Hypertensive emergencies and resistant hypertension

According to the American Heart Association (AHA), hypertensive emergency is defined as severely elevated blood pressure (>180/120 mmHg) with target organ damage [1], which includes left ventricular failure and pulmonary edema, acute myocardial infarction, ischemic stroke, intracranial hemorrhage, aortic dissection, acute kidney injury, encephalopathy, or eclampsia (Tables 44.1 and 44.2). Approximately 25 % of patients that present to the emergency department with hypertensive emergency have no previous history of hypertension [1]. The American Heart Association recommends a reduction of mean arterial blood pressure by not more than 25 % within the first hour and then, if clinically stable, to about 160/100 mmHg within next 2-6 h. Hypertensive emergencies are treated with intravenous blood pressure medications (Tables 44.3 and 44.4).