Hypertension(Katzung) 1st part lang Flashcards
Bp of 120-135/80-89
Prehypertension
Bp of >140/90
Hypertension
140-159/90-99
Stage 1
> 160/100
Stage 2
Starting at what bp pressure does cardiovascular disease risk doubles with each increment of 20/10 mmhg
115/75
Patients in whom no specific cause of hypertension can be found
Essential/ primary hypertension
Causes o lf hypertension that are amendable to surgical treatment
Renal artery constriction Coarction of aorta Pheochromocytoma Cushing's Primary aldosteronism
Functional variations of the genes of these proteins can cause essential hypertension
Angiotensinogen
ACE
B2 adrenoreceptor
A adducin
Formula for BP
BP=CO*PVR
Anotomic sites for control of BP
Resistance arterioles
Capacitance venules
Pump output of the heart
Kidney volume
Responsible for rapid moment to moment adjustments in bp
Baroreflexes
Sympathetic activation of batoreceptor reflex acts through
Arterioles
Heart
Capacitance vessels
Decresed pressure in the renal arterioles and decreased sympathetic neural activity through via b adrenoreceptors causes the kidney to release….
Renin
Causes direct constriction of resistance vessels. Stimulation of aldosterone synthesis in the adrenal cortex which causes increase renal sodium absorption and intravascular volume
Angiotensin 2
Released from the posterion pituitary gland which regulates water reabsorption by the kidneys
Vasopressin
Reduces peripheral vascular resistance. Inhibits cardiac function and increases venous pooling.
Sympathoplegic agents
Maximal lowering of bp of less than 10 mmhg bust is useful in the long term reduction of renal disease in diabetic persons and reduction of heart failure
ACE inhibitors
Reduce mortality after MI and particularly indicated in patients with an infarct and hypertension
B blockers
Contribute to vascular resistance by increasing vessel stiffness and neural activity
Sodium
Effective in lowering bp by 10-15 mmhg and adequate for treatment of mild to moderate hypertension. In severe hypertension, theses drugs are used in combination with sympathoplegic and vasodilator drugs to control tendency towards Na retention
Diuretics
Diminished by sympathoplegic and vasodilator drugs thus vasculature behaves like a inflexible tube
Vascular responsiveness
Necessary for severe hypertension when multiple drugs with Na retaining properties are used; renal insufficiency when gfr is less than 30-40 ml/ minute; and cardiac failure and cirrosis in which Na retention is marked
Furosemide ir other powerful diuretics(acts at the loop of henle)
Most common adverse effect of diuretics(except for K sparing diuretics)
K depletion
Hazardous in patients taking digitalis, in those with chronic arrhythmias and in those with MI or left ventricular dysfunction
Hypokalemia