define congestive heart failure
failure of the heart to pump adequate amount of blood supply metabolic requirements of the organs.
what are the compensatory mechanisms of congestive heart failure?
- 1. myocardial hypertrophy
- 2. ventricular dilation
- 3. physiologic mechanisms: inc. HR, intravascular volume, catecholamines, redistribution of blood flow
list 5 etiologies of congestive heart failure
- 1. ischemic heart disease
- 2. hypertension
- 3. myocarditis
- 4. cardiomyopathy
- 5. valvular disease
list 4 manifestations of CHF
- 1. right ventricular failure
- 2. left ventricular failure
- 3. left and/or right ventricular failure
- 4. CHF due to left vent failure eventually leads to right vent. failure
list 2 types of congenital heart diseases
cyanotic and noncyanotic. cyanotic have shunting of poorly-oxygenated systemic venous return to systemic arterial circulation, bypassing the lungs.
list 5 common congenital heart defects
- 1. atrial septal defect
- 2. ventricular septal defect
- 3. patent ductus arteriosus to connect the aorta and pulmonary arteries
- 4. tetralogy of fallot
- 5. transposition of the great arteries (right vent empties into aorta, left to pulmonary)
define tetralogy of fallot
ventricular septal defect where there is a narrowing of the right ventricular outflow, overriding of the aorta over the right ventricular outflow and right ventricular hypertrophy
list 4 pathogenesises of ischemic heart disease
- 1. narrowing of the coronary arteries by 75% by atherosclerosis which leads to gradual opening of collateral arteries
- 2. coronary artery thrombosis initiated by fissure in the fibrous cap of an atherosclerotic plaque
- 3. other factors including increased myocardial oxygen consumption, reduced ability to deliver oxygen, coronary artery spasm.
list 4 types of ischemic heart diseases (IHD)
- 1. angina pectoris
- 2. acute myocardial infarction
- 3. chronic ischemic heart disease
- 4. sudden cardiac death
describe angina pectoris
chest pain for several minutes associated with exercise or emotional stress relieved by rest. no myocardial necrosis occurs.
describe chronic ischemic heart disease
gradual onset of CHF with at least one large left ventricular scar. biventricular hypertrophy and dilation of all cardiac chambers
describe sudden cardiac death
sudden onset of ischemia-induced cardiac arrhythmia with or without myocardial necrosis. can occur in patients with history of IHD
describe the pathology of an acute myocardial infarction
- few hours: coagulation necrosis
- few days: neutrophil infiltration
- 1 week: granulation tissue
- weeks to months: scar formation
list 7 complications of myocardial infarctions
- 1. arrhythmia and sudden death
- 2. CHF/shock
- 3. mural thrombus/emboli
- 4. myocardial rupture
- 5. mitral valve regurgitation
- 6. ventricular aneurysm
- 7. chronic ischemic heart disease
what are two myocardial diseases?
cardiomyopathy and myocarditis
what is the difference between primary and secondary cardiomyopathy?
primary is confined to the heart muscle while secondary involves the heart as a multi-system disorder.
what are 3 morphologic patterns of cardiomyopathy?
dilated, hypertrophic, restrictive
describe dilated cardiomyopathy
familial in 25-35% of cases, dilation of all 4 heart chambers, variable fibrosis and myocyte hypertrophy
describe hypertrophic cardiomyopathy
autosomal dominant point mutation with variable expression. causes spontaneous myocardial hypertrophy, interventricular hypertrophy that obstructs left ventricular outflow tract
describe restrictive cardiomyopathy
stiffening of ventricular wall resulting in impaired ventricular filling during diastole. it is idiopathic or associated with other conditions relating to the myocardium
describe the etiology of myocarditis
most common cause is viral infection (enterovirus). can also be caused by bacterial, fungal and parasitic organisms. non-infections cases include toxins, hypersensitivity reactions and auto-immune diseases.