Lecture 3: How the CVS Fails Flashcards
what happens during haemorrhagic stroke
cerebral blood vessel rupture, bleeding in the brain
what happens during ischaemic stroke
cerebral blood vessel blockage
how does the endothelium control vasodilation
releasing NO
what is an acute myocardial infarction and how it is caused
- a region of heart tissue that is dying or dead
- caused by blocked coronary artery
what is plaque rupture
- when the fibrous cap of a plaque bursts open
- platelets try to fill in the gap, causing a thrombus or embolism
what happens as response to acute myocardial infarction
- sympathetic nervous system releases adrenaline and noradrenaline
- in response to pain and haemodynamic abnormalities
what causes pulmonary oedema and what are the symptoms
- left heart failure
- dyspnoea
- orthopnoea
- hypoxia
what are ascites
accumulation of fluid in peritoneal cavity
what is compensation
- physiological process
- maintaining homeostasis of a physiological function despite stressors or malfunctions
what is decompensated heart failure
- medical emergency
- failure of the heart to maintain adequate blood circulation after vascular disease
what is cardiac remodelling and what can it be inhibited by
- long term growth of cardiac muscle
- caused by injury
- ACE inhibitors or spironolactone inhibits it
what is eccentric growth of the ventricles
dilation due to volume overload
what is concentric growth of the ventricles
thickening of wall due to pressure overload
what is the effect of ADH and where is it secreted from
- causes kidneys to reabsorb water
- secreted from posterior pituitary
what is the effect of aldosterone and where is it secreted from
- causes kidneys to reabsorb more NaCl and therefore H2O
- secreted from adrenal cortex
what does angiotensin II do
- local vasoconstriction
- increases aldosterone and ADH secretion to increase fluid retention
- contributes to ventricular hypertrophy and remodelling
what is the function and types of diuretic drugs
- loss of fluid at nephron
- thiazide and thiazide-like
- loop
- K+ sparing
how do thiazide and thiazide-like diuretics work with example
- eg indapamide
- blocks reabsorption at distal convoluted tubule
how do loop diuretics work with example
- eg furosemide
- blocks reabsorption in thick part of loop of Henle
how do K+ sparing diuretics work with example
- eg spironolactone
- inhibites aldosterone receptors in cortical collecting duct
what does heart failure mean
when the cardiac output is insufficient for meeting the needs of the body and lungs
what is chronic low output heart failure
- cardiac output is low, usually due to accumulated damage to the heart
- chronic condition with poor 5 year survival rate
what sort of symptoms does left heart failure have and why
- respiratory symptoms
- right heart pumps into lungs but left atrium is too full
- increased hydrostatic pressure in pulmonary circulation
- leads to congestive heart failure
what sort of symptoms does right heart failure have and what can it lead to
- systemic symptoms
- central venous pressure builds up
- peripheral oedema
what are symptoms of heart failure
- fatigue
- dyspnoea: orthopnoea and paroxysmal nocturnal dyspnoea
what is cardiogenic shock and its treatment
- critically low perfusion due to low cardiac output
- aggressive intravenous fluid and oxygen + airway maintained
what is the blood pressure during shock
systolic blood pressure < 90 mmHg
what is the response to the kidney during low cardiac output
- decrease glomerular filtration rate
- increase central venous pressure
- increase venous return and preload
what are treatments for heart failure
- ACE inhibitors
- diuretics
- beta blockers
