Cardio Flashcards
How long does it take for ischemia → permanent myocyte damage?
20 minutes
What → ST elevation vs. ST depression?
ST elevation is caused by transmural ischemia
ST depression is caused by subendothelial ischemia
When do you get contraction band necrosis?
calcium from reperfusion → contraction of dead muscle
What condition is present in a systolic ejection murmur accentuated by standing?
hypertrophic obstructive cardiomyopathy
Early diastolic decrescendo murmur decreased by amyl nitrate indicates:
aortic regurgitation
This condition presents as a late diastolic murmur eliminated by atrial fibrillation
mitral (and/or tricuspid) stenosis
What is the closest atrium/ventricle to the esophagus?
left atrium
In which direction would you orient an esophageal ultrasound probe to visualize the descending aorta?
posteriorly
What congenital heart defect is associated with fetal alcohol syndrome? Down syndrome? Maternal diabetes? Turner syndrome? DiGeorge?
FAS: VSD Downs: ASD Diabetes: transposition of GVs Turner: infantile an adult coarctation of aorta DiGeorge: interrupted aortic arch
Why do you hear a loud S1 and fixed S2 split on auscultation of an ASD?
L→ R shunt → Increased volume in R heart → delayed closure of pulmonic valve
How can a PDA → differential cyanosis (legs only)?
The ductus arteriosus connects the pulmonary artery to aorta after the branches to the arms are given off of the aorta. (Note: this would be a late presentation after R→L shunt develops i.e. Eisenmenger syndrome)
Upon running around the playground, a child becomes cyanotic. He stops and squats, leading to an improvement of his symptoms. What is the congenital heart defect? Why didn’t it present sooner?
Tetrology of Fallot: squatting helps divert blood to the right side so it can get oxygenated
A late presentation means the degree of pulmonic valve stenosis is in the milder range
Which congenital anomaly will show a boot-shaped heart?
Tetrology of Fallot
Which disorders result in late cyanosis? Why?
ASD, VSD, PDA due to Eisenmenger syndrome
A child is born with early cyanosis and is found to have transposition of the great vessels. What do you give on the way to the operating room?
PGE to keep the PDA open
How does coarctation of the aorta present? What additional findings might be present?
Hypertension in arms, hypotension with weak pulses in legs
Associated with bicuspid aortic valve and notching of the ribs
Which congenital anomaly will show a boot-shaped heart?
Tetrology of Fallot
Which disorders result in late cyanosis? Why?
ASD, VSD, PDA due to Eisenmenger syndrome
A child is born with early cyanosis and is found to have transposition of the great vessels. What do you give on the way to the operating room?
PGE to keep the PDA open
How does coarctation of the aorta present? What additional findings might be present?
Hypertension in arms, hypotension with weak pulses in legs
Associated with bicuspid aortic valve and notching of the ribs
Which congenital anomaly will show a boot-shaped heart?
Tetrology of Fallot
Which disorders result in late cyanosis? Why?
ASD, VSD, PDA due to Eisenmenger syndrome
A child is born with early cyanosis and is found to have transposition of the great vessels. What do you give on the way to the operating room?
PGE to keep the PDA open
How does coarctation of the aorta present? What additional findings might be present?
Hypertension in arms, hypotension with weak pulses in legs
Associated with bicuspid aortic valve and notching of the ribs
Which congenital anomaly will show a boot-shaped heart?
Tetrology of Fallot
Which disorders result in late cyanosis? Why?
ASD, VSD, PDA due to Eisenmenger syndrome
A child is born with early cyanosis and is found to have transposition of the great vessels. What do you give on the way to the operating room?
PGE to keep the PDA open
How does coarctation of the aorta present? What additional findings might be present?
Hypertension in arms, hypotension with weak pulses in legs
Associated with bicuspid aortic valve and notching of the ribs
What are Kerley B lines?
short horizontal lines situated perpendicularly to the pleural surface that represent edema of interlobular septa
What are the triggers for ARDS?
sepsis, aspiration, pneumonia, trauma
How can ARDS be distinguished from cardiogenic pulmonary edema?
absence of JVD and cardiomegaly
How would a chest x-ray appear in primary pulmonary hypertension?
Enlarged R ventricle and pulmonary arteries
What are the findings in left heart failure on chest x-ray?
cardiomegaly (heart > 1 hemithorax), increased vascular shadowing (alveolar edema) in a batwing peri-hilum pattern, and blunting of costophrenic angles (pleural effusions)
Describe the differences between excitation-contraction coupling in cardiac, skeletal, and smooth muscle
- all 3 use voltage gated L-type Ca2+ channels
- Ca2+-induced Ca2+ release from RyR receptor in cardiac and smooth mm., physical coupling to the RYR in skeletal
- In skeletal and cardiac mm. Ca+ binds to troponin C allowing actin and myosin to bind. In smooth mm. Ca2+ binds to calmodulin → activates MLCK → phosphorylation of myosin
Describe the pathogenesis of concentric remodling in heart failure
↓ CO → ↓ BP → ↑ sympathetic activity → α-1 vasoconstriction → ↑ afterload → ↑ work → concentric hypertrophy (→ less room for filling → less starling force → ↓ CO)
Which coronary arteries are most commonly affected in IHD?
LAD 45%
RCA 30%
Circumflex 15%
Endocarditis in drug users is associated with what heart finding?
tricuspid regurgitation
What is diastolic dysfunction?
EF is normal or ↑, but HR or poor ventricular compliance → insufficient diastolic filling time → inadequate blood pumped forward → accumulation in lungs → pulmonary edema
What pigment accumulates in aging cardiomyocytes hepatocytes as a result of aging (especially when malnourished and cachectic?)
Lipofuscin - a insoluble pigment that builds up as a product of free radical injury and lipid peroxidation
What is the most common site of aneurism from hypertension, syphilis, or vasculitis in the aorta?
Where the R brachiocephalic artery branches off (the first branch of the aorta)
What conditions of the heart predispose people to infective endocarditis?
- prosthetic heart valves
2. prior valvular inflammation and scarring (may occur following RF)
What generally causes concentric vs. eccentric hypertophy?
Concentric - ↑ P
Eccentric - ↑ Vol
Differentiate between the most common causes of unstable angina and transmural MI
ulceration of atherosclerotic plaque → unstable angina (or subendocardial infarction)
rupture of atherosclerotic plaque → transmural MI
What are the two primary factors which autoregulate coronary blood flow?
NO - large arteries and pre-arteriolar vessels
Adenosine - small coronary arterioles
What is adenosine made from?
it is a product of ATP metabolism (ATP → ADP → AMP → → adenosine → coronary vasodilation)
What does A-fib look like on EKG?
- absent p waves (no coordinated contraction from SA but multiple foci)
- f waves (fibrillary waves replace p waves)
- irregular R-R intervals
- narrow QRS complexes (b/c tachy) but normal shape b/c ventricles have normal conduction
What does the circumflex artery supply?
lateral and posterior-superior walls of LV
What does the LAD supply?
anterior 2/3 of intraventricular septum
anterior wall of LV
part of anterior papillary m.
What does the RCA supply?
SA and AV nodes
PDA (in 80-90% of ppl) → inferior wall of LV
What causes plateau phase of cardiac AP?
opening of L-type dihydropyridine-sensitive Ca++ channels and closure of some K+ channels
What are the symptoms of Kawasaki disease?
- persistent fever
- bilateral conjunctivitis
- lymphadenopathy
- mucocutaneous involvement: eg. erythema of lips and strawberry tongue, eythema/edema of hands and feet, desquamation of fingertips, rash spreading toward center from extremities
When does calcific aortic stenosis occur in people with normal (tricuspid) aortic valves and those with bicuspid valves?
nml: 80s
bicuspid: 60s
What factors are protective against LV free wall rupture post-MI?
LV hypertrophy prior MI (fibrosis ↓ probability of tearing)
What occurs after less than 30 minutes of ischemia in the heart?
reversible damage called myocardial stunning: it takes hours to days (depending on how long the period of ischemia) for full return to normal contractility
What demographic has the highest risk of cor pulmonale from primary pulmonary hypertension?
♀ 20 - 40 y.o.
What is the most common cause of diastolic dysfunction?
chronic HTN → concentric hypertrophy → stiffened walls → impaired LV filling due to reduced LV compliance (this last point is the definition of diastolic dysfunction)
What part of the heart is enlarged in hypertrophic cardiomyopathy?
IV septum usually
What causes congenital QT prolongation syndromes?
decreased outward K+ currents
What increases risk for torsade de point?
long QT interval
How do you calculate TPR of a bed of parallel circuits?
1/TPR = 1/R1 + 1/R2 + 1/R3 + …
