Left Ventricular Dysfunction and Heart Failure Flashcards
How do you calculate cardiac output?
Stroke volume x heart rate (pulse)
How is stroke volume determined?
Cardiac stretch and inotropic status among other factors
How do you calculate LVEF?
(EDV-ESV) / EDV
What is LVEF?
Left ventricular ejection fraction
What does a reduced ejection fraction tell us?
Reduced heart function
Cardiac output = arterial pressure / x. What is x?
Peripheral resistance
What are common causes of heart failure ?
- Ischaemic heart disease
- Poorly controlled hypertension
- Valvular heart disease
- Heart muscle disease /loss (cardiomyopathy)
- Thytotoxucosis and alcohol
Why are some of the compensatory mechanism a problem ?
They increase cardiac work and O2 demand
What are the consequences of pump failure ?
- Forward failure
- failure to provide adequate perfusion to tissues
- hypoxia and tachycardia - Backward failure
- pressure inside cardiac chambers increases
- back pressure alters vascular haemodynamics
- exudation of fluid from vulnerable beds
What is the neurohormonal hypothesis?
Your body compensates componsatory mechanisms to combat Threaten Bp and CO
What does sympathetic activation cause?
- increase hr
- increase inotropy
- increase vascular tone
- increase bp
- activation of RAAS
What can long term activation of the sympathetic NS lead to ?
- heart cell hypertrophy
- apoptosis
- necrosis
- fibrosis
- synthe (FINISH)
What can be activated as a compensatory mechanism ?
- RAAS
- Sympathetic NS
What tests can be carried out to find evidence of systolic dysfunction ?
ECG
Brain natriuretic
Echocardiogram
What usually occurs in LHF?
Pulmonary oedema
