CVS 20 - Investigation + Management of HF

Question 1

What investigations would you do to investigate someone with potential HF?

Answer 1

1) ECG - e.g.: check for Afib.
2) Chest X-ray - e.g.: Alveolar oedema, Kerley B lines, Cardiomegaly, Pleural effusions
3) Echocardiogram - check for mitral regurgitation or aortic stenosis.

Question 2

What should the immediate symptomatic treatment be for an individual with heart failure?

Answer 2

1) Furosemide - relives congestive symptoms - a loop diuretic inhibiting Na2ClK transporter in TAL, reducing Na + Cl reabsorption increasing diuresis. Also enhances prostaglandin synthesis to have venodilatory effect. So reduced preload + afterload.

2) Oxygen if hypoxic
3) Respiratory support
4) Second line medication - i.v. nitrates, i.v. morphine

Question 3

What is the main blood test used in the diagnosis of heart failure?

Answer 3

• NT-pro BNP (brain-type natriuretic peptide)
• Hormone released in response to atrial/ventricular stretch due to fluid overload
• Typically cause increased diuresis, vasodilation and decreased RAAS activity.

Question 4

How do B-blockers work in the treatment of heart failure?

Why should they be caused cautiously?

Answer 4

• Reduce HR + BP (both reducing myocardial oxygen demand) and negate unwanted effects of catecholamines.
• Failing myocardium may be dependent on HR, initiate at slow dose, can make problem worse.

Question 5

How are ACEi’s + ARB’s used in the treatment of heart failure?

Answer 5

• RAAS activated by low BP and has deleterious effects

- ACEi’s block conversion of Agl to Agll via blocking ACE, ARB’s block the effects of Agll at Agll receptors.

Question 6

How are aldosterone receptor antagonists used in the treatment HF? (Give an example)

Answer 6

• In spite of ACEi’s + ARB’s, aldosterone levels return to normal (aldosterone escape)
• Therefore need to block effects at mineralocorticoid receptors via antagonists - e.g.: Spironolactone