Acute Coronary Syndrome

A client arrives in the emergency department reporting crushing substernal pressure that started forty minutes ago while shovelling snow. The pressure radiates to the left jaw, and the client is diaphoretic, nauseated, and says something feels very wrong. Nothing about that presentation is subtle, and it is also not the presentation you will most often miss. The client you will miss is the seventy-eight-year-old woman with diabetes who reports only unusual fatigue and indigestion, or the postoperative client whose only complaint is new shortness of breath. Acute coronary syndrome is the clinical spectrum produced by an abrupt imbalance between myocardial oxygen supply and demand, most often because an atherosclerotic plaque ruptures or erodes and a platelet-rich thrombus forms. It includes unstable angina, non-ST-elevation myocardial infarction, and ST-elevation myocardial infarction. Unstable angina causes ischemia without detectable myocardial necrosis; NSTEMI causes necrosis without the diagnostic ST-elevation pattern; STEMI usually reflects persistent, complete coronary occlusion with a larger territory at immediate risk. These categories guide treatment, but the nurse must act on the possibility of acute ischemia before the final label is known....