Heart Failure Flashcards
What is the equation for Cardiac Output (CO)?
Heart Rate (HR) x Stroke Volume (SV)
What is the equation for Stroke Volume (SV)?
End diastolic volume (EDV) - End systolic volume (ESV)
What is the equation for Ejection Fraction (EF)?
Stroke volume (SV) / End diastolic volume (EDV)
What is approximately defined as normal Ejection Fraction? What is borderline? What is HFREF?
Normal EF: 50-70%
Borderline EF: 40-50%
HFREF: <40%
What is the basic definition of Systolic / HFREF and Diastolic / HFPEF?
Systolic: When the heart can’t pump hard enough (increased end-systolic volume), leading to a reduced ejection fraction
Diastolic: When the heart can’t fill enough (decreased end-diastolic volume), leading to a preserved ejection fraction
What is the Frank-Starling law?
Refers to when stroke volume of the heart increases in response to an increase in volume of the blood in the ventricles before contraction
Left-sided heart failure is usually which, systolic, or diastolic in cause? What underlying causes are there for this type of heart failure?
Left sided heart failure is usually systolic, whereby the heart cannot generate a forceful contraction leading to increased end-systolic volume. There are three main causes:
- Ischaemic heart disease (myocardial damage)
- Chronic hypertension (myocardium struggles to pump against a hypertensive systemic circulation)
- Dilated cardiomyopathy (thinning of myocardium wall to increase LV size and filling and thus stronger contraction by Frank-Starling Law)
Left-sided heart failure can be diastolic in nature. What are some causes to this?
- Concentric hypertrophy (caused by 1. Chronic Hypertension, 2. Aortic Stenosis, 3. HOCM)
- Restrictive cardiomyopathy (stiffening of myocardial walls, not enlargement)
What are the three subtypes of Cardiomyopathy? What heart failures are they associated with?
- Dilated (systolic)
- Hypertrophic (diastolic)
- Restrictive (diastolic)
How does left-sided heart failure cause fluid retention and why?
If the heart does not pump adequate blood, there is reduced perfusion to the kidneys which in turn activates RAAS. RAAS causes fluid retention to increase filling and pre-load which in turn theoretically increases contraction strength (Frank-Starling)
In left sided failure, where does blood typically become congested? What symptoms are thus associated with this heart failure?
In left-sided heart failure: Blood congests to lungs, causing PND, Orthopnoea, Dyspnoea, Elevated pulmonary wedge pressure, Cough, Crackles, Wheeze, Haemoptysis, Tachypnoea
Give examples of causes of Right-sided heart failure
- Left-sided heart failure (Biventricular HF)
- Left-to-right cardiac shunt (ASD, VSD)
- Chronic Lung Disease
What are the six CXR findings in patients with heart failure?
- Kerley B lines
- Upper lobe venous distension
- Perihilar (batwing) shadowing
- Fluid in oblique / horizontal fissures
- Pleural effusions
- Increased cardiothoracic ratio >50% (cardiomegaly)
What vaccinations are offered to patients with heart failure?
Annual influenza vaccine
One-off pneumococcal vaccine
What are the treatment options for patients with HFPEF (diastolic)?
- No treatments have been shown to improve prognosis
- Management of HTN, diabetes, weight reduction, lipid control, diuretics, beta blockers