Just a little feedback on this one:
"El ECG consta habitualmente de 12 derivaciones: las 6 derivaciones "precordiales" (V1, V2, V3, V4, V5 y V6) se sitúan en la cara anterior del tórax (means at front); las otras 6 son las derivaciones "de los miembros", y se colocan en las extremidades (aVR, aVL, aVF, I, II, III)... Once we know this, then... Derivaciones...

"Se observa tambien la denominada "progresion de las erres".La onda R debe ir creciendo progresivamente de V1 a V6 (es algo mayor en V5 que en V6) , si no lo hace o existe necrosis septal antigua , fibrosis miocardica del anciano o cambios posicionales...

Note: Poor progression of ‘R’ is said to be present if voltage of ‘r’ wave in lead V1 to V4 remains extremely small.

"Criteria to diagnosing poor progression of R wave are (both or anyone can be present)
1. R-wave less than 2-4 mm in leads V3 or V
2. Presence of reversed R-wave progression defined as R in V4 less than R in V3 or R in V3 less than R in V2 or R in V2 less than R in V1, or any combination of these"

Almost sure the Dx is: Anterior myocardial infarction.
See also the following DXs / Left bundle branch block (LBBB), left anterior fascicular block (LAHB), Wolff-Parkinson-White syndrome(WPW syndrome), some times associated with right ventricular hypertrophy RVH (especially that associated with chronic lung diseases), even left ventricular hypertrophy may result in poor R wave progression, left sided pneumothorax, corrected transposition of the great vessels (CTGA), congenital absence of the pericardium.

Actually: This particular pattern is usually reported out as "cannot rule out anterior myocardial infarction."