CVS Heart failure Flashcards
Define heart failure
A state in which the heart fails to maintain an adequate circulation for the needs of the body despite an adequate filling pressure
What are the main causes of heart failure?
- ischaemic heart disease
- hypertension
- dilated cardiomyopathy
- valve disease
- arrhythmia
- high output heart failure
What is congestive heart failure?
When both ventricles are affected
usually left sided heart failure is first which raises pulmonary pressure causing right sided heart failure
What are the symptoms of left sided heart failure?
Shortness of breath: upon exertion, lying flat or waking from sleep Tachycardia Cardiomegaly - displaced apex beat Extra heart sounds Pulmonary crackles Murmur due to mitral regurgitation
What are the symptoms of right sided heart failure?
Peripheral oedema eg ankles Raised jugular venous pressure Hepatic enlargement Pleural effusion Fatigue
What is the role of the renin-angiotensin-aldosterone system (RAAS) in heart failure?
RAAS activated to attempt to maintain cardiac output, however actually makes the struggling heart work even harder.
BP drops due to heart failure, so renin released from kidneys (catalyses conversion of angiotensin to 1) and ACE converted angiotensin 1 to 2.
Angiotensin 2 is a powerful vasoconstrictor and promotes aldosterone release from kidneys (causes salt and water retention increasing blood volume).
What is the role of the sympathetic nervous system in heart failure?
Causes vasoconstriction via a1
Increases BP which increases the workload of the heart by increasing preload and afterload.
Also causes increase chronotropy and inotropy via B1
What are the principles of management of heart failure?
- correct underlying cause if possible
- pharmacological therapy to improve symptoms, delay progression and reduce mortality
What drugs are used to treat heart failure? Give examples
Beta blockers eg propanolol atenolol ACE inhibitors Calcium channel blockers eg verapamil Organic nitrates (vasodilator) Cardiac glycosides
