LV dysfunction and heart failure

Question 1

What is NICE and what do they do?

Answer 1

The national institute for health and clinical excellence

gives national guidance on technologies, devices, anything new coming into medicine

Question 2

What is heart failure, how is it treated (broadly speaking)?

Answer 2

HF= complex clinical syndrome of symptoms and signs that suggest the efficiency of the heart is impaired
no single test for HF
no single definition of HF
do not try and stimulate the ventricle directly- treat the peripheral effects

Question 3

What are the 2 main causes of heart failure?

Answer 3

Left ventricular systolic dysfunction- LVSD (however you can have LVSD w/o HF)
HF with preserved ejection fraction (diastolic failure)- HFPEF
theres acute and chronic HF- bulk of pharmacology is based on chronic HF, due to LVSD

Question 4

What are some characteristics of HF?

Answer 4

Caused by structural or functional abnormalities of the heart
complex clinical syndrome
most common cause is coronary artery disease
causes morbidity, mortality, hospital admission and substantial cost to the NHS
main therapy is with vasodilator therapy via neurohumoral blockage- RAAS-SNS

Question 5

What are the main symptoms of HF and how ar they caused?

Answer 5

reduced cardiac output- exercise intolerance
filling pressure increases (backward pressure):
increased left atrial pressure: pulmonary oedema
increased right atrial pressure: ankle oedema, swelling

Question 6

Whats the point of using diuretics in HF in terms of frank-starling law?

Answer 6

Move the patient out of a zone of pulmonary congestion (reduced LVEDP)- but not into a zone of hypotension (due to reduced stroke volume)

Question 7

What are the classes of diuretics?

Answer 7

Thiazides and related drugs- act on distal tubule- used in hypertension
Loop diuretics- act on the loop of henle- main choice for heart failure
Potassium-sparing diuretics- not really used now
Aldosterone antagonists- weak diuretics but are important because they block the RAAS

Question 8

Examples of thiazides?

Answer 8

Bendroflumethiazide - used in small doses
Hydrochlorothiazide
Chlorthalidone

Question 9

Examples of loop diuretics?

Answer 9

Furosemide- act v quickly, are very potent

bumetanide

Question 10

Examples of potassium-sparing diuretics?

Answer 10

Traditional:
amiloride and triamterene (blocks Enac- inhibits sodium reabsorption)
Newer ones used for HF:
Spironolactone (sfx- increase oestrogen in males- breast sensitivity)
Eplerenone ( blocks the effect of aldosterone)