February 11th Lecture Flashcards
What is coronary heart disease (CHD) characterized by?
Insufficient delivery of oxygenated blood to the myocardium
What is coronary heart disease most commonly due to?
Coronary artery atherosclerosis
How many minutes can the myocardium survive with no oxygenated blood?
20 minutes
What are 3 other causes of CHD?
Abnormalities of blood oxygen content
Poor perfusion through coronary arteries
Abnormalities of microcirculation (genetic)
What is arteriosclerosis
Chronic disease of arterial system
Abnormal thickening and hardening of vessel walls
Gradual narrowing of arterial lumen
What is atherosclerosis
Form of arteriosclerosis
Caused by an accumulation of lipid-laden macrophages in arterial wall
Leads to plaque disease
Inflammatory disorder (not a single disease)
Stages of coronary atherosclerosis
Endothelial injury
Endothelial cells become inflamed
Inflammatory cytokines and growth factors released
Macrophages adhere to injured endothelium
Macrophages create oxidative stress
What are foam cells?
Macrophages fully of oxidized LDLs
What is a fatty streak?
Accumulation of foam cells; produce progressive wall damage
How does a fibrous plaque form?
When smooth muscle cells proliferate and migrate over a fatty streak
What is cardiac muscle replaced with when it dies?
Dense, irregular, connective tissue
What is CAD (coronary artery disease)?
Any vascular disorder that narrows or occludes coronary arteries
Can diminished blood supply enough to cause ischemia
What is myocardial ischemia?
Narrowing >50%
Impairs blood flow during exercise
How long does it take for a cardiac muscle cell to become ischemic?
10 seconds, lose contractibility after several minutes
What is angina pectoris?
Chest pain due to myocardial ischemia
No permanent change, or damage if blood flow is restored
What is Acute coronary syndrome?
Sudden obstruction due to thrombus formation of ruptured plaque
What is unstable angina?
Type of acute coronary syndrome
reversible myocardial ischemia
What is a myocardial infarction?
Type of acute coronary syndrome
Prolonged ischemia causing irreversible heart muscle damage
What is sudden cardiac death?
Sudden arrest
Death from loss of heart function within 1 hour of onset of symptoms
Chronic Ischemic Cardiomyopathy
Heart failure develop insidiously
Consequence of progressive ischemic myocardial damage
History of angina or MI
Consequence of slow, progressive apoptosis of myocytes
Poor prognosis- death of CHF
Endocardial and valvular diseases are disorders of the
Endocardium
Damage heart valves
Valvular Stenosis is when
Valve orifice is constricted and narrowed, impedes forward blood flow
What does valvular stenosis lead to?
Myocardial hypertrophy
What is valvular regurgitation?
Insufficiency or incompetence of a valve
Valve cusps fail to shut completely and blood flow is permitted when the valve is closed
What is mitral stenosis?
Impairment of flow from left atria to left ventricle
What are common causes of mitral stenosis?
Acute rheumatic fever or bacterial endocarditis
What are some results of mitral stenosis
Narrowing as a result of inflammatory lesions
Incomplete atrial emptying- increased atrial pressure- dilation and hypertrophy
CO is decreased
What is mitral regurgitation?
When blood flows back from the left ventricle to the left atria during ventricular systole
Results of mitral regurgitation
Left ventricle becomes dilated and hypertrophied
Back flow volume increases- left atrium dilates
May lead to LV failure
Increases in atrial pressure, can lead to RV failure
What is mitral valve prolapse
Cusps of mitral valve billow upward Cusps are enlarged, thickened, scalloped Chordae may be elongated Leakage leads to regurgitation Minimal mortailty or morbidity
Three common causes of aortic stenosis
Rheumatic heart disease
Congenital malformation
Degeneration thickening and calcification
What happens with aortic stenosis
Diminished flow LV to aorta
Pressure increase in LV
Decreased SV, reduced systolic bp, narrowed pulse pressure, slow heart rate, faint pulse
Left ventricular hypertrophy to compensate
Aortic Regurgitation
Causes volume overload in LV during diastole- increases EDV
LV increases SV to maintain CO
What is rheumatic Heart Disease?
Diffuse inflammatory disease
Caused by delayed immune response to infection by A Beta- hemolytic streptococcus
Begins as carditis- all 3 layers affected
What is the acute form of rheumatic heart disease?
Febrile illness with joint, skin, nervous system, and heart failure
What can happen when rheumatic heart disease is untreated
Scarring and deformity of cardiac structures
Where is the primary lesion in rheumatic heart disease?
Endocardium; Swelling of heart valve leaflets
What are Aschoff bodies?
Fibrotic areas of myocardium surronded by areas of necrosis
Associated with rheumatic heart disease
How does scarring occur with rheumatic heart disease?
Clots develop along valves and cordae- progressively adherent
What happens if rheumatic heart disease is untreated?
Cardiomegaly and left heart failure
What are specific symptoms associated with rheumatic heart disease?
Carditis
Acute migratory polyarthritis
Chorea
Erythema marginatum
What is carditits?
A new heart murmur- mitral or aortic SL valve dysfunction
Chest pain from pericardial inflammation
What is erythema marginatum
Truncal rash that accompanies rheumatic fever
