Week 4 Flashcards
During pregnancy - What happens to
- systemic vascular resistance
- cardiac output
- plasma volume
- decrease in systemic vascular resistance
- increase in cardiac output
- increase in plasma volume - eventually reaches an increase of about 45% above non-pregnant values
What causes anemia of pregnancy?
- there is a large increase in plasma volume and a slight increase in RBC
- due to this ratio of small RBC to large plasma volume there is lower hematocrit → anemia
Why is there an increase in plasma volume in pregnant women?
to protect them from blood loss that happens at delivery
What happens to coagulation in pregnant women?
Hyper coagulable state during pregnancy helps prepare for hemostasis after delivery
*can predispose women to venous thrombosis
What is
- cardiac output
- stroke volume
- ejection fraction
- liters/min
- volume ejected from left ventricle on every beat
- % of blood in heart ejected on each beat
During delivery -What happens to
- stroke volume
- cardiac output
- both further increase
What happens to vena cava when pregnant women lay down?
When laying down - the weight of the gravid uterus can compress inferior vena cava and cause reduction in venous return to heart
What is cardiac tamponade?
filling of the pericardial space with fluid which puts pressure on the outside of the heart → heart is unable to pump normal and blood flow is obstructed
- can be caused by trauma, heart surgery, aortic dissection, etc
What side of the heart fails in cardiac tamponade? Explain
Right sided
- Heart does not stretch out fully between contractions so chambers don’t fill properly → leads to less cardiac output → hypotension
- Since chambers don’t fill properly then blood builds up on venous side
- Right heart failure - leads to JVD
What is pulses paradoxus?
- Decrease systolic blood pressure (more than 10 mmHg) during inspiration
- Inspiration increases right ventricular filling, shifting interventricular septum toward the left, reducing LV filling and LV stroke volume
- This is exaggerated in tamponade because right ventricle can’t stretch against pericardium so it fills up faster pushing on septum more and further reduces LV filling and stroke volume → reducing systolic blood pressure
What is becks triad and in what condition is it found in?
- Distended jugular veins
- Hypotension
- Distant heart sounds
cardiac tamponade
What ECG findings are found in cardiac tamponade?
Low QRS complex voltage
QRS have differing heights - electrical alternans
- What is endocarditis?
- What does this mostly affect?
- inflammation of the endocardium (inner lining of heart) and largely of bacterial etiology
- Valves
What is the pathogenesis of endocarditis?
- alteration of valve surface due to degeneration (wear and tear), trauma, immune destruction
- Deposition of platelets and fibrin (inflammation and thrombus at valves) → making NBTE (non-bacterial thrombotic endocarditis)
- transient bacteremia - somehow bacteria get into bloodstream and colonize on this injured valve surface. Organisms adhere to NBTE
Left or right valves are affected more in endocarditis?
left sided valves
What are specific symptoms found with endocarditis? (3)
-2 other unique symptoms but not specific to endocarditis
- Roth spots
- Osler nodes
- Janeway lesions
- splinter hemorrhages
- Conjunctival petechiae
What are roth spots?
Retinal lesions, red with pale/white center (which is fibrin) - white center is shiny
What are osler nodes
- painful bumps on the pads of fingers and toes
What are janeway lesions?
nontender red macules on palms and soles
What are splinter hemorrhages?
Red-brown lines under fingernails. Painless.
What is the Duke/Direct Criteria for infective endocarditis?
- 2 major criteria
- 5 minor criteria
What combination leads to diagnosis?
- MAJOR: positive blood culture for endocarditis (persistent bacteremia, typical organisms on blood cultures, etc)
- MAJOR: Evidence of endocardial involvement (positive echo for vegetations, prosthetic dehiscence OR new regurgitant murmur)
- MINOR: predisposition for cardiac disease or IVDU
- MINOR: high temp
- MINOR: vascular phenomena (arterial embolus, PE, etc)
- MINOR: immunologic phenomena (glomerulonephritis, osler’s, roth’s)
- MINOR: Microbiologic events (only 1 out 3 positive blood culture, or serological evidence of organism that causes IE)
- Both 1 and 2 - dx
- Either 1 or 2 + 3 minor criteria
- All 5 minor criteria
What are the (top 2) common causative organisms associated with infective endocarditis
- staph aureus (IVDU have much larger risk)
- viridans strep (typically after dental procedure - affects damaged valves)
What does this show?
What vegetations on valves in infective endocarditis look under microscope
In IE due to staph aureus what antibiotic is used for
- methicillin sensitive
- methicillin resistant
- Beta lactams
- vancomycin or daptomycin if vanco is not tolerated
In IE due to Strep species what antibiotic is used
- beta lactam plus aminoglycoside for shorter course (2 weeks)
- vancomycin if there is beta lactam allergy
In IE due to enterococci what antibiotic is used for
- symptoms <3 months
- symptoms >3 months
- allergies
- penicillin or ampicillin plus gentamicin for 4 wks
- penicillin or ampicillin plus gentamicin for 6 wks
- with beta lactam or penicillin resistance → use vanco plus gentamicin for 6 weeks
- Penicillin resistant → use ampicillin plus gentamicin for 6 weeks
In IE due to HACEK/AACEK what antibiotic is used for
- No beta lactam allergy
- beta lactam allergy
- ceftriaxone for 4 weeks
- fluoroquinalone for 4 weeks
In IE due to culture negative endocarditis what antibiotic is used for
- if acute (days)
- subacute (weeks)
- vanco plus cefepine for 4-6 weeks
- vanco plus ampicillin-sulbactam for 4-6 weeks
- With what predispositions would prophylaxis be needed for infective endocarditis
- what is prophylaxis medicine and dose
- patients with prosthetic valves
- patients with prior IE
- procedures such as dental work or pulmonary procedures
- amoxicillin 2 grams
What is myocarditis
inflammation of the myocardium (frequently with pericarditis)
Are viruses or bacteria more likely to be cause of infection in myocarditis?
- viral infection (adenovirus, herpes virus 6, enterovirus family, influenza)
What are some causes for myocarditis?
- infection (mostly viral)
- inflammatory reactions (drug reactions, rheumatic fever, lupus)
- can happen as result of transplant rejection
How does myocarditis present in young children/teenagers vs older adults
- young children/teenagers - more acute presentation
- older adults- more subtle and insidious symptoms
What clinical findings are seen with left sided failure myocarditis?
- crackles on auscultation due to blood backing up into pulmonary vasculature
- Softer S1 and S2 - positive S3
- displaced point of maximal impulse
What clinical findings are seen with right sided failure myocarditis?
- increased JVD
- hepatojugular reflux (when pushing on abdomen and jugular vein becomes more pronounced)
- peripheral edema
What x ray findings are seen with myocarditis?
- cardiomegaly
- kerly B lines
- cephalization of vessels in lungs (you can see vessels in lungs)
Treatment of myocarditis
- supportive care to maintain cardiac output (beta blockers, ACE inhibits, ARBs, etc)
- manage arrhythmias, heart block, heart condition
- Antimicrobial agents (rare)
Right image is abnormal and shows what condition
lymphocytic infiltration w/destruction of myocytes
myocarditis
What is pericarditis?
Inflammation of pericardial sac
What are causes of pericarditis?
- infections (viral infections most common but also bacterial)
- Post injury (MI can lead to dying of pericardium, radiation, pericardiotomy)
- drugs/toxins
- idiopathic (MOST COMMON)
What 5 clinical manifestations represent pericarditis?
- sharp chest pain worse when supine (laying down) because pericardium pushes on the spine
- pericardial friction rub (left lower sternal border - can hear rub at ventricular systole, ventricular diastole, atrial systole)
- ECG - shows diffuse ST elevation everywhere (not STEMI) + PR depression
- Echo will show swinging heart
- Muffled heart sounds (S1 and S2)
What is the treatment of pericarditis?
NSAIDS for decrease inflammation and symptom control
- NSAIDS + colchicine has better results
What is restrictive cardiomyopathy?
Heart muscles are stiffened and less compliant but muscles and sizes of ventricles stay the same or slightly enlarged
- ventricles can’t stretch when filling because less compliant (diastolic heart failure)
What is seen in EKG with restrictive cardiomyopathy?
- low amplitude QRS complex
What happens to atria in restrictive cardiomyopathy?
atria end up being dilated due to restriction in ventricles
What causes restrictive cardiomyopathy? (8 reasons)
- amyloidosis - misfolded proteins that are insoluble and can deposit in heart making it less compliant
- sarcoidosis - formation of granulomas (collection of immune cells)
- endocardial fibroelastosis - fibrosis of endocardium and subendocardium
- Loeffler endomyocarditis - eosinophils accumulate in lung tissue which can also affect heart
- Hemochromatosis - iron overload can lead to iron deposited in heart tissue
- Radiation - makes ROS which leads to inflammation and eventual fibrosis of heart tissue
- Endomyocardial fibrosis (not common in US) - linked to nutritional deficiencies and/or inflammation related to helminthic infections
- Genetic mutation in troponin
What does loeffler endomyocarditis look like under microscope?
orange cells are eosinophils
What does restrictive cardiomyopathy look like in gross anatomy?
- atria are dilated
- white lining on ventricles is abnormal
How do you detect amyloids in between myocytes (for restrictive cardiomyopathy) under microscope
- amyloids will stain red congo red staining
- What is hypertrophic cardiomyopathy?
- What changes happen to blood flow
- Diastolic or systolic heart failure?
When heart muscle gets thick and heavy - muscles grow much larger
- LV is most affected and muscle growth (sarcomeres in parallel) is asymmetrical so that the interventricular septum grows inward towards LV - less blood filling in LV
- Leads to smaller outflow tract - due to venturi effect the mitral valve moves closer to overgrowth muscle wall and creates even smaller LV outflow tract
diastolic heart failure
What different heart sounds do you hear with hypertrophic cardiomyopathy?
- crescendo-decrescendo murmur - due to aortic/pulmonary stenosis that is causing ventricle to work harder
- may hear an S4 sound - blood is hitting stiff muscle when going into ventricle
What are the two types of amyloidosis?
- familial amyloid cardiomyopathy (TTR misfolded protein gets deposited in heart)
- Senile cardiac amyloidosis - seen in elderly where normal TTR is deposited in heart
Hypertrophic cardiomyopathy can be inherited. What are the two types of inherited disorders?
- Missense mutations - mutation for a gene that encodes proteins in the sarcomere in heart muscle (for muscle growth)
- Mutation in beta myosin heavy chain