<P> The definition of poor R wave progression (PRWP) varies in the literature, but a common one is when the R wave is less than 2--4 mm in leads V or V and / or there is presence of a reversed R wave progression, which is defined as R in V <R in V or R in V <R in V or R in V <R in V, or any combination of these . Poor R wave progression is commonly attributed to anterior myocardial infarction, but it may also be caused by left bundle branch block, Wolff--Parkinson--White syndrome, right and left ventricular hypertrophy, or a faulty ECG recording technique . </P> <P> The point where the QRS complex meets the ST segment is the J - point . The J - point is easy to identify when the ST segment is horizontal and forms a sharp angle with the last part of the QRS complex . However, when the ST segment is sloped or the QRS complex is wide, the two features do not form a sharp angle and the location of the J - point is less clear . There is no consensus on the precise location of the J - point in these circumstances . Two possible definitions are: </P> <Ul> <Li> The "first point of inflection of the upstroke of the S wave" </Li> <Li> The point at which the ECG trace becomes more horizontal than vertical </Li> </Ul> <Li> The "first point of inflection of the upstroke of the S wave" </Li>

What does it mean when the qrs complex is inverted