Failure of the Heart

Other names for heart failure

• Heart Failure

• Cardiac Failure

• Congestive Heart Failure (CHF)

• Cardiomyopathy

• LV dysfunction

Defn of heart failure

Inability of the heart:

– to pump blood at a sufficient cardiac output

– to maintain adequate perfusion of other organs

Cardiomyopathy defn

Any pathological process affecting the myocardium which results in a disturbance in myocardial function

- Refers to the actual underlying disease process

(Patient has the clincial syndrome of heart failure – “due to a dilated cardiomyopathy”)

Name 1 systolic dysfunction & 2 diastolic dysfunctions associated with HF

Systolic dysfunction: Reduced Contractility

Diastolic dysfunction: Impaired Relaxation & Increased Stiffness (stiffness e.g. increased thickness)

What effect would cause a rise/fall in the frank starling graph representing preload

What effect would cause a rise/fall in the frank starling graph representing afterload

What is Ejection Fraction

Measure of heart function

• % emptying of the left ventricle

• Shows “systolic function”

Ejection Fraction normal %

Normal 55-60%

How is Ejection Fraction normally measured

Typically measured by echo (or MRI)

What are the 2 main types of heart failure

Heart Failure with reduced Ejection Fraction (HFrEF)

Heart Failure with preserved Ejection Fraction (HFpEF)

1 main problem & 2 resulting characteristics of HFrEF

Reduced LV ejection fraction (EF)

• Reduced Stroke volume at rest and with exercise (Reduced “forward pressure”)

• Increased intracardiac pressure (Increased “back pressure”)

1 main problem & 2 resulting characteristics of HFpEF

Diastolic dysfunction (Increased LV stiffness/Impaired relaxation)

• Reduced Stroke volume at rest and with exercise (Reduced “forward pressure”)

• Increased intracardiac pressure (Increased “back pressure”)

What are 2 resulting effects of Reduced stroke volume and cardiac output in HF

• Reduced “forward-pressure”

• Reduced organ perfusion

What are 2 resulting effects of elevated filling pressures and cardiac output in HF

• Increased “back-pressure”

• Fluid retention – affects oncotic pressure

What causes the Neuro-hormonal Response to HF

Stimulation of baroreceptors

Renal hypoperfusion (forward pressure)

Increased adrenaline & noradrenaline

Describe 2 counter-productive compensatory neuro-hormonal responses to HF

Activation of the Sympathetic System

• Increases Heart Rate → Increases myocardial work

• Increases contractility → Increases myocardial work

• Vasoconstriction (improving BP) → but also increases afterload & myocardial work

RAAS activation

• Increased Angiotensin II

  • Vasoconstriction (improves BP) → but increases afterload & myocardial work

• Hyperaldosteronism

  • Sodium retention – enhances intravascular volume – maintains CO → but leads to volume overload

Explain the significance of the Law of Laplace in HF

Explains the progressive course of HF

LV dilates → Increased wall stress → LV becomes more spherical → Progressive dilatation

Heart gets progressively bigger!

2 functional issues in HF

Reduced cardiac output

Increased filling pressures

Symptoms of reduced CO in HF

1. Cool peripheries

2. Hypotension

3. Decreased renal perfusion

– Renal dysfunction

– Activation of RAAS

– Activation of sympathetic system

4. Fatigue

Symptoms of increased filling pressures in HF

1. Pulmonary venous congestion

– Dyspnoea

– Orthopnoea

– PND

– Pleural effusions

2. Right heart dysfunction

– Ankle oedema

– Elevated JVP

– Ascities

What are 2 possible causes of acute HF

Acute myocardial infarction

Cardiogenic shock

What would cause chronic HF

Chronic LV systolic or diastolic dysfunction

Causes of Hypertrophic Cardiomyopathy

• Hypertensive

• Hypertrophic (obstructive) cardiomyopathy (Rare Genetic Sarcomeric protein mutation - Subgroup at risk of sudden cardiac death)

• Metabolic storage diseases (e.g. Anderson Fabry)

• Obesity

What type of HF could Hypertrophic Cardiomyopathy cause

HFpEF

5 causes of HFrEF

1. Ischaemic cardiomyopathy (Ischaemic heart disease - IHD)

2. Non-ischaemic Dilated Cardiomyopathy

3. Hypertension – Usually HFpEF but can get “burnt out” hypertensive HF with reduced EF

4. Valvular Heart disease – AS; AI; MR

5. Tachycardia related – rate related

7 causes of Non-Ischaemic Dilated Cardiomyopathy

What % of HFrEF is caused by ischaemic cardiomyopathy

50-70%

Causes of HFpEF

1. Idiopathic/Familial

2. Infiltrative Processes

• Sarcoidosis

• Amyloidosis

3. Storage Diseases

• Haemochromatosis

• Genetic abnormalities

4. Endomyocardial Fibrosis

How does acute HF present

Acute pulmonary oedema

Dyspnoea

Pulmonary congestion

Implies extensive damage

New major acute insult - AMI

Often pale, listless, diaphoretic

How does chronic HF present

1. Dyspnoea on exertion

• NYHA class I to IV

2. Orthopnoea

• Increased venous return when recumbent

• Measure by number of pillows

3. PND

• Specific for heart failure

• Similar mechanism to orthopnoea

4. Pedal/lower limb oedema, anasarca,

• Dependent

• Worse in evening – resolves overnight

• Can get ascites, pleural effusions etc

• Cardiac oedema is pitting

5. Fatigue

Often pale, listless, diaphoretic

What is staging of HF based on

Dyspnoea on Exertion - New York Heart Association (NYHA) Classification

What are the 4 stages of HF

Class I: No symptoms

Class II: Dyspnoea on strenuous exertion

Class III: Dyspnoea on mild exertion

Class IV: Dyspnoea at rest

What would you find on a physical exam on a HF patient

• Often pale, listless, diaphoretic

• Tachycardic (Pulsus alternans – severe HF)

• BP can be normal, high or low (with advanced HF)

• Elevated JVP

• Oedema/ascites

What feature would you find when auscultating a HF patient’s lungs

Bilateral basal rales on chest auscultation

What feature would you find when auscultating a HF patient’s heart

Third heart sound

Gallop rhythm

MR murmur

What would be a sign of severe HF when taking someone’s pulse

Pulsus alternans (alternating strong and weak peripheral pulse)

What 4 features would you find on a CXR of a HF patient

– Cardiomegaly (CTR > 0.5)

– Pulmonary venous hypertension – upper lobe redistribution – enlarged pulmonary veins

– Interstitial oedema (increased interstitial lung markings) and Pulmonary oedema – pulmonary infiltrates

– Pleural effusions

What do we use an electrocardiogram (ECG) to find out

The cause of the HF:

• Ischaemia

• LBBB (Left bundle branch block)

What do we use an Echocardiography to find out

– Determine if systolic and/or diastolic dysfunction

– Quantify severity - estimated using LV ejection fraction

– Global vs regional dysfunction?

– Evaluate for any valvular pathology or LVH

– Quantify severity of diastolic dysfunction

What is considered: (EF%)

• Normal EF

• Mild LV dysfunction

• Moderate LV dysfunction

• Moderate/severe LV dysfunction

• Severe LV dysfunction

• Normal EF = > 50%

• Mild LV dysfunction = 40-45%

• Moderate LV dysfunction = 30-35%

• Moderate/severe LV dysfunction = 20-25%

• Severe LV dysfunction < 20%

What is Brain Naturetic Peptide - BNP

Released by stretch receptors in the LV in response to an increase in LV pressure/decrease in systolic function

Why do we measure brain naturetic peptide (BNP)? What does it tell us?

Useful to help differentiate cardiac dyspnoea (HF) from pulmonary dyspnoea

Good negative predictive value - Normal value makes HF very unlikely

What could be some other differential diagnoses of breathlessness?

• Pulmonary disease (looks very like HFpEF)

• Obesity

• Anaemia

• Other systemic disease

What are some test we run for HF evaluation

Prognosis of HF in class I-IV

Prognosis of HF depends on stage & what other factors

Increasing age

Men worse prognosis

Ischaemic worse than non-ischaemic

Worse with lower ejection fraction

5 mechanisms of HF treatment

What are 7 lifestyle & dietary changes HF patients must make

1. Avoid harmful drugs (NSAIDs/Corticosteroids/Alcohol)

2. Dietary sodium restriction (< 2g/d)

3. Fluid restriction - < 2L/d

4. Weight reduction

5. Patient Education

6. Daily weights

7. Exercise programme

Name 5 drugs that improve survival in HFrEF

• ACE Inhibitors

• β-Blockers

• Aldosterone Antagonists

• (Angiotensin Receptor Blockers)

• Sacubitril/Valsartan

What are some drugs that don’t improve survival, but improve symptoms

Diuretics

Mineralocorticoid receptor antagonists

SGLT-2 inhibitors

What are 2 main types of diuretics used

Loop diuretics

Thiazide diuretics

Name 2 loop diuretics

Frusemide or bumetanide

AEs of loop diuretics

Hypokalaemia & hypomagnesaemia (due to electrolyte loss)

Muscle cramps

Exacerbate renal dysfunction

What 2 main things do ACEis have an effect on

Effects of ACEis in HF

• Reduce Hospitalisations

• Improve Survival

• Reduce symptoms

• Improve exercise tolerance

• Improve EF

• Reduce LV dimensions (Remodeling)

• Improve haemodynamics

Side effects of ACEis

• Hypotension

• Cough (dry cough) – 10% - especially women

• Renal dysfunction

• Angio-oedema

• Taste disturbances

Effects of Beta Blockers

β-Blockers have a Biphasic Effect. What are the 2 acute effects

Decrease BP and CI

β-Blockers have a Biphasic Effect. What are the 5 chronic effects

• Improve EF

• Decrease HR – decrease arrhythmia risk

• Improve Sx - Takes up to 3 months

• Reduce hospitalisations

• Improve mortality (both progressive HF and SCD)

Name 2 Mineralocorticoid Receptor Antagonists (MRAs)

Spironolactone or Eplerenone

Mineralocorticoid Receptor Antagonists (MRAs) MoA & effects

Block sodium and water retention effects of Aldosterone (Weak diuretic) → Counteract the secondary hyperaldosteronism that occurs in heart failure

3 AEs of Mineralocorticoid Receptor Antagonists (MRAs)

Hyperkalaemia (esp. in renal impairment)

Gynaecomastia

(Breast pain)

Name 2 general treatments given to acute HF patients

Diuretic (IV)

Inotropes

Name 3 Inotropes used for acute HF patients

B1 agonists

Dobutamine

Dopamine

Are Inotropes used temporarily/long term

Temporary only

Effect of inotropes

Increase contractility

Name 5 treatments for chronic HF

• Diuretics

• ACE Inhibitors

• Betablockers

• Aldosterone antagonist

• Sacubitril/Valsartan (Entresto)

What are 2 options of Electrical Therapy for HF

• Implantable Cardioverter Defibrillator (ICD)

• Cardiac Resynchronisation Therapy (CRT)

Which of the 2 options of Electrical Therapy for HF is used for Biventricular pacing

Cardiac Resynchronisation Therapy (CRT)

Who would be given an ICD

Those with life-threatening arrhythmias

At risk of sudden death

High risk HF - (symptomatic & Poor LV function (EF < 30%))

Who would be given a Biventricular Pacemaker

People with a Left Bundle Branch Block

How does a LBBB cause Dyssyncrony

Left Bundle Branch Block → Delayed contraction of lateral wall → Septal wall is relaxing when lateral wall is contracting

(ineffective contraction)

What is the main cause of death in HF NYHA Class II-IV

SCD = sudden death

Pump failure = CHF (Chronic heart failure)

3 types of Therapy for Advanced heart Failure

• Cardiac Transplantation

• Left ventricular assist devices (LVAD) (External pump)

• Surgery to correct for any evidence of ischaemia