4 Cardiovascular

• Characteristics of blood vessels:

  • Function
  • Pressure
  • Lumen diameter
  • Wall thickness
  • Wall layers
  • Connective tissue
  • Valves
• Layers of blood vessels:

  • INNER: tunica intima (endothelium)
  • MIDDLE: tunica media
  • OUTER: tunica adventitia
• Blood flow, pressure and resistance:

  • Stiffening of arteries leads to increased resistance, higher pressure, reduced flow, and increased workload
  • Coronary arteries and veins
• Prevalence of Cardiovascular Diseases (CVDs) includes:

  • Ischemic heart disease
  • Stroke
  • Peripheral vascular disease
  • Heart failure
  • Other CVDs such as congenital heart disease and cardiomyopathy
• Atherosclerosis:

  • Build-up of fatty deposits in artery walls
  • Fueled by an inflammatory response
  • LDL cholesterol accumulation stimulates the body's defense system
  • May narrow arteries and reduce blood flow
• Problems with Blood Vessels:

  • Atherosclerosis
  • Blood clots (thrombus, embolus)
  • Aneurysm
  • Common causes and locations
• Ischemic Heart Disease:

  • Fatty deposits in coronary arteries
  • Angina pectoris as a warning sign
  • Imbalance between myocardial blood supply and demand
  • Symptoms include chest pain, shortness of breath, fatigue, sweating, weakness, discomfort in various body parts, nausea, and pain
• Gender Bias and CVD:

  • Unique effects on the heart due to estrogens, menopause, and pregnancy
• Traditional Risk Factors for CVD:

  • Cigarette smoking
  • Cholesterol (Total cholesterol, LDL cholesterol)
  • Hypertension
  • Age
  • Sex
  • Type 2 Diabetes
  • Overweight or Obesity (BMI categories)
• Genetic Factors:

  • Familial hypercholesterolemia (FH) caused by inherited changes in LDLR, APOB, and PCSK9 genes
  • Risk enhancers such as family history of early CVD, early menopause, metabolic syndrome, chronic kidney disease, chronic inflammatory conditions, and high-risk ethnicity
• Who should be screened for high cholesterol:

  • Men ≥40 years of age; Women ≥40 years of age (or post-menopausal)
  • Consider earlier screening for high-risk ethnic groups
  • Screening for patients with specific conditions or risk factors
• Detecting ischemic heart disease:

  • Coronary angiogram
  • Coronary CT
• Treating ischemic heart disease:

  • Medications
  • Surgery like coronary bypass graft surgery
• Treatment with Cholesterol Drugs:

  • Consideration of total cholesterol and LDL levels, history of cardiovascular events, and other risk factors for CVD
  • Statins are common cholesterol-lowering drugs that disrupt cholesterol production by blocking an enzyme in the liver cells
• Rehabilitation after a Cardiac Event:

  • Programs to help individuals take charge of their medical condition, improve risk factors for CVD, maintain an exercise program, make healthy food choices, manage psychosocial risks for CVD
• Cardiovascular disease is the single biggest killer of men and women in the United States
• Affects slightly more men than women due to natural protection from cardiovascular disease through estrogen until menopause
• Women who have heart attacks are twice as likely to die within the following weeks as men
• Blood Clots:

  • A thrombus is a stationary blood clot that forms along the wall of a blood vessel or within the heart
  • An embolism is a blockage of a blood vessel, often caused by a thrombus breaking free and blocking blood flow
  • Can lead to stroke or heart attack
• Problems with Blood Vessels:

  • High Blood Pressure:
  • Blood pressure must be high enough to circulate blood but not too high to stress blood vessels
  • Hypertension is often called the silent killer as it does not produce symptoms but can cause fatal problems
  • Can damage the heart, brain, blood vessels, or kidneys
  • Can lead to heart attack or stroke
  • Treatment includes lifestyle changes and various drugs
• Aneurysm:

  • Weakness in artery wall can cause it to swell outward, forming an aneurysm
  • Can be life-threatening if it bursts or causes blood clots
  • Detected with MRI or ultrasound scan
  • Treatment includes surgical removal or applying support with a coil or stent
• Atherosclerosis:

  • Buildup of fatty substances in artery walls, fueled by an inflammatory response
  • LDLs carry cholesterol to cells, forming fatty deposits in artery walls
  • HDLs carry cholesterol away from cells to the liver for disposal
  • Low LDL and high HDL levels predict low risk of heart attack
  • Treatment includes healthy lifestyle, medications, and surgeries like angioplasty and coronary bypass
• Coronary artery disease is the underlying cause of the vast majority of heart attacks
• Angina pectoris is chest pain usually experienced in the center of the chest or slightly to the left, caused by a temporary shortage of oxygen to the heart
• Angina serves as a warning that part of the heart is receiving insufficient blood through the coronary arteries
• Up to 15% of people who have angina later die of a heart attack
• Coronary angiography may be used to spot areas in the coronary arteries narrowed by atherosclerosis
• In coronary angiography, a contrast dye visible in x-ray images is released in the heart to allow the coronary vessels to be seen on film
• Heart attacks, or myocardial infarctions, occur when a part of the heart muscle dies due to insufficient blood supply
• Heart muscle cells begin to die if they are cut off from their essential blood supply for more than 2 hours
• Heart attacks can be caused by coronary thrombosis, where a blood clot blocks a coronary artery
• Smoking increases the risk of cardiovascular disease by promoting atherosclerosis and raising blood pressure
• Quitting smoking reduces the risk of heart disease and stroke within 5 years
• Maintaining normal body weight can help control blood pressure and reduce the risk of cardiovascular disease
• Aerobic exercise helps lower blood pressure and keep it low
• Limiting saturated fats and trans fats in the diet can help reduce LDL ("bad") cholesterol levels
• Reducing dietary salt intake can lower blood pressure in some people with hypertension