Chronic heart failure: Difference between revisions

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===Pathophysiology===
===Pathophysiology===
'''Two-thirds''' of heart failure is caused by [[coronary heart disease]] (i.e. [[myocardial infarction]]) with the rest being caused by [[hypertension]], [[arrhythmias]] or [[valvular disease]]. [[Congenital heart defects]] may also cause heart failure but these are much rarer. Something has to make it '''harder for the heart to work''' which, when looking at it from a physics point-of-view means a '''reduction in cardiac output'''. Remember:
'''Two-thirds''' of heart failure is caused by [[coronary heart disease]] (i.e. [[myocardial infarction]]) with the rest being caused by [[hypertension]], [[arrhythmias]] or [[valvular disease]]. [[Congenital heart defects]] may also cause heart failure but these are much rarer. Something has to make it '''harder for the heart to work''' which, when looking at it from a physics point-of-view means a '''reduction in cardiac output'''. Remember:
*Cardiac output = Stroke volume x heart rate
<div style="text-align: center">Cardiac output = Stroke volume x heart rate</div>


===Risk Factors===
===Risk Factors===

Revision as of 15:59, 8 April 2009

Definition

This condition is a syndrome rather than a single pathological process. As such, it is defined by it's symptoms and signs.

Epidemiology

Pathophysiology

Two-thirds of heart failure is caused by coronary heart disease (i.e. myocardial infarction) with the rest being caused by hypertension, arrhythmias or valvular disease. Congenital heart defects may also cause heart failure but these are much rarer. Something has to make it harder for the heart to work which, when looking at it from a physics point-of-view means a reduction in cardiac output. Remember:

Cardiac output = Stroke volume x heart rate

Risk Factors

Clinical Features

The definitive features of heart failure are breathlessness or exhaustion on less than normal exertion OR at rest. Reduced heart function and associated changes in other organ systems are also used in the definition.

Investigations

Management

Prognosis