Drug Management of Heart Failure: Chronic Heart Failure Acute Pulmonary Oedema

Question 1

What happens under normal circumstances when there is an activation of the sympathetic nervous system in response to a fall in blood pressure?

Answer 1

Sympathetic nervous system activation which will drive positive chrono and inotropic responses as well as positive trophic response.

The kidney will produce much more renin. (salt and water retention)

Peripheral vasoconstriction

Cardiac remodelling

Question 2

What is cardiac remodelling?

Answer 2

A trophic response to make the heart grow.

Question 3

What symptoms does sympathetic activation associated with fall in cardiac output during heart failure result in?

Answer 3

Increase in peripheral vascular resistance

Increase in cardiac afterload

Causes cardiac arrhythmia

Question 4

What symptoms does RAAS activation associated with fall in cardiac output during heart failure result in?

Answer 4

Peripheral vascular resistance

Salt and water retention

Question 5

What symptoms does raised pulmonary venous pressure associated with heart failure result in?

Answer 5

Dyspnoea and pulmonary oedema

Question 6

What symptoms does raised central venous pressure associated with heart failure result in?

Answer 6

Peripheral and viceral oedema

Question 7

What symptoms does reduced cardiac output associated with heart failure result in?

Answer 7

Impaired organ function, fatigue

Question 8

What symptoms does peripheral vasoconstriction associated with heart failure result in?

Answer 8

Impaired organ function and fatigue

Question 9

What symptoms does cardiac remodelling associated with heart failure result in?

Answer 9

Functional deterioration

Earlier mortality

Question 10

What is afterload?

Answer 10

Obstruction blood faces when ventricle is contracting

Question 11

What is preload?

Answer 11

Pressure from the venous system

Question 12

Name some renin-angiotensin inhibitor families:

Answer 12

AtII acts on AT1 receptor which can be blocked by “sartan” blockers

ACE1 inhibitors are “pril”

Question 13

Name an aldosterone blocker:

Answer 13

Spironolactone which blocks myocardial remodelling and blocks sodium, potassium and water retention

Question 14

What does the heart do in response to the RAAS system?

Answer 14

Aldosterone has trophic effects on the ventricle

Question 15

Why are beta1 adrenoceptors blocked pharmacologically?

Answer 15

To prevent cardiac remodelling

Question 16

What are the most predictable adverse effects of beta blockers?

Answer 16

Bronchospasm (due to beta 2 receptors on bronchial smooth muscle.) [not to be used in people with airway obstructions]

Bradycardia

Acute worsening heart failure [should not be used for acute attacks because it worsens heart failure short term]

Question 17

Why are diuretics used for heart failure?

Answer 17

To reduce peripheral and pulmonary oedema

Question 18

Name a loop diuretic:

Answer 18

Frusemide

Question 19

Name an aldosterone blocker:

Answer 19

Spironolactone

Question 20

What drug can be used in short term to create an inotropic effect?

Answer 20

Digoxin

Question 21

What does digoxin do?

Answer 21

It is a cardiac glycoside due to presence of 3 sugars. Water soluble and renally excreted.

It blocks sodium potassium pump reducing the sodium and potassium gradient

It makes less efficient Ca2+ exchange increasing intracellular calcium because the calcium sodium gradient exchanger can take calcium out less effectively. This results in more calcium entering the sarcoplasmic reticulum thus causing an inotropic effect while not being chronotropic.

More efficient myocyte contraction

Question 22

What else can result from digoxin interference?

Answer 22

It decreases heart rate and slows down AV conduction.

It affects the cardiovascular center in the brain that affects vagal tone by making the vagus nerve less effective.

It interferes with potassium flow by decreasing the potassium gradient and so resting membrane potential ends up being much higher. This means too much digoxin results in arrhythmia.

Question 23

What clinical symptoms indicate a need to stop using digoxin?

Answer 23

Serious arrhythmias (due to hypokalaemia)

Nausea, confusion, and visual neurological symptoms.

Question 24

What is the half life of digoxin? What does this mean?

Answer 24

1 day. it will take some time before being completely out of the body.

Question 25

Who should doctors be very weary of giving digoxin to?

Answer 25

Digoxin becomes much more toxic in people suffering from hypokalaemia.