Heart Failure Flashcards
define heart failure
a clinical syndrome comprising of dyspnoea, fatigue or fluid retention due to cardiac dysfunction either at rest or on exertion with accompanying neuro-hormonal activation.
what increases the risk of heart failure?
> treatment of MI > aging population > hypertension > diabetes > obesity > coronary heart disease
what are the symptoms of heart failure?
> breathlessness
fatigue
oedema
reduced exercise capacity
what are the signs of heart disease?
> oedema > tachycardia > raised JVP > chest crepitation's or effusions > 3rd heart sound > displaced or abnormal apex beat
why is it usually difficult to diagnose heart failure on clinical grounds?
the signs and symptoms re often non-specific, and patients may only have symptoms.
what are the European guidelines for the diagnosis of heart failure?
- symptoms or signs of heart failure
- objective evidence of cardiac dysfunction
- response to therapy
what imaging tests can be carried out for heart failure?
> echocardiography
radionuclide ventriculography
MRI
left ventriculography
why is echocardiography used the most often?
it is the most practical and does not use radiation
what is brain (B-type) natriuretic peptide?
it is an amino acid peptide that can be measured easily in blood and s produced in heart failure.
what two potential screening tests are there?
> 12 lead ECG
> BNP
why is BNP a good screening test?
> it is highly sensitive to heart failure
stable up to 72hours
bedside testing available
relatively inexpensive
what does a low BNP rule out?
heart failure and left ventricular systolic dysfunction
what does an elevated BNP indicate?
that an echocardiography and cardiac assessment is needed
what sort of structural cardiac abnormally can lead to heart failure?
any severe structural abnormality
give some general causes of left ventricular systolic function
> ischaemic heart disease
dilated cardiomyopathy
severe aortic valve disease or mitral regurgitation
what does an echocardiography identify and quantify?
> LV systolic dysfunction > valvular dysfunction > pericardial effusion/tamponade > diastolic dysfunction > left ventricular hypertrophy > atrial/ventricular shunts > pulmonary hypertension/right heart dysfunctions
why can left ventricular ejection fraction be difficult to quantify accurately by echo?
> quality of images > experience of the operator > calculation method > use of contrast agents > time consuming to perform accurately
what is the normal range for left ventricular ejection fraction?
50-80%
what is the range of left ventricular ejection fraction in mild dysfunction?
40-50%
what is the range of left ventricular ejection fraction in moderate dysfunction?
30-40%
what is the range of left ventricular ejection fraction in severe dysfunction?
<30%
in biplane modified Simpsons rule what does the volume of each slice equal?
the area times the thickness
what are the pros of MUGA imaging?
> greater reproducibility
centre specific normal range
it is easier to obtain an accurate figure for the LVEF
what are the problems with MUGA?
it uses ionising radiation and gives no additional structural information
