L49-therapeutic Control Of Ischemia

Question 1

Agents that improve ischemic symptoms

Answer 1

Inc coronary flow
Inc O2 supply 
Vasodilators:
▪️Organic nitrates 
▪️Calcium channel blockers
▪️Potassium channel openers
Dec cardiac work
Dec O2 demand 
-ve inotropes
▪️beta blockers

Question 2

What do organic nitrates act on

Answer 2

Venular

Question 3

Types of organic nitrates

Answer 3

Rapid acting: nitroglycerine

Short acting: isosorbide mono and dinirate

Question 4

Mechanism of nitrates

Answer 4

Act on GSH-transferase
Release on nirite ion in endothelial cell
Act as NO donner mimicking action of endogenous NO

Question 5

Functions of nitrates

Answer 5

Vasodilation

Cytoprotection of endothelium

Question 6

Side effects of nitrates

Answer 6

Tachycardia
Flush and headache
Syncope

Question 7

How can there be an inc myocardial oxygen supply

Answer 7

Dilatation of collaterals which redistributes flow

Dilatation of large and resistant vessels which dec the BP and dec afterload

Question 8

What are the dihydropamines and what are they selective to

Answer 8

Nifedipine and amlodipine

Act on VSMCs

Question 9

What acts on cardiomyoctes

Answer 9

Verampril

Question 10

What has an intermediate action on both cardiomyocytes and VSMCs

Answer 10

Diltaizem

Question 11

Mechanism of Ca channel blockers

Answer 11

Bind to: L type and T type
In VSMCs they dec entry of extracellular Ca and cause vasorelaxation dec bp and afterload
In cardiomyocytes they dec entry of Ca and dec CICR from SR dec contraction and dec hr having a -ve dromotropic effect

Question 12

Why should we never use short acting nifepidine

Answer 12

Sudden dec in bp and reflex tachycardia which causes myocardial hypo perfusion and can lead to death
Use instead long acting amlodipine

Question 13

What do K channel openers do

Answer 13

Vasodilator action
Opening of Atp sensitive k channels causing hyper polarization and inhibits L type ca channel which dec VSMCs contraction in arteriolar
Used as second line therapy

Question 14

What do beta blockers do

Answer 14

-ve inotropic and chronotropic
Dec CO and afterload
Dec RAAS which dec cardiac work and O2 demand
Leads to bradycardia
Which prolongs diastole and inc coronary filling as well as perfusion time which inc myocardial O2 supply

Question 15

B1 selective drugs

Answer 15

Nebivolol
Atenolol
Bisoprolol
Metoprolol

Question 16

What can nitrates be combined with

Answer 16

Non dihydroprine group or with beta blockers to limit decrease blood pressure and reflex tachycardia

Question 17

What can calcium channel blockers be used with

Answer 17

Dihydropyridines since they don’t dec contractility and given if also HF
Non-dihydropyridines since they dont cause vasodilation but dec contractility so give for angina if HF is not severe and no bradycardia can be give if hypotension exist

Question 18

What can beta blockers be used with

Answer 18

Nitrates since they abolish its induced reflex tachycardia

With dihydropydrine calcium channel blockers but not verampril nor diltiazem for fear of conduction defect

Question 19

What is the mechanism of Pfox inhibitors

Answer 19

The shift cardio myocytes metabolism to the utilization of carbohydrates which lower the O2 demand rather than free fatty acids to spare O2 to the ischemic myocardium
They prevent beta oxidation via inhibiting enzyme responsible for transfer of free fatty acids across the mitochondrion membranes

Question 20

Agents used to prevent develop of thrombos

Answer 20

Aspirin or clopidogrel

Question 21

To hold progression of atherosclerosis

Answer 21

Statins

Question 22

To limit cardiac demand and dysrhythmias

Answer 22

Beta blockers

Question 23

To dump in the RASS damaging effects specially in presence of hypertension

Answer 23

Ace inhibitors

Question 24

What is given before and during transfer in treatment of acute myocardial infarction

Answer 24

GTN and sublingual up to three doses at five minute intervals
Analgesic such as morphine for pain
Chewable aspirin plus loading dose clopidogrel
If needed CPR or 02 or Ivy fluids

Question 25

What is given in the ER than ICU or CCU units

Answer 25

To relieve symptoms : IV GTN infusion plus analgesic IV
To open occluded vessel:
pry PCI
fibrinolytics 

Question 26

The drugs given to improve survival

Answer 26

Early beta blockers
Early statins
Ace inhibitors