Heart Failure Flashcards
What is an acute decompensated heart Failure?
In heart failure, cardiac output is not able to meet metabolic demands of the body.
Acute decompensated heart failure can occur as either new-onset (de-novo) heart failure, without any previous cardiac dysfunction or, more commonly, due to decompensation of chronic heart failure.
What is the epidemiology of an acute decompensated heart failure?
- In the UK, heart failure is responsible for over 67,000 hospital admissions per year.
- > 65 years of age
What are the risk factors of an acute decompensated heart failure?
- Increasing age
- Coronary artery disease
- Hypertension
- Valvular disease: commonly senile calcification of the aortic valve
- Diabetes
- Atrial fibrillation
- Renal insufficiency
What is the pathophysiology of decompensated heart failure?
Acute decompensated heart failure can occur as either new-onset (de-novo) heart failure without any previous cardiac dysfunction or as an acute decompensation of chronic heart failure.
In heart failure, cardiac output is not able to meet the metabolic demands of the body.
Common causes of heart failure include coronary artery disease and hypertension.
General pathophysiology:
- In response to reduced cardiac output, thesympathetic nervous systemis activated
- This results intachycardia, increasedmyocardial contractility, peripheralvasoconstriction, andRAASactivation, causing salt and water retention
- Patients with heart failure are generally hypervolemic → brain natriuretic peptide (BNP) release by ventricular myocytes in response to stretch
- These processes lead topulmonary and/or venous congestion
- Pulmonary oedemapresents with shortness of breath, whilst venous congestion causesperipheral oedema
What are the causes of de-novo heart failure?
Cardiac causes: myocardial dysfunction
- myocardial infarct
- ventricular rupture
- myocarditis
- high-output states, e.g. sepsis, thyroid storm
- drug-induced cardiomyopathy
- takotsubo cardiomyopathy
Valvular dysfunction:
- Infective endocarditis
- valvular dysfunction post - MI, e.g. mitral regurgitation
Arrythmias
Extracardiac causes: pericardial effusion -> tamponade
- aortic dissection
- pulmonary embolism
- tension pneumothorax
What are the signs of acute de compensated heart failure?
- Cool peripheries
- Signs of congestive heart failure: peripheral, pitting oedema and raised JVP
- Displaced apex beat
- Hypotension
- Crackles on auscultation: left-sided failure; usually coarse bi-basal crackles
- Third heart sound (S3)
- Stony dull percussion: if an effusion is present
What are the symptoms of acute decompensated heart failure?
-
Dyspnoea: due to pulmonary oedema
- Often a history of orthopnea and paroxysmal nocturnal dyspnoea
- Fatigue and weakness
- Cardiogenic wheeze
- Symptoms of congestive heart failure: swelling of the peripheries and ascites
What are the investigations to acute decompensated heart failure?
-
FBC:anaemia can be an underlying cause of heart failure
- U&Es: to investigate renal failureas an underlying cause of heart failure. Renal function should be monitored because loop diuretics such as furosemide are nephrotoxic.
- Arterial blood gas: demonstrates type 1 respiratory failure; degree of acidosis helps to determine which patients may require non-invasive ventilation
- BNP or NT-proBNP:BNP <100 pg/ml or NT‑proBNP <300 pg/ml suggest an alternative diagnosis
- ECG: assess for abnormalities such as arrhythmias; may be AF; left ventricular hypertrophy
-
CXR:**pulmonary congestion features include:
- A-Alveolar oedema (batwing opacities)
- B- KerleyBlines
- C-Cardiomegaly
- D-Dilated upper lobe vessels
- E- PleuralEffusion
- Transthoracic echocardiogram:**important to **assess for systolic and diastolic function, ejection fraction and valvular disease (NICE defines a reduced left ventricular ejection fraction as < 40%)
What is the acute management of acute decompensated heart failure?
If there is anunderlying cause, e.g. myocardial infarction, this should be treated in the first instance.
What is the acute management of acute decompensated heart failure?
If there is anunderlying cause, e.g. myocardial infarction, this should be treated in the first instance.
- Stabilise the patient: administer oxygen to maintain a SpO2≥94%
- Fluid restriction: fluid intake is usually limited to <1.5L/day
- IV diuretic: usually a loop diuretic e.g. furosemide is administered as a bolus or infusion to relieve fluid overload
- Inotropes or vasopressors e.g. dobutamine: only offer to patients with heart failure and cardiogenic shock (i.e. haemodynamically unstable)
- Non-invasive ventilation (NIV): consider NIV if the patient does not stabilise with initial medical management, as evidenced by desaturation or increasing respiratory distress
- Continuous positive airway pressure (CPAP) is commonly used.
- Bilevel positive airway pressure (BiPAP) can also be given
- Continuous positive airway pressure (CPAP) is commonly used.
- Intubation and ventilation: if CPAP is unsuccessful
What should not be given for acute management of Acute decompensated heart failure (ADHF)?
DO NOT GIVE:
- According to NICE,nitrates and opiates should not be routinely given.
- An example of a nitrate isglyceryl trinitrate. Sodium nitroprusside shouldnot be given according to NICE
What is the surgical management of ADHF?
- If acute heart failure is due to aortic stenosis: offersurgical aortic valve replacement
- Mechanical assist device: pump that can temporarily help the pumping action of the heart
What is the long-term management of ADHF?
1st line: ACE-inhibitor e.g. ramiprilanda cardioselective β-blocker e.g. bisoprolol
- Offer if the patient has a reduced left ventricular ejection fraction (< 40%)
- Generally,one drug should be started at a time
- Improved prognosisby slowing, or even reversing, ventricular remodelling
- Fluid restriction: fluid intake is usually limited to <1.5L/day
- Loop diuretic (e.g. furosemide) forsymptomaticrelief of oedema
What are the complications of ADHF?
- Arrhythmias: can both precipitate acute heart failure and occur as a result of it.
- Atrial fibrillation is one of the most common arrhythmias associated with heart failure.
What is the prognosis of ADHF?
- Mortality for acute heart failure ranges from 2-20%.
- Poor prognostic factors include old age, hypotension, male sex, ischaemic congestive heart failure, renal dysfunction, previous chronic heart failure, a respiratory rate on admission > 30 and an elevated BNP.
What is congestive heart failure?
In heart failure, cardiac failure describes when cardiac output cannot meet metabolic demands of the body.
Congestive cardiac failure describes a combination of left and right-sided ventricular failure.
What is the epidemiology of Congestive HF?
- M>F
- More prevalent with increasing age
What are general Risk factors for Congestive HF?
General:
- Male
- Increasing age
- Obesity
- Smoking
What is the cardiovascular risk factors for HF?
Cardiovascular
- Previous myocardial infarction: the single greatest risk factor
- Ischaemic heart disease
- Hypertension
- Hypercholesterolaemia
- Valvular heart disease
- Cardiac arrhythmias: Atrial fibrillation
- Cardiomyopathy
What are the respiratory Risk Factors for congestive HF?
Respiratory
- Cor pulmonale
- Respiratory conditions such as COPD cause pulmonary hypertension and subsequent right-sided heart failure.
What are the other risk factors for congestive HF?
Other
- Diabetes mellitus
- Renal failure: causes ‘high-output’ heart failure due to fluid overload
-
Anaemia
- Poor oxygen carrying capacity results in the heart having to pump more blood resulting in ‘high-output’ failure.
- Hyperthyroidismresults in ‘high-output’ failure
What is the causes congestive HF?
In heart failure, cardiac output struggles to meet the metabolic demands of the body.
It results when there is an insult to the heart resulting in compromise in systolic and/or diastolic function.
Heart failure can happen one of two ways: systolic failure or diastolic failure
Congestive cardiac failure describes a combination of left and right-sided ventricular failure (biventricular failure). Right-sided heart failure usually occurs as a result of left-sided heart failure. Blood starts backing up into the lungs causing pulmonary oedema and congestion. The pulmonary hypertension puts pressure on the right ventricle (cor pulmonale) and causes right-sided heart failure. The pulmonary congestion is responsible for the respiratory symptoms seen in heart failure.
MISSED IMAGE
What is systolic HF?
- Cardiac output = stroke volume x heart rate
- The ejection fraction is not preserved: an ejection fraction of 40% or less would indicate systolic heart failure.
- The low stroke volume is due to the ventricles not pumping enough blood out.
The model on the left is a normal heart during systole, whilst the model on the right shows a dilated and hypertrophied heart, as seen in heart failure.
Left-sided ventricular dysfunction results in backflow into the pulmonary circulation, eventually causing right ventricular failure (congestive cardiac failure).
What is diastolic HF?
- Cardiac output = stroke volume x heart rate
- In this case, the stroke volume is low but the ejection fraction is preserved. The reason for the low stroke volume is due to reduced filling of the ventricle (reduced preload)
What does congestive refer to?
The term ‘congestive’ refers to sodium and water retention.
What are the causes of systolic failure?
-
Systolic failure:
- Ischaemic heart disease: as less blood and oxygen get to the myocardium, the myocytes start to die
- Hypertension: as arterial pressure increases in the systemic circulation, it gets harder for the left ventricle to pump blood out into that hypertensive systemic circulation.
- Left ventricular hypertrophy: increased muscle mass requires increased oxygen supply - making it more likely for that the muscle will die
- Dilated cardiomyopathy: heart chambers dilate and thin out, leading to weaker contractions.
What are the causes of diastolic failure?
-
Diastolic failure:
- Left ventricular hypertrophy: causes the ventricular chamber to decrease in size which means less blood can enter.
- Restrictive cardiomyopathy: ventricle can’t stretch enough to accommodate the blood
- Valvular disease: e.g. aortic stenosis causes LVH or mitral regurgitation means blood doesn’t enter the ventricles in the right amount as it leaks back into atria
- Arrhythmias e.g. atrial fibrillation
What is the pathophysiology of Congestive HF?
- In anormalheart, increased ventricular filling results in increased contraction via theFrank-Starling law→ increased cardiac output
- In patients with heart failure, this mechanismfails due to the
systolic and/or diastolic compromise → inadequate cardiac output - As the heart continues to fail →compensatory mechanismsare activated to maintain cardiac output, including anincrease in heart rate,catecholamine releaseandRAAS activation (due to decreased blood flow to kidneys)
- These mechanisms are useful in theinitialperiod,
- but are usuallyoverexpressed, thus instigating avicious cycle → eventually lead to cardiac remodelling, which further exacerbate the heart failure
- Compensatory mechanisms are usually responsible for the fluid retention and fluid overload symptoms experienced by the patient
- Medicationssuch as ACE inhibitors aim to target these compensatory pathways
What is the heart failure classification?
Heart failure can be classified according to the ejection fraction or the side of the heart affected:
- Heart failure with reduced ejection fraction
- reduced ventricular contractility leading to systolic dysfunction
- causes: damage to Myocytes (e.g. ischaemic heart disease) - Heart failure with preserved ejection fraction
- reduced ventricular compliance leading diastolic dysfunction and reduced filling pressures
- causes: increased ventricular stiffness (e.g. HTN) or reduced relaxation (e.g. constrictive pericarditis) - Left sided Heart failure
- Backflow into the pulmonary circulation
- causes: increased LV afterload (e.g. HTN) or increased LV preload (e.g. aortic regurgitation) - Right sided HF
- backflow into systemic veins
- causes: increased RV afterload (e.g. pulmonary HTN) or increased RV preload (e.g. tricuspid regurgitation)
What is left sided heart failure?
Heart failure and a reduced ejection fraction. Usually caused by systolic (pumping) dysfunction.
Left sided cardiac failure →pulmonary congestion (heart is not able to pump efficiently so blood backs up in the veins that take blood through the lungs. Pressure in these vessels increases and fluid is pushed into the alveoli) and then overload of right side.
What is the aetiology of left sided heart Failure?
- IHD
- Hypertension
- As arterial pressure increases, harder for LV to pump blood out → LV hypertrophy → greater demand for oxygen
- Coronaries squeezed by extra muscle → less blood delivered to tissue
- Cardiomyopathy
- Dilated – heart chamber dilates (grows in size) in order to fill ventricle with more blood (increased preload)
- Over time, muscle wall gets thinner and weaker → systolic HF
- Restrictive – heart wall becomes stiff → less compliant → can’t stretch
- Dilated – heart chamber dilates (grows in size) in order to fill ventricle with more blood (increased preload)
- Aortic stenosis – narrowing of aortic valve
What is the pathophysiology of LSHF?
Systolic: Ischaemic heart disease, MI, cardiomyopathy
Diastolic: Tamponade, constrictive pericarditis, systemic hypertension
What is the epidemiology of LSHF?
- Annual incidence of 10% in patients over 65
- 50% of patients die within 5 years
What are some common clinical manifestation of HF?
It is important to note that approximately 15% of patients experience weight loss (‘cardiac cachexia’), which is often masked by the weight gain associated with fluid retention.
What are the symptoms of LSHF?
Dyspnoea: particularly exertional
Orthopnoea and paroxysmal nocturnal dyspnoea
Fatigue and weakness
Cough with pink frothy sputum
Cardiogenic wheeze
What are the signs of LSHF?
Trachypnoea and tachycardia
Cool peripheries
Peripheral or central cyanosis
Displaced apex beat
Stony dull percussion; if an effusion is present
Crackles on auscultation; coarse bi-basal crackles
Third heart sounds (S3)