Heart failure Flashcards
Define heart failure
The inability of the heart to deliver O2-rich blood at a satisfactory rate for the tissues’ metabolic requirement
What are the 2 types of heart failure?
- Systolic
- Diastolic
Describe systolic pathophysiology
The ventricle’s ability to contract is reduced
Describe diastolic pathophysiology
There is impaired relaxation and ventricular filling
Describe the pathophysiology of heart failure
- It begins when the heart’s ability to pump blood is affected (it can be acute or chronic)
- This leads to a reduced ejection fracture (below 50% is abnormal) and therefore reduced cardiac output
- Compensatory mechanisms then activate
- Soon these compensatory mechanisms fail, and the heart undergoes cardiac remodelling
- These remodelling changes can improve cardiac output temporarily, but these will also eventually fail
Describe the compensatory mechanisms in HF
- RAAS – Release of renin -> RAAS cascade -> vasoconstriction and water/Na retention
- Sympathetic Nervous System (SNS) – Release of catecholamines (adrenaline) -> increased heart rate and heart contractility
Describe the cardiac remodelling in HF
- Hypertrophy – Heart gets bigger
- Dilation of the Chambers – Heart chambers get bigger; however, this can lead to the thinning of the cardiac wall
Describe right HF
- The right ventricle doesn’t pump blood properly, leading to a backlog of blood going into the heart
- Causes increased systemic venous pressure, resulting in peripheral oedema
Describe left HF
- The left ventricle doesn’t pump blood properly leading to a backlog of blood into the pulmonary vessels and lungs
- Causing increased pulmonary pressure, resulting in pulmonary oedema
What are risk factors of HF?
Age (65+)
Smoking
Obesity
Previous MI
Male sex
How is HF classified?
NY Heart Association Heart Failure Severity
- Class I: no symptoms with physical activity.
- Class II: slight limitation of physical activity by symptoms.
- Class III: less than ordinary activity leads to symptoms.
- Class IV: inability to carry out any activity without symptoms
What are symptoms of HF?
Breathlessness
Cough (with frothy white/pink sputum)
Orthopnoea (breathlessness when lying flat)
Paroxysmal nocturnal dyspnoea (waking up gasping for air)
Peripheral oedema
Fatigue
What are signs of HF?
- Tachycardia
- Tachypnoea(raised respiratory rate)
- Hypertension
- Murmurs(indicating valvular disease)
- 3rd heart sound
- Bilateral basal crackles (indicating pulmonary oedema)
- Raised jugular venous pressure (caused by a backlog on the right side of the heart)
- Peripheral oedema
How do you diagnose HF?
- Blood Test (High NT-proBNP)
- ECG
- Chest x-ray
- ECHO – analyse chamber dimensions (GOLD STANDARD)
What are causes of HF?
- Coronary Heart Disease (TOP CAUSE)
- Hypertension (TOP CAUSE)
- Valvular Heart Disease
- Arrhythmias
