As the left ventricle becomes unable to compensate for an acute rise in systemic vascular resistance, left ventricular failure and pulmonary edema or myocardial ischemia may occur.In the kidneys, chronic hypertension has a great impact on the kidney vasculature, leading to pathologic changes in the small arteries of the kidney. Affected arteries develop endothelial dysfunction and impairment of normal vasodilation, which alter kidney autoregulation. When the kidneys autoregulatory system is disrupted, the intraglomerular pressure starts to vary directly with the systemic arterial pressure, thus offering no protection to the kidney during blood pressure fluctuations. The renin-aldosterone-angiotensin system can be activated, leading to further vasoconstriction and damage. During a hypertensive crisis, this can lead to acute kidney ischemia, with hypoperfusion, involvement of other organs, and subsequent dysfunction. After an acute event, this endothelial dysfunction has persisted for years. Diagnosis
The term hypertensive emergency is primarily used as a specific term for a hypertensive crisis with a diastolic blood pressure greater than or equal to 120 mmHg or systolic blood pressure greater than or equal to 180 mmHg. Hypertensive emergency differs from hypertensive urgency in that, in the former, there is evidence of acute organ damage. Both of these definitions had collectively been known as malignant hypertension, although this medical term is replaced.In the pregnant patient, the definition of hypertensive emergency (likely secondary to pre-eclampsia or eclampsia) is only a blood pressure exceeding 160 mmHg systolic blood pressure or 110 mmHg diastolic blood pressure.
Hydralazine/isosorbide dinitrate, sold under the brand name Bidil, is a fixed-dose combination medication used to treat self-identified Black people with congestive heart failure. It is a combination of hydralazine hydrochloride (an arteriolar vasodilator) and isosorbide dinitrate (a nitrate vasodilator).The American Food and Drug Administration (FDA) approved this race-specific medication to treat congestive heart failure in specifically self-identified Black patients. It provoked controversy as the first drug approved by the FDA marketed for a single racial-ethnic group. History
From 1980 to 1985, Dr. Jay Cohn of the University of Minnesota  led a clinical trial in collaboration with the US Veterans Administration called the Vasodilator-Heart Failure Trial (V-HeFT I) that tested whether the combination of isosorbide dinitrate and hydralazine increased survival in patients with heart failure. The results were promising and a follow up study, V-HeFT II, tested the novel combination against enalapril. Cohn applied for a patent on the combination treatment, which was issued in 1989 as US Patent 4868179. Cohn then licensed the patent to Medco Pharmaceuticals who went on to prepare a New Drug Application (NDA) to approve BiDil on the basis of the V-HeFT trials.The V-HeFT data was re-analyzed and found that the drug combination appeared to be more effective in treating self-identified African-Americans. This was a significant finding due to prior studies which showed that African-Americans with congestive heart failure (CHF) appeared to respond less effectively to conventional CHF treatments (particularly ACE inhibitors) than White Americans.