Prolonged QT interval https://www.ecgguru.com/taxonomy/term/675/all en Second-degree AV Block, Type II? https://www.ecgguru.com/ecg/second-degree-av-block-type-ii-0 <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/second-degree-av-block-type-ii-0"><img typeof="foaf:Image" src="https://www.ecgguru.com/sites/default/files/2nd%20deg%20Type%20II%203%20to%201.jpg" width="1887" height="1454" 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"><span style="font-size: 12.0pt; line-height: 107%; font-family: 'Arial',sans-serif;">This ECG is taken from an elderly woman who complains of feeling weak and tired. We have no other clinical information, unfortunately.</span></p><p class="MsoNormal"><span style="font-size: 12.0pt; line-height: 107%; font-family: 'Arial',sans-serif;">There is an obvious bradycardia, with more P waves than QRS complexes.  Here is what we see:</span></p><p class="MsoNormal"><span style="font-size: 12.0pt; line-height: 107%; font-family: 'Arial',sans-serif;">*  Atrial rate is around 115/min. and P waves are regular and all alike.</span></p><p class="MsoNormal"><span style="font-size: 12.0pt; line-height: 107%; font-family: 'Arial',sans-serif;">*  Ventricular rate is around 35/min. and QRS complexes are regular and all alike.</span></p><p class="MsoNormal"><span style="font-size: 12.0pt; line-height: 107%; font-family: 'Arial',sans-serif;">*  PR intervals, when they occur, are all the same at 162 ms.</span></p><p class="MsoNormal"><span style="font-size: 12.0pt; line-height: 107%; font-family: 'Arial',sans-serif;">*  QRS duration is wide at 122 ms.</span></p><p class="MsoNormal"><span style="font-size: 12.0pt; line-height: 107%; font-family: 'Arial',sans-serif;">*  QTc interval is prolonged at 549 ms. </span></p><p class="MsoNormal"><strong><span style="font-size: 12.0pt; line-height: 107%; font-family: 'Arial',sans-serif;">What does this mean?  </span></strong><span style="font-family: Arial, sans-serif; font-size: 12pt;">There is sinus tachycardia with second-degree AV block because the atrial rate is over 100/min, but not all P waves are conducted.</span><span style="font-family: Arial, sans-serif; font-size: 12pt;">  </span><span style="font-family: Arial, sans-serif; font-size: 12pt;">The AV block looks like a Type II (Mobitz II) block because the PR intervals are all the same.</span><span style="font-family: Arial, sans-serif; font-size: 12pt;">  </span><span style="font-family: Arial, sans-serif; font-size: 12pt;">This is a reliable indicator of conduction. (Not third-degree AVB).  </span><span style="font-family: Arial, sans-serif; font-size: 12pt;">The wide QRS complexes are due to right bundle branch block.</span><span style="font-family: Arial, sans-serif; font-size: 12pt;">  </span><span style="font-family: Arial, sans-serif; font-size: 12pt;">The ECG signs of RBBB are: 1) wide QRS; 2) supraventricular rhythm; and 3) rSR’ pattern in V1 and Rs, with a wide little s wave, in Leads I and V6.</span></p></div></div></div> Thu, 02 Feb 2017 05:09:56 +0000 Dawn 724 at https://www.ecgguru.com Electrolyte Effects https://www.ecgguru.com/ecg/electrolyte-effects <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/electrolyte-effects"><img typeof="foaf:Image" src="https://www.ecgguru.com/sites/default/files/DE102.jpg" width="1800" height="1239" 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"><span style="font-size: 13.008px; line-height: 1.538em;">This ECG is from a 46-year-old woman with diabetes mellitus.</span><span style="font-size: 13.008px; line-height: 1.538em;">  </span><span style="font-size: 13.008px; line-height: 1.538em;">She presented to the Emergency Dept. with a complaint of weakness.</span><span style="font-size: 13.008px; line-height: 1.538em;">  </span><span style="font-size: 13.008px; line-height: 1.538em;">Her BP was elevated at 186/102.</span><span style="font-size: 13.008px; line-height: 1.538em;">  </span><span style="font-size: 13.008px; line-height: 1.538em;">Her blood glucose was 936 mg/dL (normal 70-105).</span> </p><p class="MsoNormal"><strong><span style="color: green;">So, what does her ECG show?</span></strong></p><p class="MsoNormal"><strong></strong><span style="font-size: 13.008px; line-height: 1.538em;">1) Sinus bradycardia at 55 bpm.</span><span style="font-size: 13.008px; line-height: 1.538em;">  </span><span style="font-size: 13.008px; line-height: 1.538em;">The rhythm is regular, with no extrasystoles.</span></p><p class="MsoNormal"><span style="font-size: 13.008px; line-height: 1.538em;">2) A slightly prolonged PR interval at 218 ms (.218 seconds). Normal is 120-200 ms.</span> </p><p class="MsoNormal">3) A “wide side of normal” QRS duration at 109 ms. Normal is 70-100, but can be a little longer in normal i<span style="font-size: 13.008px; line-height: 1.538em;">ndividuals.</span></p><p class="MsoNormal">4) A prolonged QTc interval at 520 ms.  Normal QTc is 460 ms or less in women. A helpful rule of thumb i<span style="font-size: 13.008px; line-height: 1.538em;">s that the QT should be less than half the preceding RR.</span> </p><p class="MsoNormal">5) Normal P waves.</p><p class="MsoNormal">6) Normal axes of P, QRS, and T waves.</p><p class="MsoNormal">7) A large Q wave in Lead III which is not repeated in aVL.  This can be inconsequential when confined to <span style="font-size: 13.008px; line-height: 1.538em;">Lead III, or can be a pathological Q wave, especially if also seen in aVF.</span> </p><p class="MsoNormal">8) Flat ST segments.  Normal ST segments are convex upward, like a smile.</p><p class="MsoNormal">9) Tall, peaked T waves in precordial leads V<sub>2</sub> through V<sub>6</sub>, and in Lead II.<span style="font-size: 8pt; line-height: 107%;"> </span></p><p class="MsoNormal"><strong><span style="color: green;">What does it mean?</span></strong></p><p class="MsoNormal">Unfortunately, we do not have complete labs for this patient, or any information about her outcome.</p><p class="MsoNormal">We know that patients who have uncontrolled diabetes are at risk for renal failure, so we should consider electrolyte imbalances when we see abnormalities in the ECG.<span style="font-size: 8pt; line-height: 107%;"> </span></p></div></div></div> Tue, 12 Jul 2016 22:00:34 +0000 Dawn 706 at https://www.ecgguru.com