Failure of the cardiovascular system Flashcards
Describe what can happen if blood pressure is too high/
Hypertension, leads to vessel damage and heart damage
Describe what can happen if blood pressure is too low
Hypotension leads to syncope and shock
Shock- Occurs in critically ill people. Medical emergency as poor blood flow around the body. Categorised as SBP<90mmHg. Affects cerebral and kidney function
Treatment: aggressive IV fluids, oxygen and airway maintained.
Syncope- insufficient perfusion to the brain, causes fainting. Can occur in healthy people
What is meant by valve prolapse?
Valve leaflets are forced, by back pressure, to invert themselves in a backwards orientation .
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Describe what angina pectoris is. Treatment?
Possible treatment for MI?
Its a symptom of over exertion of damaged heart tissue. It doesn’t necessarily occur during exercise. Nitrates for acute onset and longterm treatment resembles that for CAD.
Aggressive reperfusion of damaged tissue quickly. Morphine Oxygen Nitrates Aspirin
Describe Chronic low output heart failure and the differences in Right and Left CLOHF
Usually due to large or numerous infracts
Poor 5 year survival rate
Left
Causes respiratory problems due to backlog in pulmonary system. Left atrium becomes full earlier on and increased hydrostatic pressure leads to congestive HF.
Fluid leaks into lungs (Pulmonary oedema)
Dyspnoea, orthopnoea, paroxysmal nocturnal dyspnoea
Hypoxia in brain causes encephelopathy, irritability, loss of attention, restlessness, stupor & coma
Right
Leads to systemic problems as blood gets backed up to the body
May be caused by left HF
Causes include shunt, hypoxia
Peripheral oedema due to increased venous pressure.
Jugular venous distention
Describe cardiogenic, distributive and hypovolaemic shock.
Cardiogenic shock refers to a decreased ability of the heart to pump blood which causes low CO leading to critically poor perfusion.
Distributive shock occurs in distributing vessels(arteries). The blood vessels are too wide so pressure is too low to transport blood as in anaphylaxis.
Hypovolaemic shock occurs in loss of blood. Total plasma volume is low, low venous return and low vessel pressure as in haemorrhagic shock
Consider treatment for cardiac maladies.
Briefly describe the action of ACE Inhibitors and give an example.
There function is to decrease cardiac output.
Decrease plasma fluid and vasodilation which causes decreased blood pressure.
Used in hypertension and congestive heart failure
E.g. Ramipril
Consider treatment for cardiac maladies.
Briefly describe the action of diuretics and give an example.
There function is to decrease cardiac output by increasing the production of urine.
Decrease plasma fluid which leads to decreased venous pressure.
E.g. Bendroflumethiazide, Indapamide, Furosemide
Consider treatment for cardiac maladies.
Briefly describe the action of beta blockers and give an example.
There function is to decrease cardiac output.
Cause vasodilation of arteries which decreases pressure.
Used in hypertension and arrhythmia.
E.g. Bisoprolol, Propranolol
Describe decompensated heart failure.
Consider fluid overload, damming, positive feedback and oedema.
Decompensated HF causes the kidneys to overcompensate by retaining more fluid which leads to fluid overload.
The heart is unable to cope with the hypervolaemia so theres a damming effect in veins alongside high hydrostatic pressure this leads increased back pressure which further damages the heart.
There is a positive feedback mechanism involved in this process which causes fast deterioration of the heart.
In extreme cases, capillaries leak into tissues and lungs causing oedema. This reduces gas exchange at the lungs.
Define hypertension and describe some risks and causes of hypertension
Mismatch between blood volume and circulatory capacity
Asymptomatic
Risk of CHD and MI
Maybe secondary to kidney disease
Chronic hypertension can lead to aneurysm/stroke, MI, Kidney and/or heart failure, cardiac hypertrophy
Describe some causes of orthostatic hypotension
Low bp on standing
Dizziness or syncope
Causes: drugs, age and hypovolaemia
Describe cardiogenic shock
Compensatory mechanism include tachycardia tachypnoea. Failure to compensate leads to acidosis, low urine output, hypotension, confusion and syncope
Define stroke and its causes in terms of stress and damage.
Rapid loss of brain function due to loss of perfusion to part of the brain.
Haemorrhagic stroke occurs when cerebral blood vessel ruptures.
Ischaemic stroke occurs when cerebral blood vessel is blocked.
Stress: Hypertension, high wall tension, low compliance, turbulent flow
Damage: Trauma, atherosclerosis, diabetes
How can acute MI cause death?
Arrhythmia (electrical disorganisation) or HF
Describe some symptoms and causes of atherosclerosis
“Furring of the arteries”
Asymptomatic
Results from (1) Hyperlipidaemia (2) Immune action (3) Unknown aetiology
Describe some symptoms,causes and potential treatment for CHD.
Angina or asymptomatic
Causes: normally caused by atherosclerosis
Treatment:
Non-invasive- drugs for hypertension/hyperlipidaemia
Invasive- Stenting or surgical removal of clogged vessels
Define plaque rupture. What is the consequence?
When the fibrous cap of a plaque bursts open. In this event, the contents flood into the blood stream and act as a magnet for platelets.
Outline the sympathetic activity during MI
- SNS releases noradrenaline and adrenaline in response to pain and haemodynamic abnormalities
- This causes increased heart rate and increased contractility
- This causes increased peripheral resistance and increased risk of arrhythmia
Describe pulmonary oedema.
Cause: Left heart failure causes damming of blood which increases hydrostatic pressure in pulmonary circulation
Effect: Fluid accumulation in lungs leading to impaired gas exchange and the length of O2 diffusion is lengthened
Symptoms: dysponoea and/or orthoponoea which are both due to hypoxia
Describe the difference between peripheral oedema and ascites
Peripheral oedema is caused by high hydrostatic pressure. It is caused by low output heart failure. Ascites is the accumulation of fluid in the peritoneal cavity. It is also caused by heart failure