Coronary artery disease is the progressive narrowing of the arteries that feed the heart muscle. It develops silently over decades, and for most people the first indication is exertional chest discomfort that is entirely predictable: it appears at a certain level of activity, feels the same each time, and settles with rest. That predictability is the defining clinical feature. A narrowed but stable artery can deliver enough blood at rest and not enough during exertion, so the discomfort tracks demand. Nothing has torn, nothing is clotting, and no muscle is dying — the supply is simply capped. Two clients can carry the same diagnosis and need entirely different responses on the same shift, and nothing on a monitor separates them — only the history does. The nurse's work divides cleanly. First, recognizing when the predictable pattern stops being predictable, because a change in the pattern is the signal that a plaque has become unstable and the client has moved from a chronic condition into an acute one. Second, delivering the risk-reduction teaching that actually alters the disease trajectory, which is...