Heart Failure/Case Based Breathlessness Flashcards
What is the NYHA Functional Classification of HF?
I: no limitation to physical activity
II=mild: slight limitation of physical activity, comfortable at rest but ordinary physical activity causes tiredness, heart palpitations or SOB
III=moderate: marked or noticeable limitations of physical activity, comfortable at rest
IV=severe: severe limitation of physical activity, unable to carry out any physical activity without discomfort. Symptoms present at rest.
What is heart failure?
A pathological state in which the heart is unable to pump blood at a rate to meet the requirements of metabolising tissue and/or can only do so at the cost of an abnormally elevated diastolic volume/pressure
What are some underlying causes of heart failure?
Primary abnormality of heart muscle
Coronary atherosclerosis
Valvular defects
Congenital defects
HTN
Cardiomyopathy
Toxins: ETOH, cocaine
Chagas disease
What is the Frank-Starling law of the heart?
SV of the heart increases in response to increased end diastolic volume when all other factors remain constant
So if there is a larger volume of blood flowing into the ventricle, it stretches the cardiac muscle fibers, so you get an increased force of contraction
Allows the CO to be synchronized with venous return etc + maintains left and right ventricular output equally
What happens with the Frank-Starling law in HF?
In HF, you have a reduced contractile state so you can’t increase the SV in response to increased EDV –> heart failure
What are some precipitating causes of HF?
Infection
Anaemia
HTN
Thyrotoxicosis
Pregnancy
Arrhythmia
Tachycardia
Rheumatic/viral/bacterial carditis
Acute MI
PE
What is the workup for suspected heart failure?
ECG
CXR
Echocardiography and BNP
What is the non-pharm management of heart failure?
Fluid restriction
Reduce salt intake to <2g/day
Daily weight after voiding in the morning
Exercise program
Lifestyle: stop smoking, reduce ETOH, no drugs
Psychologist
Social worker
What is the pharm management of a new onset stage C HFrEF?
Either an ACEI/ARB and/or Bblocker
ACEI/ARBs are often best tolerated when the patient is still congested/wet
Bblockers are often better tolerated when the patient is less congested/dry with an adequate resting HR –> don’t use in patients that are decompensated
Then a loop diuretic (frusemide) for symptomatic improvement
Which drugs for HF may reduce mortality?
ARB and ACEI
Drugs that inhibit the renin-angiotensin system have modest effects on survival
What is the DDx for suspected HF
Dilated cardiomyopathy
Viral myocarditis causing CHF
Primary valvular dysfunction
Silent IHD
What is the escalation management of HF?
If the patient has worsening renal dysfunction and lack of diuresis
Inotropic support with NA and Dobutamine and higher doses of diuretics
Can often wean off of this
