Summary QUIZ 15 hypertensions MS1

Chapter 36 HYPERTENSION Normal BP <120 and <80 Prehypertension 120–139 or 80–89 Stage 1 140–159 or 90–99 Stage 2 ≥160 or ≥100 HPT risk groups : Group A: no major risk factors, no target organ damage, and no clinical cardiovascular disease. Group B: one or more risk factors, not including diabetes; no target organ damage; and no clinical cardiovascular disease. Group C: target organ damage and clinical cardiovascular disease, diabetes, or all these conditions, with or without other risk facto rs. Anatomy and Physiology of Blood Pressure Regulation Two factors determine BP : cardiac output (CO) and peripheral vascular resistance (PVR) . CO is the volume of blood pumped by the heart in a minute. PVR is the force in the blood vessels that the left ventricle (LV) , and resulting from narrowing of the arteries, arterioles and from sodium and water retention. Increased PVR is the most prominent characteristic of HTN . Catecholamine is vasoconstrictors that cause the blood vessels to constrict and causes BP to rise. Vasoconstriction decreases blood flow to the kidneys , which then releases renin, and leads to the formation of angiotensin . Types of Hypertensions Primary HTN accounts for 90% to 95% of all cases, the cause is unknown . contributing factors : including increased sodium intake, greater than ideal body weight, diabetes mellitus, and excessive alcohol consumption . Secondary HTN is caused by underlying factors such as kidney disease, certain arterial conditions, some drugs, and occasionally pregnancy. Primary (Essential) Hypertension Risk Factors