Cardiac Conditions Flashcards
Learning outcomes
What is the pathophysiology of coronary artery disease?
MOST COMMON = Atherosclerosis
The hallmark of the pathophysiology of CAD is the development of atherosclerotic plaque. Plaque is a build-up of fatty material that narrows the vessel lumen and impedes the blood flow.
What does the build up of plaque in the arteries cause?
Narrowing, stiffening and/or blockage of the arteries which is mostly due to atherosclerosis. Eventually causing heart ischemia and decreasing function of myocytes (heart muscle cells). Due to the lack of available oxygen (O2), inflammatory chemicals are released and myocytes engage anaerobic respiration which can cause a build up of lactic acid.
Identify the risk factors for coronary heart disease?
Age (males over 45yr and females post menopausal)
Diabetes
Hypertension
High LDL in blood
What is the normal range for the ejection fraction of the heart?
50-70%. Systolic heart failure (can’t pump hard enough) would be under 40%.
Outline the pathophysiology of atherosclerosis - what is it?
What is it?
Hardening of arteries, narrowing due to plaque.
Composed of substances/cells like: lipids like cholestrol, smooth muscle cells, fibrin, macrophages (FOAM cells), lymphocytes.
Due to this build up of plaque, the BV narrow and compromise the flow of blood.
Eruption causes a clot formation.
CORONARY: CAD - myocardial ischemia
CAROTID: Stroke (blood supply to brain compromised)
PERIPHERAL: PAD
RENAL: kidneys - renin release increasese BP
Atherosclerosis - risk factors?
High LDL (animal fats and genetics)
Gender
Family history
Smoking
Hypertension
Diabetes
Obesity
Inactivity
Stress
Atheroslerosis - associated complications?
PAD - intermittant claudication
Acute Arterial Occlusion - angina, mini strokes, renal function. No blood supply (PAIN, PALLOR, PULSE, PARATHESIA, PARALYSIS, LOW TEMP)
Aneurysms - local dilation in BV ie) in AORTA
Difference between hypoxia and hypoxemia?
Hypoxia is lack of O2 in the cells and tissues
Hypoxemia is lack of O2 in the blood
What is Angina?
Angina is chest pain that occurs when the oxygen demand of the myocardium outweighs the available supply. Insufficient blood supply to meet demands of heart muscle.
Myocyte necrosis occurs in MI because of what?
prolonged myocardial ischemia
What does a transmural MI cause?
Also known as a STEMI - affects the full thickness of the myocardium (the heart muscle) from the endocardium to the epicardium.
S-T segment elevation on ECG
What is a major consequence of left sided heart failure?
pulmonary oedema
Outline the key differences between systolic and diastolic heart failure
Systolic heart failure - decreased ER
The left ventricle becomes weak and unable to contract effectively during systole (the phase of the cardiac cycle when the heart contracts to pump blood) = decreased ejection rate
Diastolic heart failure = decreased SV
Te left ventricle becomes stiff and unable to relax properly during diastole (the phase of the cardiac cycle when the heart fills with blood). Although the heart’s ability to contract may be normal, it has difficulty filling with enough blood = decreased stroke volume.
