Chronic Cardiac Failure Flashcards
Chronic (LV) Cardiac Falure: What is it?
Cardiac Failure= a condition where the cardiac muscle, specifically the left ventricle, is unable to pump blood with enough strength to meet the body’s needs.
Chronic (LV) Cardiac Falure: Risk Factors
- Male Sex
- Older age (65 years or over)
- Family history of the condition
- Certain lifestyle factors - smoking,alcoholconsumption,physical inactivity, and a diet that predisposes individuals tohigh cholesteroland high blood pressure
- drugs- calcium antagonists, anti-arrhythmics, cytotoxic medication, beta-blockers.
- cardiac co-morbidities (heart, valves and great vessels - most commonly aortic stenosis and atrial fibrillation)
- non-cardiac co-morbities (eg. COPD, diabetes, hypertension, anaemia, sepsis metabolic abnormalities, endocrine abnormalities)
- Endocrine disease: hypothyroidism, hyperthyroidism, diabetes, adrenal insufficiency, Cushing’s syndrome
The acronym HIGH-VIS is useful to remember some of the causes of CHF:
- Hypertension (common cause)
- Infection/immune: viral (e.g. HIV), bacterial (e.g. sepsis), autoimmune (e.g. lupus, rheumatoid arthritis)
- Genetic: hypertrophic obstructive cardiomyopathy (HOCM), dilated cardiomyopathy (DCM)
- Heart attack: ischaemic heart disease (common cause)
- Volume overload: renal failure, nephrotic syndrome, hepatic failure
- Infiltration: sarcoidosis, amyloidosis, haemochromatosis
- Structural: valvular heart disease, septal defects
Chronic Cardiac Failure: Physical Examination
- tachypnea, dyspnea, tachycardia
- hypotension hypertension
- cyanosis
- Palpation: a laterally displaced apex beat
- Auscultation: may be murmurs indicating valvular heart disease such as aortic stenosis or mitral regurgitation. 3rd heart sound. Bilateral basal crackles(sounding “wet”) on auscultation of the lungs, indicatingpulmonary oedema
- Features ofpulmonary edema(eg inspiratory bibasal crackles not cleared on coughing, diminishedbreath soundsand dullness to percussion)
- Raisedjugular venous pressure(JVP), caused by a backlog on the right side of the heart, leading to an engorged internal jugular vein in the neck
- Hypertension
- Peripheral oedemaof the ankles, legs and sacrum
Heart Failure: Symptoms
- Breathlessness, worsened by exertion
- Orthopnoea, which is breathlessness when lying flat, relieved by sitting or standing (ask how many pillows they use)
- Paroxysmal nocturnal dyspnoea(more detail below)
- Cough, which may produce frothy white/pink sputum
- syncope/dizziness
- Peripheral oedema
- Fatigue
There may also be signs and symptoms related to the underlying cause or complications, for example:
- Chest pain in acute coronary syndrome
- Fever in sepsis
- Palpitations with arrhythmias
Heart Failure: Signs
Clinical findings on cardiovascular examination may include:
- Dysponea, tachyponea, tachycadia at rest
- Reduced O2 sats
- cyanosis
- Hypotension (cardiogenic shock)
- Narrow pulse pressure ???
- raised JVP (right-sided heart failure)
- peripheral oedema (right-sided heart failure)
- right ventricular heave (right-sided heart failure)
- displaced apex (LV dilation)
- 3rd heart sound ???
- Gallop rhythm on auscultation (pathognomic for CHF)
- Murmurs associated with valvular heart disease (e.g. an ejection systolic murmur in aortic stenosis)
Clinical findings on respiratory examination may include:
Tachypnoea
- Bibasal end-inspiratory crackles not cleared on coughing and wheeze on auscultation of the lung fields (pulmonary oedema)
- Reduced air entry on auscultation with stony dullness on percussion (pleural effusion)
Clinical findings on abdominal examination may include:
Hepatomegaly
Ascites
TheNew York Heart Association(NYHA) classification system is used to grade the severity of symptoms related to heart failure. Here is a simplified summary:
- Class I: No limitation on activity
- Class II: Comfortable at rest but symptomatic with ordinary activities
- Class III: Comfortable at rest but symptomatic with any activity
- Class IV: Symptomatic at rest
Chronic Cardiac Disease: Investigations
- N-terminal pro-B-type natriuretic peptide(NT‑proBNP) blood test
- ECG to look for ischaemia and arrhythmias and ??
- Echocardiogram to assess LV function and for any structural heart abnormalities in the heart. A key measure of the left ventricular function is theejection fraction (the percentage of blood in the left ventricle that is squeezed out with eachventricular contraction). An ejection fractionabove 50%is considered normal.
Other investigations include:
- Bloodsfor anaemia, infection, renal function, thyroid function, liver function, lipids and diabetes
- Chest x-rayandlung function teststo exclude lung pathology
- troponin to rule of MI
- ABG
B-type natriuretic peptide(BNP) is a hormone released from the heartventricleswhen the cardiac muscle (myocardium) is stretched beyond the normal range. A raised BNP blood result indicates the heart is overloaded beyond its normal capacity to pump effectively.
The action of BNP is to relax thesmooth muscleinblood vessels. This reducessystemic vascular resistance, making it easier for the heart to pump blood through the system. BNP also acts on the kidneys as a diuretic to promote water excretion in the urine. This reduces the circulating volume, helping to improve the function of the heart in someone that is fluid-overloaded.
BNP issensitivebut notspecific.This means that when the result is negative, it helpsrule outheart failure, but it can be positive due to other causes. Other causes of a raised BNP include:
- Tachycardia
- Sepsis
- Pulmonary embolism
- Renal impairment
- COPD
Chest X-ray Findings
Cardiomegalyon a chest x-ray is classified as acardiothoracic ratioofmore than 0.5. This is when the diameter of the widest part of the heart (the widest part of thecardiac silhouette) is more than half the diameter of the widest part of thelung fields.
Upper lobevenous diversionmay also be seen. Usually, when standing erect, the lower lobe veins contain more blood, and the upper lobe veins remain relatively small. In acute LVF, there is such a back-pressure that the upper lobe veins also fill with blood and become engorged. This is referred to asupper lobe diversion. This is visible as increased prominence and diameter of the upper lobe vessels on a chest x-ray.
Fluid leaking from oedematous lung tissue causes additional x-ray findings of:
- Bilateralpleural effusions
- Fluid ininterlobar fissures(between the lung lobes)
- Fluid in the septal lines (Kerley lines)
Heart Failure: Management
There are five principles of management. You can remember this with the “RAMPS” mnemonic:
- R–Refer to cardiology
- A–Advise them about the condition
- M–Medical treatment
- P–Procedural or surgical interventions
- S–Specialist heart failure MDT input, such as theheart failure specialist nurses, for advice and support
The urgency of the referral and specialist assessment depends on theNT-proBNPresult. According to the NICE guidelines:
- From 400 – 2000 ng/litreshould be seen and have an echocardiogramwithin 6 weeks
- Above 2000 ng/litreshould be seen and have an echocardiogramwithin 2 weeks
Additional management:
- Flu, covid and pneumococcal vaccines
- Stop smoking
- Optimise treatment of co-morbidities
- Written care plan
- Cardiac rehabilitation (a personalised exercise programme)
Medical Treatment
The first-line medical treatment of chronic heart failure can be remembered with the “ABAL” mnemonic:
-
A–ACE inhibitor (e.g.,ramipril) titrated as high as tolerated
- relax the veins and arteries to lower blood pressure.
-
B–Beta blocker (e.g.,bisoprolol) titrated as high as tolerated
- manage abnormal heart rhythms
- A–Aldosterone antagonist when symptoms are not controlled with A and B (e.g.,spironolactoneoreplerenone)
- L–Loop diuretics (e.g.,furosemideorbumetanide)
Anangiotensin receptor blocker(ARB) (e.g.,candesartan) can be used instead of an ACE inhibitor if not tolerated. Avoid ACE inhibitors in patients withvalvular heart diseaseuntil initiated by a specialist.
Aldosterone antagonistsare used when there is a reduced ejection fraction and symptoms arenotcontrolled with an ACEi and beta blocker.
Patients should have theirU&Esclosely monitored whilst takingdiuretics,ACE inhibitorsandaldosterone antagonists, as all three medications can causeelectrolyte disturbances. It is particularly essential to closely monitor therenal functionin patients takingACE inhibitorsandaldosterone antagonists. Both can causehyperkalaemia(raised potassium), which is potentially fatal.
Additional specialist treatments in patients with heart failure are:
- SGLT2 inhibitor(e.g.,dapagliflozin)
- Sacubitril with valsartan(brand nameEntresto)
- Ivabradine
- Hydralazine with a nitrate
- Digoxin
Procedural and Surgical Interventions
Surgical proceduresmay be used to treat underlyingvalvular heart disease.
Implantable cardioverter defibrillatorscontinually monitor the heart and apply adefibrillator shocktocardiovertthe patient back into sinus rhythm if they identify a shockablearrhythmia. These are used in patients who previously hadventricular tachycardiaorventricular fibrillation.
Cardiac resynchronisation therapy(CRT) may be used in severe heart failure, with an ejection fraction of less than 35%. CRT involvesbiventricular(triple chamber)pacemakers, with leads in theright atrium,right ventricleandleft ventricle. The objective is to synchronise the contractions in these chambers to optimise heart function.
Aheart transplantmay be considered in suitable patients with severe disease.
Acute Left Ventricular Failure
Acute left ventricular failureoccurs when an acute event results in theleft ventriclebeing unable to move blood efficiently through the left side of the heart and into thesystemic circulation.
Heart Failure: Complications
Cardiac outputis the volume of blood ejected by the heart per minute.Stroke volumeis the volume of blood ejected during each beat.Cardiac outputis the product ofstroke volumexheart rate.
When blood cannot flow efficiently through the left side of the heart, there is a backlog of blood waiting in theleft atrium,pulmonary veinsandlungs. As these areas experience an increased volume and pressure of blood, they start to leak fluid and cannot reabsorb excess fluid from the surrounding tissues, resulting inpulmonary oedema.
Pulmonary oedemais where the lung tissue and alveoli are filled withinterstitial fluid. This interferes with normalgas exchangein the lungs, causing shortness of breath and reduced oxygen saturation.
Acute LV failure: aetiology
Acute left ventricular failure is often the result ofdecompensated chronic heart failure.
The potential triggers are:
- Iatrogenic (e.g., aggressive IV fluids in a frail elderly patient with impaired left ventricular function)
- Myocardial infarction
- Arrhythmias
- Sepsis
- Hypertensive emergency (acute, severe increase in blood pressure)
TOM TIP: Acute left ventricular failure and pulmonary oedema are common in the acute hospital setting. When a nurse asks you to review a breathless and desaturating patient, ask yourself how much fluid that patient has been given and whether they will be able to cope with that amount. For example, an 85 year old patient with chronic kidney disease and aortic stenosis is prescribed 2 litres of fluid over 4 hours and then starts to drop her oxygen saturation. This is a common scenario, and a dose of IV furosemide can work like magic to clear the excess fluid and resolve the symptoms.
Acute LVFtypically presents withacute shortness of breath. This is exacerbated by lying flat and improves on sitting up.
ALVF: Management
Patients withacute left ventricular failurerequire hospital admission. Patients withsevere pulmonary oedemaorcardiogenic shockmay require admission to thehigh dependency unitorintensive care unit. Get experienced seniors involved early.
The “sodium” mnemonic can be used for remembering the basic management of acute LVF:
- S–Sit up
- O–Oxygen
- D–Diuretics
- I–Intravenous fluids should bestopped
- U–Underlying causes need to be identified and treated (e.g., myocardial infarction)
- M–Monitor fluid balance
Sitting the patient uphelps oxygenate the lungs. When lying flat, the fluid in the lungs spreads to a larger area. When upright, gravity takes it to the lung bases, leaving the middle and upper areas clear for better gas exchange.
Oxygenshould be given for reduced oxygen saturation (below 95%). As always, be cautious with patients who have COPD, where the target saturations may be 88-92%. An arterial blood gas can help guide oxygen therapy when in doubt.
Diuretics(e.g., IVfurosemide) increase the urine output of the kidneys, reducing the volume of fluid in the circulation. Reducing the circulating volume in a fluid-overloaded patient allows the heart to pump blood more effectively.
Fluid balance monitoringinvolves monitoring the fluid intake (oral and IV), urine output, U&Es and body weight.
Severe cases may require (guided by an experienced specialist):
- Intravenousopiates, such as morphine, which act asvasodilators
- Intravenous nitratesact asvasodilators, and may be considered in severe hypertension or acute coronary syndrome
- Inotropes, such asdobutamine, to improvecardiac output
- Vasopressors, such asnoradrenalin, to improveblood pressure
- Non‑invasive ventilation
- Invasive ventilation(involving intubation and sedation)
Inotropesare medications that alter the contractility of the heart.Positive inotropesact toincrease the contractilityof the heart. This increasescardiac output(CO) andmean arterial pressure(MAP). They are used in patients with alow cardiac output, for example, due to acute heart failure, recent myocardial infarction or following heart surgery.
Vasopressorsare medications that causevasoconstriction(narrowing of blood vessels). This increases thesystemic vascular resistanceand, consequently,mean arterial pressure(MAP). Vasopressors are commonly used by anaesthetists as a bolus dose or in ICU as an infusion to improve patient’s blood pressure and, therefore, tissue perfusion.
