Session 11 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 is the primary cause of Systolic heart failure?
Ischaemic heart disease
What are some of the other causes of Heart failure?
Hypertension
Dilated cardiomyopathy (Microbes/drugs)
Valvular heart disease
Arrhythmia
How is Starling’s law related to Heart failure?
Heart can no longer produce the same force or cardiac output for a given filling pressure
What is Class I heart failure?
No symptomatic limitation of physical activity
What is Class II heart failure?
Slight limitation of physical activity
No symptoms at rest
What is Class III heart failure?
Limited physical activity
No symptoms at rest
What is Class IV heart failure?
Cannot carry out physical activity
Symptoms at rest
Discomfort increases with any physical activity
What is congestive heart disease?
Where the ventricles on both sides of the heart fail.
Which side of the heart rarely fails in isolation?
The right side. It is usually the left which then causes right side as well
What are the 5 types of heart failure?
Left sided Right sided Biventricular 9congestive) Systolic Diastolic
What are some of the symptoms of left sided heart failure?
Fatigue Shortness of Breath Tachycardia Basal pulmonary crackles Pulmonary oedema
What are some of the causes of Right sided heart failure?
Secondary to heart failure Chronic lung disease PE Valvular disease (Tricuspid/pulmonary) Left to right shunts
What are some of the symptoms of right sided heart failure?
Peripheral oedema Fatigue Nausea Raised JVP Hepatic enlargement
Why is the Renin Angiotensin Aldosterone System (RAAS) activated in heart failure?
To maintain cardiac output
They make a struggling heart work harder
What stimulates Renin release form the Kidneys?
A drop in blood pressure
What does Renin do?
Catalyses the reaction of Angiotensin to Angiogtensin I
What does ACE do?
Convert Angiotensin I to Angiotensin II
What does Angiotensin II do?
It is a powerful vasoconstrictor so causes aldosterone to be released from the Kidneys
What does Aldosterone do?
Retains Na+ and H2O so increases blood volume
How does the Sympathetic nervous system effect the Heart and vessels?
Vasocontictor on blood vessels acting via alpha 1 receptors
Increases Chronotrophy and Inotrophy using beta 1 receptors
Why are ACE inhibitors used in heart failure?
They prevent the conversion of Angiotensin I to Angiotensin II
So indirect diuretic and vasodilator effect
Why are Beta blockers used in heart failure?
Prevent sympathetic innervation of the myocardium
What are the principles in treating heart failure?
Correct the underlying cause
Lifestyle changes
Pharmacological (Improve symptoms, delay progression, reduce mortality)
Treat complications
What are the 5 groups of drugs used to treat heart failure?
Beta blockers ACE inhibitors Ca2+ channel blockers Organic nitrates Cardiac Glycosides
How do Ca2+ channel blockers help in treatment of heart failure?
They reduce the contractility of the myocardium
How do Organic nitrates help in treatment of heart failure?
Dilatory effect so blood pressure reduces
How do Cardiac Glycosides help in treatment of heart failure?
They increase the cardiac output and contractility
Inhibit Na+/K+ pump, raised Na+, NCX inhibited, Ca2+ increases, increased contractility
