Chronic Heart Failure Flashcards
What is the definition of heart failure?
Cardiac output is inadequate for the body’s requirements.
Why is mild myocardial dysfunction not associated with decreased cardiac ouput?
CO is maintained by an increase in venous pressure (and hence diastolic volume)
What is systolic heart failure?
Inability of the ventricle to contract normally, resulting in decreased CO. The ejection fraction is < 40%
What is the ejection fraction in systolic HF?
<40%
What are causes of systolic HF?
- IHD
- MI
- Cardiomyopathy
What is diastolic HF?
Inability of the ventricle to relax and fill normally, causing increased filling pressures. EF >50%
What can cause diastolic HF?
- Constrictive pericarditis
- Tamponade
- Restrictive cardiomyopathy
- HTN
What is important to note about systolic and diastolic HF?
They often co-exist
What is acute HF?
Term used to mean new onset acute or decompensation of chronic heart failure characterised by pulmonary oedema +/- peripheral oedema with or without signs of peripheral hypoperfusion
What is chronic HF?
HF that develops or progresses slowly. Venous congestion is common but arterial pressure is well maintained until late
What is low-output HF?
Cardiac output is decreased and fails to increase normally with exercise
What are causes of low-output HF?
- Pump failure
- Excessive preload
- Chronic excessive afterload
What causes of pump failure can cause low-output HF?
- Systolic +/- diastolic HF
- Decreased HR - B-blockers, heart block, post MI
- Negatively inotropic drugs
What are causes of excessive preload in low-output HF?
- Mitral regurgitation
- Fluid overload/retention
What are causes of chronic excessive afterload in low-output HF?
- Aortic stenosis
- Hypertension
What is high output HF?
Output is normal or increased in the face of greatly increased metabolic demand or shunting of blood which increases myocardial demand.
Cardiac failure occurs when CO fails to meet these increased needs. It will occur with a normal heart, but even earlier if there is heart disease

What are causes of high output cardiac failure?
- Anaemia
- Pregnancy
- Hyperthyroidism
- Paget’s disease
- AV malformation
- Beri Beri
What are features of RHF?
- Peripheral oedema
- Ascites
- Nausea
- Anorexia
- Facial engorgement
- Pulsation in the neck
- Epistaxis
What are features of LHF?
- Dyspnoea
- Poor exercise tolerance
- Fatigue
- Orthopnoea
- PND
- Nocturnal cough +/- pink frothy sputum
- Wheeze
- Nocturia
- Cold peripheries
- Weight loss/Muscle wasting
How is CO maintained in mild/moderate myocardial dysfunction?
Increased venous return plus sinus tachycardia - this is in the context of decreased ejection fraction. In more severe cardiac dysfunction, CO is maintained by more marked venous return and tachycardia
What does increased venous pressure cause both at organ and system level?
- Pulmonary oedema
- Hepatic enlargement/congestion
- Ascites
- Peripheral oedema
- Increased JVP
What pathophysiological changes occur in HF?

Why does salt and water retention occur in cardiac failure?
Increased venous pressure occurs when the ventricles fail. Reduced cardiac output also leads to diminished renal perfusion, activating RAAS, which promotes salt and water retention, which further increases venous pressure. Afterload is also increased by a combination of RAAS activity and Adrenergic activation
What is atrial natriuretic peptide released in response to?
Atrial stretching





