Cardiology Aging and Heart Failure Quiz

Blood Vessels and Heart Pathology

•  Blood vessels are composed of endothelial cells and smooth muscle cells.
•  Blood vessels include aorta, large veins, medium veins, venules, capillaries, muscular arteries, arterioles, and veins.
•  Endothelial cells maintain a permeability barrier, regulate inflammation and immunity, blood clotting, and cell growth. Smooth muscle cells are responsible for normal vascular repair, synthesizing ECM collagen (extracellular matrix), elastin, proteoglycans, and growth factors. They also control vasoconstriction and vasodilation.

Objectives

•  The objectives of the presentation are to teach students different aspects of blood vessels and heart disorders and how to recognize pathologies.

Blood Vessels

•  Blood vessels are categorized by the pressure they carry: low-pressure and high-pressure.
•  The high-pressure system includes the aorta and muscular arteries. 
•  The low-pressure system includes medium/large veins, venules, capillaries
•  The capillary system is responsible for gas and nutrient exchange.

Endothelial Cells

•  They control permeability barrier, blood clotting, and inflammation among other functions.
•  They produce anticoagulants, antithrombotic, and fibrinolytic regulators like prostacyclin, thrombomodulin, and heparin-like molecules.
•  They regulate inflammation via IL-1, IL-6, chemokines, adhesion molecules, and histocompatibility antigens.
•  They control cell growth via growth stimulators and inhibitors.
•  They are also involved in extracellular matrix production.

Vascular Smooth Muscle Cells

•  These cells aid in normal vascular repair by synthesizing ECM (extracellular matrix) collagen, elastin, and proteoglycans.
•  They also release growth factors and cytokines to aid in vasoconstriction and vasodilation.

Hypertensive Vascular Disease

• Blood pressure is a function of cardiac output and peripheral vascular resistance.
• Sustained high blood pressure (≥140 mm Hg systolic, ≥90 mm Hg diastolic) is hypertension.
• Asymptomatic until severe or long-term.
• Treatment involves lifestyle changes and drugs (diuretics, beta-blockers, ACE inhibitors, angiotensin II receptor blockers, calcium channel blockers).
•  Two types of small blood vessel disease associated with hypertension are Hyaline Arteriolosclerosis and Hyperplastic arteriolosclerosis.

Morphology

• Hyaline arteriolosclerosis: homogeneous, pink hyaline thickening of arterioles with luminal narrowing, causes diffuse impairment of renal blood supply and glomerular scarring in nephrosclerosis.
• Hyperplastic arteriolosclerosis: concentric laminated thickening of small arteries and arterioles, seen in severe malignant hypertension.

Atherosclerosis

• Involves intimal lesions called atheromas that protrude into the vessel lumen.
• The soft yellow lipid core is made of cholesterol and cholesterol esters, covered by a fibrous cap.
• Can cause thrombosis, aneurysmal formation, and obstruct blood flow.
• Risk factors have a multiplicative effect: age, gender, genetics, hyperlipidemia, hypertension, cigarette smoking, and diabetes are all important factors for an individual to develop the condition.

Pathogenesis

• Endothelial injury (increased permeability, leukocyte adhesion, thrombosis)
• Lipoprotein accumulation (LDL, oxidized forms) in vessel wall
• Monocyte migration and transformation into macrophages and foam cells
• Platelet adhesion
• Factor release
• Smooth muscle cell proliferation and ECM production
• Lipid accumulation

Aneurysms

• Aortic aneurysm is a dilatation in a portion of the aorta.
• Commonly found in the abdominal or thoracic aorta.
• Typically related to atherosclerosis.
• Possible complications include rupture, obstruction of branch vessels, impingement on adjacent structures.

Vasculitis

• Vasculitis refers to inflammation in the walls of blood vessels.
• Several forms: isolated and generalized.
• Causes: immune mechanisms (immune complex deposition, anti-neutrophil cytoplasmic antibodies, anti-endothelial cell antibodies).

Coronary Artery Disease (CAD)

• Typically caused by atherosclerosis leading to reduced coronary blood flow and decreased oxygen supply to the myocardium.
• CAD is a risk factor for MI (myocardial infarction).

Myocardial Infarction (MI)

• Localized coagulative necrosis in the myocardium, the heart muscle, due to blocked blood flow or reduced supply.
• 99% of MIs are caused by atherosclerosis, thrombosis, and/or vasospasm, which can be caused by hypertension, increased demand, or reduced oxygen.
• Clinical symptoms of MI include prolonged chest pain, crushing, squeezing, stabbing, and sweating.
• Assessment and diagnosis could be done through lab tests for myocardial proteins, ECG changes, cardiac-specific troponins T and I (cTnT and cTnI), and creatine kinase (CK-MB).

Arrhythmias

• Arrhythmias refer to abnormalities in heart rhythm.
• Can arise from conduction system abnormalities, ischemic injury, myocyte hypertrophy, inflammation, and fibrosis.
•  Types include tachycardia (fast heart rate), bradycardia (slow heart rate), and various irregular rhythm patterns.

Hypertensive Heart Disease

• A late complication of hypertension, where high blood pressure increases the heart's workload.
• This leads to hypertrophic (thickened) left ventricles as the heart works to compensate.

Valvular Heart Disease

• Diseases affecting the heart valves and their mechanisms in mitral and aortic valves.
•  Mitral Valve disease includes mitral stenosis, mitral regurgitation, mitral valve prolapse, and infective endocarditis, as well as fen-phen induced valvular fibrosis.
•  Aortic valve disease includes aortic stenosis, aortic regurgitation, and syphilitic aortitis.

Rheumatic Heart Disease

• Acute immunologically mediated, multisystem inflammatory disease usually triggered by a group A streptococcal pharyngitis infection.
• Manifested in cardiac involvement during the acute phase, evolving sometimes into chronic rheumatic heart disease (RHD) characterized by valvular abnormalities.

Rheumatic Fever

• Usually follows strep infections in the throat, causing inflammation and damage to heart tissues.
• Has characteristic symptoms such as arthritis, pancarditis, subcutaneous nodules, and erythema marginatum.

Cardiomyopathies

• A group of diseases affecting the heart muscle itself.
•  Dilated cardiomyopathy, hypertrophic cardiomyopathy, and restrictive cardiomyopathy are three major types of cardiomyopathy.

Hemangiomas

• Benign tumors of blood vessels, mostly found in superficial skin layers.
•  Can be deep, cavernous, or combined (strawberry).

Lymphangiomas

• Rare congenital lymphatic system tumors, often seen in skin and subcutaneous tissues.
• Can be deep-seated (cavernous lymphangiomas) or superficial.

Glomus Tumor

• Benign tumors of specialized cells (glomus cells).
• Located in the skin, frequently found in extremities.
• Can cause pulsatile tinnitus and hearing loss.

Kaposi's Sarcoma

• Malignant tumor of endothelial cells, often observed in older men, and frequently associated with HIV infection.
• Three different subtypes can be observed in relation to the HIV infection.

Angiosarcoma

•  Malignant endothelial tumors arising from blood vessels, primarily in older adults.
• They are often associated with exposure to certain substances, like radiation or chemicals.