subendocardial

adjective
sub·​en·​do·​car·​di·​al | \ ˌsəb-ˌen-dō-ˈkärd-ē-əl How to pronounce subendocardial (audio) \

Medical Definition of subendocardial

: situated or occurring beneath the endocardium or between the endocardium and myocardium subendocardial blood loss