Heart Failure: Presentation + Investigation Flashcards
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
What should heart failure be qualified by?
Underlying structural abnormality
What factors increase the prevalence of CHF?
- Treatment of AMI
- Aging population
- Hypertension
- CHD
- Obesity
- Diabetes
- HLP
What factors decrease the prevalence of CHF?
Treatment and diagnosis of:
- HLP
- Hypertension
- CHD
- Diabetes
- Obesity
- CHF
Describe re-admission rates of heart failure.
- High
- Often occur early
What are the symptoms of heart failure?
- Dyspnoea
- Fatigue
- Oedema
- Reduced exercise capacity
What are the signs of heart failure?
- Oedema
- Tachycardia
- Raised JVP
- Chest crepitations or effusions
- 3rd HS
- Displaced or abnormal apex beat
Why can heart failure be difficult to diagnose on clinical grounds alone?
- Non-specific symptoms
- No signs
What is mandatory for a heart failure diagnosis?
Objective evidence of cardiac dysfunction
What are the European society of cardiology guidelines for the diagnosis of heart failure?
- Symptoms or signs of HF (rest or exercise)
- Objective evidence of cardiac dysfunction
- Response to therapy
How can evidence of cardiac dysfunction be collected?
- ECHO
- Radionuclide ventriculography
- MRI
- Left ventriculography
What potential screening tests are there for heart failure?
- 12 lead ECG
- BNP
How can BNP be used in diagnosis of HF?
- Amino acid peptide can be measured in the blood
- Elevated in HF
- Low BNP effectively excludes HF
What is very unlikely if the ECG is normal?
LVSD
What are the benefits of using BNP as a screening test for HF?
- High sensitive test for HF
- Stable for up to 72 hours
- Bedside testing available
- Relatively inexpensive
What does elevate BNP indicate?
Need for an ECHO/cardiac assessment
If HF is sufficiently severe can be the underlying cause?
Almost any structural cardiac abnormality
Possible causes of HF
- LV systolic dysfunction
- Valvular heart disease
- Pericardial constriction or effusion
- LV diastolic dysfunction/ HF with preserved systolic function/HF with normal ejection fraction
- Cardiac arrhythmias
- Myocardial ischaemia/infarction
- Restrictive cardiomyopathy
- Right ventricular failure
What are the causes of LV systolic dysfunction?
- Ischaemic heart disease
- Dilated cardiomyopathy (LVSD not due to IHD or secondary to other lesions)
- Sever aortic valve disease or MR
What can cause DCM?
- Inherited
- Toxins
- Viral
- Other infective
- Systemic disease
- Muscular dystrophie
- Peri-partum
- Hypertension
- Isolate non compaction
- Tachycardia
- RV pacing induced
- End stage hypertrophic
- End stage arrythmogenic RV
What needs to be excluded when diagnosing LVSD?
- Renal failure
- Anaemia
- Thyroid problem
- Phaechromocytoma
- Sarcoid
- Muscular dystrophies
- CHD
How is LVSD evaluated?
- Detailed history
- TFTs
- Autoantibodies/viral serology
- ECG
- CXR
- ECHO
- Coronary angiography
- CT coronary angigram
- Cardiac MRI
What is ECHO used to identify and quantify?
- LV systolic dysfunction
- Valvular dysfunction
- Pericardial effusion/tamponade
- Diastolic dysfunction
- LVH
- Atrial/ventricular shunts/ complex congenital heart defects
- Pulmonary hypertension/ right heart dysfunction
What may an ECHO miss?
-May not identify constriction/ may miss shunts but will see atrial dilatation
What is a continuous biological variable?
LV ejection fraction
What can increase/decrease LVEF?
Disease/physiological states
What is LVEF analogous to?
Haemoglobin/anaemia
Why can LVEF be difficult to quantify accurately and reproduce by ECHO?
- Quality of images
- Experience of operator
- Calculation method
- Use of contrast agents
- Time consuming to perform accurately
- Normal range is centre specific but LVEF not routinely measured and NR not routinely established
What is the scale of LVEF?
- 50-80% Normal
- 40-50% Mild
- 30-40% Moderate
- <30% Severe
How does the Biplane modified Simpsons rule divide the LV?
Divides LV cavity into multiple slices of known thickness and diameter
What type of slices in the biplane modified Simpson’s rule have the most accurate volume estimation?
Thinner slices
What does the Biplane modified Simpson’s rule require?
Endocardial border traced accurately (often major technical difficulty with this method)
What 2 methods can be used to calculate LVEF?
- M-mode
- Simpsons biplane
What are the advantages of using MUGA for the LVEF?
- Much easier to obtain an accurate figure
- Greater reproducibility
What are the disadvantages of using MUGA for the LVEF?
- Ionising radiation
- No additional structural information
- Centre specific normal range
NYHA class I HF
No symptoms during usual activity with no limitation on exercise tolerance
NYHA class II HF
Comfortable with rest or mild exertion with mild limitation on exercise tolerance
NYHA class III HF
Comfortable only at rest with moderate limitation on exercise tolerance
NYHA class IV HF
Any physical activity brings on discomfort and symptoms occur at rest with severe limitation on exercise tolerance
Why is HF not all about cardiac output?
A dilated heart can have the same CO with the same HR despite having half the EF by having double the EDV
Why is HF considered a systemic disorder?
- Cardiac dysfunction
- Renal dysfunction
- Skeletal muscle dysfunction
- Systemic inflammation
- neurohormonal activation
What role does the renin-angiotensin-aldosterone system play in HF?
- Salt and water retention
- Adverse haemodynamics
- LV hypertrophy/remodelling and fibrosis
- Hypokalaemia and hypomagnesaemia
What pharmacological therapy is there for HF due to LVSD?
- Diuretics
- ACEI
- B blockers
- Aldosterone receptor blockers
- ARBs
What role does the SNS play in HF?
- Arrhythmogenic
- Adverse haemodynamics
- Increase renin etc
What 2 systems foes the neurohormonal hypothesis of HF include?
- Renin-angiotensin-aldosterone system
- Sympathetic nervous system
