Heart failure Flashcards
what is the definition of heart failure?
• The inability of the heart to deliver blood and thus O2 at a rate that is commensurate with the requirement of metabolising tissue of the body
• Is a syndrome and not a diagnosis on its own
• Can result from any structural or functional cardiac disorder that impairs the heart’s ability to function and meet the demands of supplying sufficient oxygen and nutrients to the metabolising body
E.g. ischaemic, valvular, myopathic, cor pulmonale
what is the epidemiology of heart failure?
- 25-50% of patients die within 5 years of diagnosis
- 1-3% of the general population
- Around 10% among the elderly
what is the aetiology of heart failure?
- Ischaemic heart disease (IHD) - MAIN CAUSE
- Cardiomyopathy (disease of heart muscles, where the walls have become thickened, stiff or stretched)
- Valvular heart disease e.g. aortic stenosis, aortic and mitral regurgitation
- Cor pulmonale
- Hypertension
- Alcohol excess
- Any factor that increases myocardial work e.g. anaemia, arrhythmias, hyperthyroidism, pregnancy and obesity
what are the risk factors for heart failure?
- 65 and older
- African descent
- Men (due to lack of protective effect provided by oestrogen resulting in the
early onset of IHD in men - Obesity
- People who have had an MI
- diabetes
- family history
- smoking
- arrhythmias
- systemic conditions
- chemo
- medications
- hypertension
what is the pathophysiology of heart failure?
- Systolic:
Inability of the ventricle to contract normally resulting in a decrease in cardiac output
Caused by ischaemic heart disease, myocardial infarction and cardiomyopathy (disease of heart muscle thus impairing function) - Diastolic:
Inability of the ventricles to relax and fill fully thereby decreasing stroke volume and decreasing cardiac output
Caused by hypertrophy (due to chronic hypertension which results in increased blood pressure thereby increasing afterload so heart pumps against more resistance and thus cardiac myocytes grow bigger to compensate for this) of ventricles resulting in there being less space for blood to fill in and thus decreased cardiac output
Also caused by aortic stenosis (the narrowing of the aortic valve) which also increases afterload and thus decreases cardiac output
• Acute vs chronic heart failure: - Acute:
Often used exclusively to mean new onset or decompensation of chronic heart failure characterised by pulmonary and/or peripheral oedema with or without signs of peripheral hypotension - Chronic:
Develops slowly, Venous congestion is common but arterial pressure is well maintained until very late
what are the key presentations of heart failure?
shortness of breath, fatigue, ankle swelling, neck vein distension, S3 gallop, cardiomegaly, hepatojugular reflux, rales, orthopnoea, nocturia
what are the signs of heart failure?
Raised jugular venous pressure, murmurs and displaced apex beat, third and fourth heart sounds, bi-basal crackles
what are the symptoms of heart failure?
Dyspnoea, cold peripheries, hypotension, ankle swelling, tachycardia, ascites
Use New York Heart Association (NYHA) classification for the assessment
of the severity of symptoms:
• Class I: No limitation (asymptomatic) - exercise = no fatigue, dyspnoea or palpitation
• Class II: Slight limitation (mild HF (heart failure)) - comfortable at rest, normal activity = fatigue, dyspnoea and palpitations
• Class III: Marked limitation (moderate HF) - comfortable at rest, gentle activity = fatigue, dyspnoea & palpitations
• Class IV: Inability to carry out any physical activity without discomfort (severe HF) - symptoms occur at rest
what are the first line and gold standard investigations for heart failure?
transthoracic echocardiogram - systolic heart failure: depressed and dilated left and/or right ventricle with low ejection fraction; diastolic heart failure: LVEF normal but LVH and abnormal diastolic filling patterns
ECG - evidence of underlying coronary artery disease, left ventricular hypertrophy, or atrial enlargement; may be conduction abnormalities and abnormal QRS duration
CXR - ABCDE
Blood tests:
• Brain natriuretic peptide (BNP) - Secreted by ventricles in response to increase myocardial wall
stress, Increased in patients with heart failure, Levels correlate with ventricular wall stress and the severity of heart failure - FIRST LINE
FBC - could show cause
serum electrolytes - decreased sodium and potassium
blood glucose - diabetes
serum creatinine - normal or elevated
TFTs - primary hypothyroidism: elevated TSH, decreased free thyroxine (FT4); hyperthyroidism: decreased TSH, elevated free triiodothyronine, elevated FT4
LFTs - normal or elevated
blood lipids - elevated in dyslipidaemia, decreased in end-stage heart failure, especially in the presence of cardiac cachexia
serum ferritin - elevated (normal value 22-449 picomol/L [10-200 nanograms/mL])
transferin saturation - elevated level of transferrin saturation; complete or almost complete transferrin saturation (normal transferrin saturation 22% to 46%)
what are the differential diagnoses for heart failure?
Renal failure, respiratory failure, other cardiac problems, MI, ageing or physical inactivity, COPD, pneumonia, PE
how is heart failure managed?
- lifestyle changes
- diuretics
- ace inhibitors
- beta blockers
- revascularisation
- heart transplant in young people
how is heart failure monitored?
Monitor medications, heart rate and rhythms, respiratory rate, oxygen saturation, blood pressure, weight
what are the complications of heart failure?
Arrhythmia, heart valve problems, kidney damage, anaemia, liver damage, lung problems, angina, MI
what is the prognosis of heart failure?
Around 50% survive beyond 5 years
