Lecture 10- CHF 9/13 Flashcards
6 principal mechanisms of heart disease
- failure of pump
- flow obstruction
- shunted flow
- bad valves
- conduction disorders
- rupture of heart/vessel
… is the failure to pump an adequaye amt of blood to supply the metabolic needs of the organs
Congestive heart failure
CHF affects nearly … people in the US and annually contributes to … deaths
5 million
300,000
2 neurohumoral systems that are compensatory mechanisms of CHF
- release of NE w/ increased HR and contractility
2. renin-angiotensin system with water/salt retention
Compensatory mechanism of CHF where increased end diastolic filling volume increases stretch in cardiac fibers. At first the fibers contract more forcefully (compensated), increasing CO but eventually cannot keep up (decompensated)
Frank-starling
Compensatory mechanism of CHF where there is an increase in muscle fiber size resulting in increased thickness of the ventricular wall but without increase in size of lumen
myocardial hypertrophy
Compensatory mechanisms of CHF usually fail because with heart working harder, there are great oxygen requirements w/o an increased capillary supply resulting in…
susceptibility to ischemia
5 causes of left sided heart failure
- IHD
- HTN
- valvular dz
- myocarditis
- cardiomyopathy
4 causes of right sided heart failure
- left sided failure (b/c of pulm congestion)
- pulmonary HTN
- valve dz
- septal defects (L–>R shunts)
L. ventricular failure clinical manifestations (3)
- pulmonary edema/conges. resulting in dyspnea
- chronic cough
- orthopnea/ SOB
L. and R. ventricular failure clinical manifestation
cerebral hypoxia
R. sided failure clinical manifestations (2)
- liver congestion (nutmeg liver) and spleen
2. edema of subcutaneous tissues especially lower extremities
Congenital heart disease occurs in … out of … live births in the US
6-8 out of 1000
3 causes of congenital heart disease
- environmental (congenital rubella, maternal diabetes)
- chromosomal abnorm.
- 90% are unknown and multifactorial
3 most common forms of noncyanotic congenital HD
- VSD (most common)
- ASD (2nd most common)
- PDA
A VSD occurs in … out of every …. live births
4/1000
2 most common forms of cyanotic congenital HD
- Tetralogy of fallot
2. transposition of the great arteries
What are the 4 abnormalities in tetralogy of fallot
- overriding aorta
- narrowed RV outflow
- RV hypertrophy
- VSD
… is leading cause of death in US (500k annually)
IHD
90% of IHD is due to…
coronary atherosclerosis (coronary artery dz)
There are … MI’s annually and … are fatal
1.5 million
one-third
During an MI, severe ischemia lasting longer than…. minutes will cause irreversible myocyte injury and death
20-40
3 types of cardiomyopathies
dilated (most commom)
hypertrophic
restrictive
dilated cardiomyopathy can be… , …. or acquired
secondary
genetic
… cardiomyopathy involves dilation of all 4 chambers, poor ventricular contractility and nonspecific histologiy w/ fibrosis and myocyte hypertrophy
dilated
… cardiomyopathy is a primary, genetic cardiomyopathy where there is a missense point mutation in one of several sarcomeric gene loci.
There are stiff ventricles which prevent adequate filling (diastolic dysfxn) and the histology will show myocyte dissarray w/ fibrosis
hypertrophic
…. cardiomyopathy is when the walls of the ventricles become stiffer with impaired filling during diastole, can be idiopathic or secondary to systemic conditions that affect the myocardium– radiation-induced fibrosis, amyloidosis, hemochromatosis, sarcoidosis
restrictive
viruses that cause myocarditis
coxsackie a and b
