Inotropic Agents.

Question 1

What is an Inotrope?

Answer 1

It increases or decreases action of the heart (rate, force). (+ve Inotrope increases action USED TO TREAT HEART FAILURE).

Question 2

Chronic heart failure life expectancy.

Answer 2

50% die in 6 months, 50% die within 5 years (mild-moderate).

Question 3

Compensatory mechanism of heart failure.

Answer 3

Reduced cardiac output causes the kidneys to release renin. Renin leads to the release of Angiotensin 2 which cause vasoconstriction and the production of Adolsterone. Vasoconstriction increases afterload whereas Adolsterone cause water retention leading to increase in preload. These two actions can cel each other out but cardiac failure also causes SNS activation which increases heart rate and force. This along with the increased preload attempts to increase cardiac output. The heart will also increase in size to increase cardiac output.

Question 4

Describe the signs and symptoms of heart failure.

Answer 4

Breathlessness, Tiredness, Palpitations, Orthopnea, Confusion, (Nocturia, Pedal Oedema - due to water retention).

Question 5

What would a chest X-ray show in a patient with heart failure?

Answer 5

An enlarged heart.

Question 6

What is the principle behind the treatment of acute heart failure.

Answer 6

Symptomatic relief.

Question 7

What are the principles behind treatment of chronic heart failure?

Answer 7

Symptomatic relief, Better hemodynamics, Better mortailty.

Question 8

Drugs given in the management of heart failure?

Answer 8

Diuretics, ACE-inhibitors, ARB (in patients sensitive to ACE inhibitors), Betablockers, Vasodilators, Postivie Ionotroped (digoxin).

Question 9

Name some ACE inhibitors.

Answer 9

PRIL - ENalapril, Captopril, ramipril.

Question 10

Side effects of ACE inhibitors?

Answer 10

Cough and Increased Potassium.

Question 11

Name some ARB’s?

Answer 11

Losartan, Irbesatan, Candesartan.

Question 12

What do Diuretics do?

Answer 12

Increase water and sodium excretion.

Question 13

How do DIuretics works?

Answer 13

THey work by decreasing the reabsorption of Na= and Cl- from kidney filtrate. Fluid loss can decrease edema, and preload.

Question 14

Side effects of diuretics?

Answer 14

Toxicity as some stuff won’t be excreted right, Electrolyte imbalance.

Question 15

TPR?

Answer 15

Total Peripheral Resistance?

Question 16

What are diuretics commonly used with?

Answer 16

ACE inhibitors (have the same outcome).

Question 17

Method of action of Adolsterone antagonists?

Answer 17

Increase salt and water excretion. (Adolsterone causes water and sodium retention).

Question 18

Name some beta blockers used in heart failure management.

Answer 18

LOLS, Carvedilol, Bisoprolol, Metoprolol.

Question 19

Why should caution be exercise when beta blockers are used for cardiac failure treatment?

Answer 19

They can have negative Inotropic effects.

Question 20

How can beta blockers be beneficial in the treatment of heart failure?

Answer 20

Decreases heart rate and force, thereby increasing filling time and ejection volume,
Reduces sympathetic outflow from the brainstem, thereby reducing cardiac remodelling (reduces cardiac contractility),
Reduces Renin, angiotensin and adolsterone causing decrease in preload and afterload,
Reduce hypertension and arrhytmias.

Question 21

Adverse effects of Beta blockers.

Answer 21

Bronchoconstriction, Diabetes, Disturbances in lipid metabolism.

Question 22

How would vasodilators help in the management of heart failure?

Answer 22

Decrease preload and afterload.

Question 23

Name an ateriolar dialator.

Answer 23

Hydralazine.

Question 24

Name a venodialator.

Answer 24

Isosorbide dinitrate.

Question 25

Non-selective vasodilators.

Answer 25

Nitroprusside.

Question 26

Name some Positive Inotropes.

Answer 26

Digoxin, 
B1 agonists - Dobutamine, 
Bipyridines, 
Dopamine, 
Levosimendan.

Question 27

Digoxin.

Answer 27

A positive Ionotrope. Increase force of contraction.

Question 28

How does Digoxin work?

Answer 28

Inhibit Na+/K+ ATPase causing increased intracellular calcium leading to increased myocardial contractility.

Question 29

Adverse effects of Digoxin?

Answer 29

Arrythmia, Nausea and vomiting, Visual disturbances.

Narrow safety margin as antibodies made to overdose.

Question 30

How does Dobutamin work?

Answer 30

B1 selective agonist which increases cAMP synthesis and inward Calcium influx. Stimulates myocardial contractility.

Question 31

How would Bipyrdines work?

Answer 31

They are postive ionotropic agents with vasodilator activity. They can also inhibit PDE which normally degrades cAMP. Increased cAMP increases inward calcium influx and heart contractility.