Chronic Heart Failure: epidemiology, investigation and diagnosis Flashcards
What is the definition of 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
Why is heart failure not the ending diagnosis
As need to investigate underlying cause
Aetiology of heart failure
Valve heart disease
aortic stenosis - excessive afterload
Mitral/aortic regurgitation - excessive preload
Arial/ventrical septal defect/ tricuspid incompetence - excessive preload
Hypertension
Coronary heart disease
Stuctural abnormailites
Myocardial ischaemia
dilated cardiomyopathy
What is the symptoms of heart failure
breathlessness
Fatigue
Reduced exercise capacity
What is the signs of heart failure
Odema Tachycardia raised JVP chest crepitations or effusions 3rd heart sound Displaced or abnormal apex beat
Why is making a diagnosis of heart failure difficult
Majority of the symptoms and sings are non specific therefore evidence of cardiac dysfunction is mandatory
What are the non specific signs and symptoms of heart failure
Chest crepitations, oedema,
tachycardia
dyspnoea
fatigue
What is the specific signs and symptoms of heart failure
Increased JVP
Third systolic heart sound S3
Displaced apex
What is the three steps in the diagnosis of heart failure
1 symptoms or signs of HF (rest or exercise)
and
2 objective evidence of cardiac dysfunction
3 response to therapy
What therapy is used to test the response in doubtful cases of heart failure
Diuretics
What will provide objective evidence of cardiac dysfunction in the diagnosis of heart failure than
abnormal ECHO
-cardiomegaly
Cardiac murmurs -S3
raised natriuretic peptide concentration
What is LVSD defined as on an ECHO
LV ejection fraction
What is the benefits of ECHO investigation
Easy to perform
non invasive
Looks at valve function
detects atrial fibrillation
What are the two screening tests for heart failure
12 lead ECG
BNP
If ECG appears normal in heart failure, what aetiology becomes unlikely
Left ventricular systolic disfunction
How does BNP working in detecting heart failure
BNP is an amino acide peptide that becomes elevated in heart failure (if low not HF)
An elevated BNP requires what further action
ECHO/cardiac assessment
When would heart failure be classed as diastolic
Has normal systolic function:
Normal ejection fraction and no obvious increased myocardial demand
What does an ECHO enable the assessment of
Over all LV systolic function - LV ejection fraction
pericardial effusion
Diastolic function
LV wall thickness - cardiomegaly
Valvular disease
Estimation of pulmonary artery systolic pressure
What are further imaging investigations for heart failure LVSD
MRI
CXR
MUGA
ECG
What is a normal LV ejection fraction and a severe
Normal 50-80%
severe - <30%
Why is it difficult to quantify LV ejection fraction on an ECHO sometimes
Quality of the images experience of the operators the calculation method use of contrasting agents Time consuming to perform accurately
How does simpsons biplane work in calculating the volume of the ejection fraction
divide LV cavity into multiple slices of known thickness and diameter, then work out the volume by timing the area by the thickness
(thinner slices more accurate volume)
What is the imaging technique MUGA composed of
radionuclide angiogram
evaluates the pumping function of the ventricles as the radioactive tracer is injected into the vein
Why is MUGA better than ECHO
Much easier to obtain the acurate figure for LVEF
Greater reproducibility
No additional structural information
What is the causes of LV systolic dysfunction
dilated cardiopathy
coronary heart disease
Valve heart disease
How does aortic stenosis cause heart failure
cause left ventricular hypertrophy (LVH) due to chronic excessive afterload.
What is the exercise tolerance and symptoms in class 1 -4 of graded heart failure
CLASS 1
Exercise tolerance - no limitations
Symptoms - none during usually activity
CLASS 2
Exercise tolerance - mild limitations
Symptoms - comfortable with rest of mild exertion
CLASS 3
Exercise tolerance - moderate limitations
Symptoms - comfortable only at rest
CLASS 4
Exercise tolerance - severe limitations
Symptoms - any physical activity brings on discomfort and symptoms occur at rest
Why is heart failure not always to do with cardiac output
As the greater the size of the heart, it has the same cardiac output, but has a greater end diastolic volume, therefore smaller LV ejection fraction
What is the pharmacological therapy for heart failure
– Diuretics
–ACE inhibitors
– Betablockers
–Aldosterone receptor blockers
–In some pateints ACE I or ARDB now replaced by angiotensin receptor neprilysin inhibitor
How is heart failure a systemic disorder
as envolves neurohormonal activation
What can causes neurohormonal activation w
Vasoconstriction
Endothelial dysfunction
Renal sodium retention
What is the possible outcomes of neurohormonal activation
Left ventricular injury
Left ventricular dysfunction
heart failure
