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.
Causes of heart failure?
Ischaemic heart disease Hypertension Congenital heart diseases Restrictive cardiac myopathy Hypertrophic cardiac myopathy Arrhythmias Pericardial disease
What is Class I heart disease?
No symptomatic limitation of physical activity
What is seen in class II heart disease?
Slight limitation of physical activity
Ordinary physical activity results in symptoms
No symptoms at rest
What is seen in class III heart disease?
Marked limitation of physical activity - leads to symtoms
No symptoms at rest
What is seen in class IV heart disease?
Inability to carry out physical activity without symptoms
May have symptoms at rest
Cardiac output of the heart normally?
5L/minute
Stroke volume of the heart?
75ml/beat
What are the factors that affect cardiac output?
Heart rate
Myocardial contractility
Venous capacity (LV preload)
Aortic and peripheral impedance (afterload)
Signs and symptoms of left sided heart failure?
Fatigue Shortness of breath upon exertion or when lying flat Tachycardia Cardiomegaly S3 or S4 heart sounds Functional murmur of mitral regurgitation Basal pulmonary crackles Pulmonary oedema
What is congestive heart failure?
When both sides are affected
Causes of right sided heart failure?
Secondary to left heart failure Chronic lung disease Pulmonary embolism Pulmonary hypertension Pulmonary/tricuspid valvular disease Left -> right shunts (ASD/VSD) Isolated right ventricular cardiomyopathy
What is cardiomegaly?
Displaced apex beat
Signs/symptoms of right sided heart failure?
Peripheral oedema Fatigue Dyspnoea Anorexia Nausea Raised JVP Tender, smooth hepatic enlargement Dependent pitting oedema Pleural effusion
How is angiotensin II produced?
Drop in blood pressure causes release of renin in kidneys
Angiotensin -> Angiotensin I
Angiotensin I -> Angiotensin II (ACE)
What does angiotensin II do?
Powerful vasoconstrictor
Promotes release of aldosterone from the kidneys
What does aldosterone do?
Causes salt and water retention in the kidneys, increasing blood volume
Which receptor causes vasoconstriction of blood vessels?
alpha-1
Which receptor increases chronotropy and inotropy?
beta-1
Which drugs are used in the treatment of heart failure?
ACE-inhibitors
Diuretics
Beta-blockers
How do ACE-inhibitors work?
Prevent conversion of angiotensin I to II
Indirect vasodilatory effect and diuretic effect
Reduces workload of the heart
What do beta blockers do in the treatment of heart failure?
Block beta-1 receptors on the myocardium
Lowers chronotropy and inotropy
Reduces workload of the heart
Aims of pharmacological therapy in heart failure?
Symptomatic improvements
Delay progression of heart failure
Reduce mortality
What do calcium channel blockers do in the treatment of heart failure?
Reduce contractility of the myocardium
What do organic nitrates do?
Veno/vasodilator to reduce blood pressure
What do cardiac glycosides do?
Increase cardiac output and contractility of the heart by inhibiting the Na-K pump
This raises intracellular Na, inhibiting the NCX, so intracellular calcium increases
Increase in contractility
