Fig. 8. Precocious patterning of ventricular activation sequences by ventricular pressure overload (A) Isochronal map of control E6-6.5 heart with an immature lateral activation pattern across the dorsal surface of the ventricle. (B) As in A but the ventral view. (C) As in A but CTB-heart already exhibiting the apex-to-base activation pattern. (D) As in C but the ventral view with a mature pattern. (E) Proportion of hearts exhibiting immature (nonapex-to-base, open bar) and mature (apex-to-base, filled bar) activation patterns following no operation (control), sham operation and CTB. at, atrium; avj, atrioventricular junction; ec, endocardium; ivs, interventricular septum; lv, left ventricle; ot, outflow tract; rv, right ventricle; tb, trabeculum.