L19- Cardiac Failure and Angina

Question 1

Which rceptors are primarily respinsable for the sympathetic increase of heart contractions?

Answer 1

Beta-1 receptors

Question 2

What are the additional effects of beta blockers?

Answer 2

Blooc can flow through the coronary vessels during diastole, B blockers prolong diastole so theat more O2 can get to heart.

Question 3

hat are the principal and secondary effecs of beta blockers in relieving angina of effort?

Answer 3

Principal- reduction in cardiac work, reducing O2 demand.

Secondary- making diastole longer, improving blood flow to cardiac muscle

Question 4

Which 2 drugs can be used for angina, bind to the alpha subunit of the L type Ca channel?

Answer 4

Verapamil = use dependent block

Nifedipine = NOT use dependent block

Question 5

What can verapamil treat?

Answer 5

dysrhythmias and angina and hypertension

Question 6

How does the use dependence determine the mechanisms of ca blockers in angina treatment?

Answer 6

verapamil = use dependent. more potent on the heart than vasuclar smooth muscle. so reduces cardiac output

nifedipine= not use dependent. more potent on vascular smooth muscle than heart. so causes vasodilation.

Question 7

Which drugs reduce risk of thrombosis?

Answer 7

Anti- coagulents eg heparin and aspirin

Question 8

Which drugs relieve symptoms of angina?

Answer 8

beta blockers

organic nitrates

calcium antagonists

Question 9

Which drugs relieve pain after an MI?

Answer 9

Opioids eg morphine

Question 10

What;s a symptom of heart failure?

Answer 10

Oedema. Build up of fluid at the extremities. eg fat ankles

Question 11

WHat is hypertrophy?

Answer 11

When the muscle thickness increases in the heart and the ventricles can’t fill as well.

Question 12

WHat is dilated cardiomyopathy?

Answer 12

When the chambers become enlarged, filling more than normal and can’t pump as much

Question 13

What are 3 causes of heart failure?

Answer 13

1. chronic hypertension
2. ischaemia
3. heart valve disorders

Question 14

What’s wrong with the compensatory mechanisms the body uses to deal with short term heart failure?

Answer 14

Blood pressure rises

Salt and water are retained

vasoconstriction

these end up causing more work for the heart and just make it aaall worse!!

Question 15

What is a classification system for chronic heart failure?

Answer 15

left- left side failing

right- right side failing

forward- failure for pushing blood out heart

backward- failure for blood going back into the heart

Question 16

What type of heart failure causes:

1. problems in the lungs
2. oedema in the rest of the body?

Answer 16

1. lef-sided backwards
2. right-sided backwards

Question 17

What are the symptoms for:

1. forward failure?
2. backwards failure?

Answer 17

1. tiredness, preipheral cyanosis, salt and water retention
2. breathlessness, engorgement of liver, oedema of legs and ankles

Question 18

What are 3 strategies for treating congestive heart failure?

Answer 18

1. reduce cardiac work
2. reduce pulmonary congestion and peripheral oedema
3. increase cardiac output

Question 19

How do you reduce cardiac workload?

Answer 19

1. rest
2. ACE inhibitor (reduce preload and afterload)
3. Organic nitrate

Question 20

How do you reduce oedema in tissue and lungs?

Answer 20

1. diet- reduce salt
2. Thiazide diuretics
3. loop diuretics

Question 21

How do you increase cardiac output?

Answer 21

With a positive inotropic agent.

eg Digoxin.

Improved quality of life but not survival

Question 22

Where does digoxin come from?

Answer 22

Fox Gloves.

Digitalis lanata (digit finger)

Question 23

What are the 4 parts in digoxin?

Answer 23

a glycone- determines pharmodynamic properties

lactone

steroid- lipid soluble

sugar residues - water soluble

Question 24

Which drug has a positive inotropic effect on the heart without increasing oxygen demands?

Answer 24

Digoxin

Question 25

What is the mechanism of digoxin?

Answer 25

Not understood. believed to involve the sodium potassium pump

Question 26

What does digoxin do at pharmaceutical doses and toxic doses?

Answer 26

pharma- increases vagus nerve activity toxic- increases sympathetic tone, causing arrhythmias. and inhibits na k atpase

Question 27

When is digoxin used?

Answer 27

1. To treat heart failure with atrial fibrillation and dysrhythmias 2. Heart failure when diuretics and ACE inhibitors used and still have symptoms.

Question 28

What;s the problemo with digoxin?

Answer 28

Low therapeutic index. small window. causes nausea and blurred vision.

Question 29

How is digoxin toxicity treated?

Answer 29

Withdrawing it and trying to control the arrhythmias. Propranalol or phenytoin for the arhythmias,. KCl for hypokalaemia.

Question 30

Name three other treatments for congestive heart failure?

Answer 30

1. Phosphodiesterase inhibitors (PDE) ed milrinone 2. B1- AGONIST eg dobutamine 3. B1 ANTAGONIST WHEN BROUGHT IN SLOWLY eg carvedilol and metoprolol (as well as digoxin)