Atherosclerosis & PAD Flashcards
What is atherosclerosis?
Atherosclerosis is a degenerative disease of the arteries characterized by the accumulation of plaques within the arterial walls. These plaques, made up of fat, cholesterol, and other substances, lead to the narrowing and stiffening of the arteries, causing chronic ischemia and potentially resulting in thrombosis.
What causes the narrowing of the arterial walls in atherosclerosis?
The narrowing of the arterial walls in atherosclerosis is caused by the accumulation of plaques (atheromas) within the intima of the arteries, leading to degeneration of the media and irregularity of the lumen.
What are the major risk factors for atherosclerosis?
Major risk factors for atherosclerosis include:
Non-modifiable factors: Male gender, family history of early heart disease, advanced age.
Modifiable factors: Smoking, diabetes mellitus, hypertension, dyslipidemia, obesity, physical inactivity, poor diet, high alcohol consumption, stress.
How does atherosclerosis lead to acute ischemia?
Atherosclerosis can cause acute ischemia through:
Acute thrombosis on top of existing plaques.
Hemorrhage within the plaque, leading to sudden complete occlusion.
Ulceration or sloughing of plaques, causing thrombosis and embolization.
Formation of dissecting aneurysms.
What is the pathophysiology of atherosclerosis?
The pathophysiology of atherosclerosis involves:
Endothelial injury triggering an inflammatory response.
Lipid accumulation (mainly LDL) within the intima, leading to foam cell formation.
Plaque formation from fatty streaks developing into advanced plaques.
Plaque rupture, which can cause thrombus formation and arterial occlusion.
What are the clinical features of atherosclerosis?
Clinical features of atherosclerosis include:
Chronic ischemia, which can progress to dry gangrene.
Intermittent claudication, rest pain, and in severe cases, tissue loss.
Specific manifestations depending on the affected arteries (e.g., coronary arteries, renal arteries, peripheral arteries).
How is atherosclerosis diagnosed?
Atherosclerosis is diagnosed through:
Lipid screening to measure cholesterol levels.
Imaging tests like ultrasound, angiography, and CT scans.
Ankle-Brachial Index (ABI) to assess blood flow.
Stress tests and ECG for cardiovascular evaluation.
What are the treatment options for atherosclerosis?
Treatment options for atherosclerosis include:
Lifestyle changes: Diet modification, exercise, smoking cessation.
Medications: Statins, antiplatelet agents, antihypertensive drugs.
Surgical interventions: Angioplasty, stenting, bypass surgery, endarterectomy.
What is the role of angioplasty in the treatment of atherosclerosis?
Angioplasty is a minimally invasive procedure used to widen narrowed arteries by inflating a balloon and placing a stent to keep the artery open. It is commonly used for patients not suitable for open surgery.
What is the difference between dry and wet gangrene in the context of atherosclerosis?
Dry gangrene is localized, often affecting the toes, resulting from chronic ischemia and minor trauma, leading to tissue death. Wet gangrene is usually more severe, associated with bacterial infection and rapid tissue decay, often requiring urgent surgical intervention.
What is atherosclerosis?
Atherosclerosis is a progressive degenerative disease characterized by the accumulation of plaques within the arterial walls, leading to the narrowing and stiffening of the arteries.
What causes chronic ischemia in atherosclerosis?
Chronic ischemia in atherosclerosis is caused by the narrowing and irregularity of the arterial lumen due to the accumulation of intimal plaques (atheromas), which can lead to thrombosis.
What is the role of LDL in the pathogenesis of atherosclerosis?
In atherosclerosis, low-density lipoprotein (LDL) penetrates the endothelium, becomes oxidized, and contributes to plaque formation by attracting monocytes that transform into foam cells.
How does plaque rupture lead to arterial occlusion?
Plaque rupture exposes thrombogenic materials like collagen, which leads to thrombus formation and potential arterial occlusion.
What is the significance of endothelial injury in atherosclerosis?
Endothelial injury triggers an inflammatory response, increasing permeability and adhesion, which facilitates the accumulation of lipids and inflammatory cells, contributing to plaque development.
What are common sites for atherosclerotic plaque development?
Common sites include bifurcations, origins of major arteries, and areas where arteries pass through fascial slings, such as the coronaries, carotids, and lower limb arteries.
What is dry gangrene, and how is it related to atherosclerosis?
Dry gangrene is localized tissue death often seen in the extremities, typically following minor trauma or infection, and it results from severe ischemia caused by atherosclerosis.
What are the major risk factors for atherosclerosis?
Major risk factors include smoking, diabetes mellitus, hypertension, dyslipidemia, obesity, physical inactivity, and a family history of early heart disease.
How is the ankle-brachial index (ABI) used in diagnosing peripheral artery disease (PAD)?
The ABI compares blood pressure in the ankle and arm to assess blood flow. An ABI of less than 0.9 indicates PAD.
What are the clinical features of atherosclerosis of the abdominal aorta?
Clinical features include abdominal pain, constipation, a systolic murmur in the midline above the navel, and in severe cases, Leriche’s syndrome.
What are PCSK9 inhibitors, and how do they function in treating atherosclerosis?
PCSK9 inhibitors, like alirocumab and evolocumab, reduce LDL receptor degradation, leading to lower plasma LDL levels, thus helping manage atherosclerosis.
What is intermittent claudication, and what causes it?
Intermittent claudication is muscle pain or cramping in the legs during exercise, caused by insufficient blood flow due to narrowed arteries in atherosclerosis.
What are the potential complications of atherosclerosis in the renal arteries?
Atherosclerosis in the renal arteries can lead to renovascular hypertension, proteinuria, and the presence of red blood cells and casts in urine.
What is the role of lifestyle changes in managing atherosclerosis?
Lifestyle changes such as smoking cessation, regular exercise, and a healthy diet help reduce risk factors and slow the progression of atherosclerosis.
What are the indications for coronary artery bypass grafting (CABG)?
CABG is indicated for severe coronary artery disease with multiple blockages, failure of other treatments like angioplasty, and when there is a significant risk of myocardial ischemia.
How is plaque formation initiated in atherosclerosis?
Plaque formation begins with endothelial injury, followed by the accumulation of lipids, inflammatory response, foam cell formation, and the development of fatty streaks.
What are the characteristics of atheromatous plaques?
Atheromatous plaques consist of smooth muscle cells, connective tissue, and accumulated cholesterol, triglycerides, and phospholipids, leading to arterial narrowing.
What is the role of macrophages in atherosclerosis?
Macrophages engulf oxidized LDL to form foam cells, secrete matrix metalloproteinases that weaken the fibrous cap of plaques, and contribute to plaque rupture and thrombus formation.
What are the clinical manifestations of peripheral arterial disease (PAD)?
Clinical manifestations of PAD include intermittent claudication, rest pain, non-healing wounds or ulcers, and skin changes like pallor or cyanosis.
How do statins help in the treatment of atherosclerosis?
Statins lower cholesterol levels, reduce LDL, stabilize plaques, and have anti-inflammatory effects, which help slow the progression of atherosclerosis.
