ECG question

[saint21]

Hello!
I have a question that might sound stupid, but i'm at a point that i can't get through with it.

In an ideal ECG, in Lead1 for example, there's the QRS complex - the one with a small q wave, the positive (R) wave followed by the second negative wave (S). In this case, in lead V1 how many waves are? Two or three? I always find explanations in books about those 2 waves - RS - and maybe in V6 and V5 a small q wave, but I find it logical to observe three waves as well, maybe a rSr' complex?
I understand that in V1, the r = the septum depolarization and S = the ventricular mass. But at the same time, in D1, q = the septum, R = the ventricular mass, S = the posterior ventricular part. Shouldn't there be a wave in V1 for the posterior part?

Thank you for your time and answers!

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[Jabbed]

Hello!
I have a question that might sound stupid, but i'm at a point that i can't get through with it.

In an ideal ECG, in Lead1 for example, there's the QRS complex - the one with a small q wave, the positive (R) wave followed by the second negative wave (S). In this case, in lead V1 how many waves are? Two or three? I always find explanations in books about those 2 waves - RS - and maybe in V6 and V5 a small q wave, but I find it logical to observe three waves as well, maybe a rSr' complex?
I understand that in V1, the r = the septum depolarization and S = the ventricular mass. But at the same time, in D1, q = the septum, R = the ventricular mass, S = the posterior ventricular part. Shouldn't there be a wave in V1 for the posterior part?

Thank you for your time and answers!

The rsr' wave appears in V1 when there is delayed activation of the right ventricle (illustrated by the r' wave). This most commonly occurs due to IVCD or a normal variant that's possibly due to delayed activation of the crista supraventricularis (differentiation is based on the QRS interval). I think that you're confused about vector orientation in the precordial leads. In V1 the "posterior force" is left ventricular activation, which provides the dominant vector. In the limb leads, the late activation of the high lateral wall produces the terminal S wave (except in the case of IVCD).