Myocardial + Pericardial Dz Flashcards
(34 cards)
Ventricular loading can be due to these two factors, which will result in drastically different phenotypes
Pressure load: requires an increase in fiber tension, leading to concentric hypertrophy
Volume load: requires increase shortening, leads to eccentric hypertrophy
What are examples of LV pressure loading?
What type of hypertrophy does this result in?
What type of heart sound can be heard as a result of LV pressure loading?
HTN - increased afterload
Aortic stenosis - obstruction of outflow
leads to concentric hypertrophy.
S4 kick
What are the pros (1) and cons (3) of concentric hypertrophy?
pros: allows heart to generate a higher systolic pressure without increasing individual scaromere tension requirements
bad: 1) makes LV less compliant, resulting in an increase in atrial/pulmonary pressures in order to maintain adequate LV filling/CO. 2) Ultimately leads to backward failure/pulmonary congestion as a result of impaired filling. 3) myocardium is more prone to ischemia
What are examples of LV volume loading?
What type of hypertrophy does this result in?
What type of heart sound can be heard as a result of LV volume loading?
AV fistula
Aortic/Mitral Regurgitation - to maintain adequate forward flow, the ventricles increases in size to maintain normal CO
Eccentric hypertrophy
S3 gallop
What are the pros (2) and cons (1) of eccentric hypertrophy?
pros: 1) increase CO without increasing shortening requirements, 2) less prone to ischemia compared to concentric hypertrophy
cons: can lead to LV systolic dysfunction (impaired ejection). Note that LV systolic dysfunction is not impaired
What are examples of RV pressure loading?
What type of hypertrophy does this result in?
cor pulmonale - failure of R side of the heart brought upon by long-term increases in BP in PULMONARY arteries
pumonary stenosis - obstruction of RV outflow tract
–> concentric hypertrophy
What are examples of RV volume loading?
What type of hypertrophy does this result in?
tricuspid regurgitation
atrial septal defect
–> eccentric hypertrophy
What are examples of ventricular underloading? What type of dysfunction is this also known as?
diastolic dysfunction
Ventricular underloading = decreased venous return limits ventricular pump function even though the myocardium function is normal.
Examples are:
mitral stenosis
hypovolemia
restrictive cardiomyopathy (non-dilated, rigid ventricle due to infiltrative disease ex: amyloidosis, sarcoidosis)
constrictive pericarditis (thickened, scarred pericardium due to inflammation and infetion)
RV infarction
What are 3 types of cardiomyopathy?
dilated - ventricular systolic dysfunction
hypertrophic - ventricular diastolic dysfunction
restrictive - stiffening
What are some causes of dilated cardiomyopathies?
ABCCCD Alcohol Beriberi (def. in vitamin B1) Coxsackie B Cocaine Chagas Doxorubicin toxicity
What is the pathology of dilated cardiomyopathy?
dilated heart on ultrasound; balloon appearance on CXR
What is the pathophysiology of dilated cardiomyopathy?
failure of systolic contraction, resulting in LOW EJECTION FRACTION
eccentric hypertrophy
sarcomeres do not work as well -> decrease contractility, increase preload -> increase eccentric hypertrophy
What are the 4 clinical features of dilated cardiomyopathy?
1) congestive heart failure (LHF, RHF)
LHF: dyspnea, orthopnea, crackles, displaced apex, S3 gallop, enlarged heart + pulmonary congestion
RHF: peripheral edema, elevated JVP, hepatomeagly, enlarged RV
2) Systolic HF = large heart = LOW EF
3) Thromboembolism
4) Arrhythmias
How do you diagnose dilated cardiomyopathy?
ECHO - measure biventricular enlargement + calculate EF
How do you treat dilated cardiomyopathy?
Na+ restriction ACE inhibitors Diuretics Digoxin heart transplant
What are some causes of hypertrophic cardiomyopathies?
familial/genetics (autosomal dominant)
What is the pathology of hypertrophic cardiomyopathy?
myofibrillar disarray + concentric hypertrophy
myofibrillar disarray impairs tension development, so the heart compensates by via concentric hypertrophic to maintain a normal tension development
What is the pathophysiology of hypertrophic cardiomyopathy? (2)
non-obstructive = diastolic dysfunction due to increased LV stiffness/decreased compliance = leads to impaired filling. The heart compensates by increasing tension to generate a higher filling pressure to restore normal filling + CO
obstructive = aortic stenosis or sub-aortic stenosis, where the latter is caused by hypertrophied septum, which impinges upon the mitral valve during systole and causes a dynamic obstruction to LV outflow
What are the clinical features of hypertrophic cardiomyopathy?
General: angina dyspnea syncope, esp. following exercise heart murmur + S4 gallop @ lower L sternal border
If diastolic HF (impaired filling)
+ systemic edema
+ pulmonary congestion and dyspnea
+ CXR: small heart but NORMAL EF
if Systolic HF (impaired ejection)
- dyspnea, orthopnea, S4 gallop
- CXR: pulmonary congestion but normal heart size
How do you diagnose hypertrophic cardiomyopathy?
ECHO - look for LVH and calculate normal or increased EF
How do you treat hypertrophic cardiomyopathy?
b blockers to
- relax myocardium
- increase diastolic filling time
- relief ischemia (angina) and decrease outflow obstruction
What is the etiology of systolic dysfunction?
Diastolic dysfunction:
Forward failure - decrease CO due to poor emptying
Backward failure - increase filling pressure/fluid retention
Diastolic dysfunction:
Forward failure - decrease CO due to small heart size
Backward failure - increase filling pressure/poor pressure
What are the 3 types of pericardial disease?
chronic constrictive pericarditis
acute pericarditis
pericardial tamponade
What is the etiology of acute pericarditis?
infection, toxic uremia (end stage renal dz), metastatic carcinoma, direct injury/trauma, autoimmune, idiopathic
