CHF

Question 1

Define heart disease and failure

Answer 1

Heart disease = inability to maintain CO at normal filling pressures.
Heart failure = when CO doesn’t equal venous return (oedema) or when CO is not adequate to perfuse the body

Question 2

What is backward vs forward failure

Answer 2

Backward = venous congestion (usually leads to dyspnoea) due to volume overload
Forward = inability to maintain CO/BP as myocardial o2 demand is overloaded

Question 3

What is the main aim of the CV systems control mechanisms?

Answer 3

To maintain cardiac output

Question 4

Why does physiologic control of the heart go wrong in disease?

Answer 4

Because they are meant to be short term measures. Longer term the compensatory mechanisms will further the cardiac damage and eventually the hearts capacity to cope will be overloaded.

Question 5

What are the normal regulators of CO?

Answer 5

PICA & RAAScal
Preload: venous return/tone
Inotropy: Frank-Starling, Baroreceptors, Chemoreceptors, sympathetic tone, RAAS
Chronotropy: sympathetic tone and receptors
After load: RAAS, sympathetic tone/receptors

RAAS combines after load (vasoconstriction) and loading (preload)

Question 6

Outline the RAAS

Answer 6

Prorenin–>Renin by juxtaglomerular cells
Renin converts angiotensiongen to ANG1
ACE converts ANG1 to ANGII
AND II direct effects: vasocontrics, remodels heart. NaCl retention
Aldosterone released in response to ANG II which causes sodium retention and water retention.
Vasopressin also released.

Question 7

How does the pathophysiologic compensation of heart disease relate to chronic treatment options?

Answer 7

Fluid overload - reduce fluid
Venous pressure - venodilators
After load - vasodilators
Inotropy - positive inotropes
chronotropy - rhythm control

Question 8

What are the main adverse effects of diuretics?

Answer 8

Volume depletion

Electrolyte abnormalities

Question 9

What are the most useful diagnostic tests for CHF?

Answer 9

Right lateral thoracic radiograph
Echo
pro-BNP

Question 10

Why is a thoracic radiograph desirable in diagnosing CHF?

Answer 10

Can show evidence of pulmonary congestion as well as cardiomegaly.

Question 11

What initial monitoring should be performed on CHF patients?

Answer 11

Baseline electrolytes and renal function
Blood pressure
Radiography and echocardiography.