Effects of Systemic Disease on CVS Flashcards
Identify some systemic diseases which affect the CVS.
– Diabetes mellitus – Hypertension – Chronic obstructive pulmonary disease – Amyloidosis – Rheumatoid arthritis – Vasculitides & SLE – Thyroid disease – Sarcoidosis – Nutrition – Drugs
Explain how diabetes mellitus affects the CVS.
“Hyperglycemia causes glycation of virtually all proteins, inducing collagen cross-linking with other extracellular matrix proteins in the arterial wall. Long-term exposure to elevated glucose levels alone can cause the endothelial cell dysfunction observed in diabetes (because instead of a carefully regulated protein sugar water gel, glucose molecules change the charge, changing the amount of water BM will allow) “
- In the glomerulus, this means that the BM will not act as a good filter and will leak, so proteins will leak out (proteinuria)
- If this happens in small vessels or eye, or brain, capillary thickens and becomes less efficient at letting the right things through and preventing the wrong things through
- If microvessel damage occurs in the aorta, ichaemia to wall of aorta may occur, promoting ulceration and genesis of atheroma)
- Similarly, if microvessel damage occur to the blood supply of a nerve, neuropathy may occur
-Besides the problem of glycation, it also seems that “elevated oxidative stress (associated with diabetes) can cause CV effects. Many diabetes-associated metabolic disorders are associated with this oxidative stress, including hyperglycemia, hypertriglyceridemia, hypercholesterolemia, hypoalphalipoproteinemia, and increased levels of advanced glycation end products, glycated and oxidized lipoproteins”
What are type I and II diabetes ? How are they treated ?
TYPE 1:
- Destroy islet cells (autoimmune) which produce insulin
- Treated with insulin
TYPE 2:
- Insulin resistance
- Treated with anti-hyperglycaemic (not insulin usually)
How can we measure long-term sugar consumption in a diabetic patient ?
Using non-enzymatic glycolsylation of haemoglobin (since half life of haemoglobin is 60 days)
Poor diabetic control would be shown through elevated glycated haemoglobin
Define glycation.
The nonenzymatic covalent bonding of a sugar molecule to another molecule, especially a protein.
Explain how hypertension affects the CVS.
- “The increased workload caused by hypertension leads to compensatory left ventricular hypertrophy. The left ventricular free walls and interventricular septum become thickened
- Hypertension also is associated with more severe coronary artery atherosclerosis.”
Explain how familial hyperlipideamia affects the CVS.
Promotes atherosclerosis (can result in thrombus, emboli) which affects heart and coronary arteries (may well present with MI for a relatively young person).
Explain how COPD (and specifically emphysema) affects the CVS.
Through “abnormal cell repair, increased airway inflammation, oxidative stress and extracellular matrix destruction”.
In the case of emphysema, resistance increases due to the joining of separate blood vessels (due to damage to some), decrease the number of parallel circuits we have. As a result, ability to oxygenate blood decrease. This may also result in pulmonary hypertension, which causes an enlargement of the RV.
Explain how pulmonary hypertension arises, and how it affects the CVS.
As a result of chronic lung disease (e.g. acute emphysema, recurrent pulmonary emboli, chronic bronchitis) or mitral stenosis or L ventricular failure
Causes an enlargement of the RV and possibly cor pulmonale (i.e. R sided heart failure)
Define Amyloidosis. What are its causes ?
Progressive, incurable, metabolic disease characterized by abnormal deposits of protein in one or more organs or body systems (can either by AA amyloid or AL amyloid which accumulates between cells and starves them).
AA amyloid accumulation is caused by conditions with chronic inflammation (osteomyelitis, rheumatoid disease) since it is produced in acute phase response.
AL amyloid accumulation is caused by myeloma
Explain how amyloidosis affects the CVS.
-Amyloidosis impairs function of the organ it is deposited in.
-For instance, if this affects the kidney, or in brain, or aorta, it will be more difficulty to get
nourishment to those cells
-Heart failure and nephrotic syndrome are common complications
What are other names for AL and AA amyloid ?
AA amyloid (i.e. secondary amyloidosis) AL amyloid (i.e. Amyloid light-chain, primary amyloidosis)
Is the structure of the amyloid normal in amyloidosis ?
No, in such cases, it forms a beta pleated sheet (abnormal structure)
Which cells are AL and AA amyloid produced by ?
AA - production by liver is stimulated by secretion of cytokines by chronic inflammatory cells
AL - produced by neoplastic plasma cells
Explain how R. arthritis affects the CVS.
1) It is a cause of AA amyloidosis
2) In addition to this, other reasons
Overall, R. arthritis is associated with increased mortality from CV disease
