CV drugs

Question 1

2 main causes of arrhthmias

Answer 1

1. abberant pulse generations

2. defection in conduction system

Question 2

what is cardiac output

Answer 2

SV x HR

Question 3

what determines CO (3)

Answer 3

1. preload
2. afterload
3. contractility

Question 4

3 major determinants of myocardial O2 demand

Answer 4

1. HR
2. contractility
3. ventricular wall stess

Question 5

what is formula for ABP

Answer 5

HRxSVxTPR

Question 6

2 ways Ca is involved in contraction

Answer 6

1. influx from channels in sarcolemma

2. release of intracellular Ca from sarco reticulum

Question 7

pathway of vasocontriction

Answer 7

depolarization>Ca in>activates calmodulin>activates MLCK>binds with actin

Question 8

pathway of vasodilation

Answer 8

bind to GCPR>activate guanylate cyclase>cGMP>activates PKA>phosphoylates MLCphosphotase>no action

Question 9

2 targets for hypertension

Answer 9

1. CO

2. peripheral resistance

Question 10

3 aspects of hypertension

Answer 10

1. inceased vascular tone
2. increase resistance
3. lower venous capacitance
   (see chart)

Question 11

classes of antihypertensives

Answer 11

1. diuretics
2. B blockers
3. ACEi
4. ARBs
5. Ca channel blockers
6. vasodilators

Question 12

4 diuretics in order of use and mechanism

Answer 12

1. thiazides - Na/Cl inhibition
2. loops - Na/K/2Cl inhibition
3. spironolatone - aldosterone antag
4. amiloride - Na channel antag

Question 13

2 antihypertensive functions of B-blockers

Answer 13

1. lower HR/contractility

2. lower renin

Question 14

how do ACEi help (2)

Answer 14

1. inhib. Ang2 which is a vasoconstrictor

2. less Na retention by blocking aldo

Question 15

how do ARBs help

Answer 15

same as ACE, but by blocking the Ang2 receptor

Question 16

how do CCBs work

Answer 16

inhibit Ca influx for heart can’t contract and smooth muscle can’t constrict

Question 17

other effects of CCBs (2)

Answer 17

1. dilate coronary arteries, which improves flow

2. cardiac myocyte decreased action

Question 18

3 binding site of Ca channel and drug that work on them

Answer 18

N - nifedipine
D - diltiazem
V - verapamil

Question 19

which has less heart action and most vasculr

Answer 19

N - nifidepine

Question 20

what is sodium nitroprusside

Answer 20

liberates NO which dilates both Art and veins

- stimulates RAAS

Question 21

2 actions of NO

Answer 21

1. activates guanylate cyclase> cGMP>MLCphosphoatse

2. activates Ca dependent K channel which hyperpolarizes the cells - less active

Question 22

what is angina pectoris

Answer 22

sudden sever crushing pain due to heart iscemia due to increased heart demand or supply of oxygen

Question 23

how to help angina

Answer 23

lower o2 demand via BP, venous return, HR, contractility

Question 24

3 agents for angina

Answer 24

1. nitrates
2. B blocker
3. CCBs

Question 25

what do nitrates predominantly dilate

Answer 25

venous system

Question 26

pathway of nitrate actions

Answer 26

venous dilation>less R heart blood>lower EDP in vents>less preload>less O2 demand

Question 27

nitrates for chronic and acute angina

Answer 27

acute: nitroglycerine under the tongue
chronic: isosorbide dinitrate or patch – longer half-life

Question 28

nitrate limitations

Answer 28

• tolerance to antianginal effects

- many contraindications

Question 29

2 aspects of heart failure

Answer 29

1. can’t fill heart

2. can’t pump blood out

Question 30

2 types of congestive heart failure

Answer 30

1. pulmonary congestion - Left heart failure

2. peripheral edema - Right heart failure

Question 31

best treatment for heart failure

Answer 31

digoxin+diuretic+ACEi

Question 32

digoxin mech

Answer 32

inhibitits Na/K exchanger>high intracellular Na> slows the Na/Ca exchanger>more Ca in cell