HEART FAILURE

Question 1

what is heart failure?

Answer 1

the inability of the heart to deliver adequate blood to the body to meet end organ metabolic needs and oxygenation at rest or mild exertion

Question 2

what is systolic heart failure?

Answer 2

when the heart cant contract enough and pump the blood hard enough during systole
has an ejection fraction of <40

Question 3

what is diastolic heart failure?

Answer 3

when the heard cannot relax enough to adequately fill with blood during diastole
normal ejection fraction as both stroke volume and total volume are decreased

Question 4

what is pre-load?

Answer 4

the pressure in the ventricle just before it begins contraction

Question 5

what is after-load?

Answer 5

the systemic vascular resistance - the resistance the heart must overcome to open the aortic valave and push blood out of the heart

Question 6

what is the Frank-Starling relationship?

Answer 6

the force developed in a muscle fivre depends on the extent to which the fibre is stretched (e.g. more blood fills ventricles = harder ventricles contract)

Question 7

what is the cardiac output?

Answer 7

the volume of blood ejected from the heart in 1 minute

norm = 4-8L/min

Question 8

what is the ejection fraction?

Answer 8

stroke volume/total volume

norm = 50-70%

Question 9

what is it called when you get heart failure of both ventricles?

Answer 9

biventricular HF

Question 10

what are some causes of systolic HF

Answer 10

ischaemic heart disease
long standing hypertension
dilated cardiomyopathy

Question 11

how does long standing hyertension lead to systolic HF?

Answer 11

increased vascular peripheral resusrance leads to left sided hypertrophy which increases metabolic demands as well as compressing the coronary vessels and therefore reducing suppky
increased demand and reduced supply leads to failure

Question 12

how does dilated cardiomyopathy lead to heart failure?

Answer 12

heart chambers dilate in an attempt to fill the ventricle with larger volumes of blood so it will contract more (Frank-Starling law)
overtime muscles thin and get weak

Question 13

what are some causes of diastolic HF?

Answer 13

hypertension
aortic stenosis
hypertophic cardiomyopathy
restrictive cardiomyoapthy

Question 14

why do hypertension, aortic stenosis and hypertrophic cardiomyopathy cause diastolic HF?

Answer 14

they lead to concentric hypertrophy (thickening of chamber walls) leaving less room for filling

Question 15

how does restrictive cardiomyopathy lead to diastolic HF?

Answer 15

the muscles become stiff and less compliant so the ventricles cannot easily expand and fill with as much blood

Question 16

outline how the kidneys play a role in HF?

Answer 16

when the blood doesnt pump out enough blood there is less blood flow to the kidneys, this activates RAAS causing Na+ and H2O reabsorbiton = fluid retention which can increase pre-load of the heart but in the long term this leads to a lot of fluid leaking from the vessels

Question 17

what are the heart failure?

Answer 17

pulmonary oedema symptoms
anasarca
fatigue

Question 18

what is anasarca?

Answer 18

fluid in the wrong place presenting as gradual weight gain, oedema, ascites and pleural effusions

Question 19

what are some typical x-ray findings of pulmonary oedema?

Answer 19

upper lobe diversions
kerley B lines
cardiomegaly
interstital oedema/pleural effusions

Question 20

what are the signs of pulmonary oedema?

Answer 20

breathlessness
orthopnoea
paroxysmal noctural dyspnoea
using accessoru muscles
sweating
cold
clammy
cysnosed
pink frothy sputum

Question 21

why do we get pulsus alternas in severe left ventricular HF?

Answer 21

reduced ejection fracture leaving blood in the ventrcile (weak pulse) and then on the next beat it will be strong as ventricle is already half full (strong pulse)

Question 22

what are some signs of right ventricular sided HF?

Answer 22

JVP distention

hepatospenomegaly

Question 23

how do we diagnose HF?

Answer 23

BNP in blood >400pg/ml
echocardiography to estimate ejection fraction, ventricular wall and chamber size, asses heart valves and pulmonary arterial pressures

Question 24

how do we classify heart failure?

Answer 24

using the New York Heart Association classification:
class 1 - symptoms on extreme exertion
class 2 = symptoms on moderate exertion
class 3 = symptoms on mild exertion
class 4 = symptoms at rest

Question 25

whats the aim of treatment for heart failure?

Answer 25

reducing bp to reduce the workload of the heart

Question 26

outline the treatment of HF?

Answer 26

reduce Na+ and fluid intake
beta blocker
ACEi
if class 2 add a diuretic
if class 3 add aldosterone antagonists or vasodilators
if class 4 ass an inotrope (e.g. digoxin) and get a heart transplant