CVD Flashcards
Question 1:
Define cardiovascular disease (CVD) and list four types of diseases included under this term.
Model Answer: Cardiovascular disease (CVD) refers to a group of disorders affecting the heart and blood vessels. It encompasses multiple conditions, including:
* Coronary artery disease (CAD)
* Ischemic stroke
* Peripheral vascular disease
* Heart failure and cardiomyopathy.
Question 2:
Differentiate between an ischemic stroke and a hemorrhagic stroke.
Model Answer:
* Ischemic stroke results from a blockage (usually by atherosclerosis or a clot) that obstructs blood flow to a part of the brain, causing tissue death due to lack of oxygen.
* Hemorrhagic stroke occurs when a blood vessel ruptures, leading to bleeding into brain tissue, which causes compression and damage.
Question 3:
Explain why the prevalence of CVD remains high despite advances in treatment.
Model Answer: Despite improved treatments such as stents, statins, and bypass surgeries, CVD remains prevalent due to several reasons:
* Modifiable risk factors such as obesity, diabetes, and sedentary lifestyles are increasing globally.
* Non-modifiable risk factors like aging populations and genetic predispositions persist.
* 25% of CAD patients have no traditional risk factors, suggesting unknown genetic or molecular contributors.
* Survival after MI has improved, but this increases long-term complications such as heart failure.
Describe the sequence of events from sustained hypertension to end-organ damage.
Model Answer:
1. Sustained high blood pressure leads to increased mechanical stress on vessel walls.
2. Endothelial damage occurs, exposing underlying tissues.
3. Vascular remodeling follows, including smooth muscle proliferation and ECM changes like collagen crosslinking.
4. Arterial stiffening impairs blood flow dynamics, further increasing pressure.
5. Capillary beds in organs (kidneys, brain, retina) become damaged.
6. This leads to proteinuria, retinopathy, stroke, and renal failure.
Why are people more likely to have a heart attack in the early morning hours?
Model Answer: In the early morning, there is a natural rise in blood pressure due to circadian rhythms. In individuals with pre-existing atherosclerotic plaques, the sudden surge in hemodynamic force can lead to plaque rupture, triggering thrombosis and myocardial infarction.
A patient has hypertension and arterial stiffening. Explain the biological and physical changes occurring at the vessel wall.
Model Answer:
* Biologically, hypertension causes endothelial damage, calcium deposition, chronic inflammation, and recruitment of macrophages.
* Physically, there is degradation of elastin fibers (mediated by MMPs) and increased collagen crosslinking, leading to stiffer, less compliant vessels.
* These changes impair normal vascular recoil during cardiac cycles, increasing systolic blood pressure and risk of vascular complications.
Describe how extracellular matrix (ECM) remodeling contributes to aortic aneurysm formation.
Model Answer:
* Hypertension induces stress that leads to medial degeneration of the aorta.
* Smooth muscle cells undergo a phenotypic switch from contractile to synthetic, promoting ECM degradation.
* Increased MMP activity breaks down elastin and collagen, weakening the vessel wall.
* Cytokine release (e.g., TGF-β) promotes inflammation.
* As the aortic wall thins and weakens, dilation occurs, forming an aneurysm.
Outline two lifestyle interventions to prevent hypertension and explain their physiological benefits.
Model Answer:
1. Regular Exercise: Lowers systolic and diastolic blood pressure by enhancing endothelial function and reducing vascular resistance.
2. Dietary Salt Reduction: Decreases water retention, reducing circulating blood volume and cardiac output, thus lowering blood pressure.
