Heart failure Flashcards
What is heart failure
Inability of the heart to pump blood to all other parts of the body
Usually as a result of damage to the left ventricle Increased pressure in the left heart -fluid in the lungs causes breathlessness Increased pressure may reflect into right heart leading to congestive symptoms.
Fluid collects in the legs, enlarged liver, elevated JVP Poor blood supply to the muscles causes tiredness and wasting
Causes of heart failure
IHD ( Myocardial Infarction)
Hypertension
Dilated cardiomyopathy, restrictive and hypertrophic cardiomyopathies
Alcohol
Valvular heart disease
Pericardial disease
Congenital heart disease
Myocarditis or endocarditis
Symptoms of heart failure
Pulmonary congestion: SOBOE, orthopnoea, PND
Poor perfusion to muscle: Fatigue, weakness
Raised CVP: Fluid retention
Oedematous GIT, malabsorption, muscle atrophy: Weight loss, cachexia
Poor perfusion to brain: Confusion, poor concentration and memory, insomnia
Signs of heart failure
S3 gallop/ third heart sound
Pulmonary basal crackles
Pulsus alternans
Elevated JVP
Ankle oedema
Tender hepatomegaly
Investigations in a patient with heart failure
CXR: cardiomegaly, bilateral pleural effusions, pulmonary congestion
ECG: likely to be abnormal, LBBB
Bloods for anaemia, thyrotoxicosis, U+E, BNP
BNP (Brain Natriuretic Peptide)
Echocardiography
NYHA score
Used for classification of heart failure
1 - no limittation of physical activity
2 - slight limitation of physical activity, breathless on exertion (stairs)
3 - marked limitation of physical activity, breathless walking short distances
4 - breathless at rest, impaired physical activity
Systolic heart failure
Left heart failure.
Inadequate cardiac output leads to elevated left atrial pressures. This causes back pressure in the pulmonary veins leading to pulmonary congestion (and pulmonary oedema), back pressure can spread to right heart, causing a rise in CVP.
Right heart failure
Secondary to chronic lung disease, PE, pulmonary hypertension, right heart valve disease - left ventricle normally unaffected
Can also be secondary to left ventricular failure (congestive heart disease)
Elevated RA pressure leads to peripheral fluid retention
Acute heart failure
Emergency. Develops rapidly so there is no time for compensatory changes e.g. sepsis, acute MI, valve dysfunction
Presents as acute breathlessness, orthopnoea, wheezing, anxiety and sweating.
Treated pharmacologically - MONaD
Morphine, high flow O2, IV GTN, Diuretics
Chronic heart failure
Long term condition associated with adaptive responses in the heart (hypertrophy, dilation)
Commonest causes MI and CAD
Results in changes in cardiac function, neurohumoural status, systemic vascular function, blood volume.
Treatment: beta-blockers, vasodilators (GTN), spironolactone/ACEi (prevent water retention)
Pathophysiology of heart failure
Cardiac dysfuntion results in a decrese in cardiac output due to impaired systolic function (low SV).
This results in a higher EDV, the ventricle dilates to compensate.
Reduced CO, results in a fall in blood pressure because of arterial underfilling, TPR falls. This stimulates NorA release from the sympathetic system causing vasoconstriction to maintain arterial pressure and increase heart rate to raise CO (tachycardia)
Fall in BP also decreases renal perfusion, activates RAAS to increase Na+/H20 retention (aldosterone) and vasoconstriction (Angiotensin II) to increase BP.
Raised TPR increases ventricular afterload, which reduces SV and raises preload. Increased blood volume raised CVP. Causes pulmonary congestion and oedema.
Why is aldosterone harmful for the heart
Exacerbates progression of heart failure by causing salt and water retention.
This increases ventral venous pressure, and therfore increase preload promoting pulmonary congestion. Failing hearts are less responsive to changes in preload
Causes sudden cardiac death by increasing fibrosis and arrythmia
Causes ischemic events
Precipitating factors in heart failure
PE
Infection
MI
Anaemia
Arrythmias
Endocarditis
Poorly controlled hypertension
Lifestyle: physical activity, emotional stress, diet
Cause decompensation of cardiac function.
Treatment of acute heart failure
Propped up position, high flow oxygen
IV morphine
High dose intravenous GTN
IV Frusemide (diuretics)
Positive inotropes
Diastolic heart failure
Heart failure with good LV systolic function but poor LV relaxation usually due to hypertrophy
Common in elderly females with hypertension
Common causes are hypertension, HCM, Aortic stenosis (LVH) and CHD
Diagnosed from signs of heart failure + abnormal relaxation of LV assessed by echo
