![]() This is not what should be seen with simple RBBB. This is not what we see in lead V3 - in which the amount of J-point ST depression has again increased ( relative to lead V2) - and the shape of the ST segment is now clearly coved ( similar to the curved RED line in this lead) - followed by a deepening of symmetric T wave inversion. But when the only thing going on is RBBB - then the relative amount of this ST-T wave depression should progressively decrease as one moves across the precordium. ![]() As emphasized earlier - there may normally be some ST-T wave depression in right-sided lead V1 with RBBB.The ST segment in this lead is also unusual and probably abnormal - in that rather than initial downsloping ( as is seen for the ST segment in lead V1) - the slightly depressed ST segment in lead V2 is upsloping! Assuming the chest lead V2 electrode is correctly placed - the small Q wave in this lead is abnormal. Lead V2 is indeed unusual in manifesting a huge positive R wave ( over 30 mm tall).This is precisely what we see in ECG #1 - in that the upright T wave in leads I and V6 is oppositely directed to the wide terminal S wave - and the depressed ST-T wave in lead V1 is oppositely directed to the all positive RR' complex that we see in lead V1. With regard to the expected ST-T wave changes with simple RBBB - we should expect to see the ST segment and T wave in leads I, V1 and V6 oppositely directed to the last QRS deflection in that lead. As I reviewed in My Comment in the July 1, 2019 post - typical RBBB or LBBB both alter the sequence of ventricular depolarization and repolarization in a predictable fashion in the 3 KEY leads.While true that normal septal q waves are commonly seen in one or more lateral leads ( due to the left-to-right vector of septal depolarization, that does not change direction with RBBB) - I thought the Q wave in lead aVL in ECG #1 was slightly more prominent than expected for a septal q wave. The Q wave in lead aVL may or may not be significant ( RED arrow in this lead).While not definitive - this small Q wave in lead V2 may be a marker of anterior infarction having occurred at some point in time. The Q wave in lead V2 is definitely not normal ( RED arrow in this lead in Figure-1) - since as described above, an initial positive deflection is normally seen in lead V1 ( and usually also in lead V2) with a "typical" RBBB. Q waves are present in leads aVL and V2.This amount of fragmentation often implies "scar" and/or prior infarction. There is excessive fragmentation in a number of QRS complexes in this tracing (ie, in the upslope of the S wave in leads II, III, aVF - and in the slurred R waves in leads aVR and V1).LAHB ( Left Anterior Hemi Block ) is diagnosed in addition to RBBB - by the predominant negativity in the initial descent of the S wave in each of the inferior leads.NOTE: For those interested in my user- friendly approach that allows ECG diagnosis of the type of conduction defect within seconds - Please check out my 13-minute ECG Video and downloadable PDF at the bottom of this page.RBBB ( Right Bundle Branch Block ) - is defined as a supraventricular rhythm in which the QRS complex is wide - and - QRS morphology in the 3 KEY leads is consistent with RBBB (ie, an rsR' pattern or it's "equivalent" in right-sided lead V1 - and an R wave with a wide terminal S wave in left-sided leads I and V6).The reasons this approach allows me to diagnose the type of conduction defect in less than 5 seconds are that: i ) You only have to look at 3 leads (ie, left-sided leads I and V6 - and right-sided lead V1) and, ii ) Assuming you've ruled out VT, WPW, hyperkalemia and other toxicity as the cause of QRS widening - there are for practical purposes, only 3 possible answers (ie, RBBB, LBBB or IVCD). I have previously reviewed my approach to the ECG diagnosis of RBBB ( See My Comment at the bottom of the page in the Jpost in Dr. Always compare with a previous ECG if one is available. Make sure you identify the end of the QRS in any BBB before attributing deviations to the ST segment.ģ. ![]() If there is no R'-wave, then ST depression should be considered ischemic.Ģ. ![]() ST depression is only normal following an R'-wave in V1-V3. No matter the etiology, it did manifest on the ECG and was easily, but mistakenly, attributed to RBBB and high voltage.ġ. There was indeed OMI of a very small vessel. Based on lesion of filling defect there is high suspicion for thromboembolic occlusion secondary to a proximal atrial fibrillation versus proximal coronary plaque rupture, thought to be less likely. Otherwise, mild Plaque no angiographically significant obstructive coronary artery disease Vessel is less than 1 mm in diameter and flow improved with IC TNG. Severe distal small (one vessel) disease involving the small LPL1 with an apparent filling defect. T-wave is more upright in V2, and more inverted in V4-V6. ![]()
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