Heart failure Flashcards
What is heart failure
-inability of heart to pump enouugh blood either due to:
ventricles inability ro pump sufficient blood during systole(SHF)/ blood not filling sufficient blood during diastole (DHF)
- both cases, blood will back up into lungs causing congestion/fluid build up( CHF)
Causes of HF
- LVSD/LVF? due to Ischaemic heart disease (MI)
- HF due to severe arotic stenosis
- severe structural HD
Symptoms of HF
- breathlessness (paraoxysmial noctornal dysponea/ difficulty breathing when lying flat due to the fluid build up in lungs )
- fatigue
- oedema
- reduced exercise capacity
Signs
- tachycardia
- dema
- raised JVP
- chest creptiations/effusions
- 3rd heart sound (S2)
- displaced/abnormal apex beat
S3/S4 sounds
( S3(mainly LVF when blood fills ventricles rapidly )/S4(mainly DHF as ventricles are stiff so atria contracts, blood forcibly pushed against ventricle wall producing S4)
Why isn’t the symptoms sufficient to diagnose HF?
- the symptoms are nonspecific and can sometimes indicate a different diagnosis.
- objective evidence of cardiac dysfunction is required
Objective evidence of cardiac dysfunction - Investigation
- ECHO ( lacks radiation/can be used at bedside)
- Radionucleotide scan ( uses cameras and radioactive substance called a tracer to create pictures of heart. Tracer injected into blood>heart)
- Left ventriculogram ( test during cardiac catheterisation that evaluated main pumping chamber of LV. Dye injected and shows up on X ray)
- Cardiac MRI
- Bloods ( serology, anaemia, TFTs?, ferritin?)
- CXR
- ECG
- CA (CT)
most should be assessed by cardiologist
Tests to see if you are eligible for an ECHO scan
12 LEAD ECG
- LVSD unlikely if ECG is normal
- BNP ( brain B-type natriutetic peptide) ; amino acid peptide measured in blood. Often low, if elevated indicates HF
Other reasons why BNP may be elevated
- AF
- Elderly
- Valve disease
Examples of structural heart disease
- LV systolic dysfunction
- valvular HD
- pericardial constriction/effusion
- LV diastolic dysfunction/heart fialyre with preserved systolic fuction/HF with normal ejection fraction
- Cardiac arrhythmias ( tachy/brady)
- myocardial ischaemia/infarction ( usually via LVSD)
- restctive cardiomyopathy ( amyloid, HCM)
- Right ventricular failure ( primary/secondary to pulmonary hypertension)
Causes of LV systolic dysfunction
- ischaemic HD ( MI)
- severe AV disease/MR
- dilated cardiomyopathy
- inheriteed
- toxins
- viral/infective
- ends stage hypertrophic cardiomyopathy
- end stage arrhythmogenic RV cardiomyopathy
- systemic disease
- muscular dystophy
- peri-partum cardiomyopathy
- hypertension
- tachycardia related cardiomyopathy
- RV pacing induced cardiomyopathy
Why is ECHO esssential/not?
Looks at:
- LV systoli/valvular/diastolic dysfunction
- tamponade/pericardial effusion
- LVH
- atrial/ventricular shunts/complex congenital HD
- pulmonary hypertension/right heart dysfunction
MAY NOT IDENTIFY PERICARDIAL CONSTRICTION / MISS SHUNTS ( but can see atrial dilation)
What is the LV EF
- fraction of blood pumped from heart with each heart beat
- decreases with LVSD
Severity of LV EJ
Normal 50-80%
Mild 40-50%
Moderate 30-40%
Severe < 30%
LV EJ - ECHO
-May be fiddicult to quantify accurately due to
-quality of images
-experience of operator
-calculation method ( M-mode / Simpson’s biplane)
-use of contrasts
-time consuming
-
What is the biplane mdofified simpson’s rule?
- divides the LV cavity into multiple slices of known thickness/diameter/volume of each slice
- thinner slices will have a more accurate volume estimate
- endocardial border traced accurately
- tehcnical error but still acccurate
