Search results
Results from the WOW.Com Content Network
Precordial concordance, also known as QRS concordance is when all precordial leads on an electrocardiogram are either positive (positive concordance) or negative (negative concordance). [1]
It is normal to have a narrow QS and rSr' patterns in V 1, and this is also the case for qRs and R patterns in V 5 and V 6. The transition zone is where the QRS complex changes from predominantly negative to predominantly positive (R/S ratio becoming >1), and this usually occurs at V 3 or V 4.
ST elevation ≥1 mm in a lead with a positive QRS complex (i.e.: concordance) - 5 points; concordant ST depression ≥1 mm in lead V1, V2, or V3 - 3 points; ST elevation ≥5 mm in a lead with a negative (discordant) QRS complex - 2 points; ≥3 points = 90% specificity of STEMI (sensitivity of 36%) [2]
This refers to the appearance of leads I and II. If the QRS complex is negative in lead I and positive in lead II, the QRS complexes appear to be "reaching" to touch each other. This signifies right axis deviation. Conversely, if the QRS complex is positive in lead I and negative in lead II the leads have the appearance of "leaving" each other.
In lead V 1, the QRS complex is often entirely negative (QS morphology), although a small initial R wave may be seen (rS morphology). In the lateral leads (I, aVL, V 5-V 6) the QRS complexes are usually predominantly positive with a slow upstroke last >60ms to the R-wave peak. [4] Notching may be seen in these leads but this is not universal.
First, examine the QRS complex in both leads I and avF and determine if the QRS complex is positive (height of R wave > S wave), equiphasic (R wave = S wave), or negative (R wave < S wave). If lead I is positive and lead aVF is negative, then this is a possible LAD. To determine a true LAD, examine QRS in lead II.
The IRS boosted taxpayer services through Democrats’ Inflation Reduction Act but still faces processing claims from a coronavirus pandemic-era tax credit program and is slow to resolve certain ...
A shortcut for determining if the QRS axis is normal is if the QRS complex is mostly positive in lead I and lead II (or lead I and aVF if +90° is the upper limit of normal). [59] The normal QRS axis is generally down and to the left, following the anatomical orientation of the heart within the chest. An abnormal axis suggests a change in the ...