How the CVS fails Flashcards
Ischaemic stroke
cerebral blood vessel blockage
Haemorrhagic stroke
cerebral blood vessel rupture
Give stress causes leading to a blood vessel bursting
- high pressure - turbulent blood flow - large diameter/high wall tension - low compliance
Damage causes of blood vessels bursting
- Trauma i.e transluminal procedures - Atherosclerosis - diabetes
What is Atherosclerosis ?
a disease process the furring of blood vessel, caused by fat deposits in the lumen of the arteries
Define Compliance
change in volume caused by change in pressure
What are the causes of turbulent flow?
- high speed - branching - obstacles - low viscosity - branching - mixing
What are the actions of the endothelium?
- Blood vessel tone - Vasodilation - Fluid filtration - Haemostasis - White cell recruitment - Angiogenesis - Hormone trafficking
What is a Myocardial Infarction (MI)
a region of the heart that is dead or dying
Causes of MI
- blocked coronary artery
Causes of Atherosclerosis
- Hyperlipidemia - Immune action - unknown aetiology
What is Coronary Artery Disease ?
disease process in which the arteries of the heart are obstructures
What is a Plaque rupture
when the fibrous cap of a plaque bursts open
Describe the sympathetic activity of MI
- release of adrenaline and noradrenaline
- this increases the rate and contractility of the heart
- increases peripheral resistance and increased risk of arrhythmia
- helps to compensate during heart failure
List compensatory mechanisms for MI
- increased HR - increased contractility - increased peripheral resistance - increased risk of arrhythmia
What is Left Heart Failure
- blood building up leading to increased hydrostatic pressure in the pulmonary circulation,leading to pulmonary oedema
Define Compensation
- maintaining homeostasis of a physiological function despite stressors or malfunction
What is Decompensated Heart Failure
the failure of the heart to maintain adequate blood circulation after-long standing previously compensated vascular disease
Symptoms in decompensated Heart failure
- respiratory distress
What is cardiac remodelling, and how can it be reduced?
- growth of cardiac muscle, this can be a compensatory and a pathological process
Reduced by
- ACE inhibitors: enalapril, captopril
- Aldosterone Receptor inhibitor (K+ sparing diuretics): spironolactone
- 3rd gen. Beta lovers: carvedilol
Eccentric cardiac remodelling
dilatation due to volume overload
Concentric cardiac remodelling
thickening of cardiac muscles due to pressure overload, ineffective systole
Antiduretic Hormone
- secreted from the posterior pitutary
What is Aldosterone and how is relevant to cardiovascular function?
- hormone produced in the adrenal cortex that
- causes kidney to reabsorb more NaCl (and more water)
- this increases the plasma volume and increases the blood pressure
- it acts at the collecting ducts of the nephron
- blocked by spironalactone, used to treat hypertension
- steroid hormone: mineralocorticoids
What is Angiotensin II and what does it do?
- very strong vasoconstrictor
- increases fluid retention by increasing Na+ reabsorption
- contributes to ventricular hypertrophy and cardiac remodelling
- stimulates aldosterone secretion from the adrenal gland
Formation of Ang II
Angiotensinogen from the kidney ~ enzyme renin in the kidney –> angiotensin I ~ enzyme ACE in the lungs–> Angiotensin II
Drug action on the nephrons tubule system
-
GIve two types of Heart Failure
- Chronic Low output failure
- Decompensated heart failure
Chronic low output
- low cardiac output due to damage - poor survival rate - compensation via increased sympathetic processes
Left Heart Failure and it’s symptoms
- The left atrium is too full as the left ventricle isn’t carrying out systole effectively
- Respiratory symptoms: dyspnoea, orthopnoea and paroxysmal nocturnal dyspnoea
Right Heart Failure
- Systemic/ peripheral symptoms
- increased venous pressure leading to oedema or ascites
Symptoms of Heart failure
- fatigue, especially during exercise
- peripheral oedema
- dyspnoea/ orthopnoea
Cardiogenic shock
low perfusion due to low cardiac output
Definition of Shock
- the Systolic Blood Pressure goes below 90mmHg
What is decompensated Heart Failure and what is the treatment goals?
The body deals with heart failure as if it is a haemorrhage
- the kidney increases the plasma volume, to compensate for poor perfusion of renal tissue
- leads to fluid overload
- the heart is unable to pump the extra fluid
- fluid damning leads to increased venous hydrostatic pressures, further damaging the heart
- positive feedback loop forms, leading to further damage to the heart
- capillaries leak fluid into tissues (lung and ankles oedema)
Treatment goals
- prevent acute decompensated heart failure
- counteract cardiac remodelling- ACE inhibitors and Beta blocking
- minimize symptoms
Give three processes that might damage a blood vessel rather than damaging the tissue around it
- Intravascular trauma such as PCI
- Atherosclerosis
- Diabetes
What is Renin and why is relevant to the cardiovascular function?
- An enzyme in the RAA system
- converts angiotensinogen to angiotensin I which is later converted tot he active form angiotensin II
- the RAAS activation needs to vasoconstriction and fluid retention which acts to increase blood pressure
- the antagonist of renin is antihypertensives
What is Ascites?
- abnormal filling of fluid in the abdomen
What is paroxysmal nocturnal dyspnoea
- severe attack SOB and coughing that usually wakes up the individual in the night (it can be frightening)
What are the symptoms of pulmonary oedema?
- dyspnoea
- paleness
- excessive sweating
- hypoxia
What are the treatments for heart failure?
- ACE inhibitors
- Loop diuretics
- Beta-blockers
- Angiotensin receptor blockers
Sometimes
- Aldosterone receptor antagonists (K+ sparing diuretics)
and Digoxin only improves symptoms
Name 4 classes of diuretic drugs/
- Thiazide diuretics
- Loop diuretics
- Thiazide-like diuretics
- K+ sparing diuretics
