Chronic heart failure Flashcards
What is Class I according to the NYHA classification?
No limitation to physical activity
What is Class II according to the NYHA classification?
Slight limitation of ordinary activity
What is Class III according to the NYHA classification?
Marked limitation, even during less-than-ordinary activity
What is Class IV according to the NYHA classification?
Severe limitation with symptoms at rest
What are some clinical sign of cardiac failure?
-cool, pale, cyanotic extremities
- tachycardia
- elevated JVP
third heart sound S3
- displaced apex: LV enlargement
- crackles or decreased breath sounds
- peripheral oedema
- Ascites
- Hepatomegaly
Give 5 clinical tests are used to diagnose heart failure
- CXR
- ECG
Blood investigations - Echo/Cardiac MRI or CT
- Coronary angiography/ CTCA
What are some medical treatments for LVSD?
LVSD: Left Ventricular Systolic Dysfunction
- Using Loop Diuretics
- Mineralocorticoid Receptor Antagonists ( Aldosterone antagonist, potassium-sparing)
- ACE inhibitors
- Beta-Blockers
- SA Node Blockade
- Digoxin
- ARNI
- surgical interventions
Give example of loop diuretics and their action
- Frusemide - Bumetanide
given iv or orally - Inhibit Na+ reabsorption from the proximal tubule
- K+ loss from distal tubule
What are some side effects of loop diuretics?
- electrolyte abnormalities
- hypovolaemia and diminished renal function
- hypokalaemia
Give example of mineralocorticoid receptor antagonists. What is their action?
- Eplerenone, Spironolactone
- acts on distal tubule as an aldosterone agonist, and is potassium-sparing
- promotes Na+ secretion and K+ re-absorption
- reduces hypertrophy and fibrosis
What are some side effects of mineralocorticoid receptor antagonists ?
- Gynecomastia (enlargement of men’s breast): especially spironolactone
- Hyperkalaemia, renal function abnormalities
Give an example of ACE inhibitors and their action
- Ramipril, Perindopril, Enalapril, Captopril, Lisinopril
- act on the activated RAAS, given in small slowly titrated doses
- block production of angiotensin:–> vasodilation, lower BP, reduced cardiac output
What are some side effects of ACE inhibitors?
- cough
- hypotension
- renal impairment
How does heart rate contribute to chronic heart failure?
- excessively high heart rate –> decreased time for ventricular filling – decreased SV and CO
- ventricles contract harder, due to reduced volume
- increased atrial preload is too much
- atrial/ ventricular hypertrophy
What is Frank-Starling’s Law?
- this describes the relationship between Preload and Cardiac output
- an increase in volume of blood filling the hear stretches the fibres causing greater contractile force, increasing the stroke volume
- only to a point after which the fibres are overstretched, and contrile force is decreased
Give two examples of low output heart failure
- systolic heart failure
- diastolic heart failure
What is High output heart failure?
- when other medical conditions cause an increased demand on cardiac output
- the heart itself is functioning normally but cannot keep up with unusually high demand for blood to one or more organs
What are causes of high output heart failure?
- thyrotoxicosis
- profound anaemia
- pregnancy
- pagets disease:abnormal
- acromegaly
- sepsis
What is pagets disease?
formation of new bone when - replacing old bone is abnormal
- gradually bone becomes weak and brittle
What is systolic heart failure?
- the progressive deterioration of myocardial contractile function
What causes systolic heart failure?
- Ischaemic injury
- Volume overload
- Pressure overload
What is diastolic Heart Failure?
- inability of the heart chamber to relax, expand and fill sufficiently during diastole to accommodate an adequate blood volume
What causes diastolic heart failure?
- significant left ventricular hypertrophy
- infiltrative disorders
- constrictive pericarditis
- restrictive cardiomyopathy
Define Cardiomyopathies
Disease of the heart muscle leading to functional impairment
What is dilated cardiomyopathy and its causes?
- the hearts ability to pump blood is decreased due to lower function of the left ventricle
- 50% familial aetiology
- ETOH, pregnancy, systemic disease, muscular dystrophies
- Myocarditis
What is hypertrophic cardiomyopathy?
- hereditary disease
- where the myocardium becomes abnormally thick
What is restrictive cardiomyopathy?
- least common
- where the myocardium is rigid, but not thickened, therefore heart is unable to pump blood
- main cause in the uk in the amyloid, protein produced in the bone marrow
Describe the neurohormonal compensatory mechanism for heart failure
- release of noradrenaline, increases heart rate and myocardial contractility
- release of ANP/ BNP
- activation of renin-angiotensin - aldosterone system
What is ANP/BNP?
- (B-type) Atrial natriuretic peptide
- secreted by the cardiac atria
- promotes excretion of water and sodium
- lowering blood pressure
Describe the Renin- Angiotensin-Aldosterone System
- Renin, ACE
- Angiotensinogen –> Angiotensin I –> Angiotensin II
- vasoconstriction, ADH secreted, Aldosterone secretion
- more water and sodium moves out of the collecting duct, retained in the blood
Describe the NP (naturistic peptide) System
- proBNP released
- BNP(active), NT-proBNP (non-active)
What is the action of active BNP?
- stimulates diuresis
- vasodilation
- inhibits RAAS
- inhibits the SNS
What does RAAS stand for
the Renin-Angiotensin-Aldosterone System
What are the 7 clinical types of heart failure?
- Left-sided HF
- Right-sided HF
- Biventricular HF: left HF causing right HF due to overload of pulmonary circulation
- Chronic HF
- Acute HF
- Compensated HF
- Decompensated HF
What is Left-sided Heart failure and what are the causes?
- when there is insufficient afterload on the left heart, resulting in overload in the left atrium - leading to increased pressure in the pulmonary circulation (oedema and congestion)
Causes
- Ischaemic heart disease
- Hypertension
- Valvular heart disease
- Myocardial disease
What is the effect of left ventricular failure on the kidneys?
- Decreased renal failure due to reduced cardiac output
- activation of RAAS
- retention of salt and water with consequent expansion of interstitial fluid and blood volume
What is the effect of left ventricular failure on the Brain?
- causes Hypoxic encephalopathy ( lack of oxygen brain disorder)
- Irritability
- Loss of attention
- Restlessness
- Stupor and coma
What is right-sided heart failure and what is its cause?
- the inability of the heart to properly expel the contents of the right ventricle
Causes
- Cor-pulmonale: Right-sided HF due to significant pulmonary hypertension, due to increased resistance in the pulmonary circulation
- usually the result of a respiratory disease: COPD,
pulmonary emboli - Valvular heart disease
- Congenital heart disease
What are the systemic effects of Right Heart failure?
- Liver and portal system
- Spleen
- Abdomen
- Subcutaneous tissue
- Liver and portal system: congestive hepatomegaly, centrilobular necrosis if severe, cardiac cirrhosis
- Spleen: congestive splenomegaly
- Abdomen: Ascites- accumulation of transudate in the peritoneal cavity
- Subcutaneous tissue: peripheral oedema (ankles), sacral oedema if bedridden
- pleural and pericardial effusion
Give examples of Beta-blockers and explain their action.
- What apart from CHF can it be used to treat?
- Bisoprolol, Carvedilol, Metoprolol
- block the action of adrenaline and noradrenaline on adrenergic beta receptors
- slows HR + reduces BP
- given orally in small doses in slow titrations
- Can be used to treat arrhythmias
What are the side effects of Beta-blockers?
- Bronchospasm
- Claudication: pain caused by too little blood flow to the arms and legs
Give an example of a SA Node Blockade and explain their action.
- Ivabradine
- blocks the If channel (funny current) within the SA node
- Slow HR, no effect on BP
- Given orally with dose titration
What are the side effects of SA Node Blockades?
- Visual aura (hallucinations)
- Bradycardia ( too slow heart rate)
What is the action of Digoxin and when is it indicated?
- Increase myocardial contractility
- Slows conduction at the AV node (used in AF)
- Excreted by kidney
Indication
- Acute HF especially in AF
- Chronic HF in selected cases
Give an example of Angiotensin Receptor Neprilysin Inhibitor (ARNI). What is its action?
- Sacubitril, Valsartan
- acts on the activate RAAS
- blocks the break down of natriuretic peptides (A and B)
- blocks production of angiotensin: vasodilation, BP lowered, reduced cardiac work
- promote natriuresis: increased Na extraction, vasodilation, reduce hypertrophy and fibrosis
What are the side-effects of Angiotensin Receptor Neprilysin Inhibitor (ARNI)
- Hypotension
- renal impairment
What are other non-pharmcological treatments for LVSD?
- Cardiac Resynchronisation therapy
- Implantable Cardioverter Defibrillator (ICD)
- Dialysis and Ultrafiltration
- Ventricular Assist Device (LVAD/RVAD)
- Intra-aortic balloon pump
- Cardiac transplantation
- Stem cell therapy**
