Pharmacological Treatment of Cardiac Failure

Question 1

What is the standard drug treatment of chronic heart failure?

Answer 1

D
A
B

Question 2

What are the signs and symptoms of chronic heart failure?

Answer 2

• shortness of breath
• swollen legs and feet
• chronic lack of energy
• cough frothy sputum
• increased urination at night

Question 3

What type of D are used?

Answer 3

loop diuretics

Question 4

what are the loop diuretics used?

Answer 4

furosemide

Question 5

what is the mechanism of action of loop diuretics?

Answer 5

• function in the ascending loop of the nephron
• inhibit pump bringing in 2Cl 2Na 1K
• less fluid reabsorbed

Question 6

What ACE inhibitors are used?

Answer 6

• ramipril

- lisinopril

Question 7

what ARBs are used?

Answer 7

candestartan

Question 8

what aldosterone antagonist is used?

Answer 8

spironolactone

Question 9

Why would using B seem paradoxical?

Answer 9

they slow the rate of the heart which would decrease the CO

the heart is already struggling to produce efficient CO to meet the metabolic demands of tissues

Question 10

what is the benefit of using B to treat heart failure?

Answer 10

• stops the elevated blood pressure putting undue stress on heart
• slowing heart allows ventricle to fill more completely

Question 11

what 2 Beta blockers are used?

Answer 11

• bisoprolol

- Carvedilol

Question 12

What is the extra benefit of using the B Carvedilol?

Answer 12

-reduce the afterload of heart since it affects alpha receptors too resulting in vasodilation and therefore decreasing TPR hence CO can still be maintained at a sufficient level despite slowed HR

Question 13

what are the side effects of loop diuretics?

Answer 13

acute gout, high concentrations of uric acid forming crystals around joints

Question 14

what is the mechanism of action of Digoxin?

Answer 14

• increase vagal efferent activity to heart increasing parasympathetic tone
• decrease SA node firing decreasing HR and conduction velocity of AV node

Question 15

how does digoxin increase contractility of the heart?

Answer 15

• increases Ca intracellular storage in sarcoplasmic reticulum
• inhibits NaK ATPase hence increasing intracellular sodium
• sodium calcium exchanger reverses activity to get rid of increased Na hence bringing calcium into the cell
• Ca repackaged in SR so when next released it increases for of contractility

Question 16

what is the aim for treating acute heart failure?

Answer 16

-decrease afterlaod and preload since heart can’t cope with volume overload

Question 17

what is the initial treatment for acute heart failure?

Answer 17

• loop D
• IV opiates
• IV, buccal or sublingual nitrates

Question 18

what is the purpose of second line treatment in acute heart failure?

Answer 18

try and restore blood supply to tissues.

increase CO to get blood pressure back up to sufficient level to perfuse

Question 19

what are the drugs used in second line treatment of acute heart failure?

Answer 19

• inotropes, beta agonist= dobutamine
• dopamine
• adrenaline (inotrope)

Question 20

how do inotropes increase cardiac contractility?

Answer 20

• increase SV by increasing contractility increasing CO
• however as CO increases baroreceptors decrease sympathetic output lower TPR and increase parasympathetic tone dominating your HR
• however parasympathetic effect doesn’t effect cardiac muscle so contractility increased by dobutamine despite low HR so increased CO

Question 21

What is the mechanism of action of dobutamine?

Answer 21

increases myocardial contractility

Question 22

What is the mechanism of action of dopamine?

Answer 22

increases renal perfusion hence increasing Blood Pressure

Question 23

What is the mechanism of action of adrenaline?

Answer 23

constricts blood vessels casing increased contractility increasing HR and blood pressure