Cardiovascular Flashcards
Hypertension
BP = CO x SVR
When there is increased peripheral resistance, blood flow is imposed by friction between the artery walls, blood pressure increases due to blood viscosity and diameter of the arteries. 2 + readings of 140/90 = pre hypertension. Primary / idiopathic / essential HTN - due to unknown causes
Secondary HTN
Due to other organ damage such as renal
Modifiable risk factors
Diet, smoking, alcohol, lack of exercise
Non modifiable risk factors
Age, gender, family history
Pathophysiology of HTN
Genetic and environmental factors, Sympathetic nervous system stimulation, Excess adipose tissue = increased renin-angiotensin and aldosterone, insulin resistance, Na+ retention in the kidneys, Vasoconstriction - increased CO & SVR = HTN
Six classes of anti hypertensives
ACE inhibitor Angiotensin II inhibitors A blocker B blocker Ca+ channel blockers Diuretics
Three types of diuretics
Loop
Thiazides
Potassium sparing
Mechanism of action of b blocker
Inhibits the action of epinephrine on the B1 receptors of the cardiac muscle to reduce contractility and reduce SVR = reduced BP
Mechanism of action of Ca channel blockers
By inhibiting calcium ion channels it prevents calcium from entering the cardiac muscle and arteries, vasodilation can be accomplished by reducing contraction caused my Ca.
Spironolactone is
A potassium sparing diuretic, MOA inhibits NA/K exchange channel, increasing NA elimination and therefore H2O but sparing K
Amiloride
K sparing diuretic. MOA acts independent of aldosterone decreases water retention and Na in DCT
‘Prils’
ACE inhibitors - inhibits enzyme ACE to prevent conversion of angiotensin I to II
Metoprolol
B blocker - reduce the speed and force of heart contractions by blocking the effects of adrenergic (norepinephrine) receptors on the b1 receptors of the heart
Valsartan, Losartan
Angiotensin II receptor blockers. Angiotensin II causes vasoconstriction.
Furosemide
Loop diuretic, blocks reabsorption of Na, K and H2O in the loop of henle therefore increasing urine output
Atherosclerosis
Inflammatory cellular response leading to formation of fibro-fatty lesions (plaques) in the intimal layer of M&L arteries. Progressive accumulation of smooth muscle cells, lipids, and connective tissue.