Heart Failure

Question 1

What does heart failure represent?

Answer 1

Clinically represents end point of number of diseases that can affect the heart.
Cardiac output insufficient to meet the body’s demand

Question 2

What are the most common causes?

Answer 2

Hypertension
Diabetes
Ischaemia
Acute MI
Valvular disease
Cardiomyopathy
Pericardial disease
Infection

Question 3

What is the Frank-Starling mechanism?

Answer 3

When ventricular end-diastolic volume increases, stroke volume increases

Question 4

What is cardiac pre-load?

Answer 4

So stretch (on normal myocyte) augments contraction (within limits) in response ti stretch

This is cardiac preload – so within limits, stretch on a normal myocyte with augment contraction and refer this to preload

Question 5

What increases cardiac output?

Answer 5

When cardiac muscle is stretched (more blood entering the ventricle) -
Stretched muscle contracts with greater force -
So automatically pumping extra blood out -
Increase venous return when you increase cardiac output

So stretch (on normal myocyte) augments contraction (within limits) in response to stretch

Question 6

What is after-load?

Answer 6

Afterload is the load against which the heart must contract to eject blood from the ventricle

Question 7

What can cause ventricular remodelling?

Answer 7

An increase in afterload (pressure overload)

An increase in preload (volume overload)

Myocardial injury (usually due to MI)

Question 7

What is ventricular remodelling?

Answer 7

Can be defined as any structual change of the ventnricle in reponse to change in loading conditions – includes changes in ventricular mass, chamber size and shape – can help to maintain cardiac output and then worsening heart failure

Question 7

Can ventricular remodelling be reversed?

Answer 7

Yes

Question 8

What is concentric hypertrophy?

Answer 8

Increased amount of work that is demanded of the heart eg. chronic hypertension

Question 9

What is eccentric hypertrophy?

Answer 9

Increased filling pressure or a diastolic overload

Question 10

What is the ejection fraction?

Answer 10

Proportion of the volume of blood present at the end of diastole that is ejected from the ventricle on contraction

Question 10

How can the systolic function of the LV be approximated by?

Answer 10

Ejection fraction

Question 11

How do you work out ejection fraction?

Answer 11

EDV - ESV / EDV

Question 12

What is the normal ejection fraction percentage?

Answer 12

50-60%

Question 13

What does the LVEF correlate and not correlate to?

Answer 13

Not correlate = functional capacity
Does describe the pattern of ventricular remodelling

Question 14

What is the value for heart failure reduced ejection fraction?

Answer 14

EF < 45%

Question 14

What is the value for heart failure normal ejection fraction?

Answer 14

EF > 45%

Question 15

What is the progression of HF?

Answer 15

Damage to the myocardium
(essentially adaptive mechanism / neurohumoral activation)
Systemic body response
(long term systemic response is harmful to the patient)
Progression of damage to myocardium
(downward clinical spiral)
Death

Question 16

What is neurohumoral activation?

Answer 16

Activation of nervous system, different endocrine signals and essentially adaptive mechanism to help heart maintain cardiac output

Question 17

What is long-term systemic response?

Answer 17

Changed in circulating blood volume, changes in other systems – can be harmful to patient

Question 18

Why can HF lead To death?

Answer 18

If unable to intervene somewhere in the spiral and try and restire normal function of the myocardium

Question 19

What are the changes observed in HF?

Answer 19

Ventricular remodelling (dilatation and hypertrophy)
Changed in:
Cardiac function
Neurohumoral status (activation of sympathetic nervous and renin-angiotensin-aldosterone system)
Systemic vascular function
Blood volume

Question 20

What are the signs and symptoms of HF?

Answer 20

Breathlessness on exertion and at rest
Orthopnoea (SOB when supine) - most commonly you see an increase in venous return when lay down in normal healthy person, no matter heart can effectively pump excess. In pt with HF the left ventricle is often weakened and isn’t able to do that
Paroxysmal nocturnal dysponea
Defined by New York Heart Association

Fatigue and ‘lack of energy’
SOB/dyspnea
Ptting oedema – particularly around ankles
Coughing
Elevated JVP
Pulmonary oedema/pleural effusion – fluid in pleural space, lining of the lungs
Ascites – fluid in the abdomen
Tachycardia
S3 gallops (3rd heart sound – deceleration of blood entering the LV from LA)

Question 21

What are the stages of HF?

Answer 21

Stage 1: no symptoms / no limitations of ‘ordinary’ physical activity
Stage 2: mild symptoms slight limitations of ordinary activity
Stage 3: marked limitations during less-than-ordinary activity
Stage 4: severe limitations, experiences symptoms at rest

Question 22

What investigations are undertaken to diagnose HF?

Answer 22

Diagnosis based on overall picture (signs, symptoms and evidience of funtional or structural change)
FBC – full blood count
Haematinicins
U+E
TFT
CXR – chest xray
BNP – brain derived natriuretic peptide – polypeptide produced by ventricles in response to stretching. If normal unlikely patient has HF but higher levels coreelate with functionally worse clinical outcomes
ECG – AF and other arrhythmias, evidence of an old MI, LBBB, left ventricular hypertrophy
Echo – ejection fraction, assessment of valves, assessment of previous MI, infarction of chamber dimensions

Question 23

What is the management for someone with HFNEF >45%?

Answer 23

Diuretics, managing hypertension and underlying causes eg. Diabetes

Question 24

What is the management for someone with HFRNEF <45%?

Answer 24

ACE inhibitors, beta blockers, aldosterone receptor antagonists, devises