Heart Failure
Original Editors - Students from Glasgow Caledonian University's Cardiorespiratory Therapeutics Project.
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Definition/Description[edit | edit source]
Heart failure is a complex clinical syndrome of symptoms and signs that suggest impairment of the heart as a pump supporting physiological circulation. It occurs when the heart becomes less efficient at pumping blood around the body at the right pressure in order to sustain bodily functions to a high standard. It commonly is a result of myocardial muscle dysfunction or loss, and is characterised by left ventricle dilation or hypertrophy, elevated cardiac filling pressure and/or inadequate peripheral oxygen delivery, at rest or during stress.
The condition can be acute, transient, or chronic:
• Acute is the first presentation of heart failure or a sudden onset of heart failure
• Transient is when heart failure is recurrent or episodic
• Chronic is heart failure that is persistent, worsening, or decompensate. It usually offset at first by compensatory mechanisms to maintain tissue perfusion, but eventually cardiac function declines and symptoms develop.
Heart failure can be classified into three different types:
1. Left Ventricular Failure (LVF): this is the most common form of heart failure, gradually pushing up pressure in the left atrium and pulmonary vascular system. The resulting pulmonary hypertension may force fluid into the alveoli creating a pulmonary oedema. This can cause compensatory mechanisms:
• Fast acting neural systems increase sympathetic acting, raising heart rate and myocardial contractility
• The slower response of the retin-antiogtensin mechanism promotes the retention of sodium and water by the kidney, increasing preload and encouraging myocardium to contract
The compensatory mechanisms raise the workload of the left ventricle further because angiotensin is an arterial vasoconstrictor and increases the afterload. Other factors that can increase the workload of the left ventricle are increased volume load as in aortic valve regurgitation, or increased resistance to flow such as with systemic hypertension.
2. Right Ventricle Failure (RVF): this generally occurs secondary to cardiopulmonary disorders such as pulmonary hypertension, right ventricle infraction, congenital heart disease, pulmonary embolism or COPD. It is usually irreversible unless the ventricles is underloaded e.g. by lung transplant for pulmonary hypertension. Enlargement of the right ventricle that has resulted from lung disease is referred to as cor pulmonale and is caused by hypoxic vasoconstriction and pulmonary hypertension.
3. Congestive Cardiac Failure (CCF): combination of LVF and RVF with congestion in the pulmonary and systemic circulations
Helpful Terminology:
• Stroke volume: volume of blood ejected by the ventricle in one contraction, usually 70ml
• End diastolic volume: volume of blood in the ventricle at the end of filling, just before it contracts, usually 120ml
• Ejection fraction: stroke volume expressed as a percentage of end diastolic volume, normally >55%
• Systolic heart failure: reduced or weakened pumping action of the heart, with ejection fraction <55%
• Diastolic heart failure: low compliance of myocardium, but with normal contraction and normal ejection fraction
• Preload: degree of stretch applied to the ventricle before contraction
• Afterload: load that the ventricle must overcome to eject blood
Epidemiology[edit | edit source]
Background epidemiology to the disease or condition (to include prevalence and incidence as appropriate from a UK or Scottish perspective. (You may want to also look at the disease prevalence across different social economic groups).
Aetiology[edit | edit source]
The causes of the disease or condition, current thinking and research activity as appropriate
Investigations[edit | edit source]
This may well include any investigations used to gain a diagnosis or that you might need to gain information about your patient assessment.
Clinical Manifestations[edit | edit source]
Clinical manifestations (the signs and symptoms your patient may well present to you on an examination) ensure you relate this back to the underlying pathophysiology.
Physiotherapy and Other Management[edit | edit source]
Physiotherapy and other management. Other health professionals will be treating your patient. What is their input?
Prevention[edit | edit source]
Brief consideration of how this pathology could be prevented and the physiotherapy role in health promotion in relation to prevention of disease or disease progression.
Resources
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add appropriate resources here
Recent Related Research (from Pubmed)[edit | edit source]
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References[edit | edit source]
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