Cardiovascular conditions Flashcards
What is ischemia?
An area of black or dead necrotic tissue.
Limb ischemia is one of the reasons why people may need an amputation. The cells there will not be replaced nor rejuvenated so we can treat it by removing it to stop the spread of infection.
Ischemia can also exist in the heart.
Describe collated flow.
Blocked vessels mean tissues that are distilled to the plug are metabolically deprived and become ischemic leading to a psychological infarction.
Therefore, the body congratulate form new vessels to bypass the clot and blood flow to the area can be maintained with multiple smaller vessels.
This is a process known as collateral flow.
Define Atherosclerosis.
Atherosclerosis: It is the buildup of fatty deposits (plaque) within arteries, leading to reduced blood flow due to the narrowing of the arterial lumen. Plaque formation can result in hardening of the arteries, potentially causing ischemia.
Describe the stages of atherosclerosis progression from the first decade to the fourth decade of life.
Onset and Progression: Atherosclerosis can begin in the first decade of life with fatty streaks, progressing to more severe lesions and plaque buildup by the third or fourth decade of life, eventually leading to advanced stages like thrombosis or hemorrhage.
Plaque Rupture: Plaque can rupture, enter the bloodstream, and cause clotting, leading to ischemia. Plaques are thrombogenic, and the body has mechanisms to reduce clotting risk.
- What is this mechanism?
To keep the thrombogenic material away from the blood collagen is sent to the tunica intima to create a fibrous cap. This is to help it prevent rupturing and to keep the content away , called the necrotic core, the blood.
Briefly outline the stages in the pathophysiology of atherosclerosis:
- Cholesterol in the blood can move around freely until the endothelium layer within the vessels is damaged. This makes the lining more permeable and low density lipids can move into the tunica intima.
- This trick is an inflammatory process and monocytes are called to become macrophages. These destroyed the low density lipids biphagocytosis however, their consumption is uncontrolled and they themselves over feed dye and turn into foam cells.
- The apoptosis of the macrophage is a signal more monocytes to the tunica intima which causes a positive feedback cycle that loops around and round of more cell death and more cells being signal to the area.
- While this is going on, The smooth muscles of the tunica media begin to proliferate and move in into the tunica intima and remain deep to the endothelium lining. This bulge limits blood Flow and it’s thrombogenic therefore, the body tries to avoid it becoming in contact with the blood and becoming a clogged, cause infection or becoming a platelet plug .
- To keep the thrombogenic material away from the blood collagen is sent to the tunica intima to create a fibrous cap. This is to help it prevent rupturing and to keep the content away , called the necrotic core, the blood.
What causes Aneurysms?
Aneurysm is caused by a weakened artery wall and a change in compliance as a result.
Explain how right sided heart failure could be caused by Chronic Obstructive Pulmonary Disease (COPD). (10 marks)
Plan:
Premis:
COPD (para. Emphysema) causes pulmonary hypertension that can result in right sided heart failure.
Justify:
Collapse of acinus and vascular remodeling:
- Terminal bronchiole collapses, alveolar surface area decreases as acenunn die from lack of perfusion.
- Vascular structure abandons site for healthy structures.
- This reduces area for perfusion but blood volume remains. This means the Pressure= force/surface area is decreased and hypertension in the pulmonary arteries incurs.
- This is a closed system, son pressure is pushed back through the pulmonary arteries and into the right ventricle.
Claim: backwards buildup of pressure causes right atrium to fill with blood, increasing it’s Volume and stretching the walls, causing them to swell.
Define pneumonia.
Infection of the parenchyma which causes acute inflammation. This mainly affects the alveoli and adjacent connective tissues. Sacs fill with micro organisms, fluid and macrophages which reduces the functional capacity of the lungs.
Who is at risk of pneumonia?
- Drug users, alcoholics and epileptics: inhailation during unconsciousness.
- The Elderly aged over 65- broncho, due to immune deficits, can be terminal.
- People with viral infections, such as chicken pox.
- Those living in closed communities- nsocominal pneumonia
- Malnourished
- Imunospressed people
- Uncontrolled diabetes
- Those with respiratory diseases such as COPD, CF and Bronchiectasis.
What are the two main causes of right sided Heart Failure? Can you justify your answer?
Pulmonary Embolism:
Pressure on lungs pushes blood flow backward
Left Ventricular Failure:
Blood fills the left ventricle due to failure. This causes congestion & dilation of the left atrium, leading to pressure building up in the pulmonary vascular system. This can back up the right side and cause issues in the Right ventricle.
These occurrences thin & weaken the walls of the right ventricle, leading to an inability for it to pump blood into the pulmonary circulation system.
List the causes of Right sided Heart failure.
-Gradual development with asymptomatic onset.
- myocardium fx declines when compensations tire.
Advances with age
co-morbid with:
- Anemia
- Lung Disease
- Hypertension
- Pre-existing Cardiac Disease.
What are the affects of left Side heart failure?
- Ventricular failure (congestion & dilation of left atrium leads to Pulmonary blood pressure, back up in Right side of ment causes systemic venous congestion).
-Reduced Exercise tolerance ( especially with cough, caused by pulm. Odema). - Easily fatigued.
- Poor Peripheral perfusion
- low BP
- Congestion, odema & Dyspnoea worsen at night. (per. Odema reabsorbed).
what compensations does the body employ to manage Heart failure?
Justify your answers.
Increased cardiac muscle mass:
- increased cardiac workload imposes the demand (SAID) on the myocardium to adapt to meet the force requirements. This muscle type is delicate & sensitive to changes so overload is easier here than in skeletal muscle.
Enlarged chambers:
- The heart increases it’s volume resulting in a decrease of pressure because P= F/A and the additional cardiac workload can be distributed across the internal surfaces of the chambers to produce an inversely proportionate relationship between volume and pressure (Boyle’s law).
Increased blood volume:
This contributes to the build up of pressures in the system. It occurs because the heart can not contract forcefully enough.
Increased cardiac work load:
It tries to increase its output to meet body demands
Explain General Myopathy in terms of it’s effect on the heart.
The loss of compliance is a main driving force with in the pathophysiology of cardiomyopathy. For example, a reduction in stretch means the material is no longer getting ATP free energy from the properties of the myocardium. Such as the elastic recoil when stretching a balloon which can help propel blood forward. Even if the neural innovation of the heart was fine, this tissue will still be dysfunctional due to the change in biomechanical properties resulting in weakness.
what is dilated myopathy?
Dilated myopathy is a reduction in force and an increase in volume of the heart dilates. This thins the heart wall causing it to weaken and the myocardium stretches. This reduces the full systolic contraction.
