Flashcards in Heart Failure Presentation and Investigation Deck (21)
What is heart failure?
A clinical syndrome comprising of dyspnoea, fatigue or fluid retention due to cardiac dysfunction, either at rest or on exertion, with accompanying neurohormonal activation
HF should be qualified by the underlying structural abnormality and cause
What structural abnormalities can cause heart failure?
Almost any structural abnormality will cause HF is sufficiently severe:
Left ventricular systolic dysfunction
Valvular heart disease
Pericardial constriction or effusion
LV diastolic dysfunction
Myocardial ischaemia or infarction
Right ventricular failure
What are the causes of left ventricular systolic dysfunction?
Ischaemic heart disease
Severe aortic valve disease or mitral regurgitation
Systemic disease e.g. sarcoidosis, haemachromatosis
RV pacing induced cardiomyopathy
End-stage hypertrophic cardiomyopathy
End-stage arrhythmogenic RV cardiomyopathy
What is the prevalence of heart failure?
What is the prevalence of asymptomatic LVSD?
What are the symptoms of heart failure?
Reduced exercise capacity
What are the signs of heart failure?
Chest crepitations or effusions
Third heart sound
Displaced or abnormal apex beat
Why is heart failure difficult to diagnose?
Chest crepitations, oedema and tachycardia are non-specific
Third heart sound, increased JVP and displaced apex are insensitive
Many patients only have symptoms e.g. dyspnoea and fatigue which are non-specific
What investigations can be used to obtain objective evidence of cardiac dysfunction?
What are the potential screening tests for heart failure?
12 lead ECG - LVSD unlikely if ECG is normal
Brain B-type Natriuretic Peptide (BNP) - elevated in heart failure
How is BNP used as a screening test for heart failure?
Highly sensitive test
Stable for up to 72 hours
Bedside testing available
Low BNP effectively rules out heart failure or LVSD, elevated BNP indicates a need for an echo/further cardiac assessment
What is/might be used in the diagnostic evaluation of patients with LVSD?
Detailed history - MI, DM, hypertension, alcohol etc.
History of Lyme disease, IVDA or HIV
Exclude renal failure and anaemia
Autoantibodies, viral serology, ferritin
Consider other causes e.g. sarcoid, muscular dystrophy
ECG, CXR, echo
Consider coronary angiography/CTCA
Evaluate for ischaemia/revascularisation
What can echocardiography identify and quantify?
LV systolic dysfunction
Complex congenital heart defects
Right heart dysfunction
What can make left ventricular ejection fraction difficult to quantify accurately and reproducibly?
Quality of images
Experience of operator
Use of contrast agents
Time consuming to perform accurately
Normal range is centre-specific but LVEF is not routinely measures and normal range is not routinely established
How can disease affect the LVEF?
Disease/physiological changes can both decrease and increase the LVEF
What is the normal LVEF?
What is a mildly impaired LVEF?
What is a moderately impaired LVEF?
What is a severely impaired LVEF?
What are the features of Biplane Modified Simpson's Rule?
Divides LV cavity into multiple slices of known thickness and diameter
Volume of each slice = area x thickness
Thinner slices allow a more accurate volume to be estimated
Endocardial border is traced accurately (often major technical difficulty with this method)
Still one of the most accurate methods available
Relatively easy but not routinely done