient WITHOUT atrial fib, and the pacemaker is pacing the atria AND the ventricles, in a sequential fashion.&nbsp; The spikes are very hard to see, as this is a “bipolar” pacemaker, which makes much smaller spikes than a “unipolar” pacemaker.&nbsp; Some ECG machines will automatically enhance the spikes, but this one did not.&nbsp; We have marked a “sample” atrial spike in blue for you and one of the ventricular spikes in red.&nbsp; Each beat on this ECG actually has appropriately-timed atrial and ventricular stimuli (spikes), and the patient has optimized cardiac output provided by the “atrial kick”. A P wave occurring just before a QRS indicates that the ventricles are filling from the forceful contraction of the atria.&nbsp; This provides much better filling than when the atria are not beating or are fibrillating.<span style="font-size: 13.008px; line-height: 1.538em;">&nbsp;</span></p><p class="MsoNormal">This is a good ECG to use to show your students how we can recognize a paced rhythm without being sure of the spikes.&nbsp; Of course, without other evidence (patient history and exam), we can’t know for sure that this is a paced rhythm, but the steady, normal rate, wide complexes, and left axis deviation are signs of RV pacing.&nbsp; Look for negatively-deflected QRS complexes in II, III, and aVF and positive QRSs in aVL and aVR.<span style="font-size: 13.008px; line-height: 1.538em;">&nbsp;</span></p><p class="MsoNormal">When pacing only one ventricle, the impulse travels relatively slowly through the other ventricle, resulting in wide QRS complexes.&nbsp; This then results in SECONDARY ST-T WAVE CHANGES.&nbsp; Wherever the QRS is positive, you will normally see some ST depression and T wave inversion.&nbsp; In leads with negative QRS complexes, the opposite is true, and you will see ST elevation and upright T waves.&nbsp; This can make evaluation of ST segments for acute M.I. difficult.</p><p>&nbsp;</p><p class="MsoNormal">&nbsp;&nbsp;&nbsp;&nbsp;</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/134/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 Paced Rhythm Following AV Node Ablation 1/5</option><option value="40">Give Paced Rhythm Following AV Node Ablation 2/5</option><option value="60">Give Paced Rhythm Following AV Node Ablation 3/5</option><option value="80">Give Paced Rhythm Following AV Node Ablation 4/5</option><option value="100" selected="selected">Give Paced Rhythm Following AV Node Ablation 5/5</option></select> <div class="description"><div class="fivestar-summary fivestar-summary-average-count"><span class="average-rating">Average: <span >4.7</span></span> <span class="total-votes">(<span >6</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-1ACcGYEIxS-cm5U4U7oqTQvl7URBgDbviKugCPWn0W0" /> <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/pacemaker" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">Pacemaker</a></div><div class="field-item odd"><a href="/ecg/paced-rhythm" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">Paced rhythm</a></div><div class="field-item even"><a href="/ecg/complete-heart-block-1" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">Complete heart block</a></div><div class="field-item odd"><a href="/ecg/complete-av-block" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">Complete AV block</a></div></div></div><ul class="links inline"><li class="addtoany first last"><span><span class="a2a_kit a2a_target addtoany_list" id="da2a_2"> <a class="a2a_dd addtoany_share_save" href="https://www.addtoany.com/share#url=https%3A%2F%2Fwww.ecgguru.com%2Fecg%2Fpaced-rhythm-following-av-node-ablation&amp;title=Paced%20Rhythm%20Following%20AV%20Node%20Ablation"><img src="/sites/all/modules/addtoany/images/share_save_256_24.png" width="256" height="24" alt="Share"/></a> </span> </span></li> </ul> Mon, 28 Dec 2015 02:38:52 +0000 Dawn 682 at https://www.ecgguru.com https://www.ecgguru.com/ecg/paced-rhythm-following-av-node-ablation#comments Atrial Pacing With Right Bundle Branch Block https://www.ecgguru.com/ecg/atrial-pacing-right-bundle-branch-block <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/atrial-pacing-right-bundle-branch-block"><img typeof="foaf:Image" src="https://www.ecgguru.com/sites/default/files/PM109%20%20Atrial%20pacing%20with%20RBBB.jpg" width="1800" height="1092" 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>No instructor's collection should be without an atrial paced rhythm OR a right bundle branch block. &nbsp;Here, you get both. &nbsp;First, the atrial pacing. &nbsp;This patient had a sinus node problem, but his AV conduction system was functional (if not perfect). &nbsp;At this time, he is able to conduct impulses from the atria to the ventricles. &nbsp;What he cannot do is reliably produce the impulse in his atria. &nbsp; So, this pacemaker is currently pacing the right atrium, producing a paced "P" wave, which is then conducted to the ventricles. &nbsp;The fifth beat on the strip shows a "native" beat - one produced by the patient. &nbsp;No P wave is seen, so it is presumed to be a junctional beat.</p><p>As for conduction through the ventricles, there is a right bundle branch block. &nbsp;The left bundle branch is ensuring that the ventricles receive the depolarization "message", and the ventricles are depolarizing and contracting. &nbsp;However, the right ventricle gets the message a little late, since is arrives from the left ventricle, and not through a functioning right bundle branch. &nbsp;This produces a terminal wave on each QRS that represents this delayed depolarization of the right ventricle. &nbsp;In leads oriented to the left side of the heart, like I and V6, it is seen as a wide little S wave. &nbsp;In V1, which is oriented to the patient's right, we see an R prime (R'), producing the easily-recognizable rSR' pattern of RBBB.</p><p>For your more advanced students, this patient has atypical T waves for RBBB. &nbsp;Normally, the T waves axes should be OPPOSITE that of the terminal portion of the QRS. &nbsp;So, Lead V1 correctly shows an inverted T wave, since the R' is a positive deflection. &nbsp;There are inverted T waves in Leads III, aVF (II is biphasic), as well as in V4, V5, and V6. &nbsp;We expected upright T waves here. Because we do not have clinical information for this patient, we will call them "non-specific" T wave changes, remembering that inverted T waves can be a sign of ischemia.</p><p>ALSO: &nbsp;As noted in Dave Richley's comment below, there is a left axis deviation, with a negative Leads II, aVF and III, and a positive I and aVL. &nbsp;This &nbsp;indicates left anterior fascicular block, which is rather common with RBBB, since the right bundle branch and the left anterior fascicle share a blood supply. So, this person as a "bi-fascicular block".&nbsp;</p><p>&nbsp;</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/134/feed" method="post" id="fivestar-custom-widget--2" 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--4" name="vote" class="form-select"><option value="-">Select rating</option><option value="20">Give Atrial Pacing With Right Bundle Branch Block 1/5</option><option value="40">Give Atrial Pacing With Right Bundle Branch Block 2/5</option><option value="60">Give Atrial Pacing With Right Bundle Branch Block 3/5</option><option value="80">Give Atrial Pacing With Right Bundle Branch Block 4/5</option><option value="100" selected="selected">Give Atrial Pacing With Right Bundle Branch Block 5/5</option></select> <div class="description"><div class="fivestar-summary fivestar-summary-average-count"><span class="average-rating">Average: <span >4.3</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--2" name="op" value="Rate" /><input type="hidden" name="form_build_id" value="form-wL0VUstFE2jEBYPAbEZKnGEwkVu1Sraa0WcItrHeRHE" /> <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/pacemaker" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">Pacemaker</a></div><div class="field-item odd"><a href="/ecg/atrial-pacing" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">Atrial pacing</a></div><div class="field-item even"><a href="/ecg/paced-rhythm" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">Paced rhythm</a></div><div class="field-item odd"><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 even"><a href="/ecg/rbbb" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">RBBB</a></div><div class="field-item odd"><a href="/ecg/bundle-branch-block" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">Bundle branch block</a></div><div class="field-item even"><a href="/ecg/left-anterior-fascicular-block" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">Left anterior fascicular block</a></div><div class="field-item odd"><a href="/ecg/hemiblock" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">Hemiblock</a></div></div></div><ul class="links inline"><li class="addtoany first last"><span><span class="a2a_kit a2a_target addtoany_list" id="da2a_3"> <a class="a2a_dd addtoany_share_save" href="https://www.addtoany.com/share#url=https%3A%2F%2Fwww.ecgguru.com%2Fecg%2Fatrial-pacing-right-bundle-branch-block&amp;title=Atrial%20Pacing%20With%20Right%20Bundle%20Branch%20Block"><img src="/sites/all/modules/addtoany/images/share_save_256_24.png" width="256" height="24" alt="Share"/></a> </span> </span></li> </ul> Mon, 19 May 2014 18:32:22 +0000 Dawn 575 at https://www.ecgguru.com https://www.ecgguru.com/ecg/atrial-pacing-right-bundle-branch-block#comments ECG Basics: NIPS Procedure, ICD Test https://www.ecgguru.com/ecg/ecg-basics-nips-procedure-icd-test <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/ecg-basics-nips-procedure-icd-test"><img typeof="foaf:Image" src="https://www.ecgguru.com/sites/default/files/114%20NIPS%20Procedure.jpg" width="1800" height="213" 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>This is a rhythm strip from a NIPS procedure (non-invasive programmed stimulaltion), which is a programming test for an implantable cardioverter defibrillator (ICD). &nbsp;The test is done under light anesthesia, similar to that used for colonoscopy. &nbsp; In this example, the patient is in normal sinus rhythm at the beginning of the procedure. &nbsp;The pacemaker technician overdrives the patient's rate to observe the pacing function, then a stimulus is delivered to cause ventricular fibrillation (V Fib). &nbsp;Initially, the ventricular rhythm is somewhat organized and coarse (V flutter), but it will rapidly deteriorate if not corrected. &nbsp;Before it deteriorates, the ICD delivers a shock, and the patient's rhythm is restored. &nbsp;In this example, bi-ventricular pacing was conducted for a few minutes before the patient resumed NSR. &nbsp;The patient is then recovered from the anesthesia and discharged home.</p><p>For your students, this is a good example of the relative safety of shocking the well-perfused heart. &nbsp;Although it is possible to put the heart into an intractable V Fib with this test, the ICD usually is able to convert the potentially lethal rhythm easily. &nbsp;It is a good reminder that we need to perfuse the heart well before performing defibrillation on a person with unwitnessed cardiac arrest.</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/134/feed" method="post" id="fivestar-custom-widget--3" 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--6" name="vote" class="form-select"><option value="-">Select rating</option><option value="20">Give ECG Basics: NIPS Procedure, ICD Test 1/5</option><option value="40">Give ECG Basics: NIPS Procedure, ICD Test 2/5</option><option value="60">Give ECG Basics: NIPS Procedure, ICD Test 3/5</option><option value="80" selected="selected">Give ECG Basics: NIPS Procedure, ICD Test 4/5</option><option value="100">Give ECG Basics: NIPS Procedure, ICD Test 5/5</option></select> <div class="description"><div class="fivestar-summary fivestar-summary-average-count"><span class="average-rating">Average: <span >3.7</span></span> <span class="total-votes">(<span >7</span> votes)</span></div></div> </div> </div> </div><input class="fivestar-submit form-submit" type="submit" id="edit-fivestar-submit--3" name="op" value="Rate" /><input type="hidden" name="form_build_id" value="form-dSG4OLOWYJ7Q8Gv5ZoQu9MWHRjrT1gC_dk-MNogvW6o" /> <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/ecg-basics" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">ECG Basics</a></div><div class="field-item odd"><a href="/ecg/rhythm-strip" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">Rhythm strip</a></div><div class="field-item even"><a href="/ecg/nips-procedure" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">NIPS Procedure</a></div><div class="field-item odd"><a href="/ecg/icd-test" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">ICD Test</a></div><div class="field-item even"><a href="/ecg/pacemaker" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">Pacemaker</a></div><div class="field-item odd"><a href="/ecg/cardioversion" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">Cardioversion</a></div><div class="field-item even"><a href="/ecg/defibrillation" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">Defibrillation</a></div><div class="field-item odd"><a href="/ecg/ventricular-fibrillation" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">Ventricular fibrillation</a></div><div class="field-item even"><a href="/ecg/vf" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">VF</a></div><div class="field-item odd"><a href="/ecg/paced-rhythm" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">Paced rhythm</a></div></div></div><ul class="links inline"><li class="addtoany first last"><span><span class="a2a_kit a2a_target addtoany_list" id="da2a_4"> <a class="a2a_dd addtoany_share_save" href="https://www.addtoany.com/share#url=https%3A%2F%2Fwww.ecgguru.com%2Fecg%2Fecg-basics-nips-procedure-icd-test&amp;title=ECG%20Basics%3A%20%20NIPS%20Procedure%2C%20ICD%20Test"><img src="/sites/all/modules/addtoany/images/share_save_256_24.png" width="256" height="24" alt="Share"/></a> </span> </span></li> </ul> Fri, 27 Sep 2013 19:20:52 +0000 Dawn 499 at https://www.ecgguru.com https://www.ecgguru.com/ecg/ecg-basics-nips-procedure-icd-test#comments ECG Basics: Biventricular Pacemaker https://www.ecgguru.com/ecg/basic-ecg-week-august-16-2013-biventricular-pacemaker-1 <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/basic-ecg-week-august-16-2013-biventricular-pacemaker-1"><img typeof="foaf:Image" src="https://www.ecgguru.com/sites/default/files/111%20BiV%20pacer.jpg" width="1800" height="279" 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>This is a Lead II rhythm strip from a patient with a biventricular pacemaker. The second and sixth beats are PVCs. &nbsp;In this lead, the pacemaker spikes are very difficult to see, but they are present. &nbsp;The pacemaker is operating in a "demand" mode for pacing the atria. &nbsp;Some of the P waves appear to be the patient's own, and some appear to be caused by the pacing stimulus. &nbsp;For example, the first beat appears to have no pacer spike before the P wave, and the second beat does have one (albeit tiny). &nbsp;The morphology of the P waves appears to change, also. &nbsp;</p><p>This pacemaker has been programmed to cause a QRS complex after every P, whether the P wave was made by the patient or by the pacemaker. &nbsp;The patient originally had a left bundle branch block, making his QRS complexes very wide, and lowering his cardiac output. &nbsp; The biventricular pacemaker paces both ventricles, synchronizing their depolarization and narrowing the QRS. &nbsp;This improves cardiac output. &nbsp;The physician has programmed this pacemaker to pace the ventricles after every P wave, whether native or paced. &nbsp;The paced QRS happens slightly before the native (wide) QRS would have, giving the patient the benefit of narrow QRS complexes. &nbsp;Biventricular pacemakers have been shown to improve cardiac output in patients with wide complexes.</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/134/feed" method="post" id="fivestar-custom-widget--4" 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--8" name="vote" class="form-select"><option value="-">Select rating</option><option value="20">Give ECG Basics: Biventricular Pacemaker 1/5</option><option value="40">Give ECG Basics: Biventricular Pacemaker 2/5</option><option value="60">Give ECG Basics: Biventricular Pacemaker 3/5</option><option value="80" selected="selected">Give ECG Basics: Biventricular Pacemaker 4/5</option><option value="100">Give ECG Basics: Biventricular Pacemaker 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 >12</span> votes)</span></div></div> </div> </div> </div><input class="fivestar-submit form-submit" type="submit" id="edit-fivestar-submit--4" name="op" value="Rate" /><input type="hidden" name="form_build_id" value="form-l_yjRGYk8ZATFC81OmbDI5sQOW8MxwEyKL_uh-emHgU" /> <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/paced-rhythm" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">Paced rhythm</a></div><div class="field-item odd"><a href="/ecg/basic-ecg" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">Basic ECG</a></div><div class="field-item even"><a href="/ecg/biventricular-pacemaker" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">Biventricular pacemaker</a></div><div class="field-item odd"><a href="/ecg/ecg-basics" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">ECG Basics</a></div><div class="field-item even"><a href="/ecg/rhythm-strip" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">Rhythm strip</a></div></div></div><ul class="links inline"><li class="addtoany first last"><span><span class="a2a_kit a2a_target addtoany_list" id="da2a_5"> <a class="a2a_dd addtoany_share_save" href="https://www.addtoany.com/share#url=https%3A%2F%2Fwww.ecgguru.com%2Fecg%2Fbasic-ecg-week-august-16-2013-biventricular-pacemaker-1&amp;title=ECG%20Basics%3A%20%20Biventricular%20Pacemaker"><img src="/sites/all/modules/addtoany/images/share_save_256_24.png" width="256" height="24" alt="Share"/></a> </span> </span></li> </ul> Fri, 16 Aug 2013 05:13:25 +0000 Dawn 484 at https://www.ecgguru.com https://www.ecgguru.com/ecg/basic-ecg-week-august-16-2013-biventricular-pacemaker-1#comments Pacemaker Rhythm, Right Ventricular Pacing Triggered by Native P Waves https://www.ecgguru.com/ecg/pacemaker-rhythm-right-ventricular-pacing-triggered-native-p-waves <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/pacemaker-rhythm-right-ventricular-pacing-triggered-native-p-waves"><img typeof="foaf:Image" src="https://www.ecgguru.com/sites/default/files/PM106.png" width="1800" height="992" 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>This patient's electronic pacemaker has pacing electrodes in the right atrium and the right ventricle, which is typical.&nbsp; In this ECG, the patient produces P waves, but fails to transmit them to the ventricles due to AV block.&nbsp; The electronic pacemaker&nbsp;SENSES the native P waves, and TRIGGERS the ventricular wire to pace the ventricle in response.&nbsp; Using this pacemaker function, the heart rate can be controlled by the patient's own nervous system, as P waves are produced naturally.&nbsp; Should the patient fail to produce a P wave within rate guidelines set by the implanting physician, the pacer will pace the atrial as well.</p> <p>The QRS complex is wide when only the right ventricle is paced, as the impulse has to travel from the RV to the LV cell-by-cell.&nbsp; This slows conduction in the same way a ventricular rhythm like VTach is slowed, producing a wide QRS.&nbsp; Remember, a wide QRS causes lower cardiac output, as much as 15%.</p> <p>For your students who are learning axis, show them an illustration of the heart with the pacing wire in the right ventricle.&nbsp; It is easy to see why the axis is leftward when the left ventricle is being paced from the right ventricle.</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/134/feed" method="post" id="fivestar-custom-widget--5" 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--10" name="vote" class="form-select"><option value="-">Select rating</option><option value="20">Give Pacemaker Rhythm, Right Ventricular Pacing Triggered by Native P Waves 1/5</option><option value="40">Give Pacemaker Rhythm, Right Ventricular Pacing Triggered by Native P Waves 2/5</option><option value="60" selected="selected">Give Pacemaker Rhythm, Right Ventricular Pacing Triggered by Native P Waves 3/5</option><option value="80">Give Pacemaker Rhythm, Right Ventricular Pacing Triggered by Native P Waves 4/5</option><option value="100">Give Pacemaker Rhythm, Right Ventricular Pacing Triggered by Native P Waves 5/5</option></select> <div class="description"><div class="fivestar-summary fivestar-summary-average-count"><span class="average-rating">Average: <span >2.7</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--5" name="op" value="Rate" /><input type="hidden" name="form_build_id" value="form-IL-MetDuxlm5Nq12dvPOhN7zsGcin0WUBYVr3DtDia4" /> <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/pacemaker" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">Pacemaker</a></div><div class="field-item odd"><a href="/ecg/paced-rhythm" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">Paced rhythm</a></div><div class="field-item even"><a href="/ecg/triggered-pacing" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">Triggered pacing</a></div></div></div><ul class="links inline"><li class="addtoany first last"><span><span class="a2a_kit a2a_target addtoany_list" id="da2a_6"> <a class="a2a_dd addtoany_share_save" href="https://www.addtoany.com/share#url=https%3A%2F%2Fwww.ecgguru.com%2Fecg%2Fpacemaker-rhythm-right-ventricular-pacing-triggered-native-p-waves&amp;title=Pacemaker%20Rhythm%2C%20Right%20Ventricular%20Pacing%20Triggered%20by%20Native%20P%20Waves"><img src="/sites/all/modules/addtoany/images/share_save_256_24.png" width="256" height="24" alt="Share"/></a> </span> </span></li> </ul> Sat, 14 Jul 2012 05:28:53 +0000 Dawn 249 at https://www.ecgguru.com https://www.ecgguru.com/ecg/pacemaker-rhythm-right-ventricular-pacing-triggered-native-p-waves#comments Paced Rhythm With Acute Anterior Lateral M.I. https://www.ecgguru.com/ecg/paced-rhythm-acute-anterior-lateral-mi <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/paced-rhythm-acute-anterior-lateral-mi"><img typeof="foaf:Image" src="https://www.ecgguru.com/sites/default/files/AWPM100.jpg" width="1400" height="1062" 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>We caution students that the signs of acute M.I. (ST elevation) cannot reliably be seen in cases of wide QRS. This is because, in wide QRS situations like left bundle branch block, ventricular rhythms, or right ventricular pacing, the ST segments will elevate in leads with downward QRS complexes, and depress when the QRS is upright. &nbsp;These is called discordant ST changes.</p> <p><br> In this ECG, a man in his 60's presented with chest pain. His ECG showed AV sequential pacing, with ventricular pacing from the right ventricle. The QRS is 162 ms in duration. He has ST segment elevation in Leads I, aVL, and Leads V2 through V6.</p> <p><br>The ST elevations are more pronounced than expected in this paced patient. But, the real clue here is the ST elevation in Leads I, aVL, and V2 - leads that should have ST depression because of their upright QRS complexes, have elevation! This patient was taken to the cath lab and the left coronary artery wass reperfused and stented. For more information about ST elevation in wide QRS complex rhythms, see this <a title="LITFL Sgarbossa" href="http://lifeinthefastlane.com/ecg-library/basics/sgarbossa/">LINK</a>.<br><br>&nbsp;</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/134/feed" method="post" id="fivestar-custom-widget--6" 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--12" name="vote" class="form-select"><option value="-">Select rating</option><option value="20">Give Paced Rhythm With Acute Anterior Lateral M.I. 1/5</option><option value="40" selected="selected">Give Paced Rhythm With Acute Anterior Lateral M.I. 2/5</option><option value="60">Give Paced Rhythm With Acute Anterior Lateral M.I. 3/5</option><option value="80">Give Paced Rhythm With Acute Anterior Lateral M.I. 4/5</option><option value="100">Give Paced Rhythm With Acute Anterior Lateral M.I. 5/5</option></select> <div class="description"><div class="fivestar-summary fivestar-summary-average-count"><span class="average-rating">Average: <span >2</span></span> <span class="total-votes">(<span >1</span> vote)</span></div></div> </div> </div> </div><input class="fivestar-submit form-submit" type="submit" id="edit-fivestar-submit--6" name="op" value="Rate" /><input type="hidden" name="form_build_id" value="form-GjlIFmnF7OoRVattr9e8B48BNLzypgd-bhAj5RnK0cw" /> <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/anterior-mi" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">Anterior M.I.</a></div><div class="field-item odd"><a href="/ecg/pacemaker" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">Pacemaker</a></div><div class="field-item even"><a href="/ecg/paced-rhythm" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">Paced rhythm</a></div><div class="field-item odd"><a href="/ecg/stemi" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">STEMI</a></div><div class="field-item even"><a href="/ecg/anterior-lateral-mi-0" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">Anterior-lateral M.I.</a></div></div></div><ul class="links inline"><li class="addtoany first last"><span><span class="a2a_kit a2a_target addtoany_list" id="da2a_7"> <a class="a2a_dd addtoany_share_save" href="https://www.addtoany.com/share#url=https%3A%2F%2Fwww.ecgguru.com%2Fecg%2Fpaced-rhythm-acute-anterior-lateral-mi&amp;title=Paced%20Rhythm%20With%20Acute%20Anterior%20Lateral%20M.I."><img src="/sites/all/modules/addtoany/images/share_save_256_24.png" width="256" height="24" alt="Share"/></a> </span> </span></li> </ul> Tue, 29 Nov 2011 00:57:13 +0000 Dawn 101 at https://www.ecgguru.com https://www.ecgguru.com/ecg/paced-rhythm-acute-anterior-lateral-mi#comments