U-World Explanations Flashcards
Nesiritide
Recombinant form of BNP- Brain Natriuretic Peptide (BNP) and can be used in patients with decompensated left ventricular dysfunction leading CHF. In heart failure especially systolic dysfunction, the increased blood volume leads to stretching of the atria and ventricles. The increased stretch in the ventricles leads to release of BNP. Both ANP and BNP activate guanylate cyclase, induces intracellular cyclic GMP. Natriuretic peptides cause vasodilation, diuresis/natriuresis and a decrease in bp. They counteract endothelin, sympathetic effects and AG2
Endorphin Function
Endogenous - acts on the same receptors as analgesics.
-released by hypothalamic-pituitary axis and plays no role in diuresis or vasodilation.
Bradykinin
- vasoconstricts veins
- dilates arterioles
- produced by Kidney, when Renin-Angiotensin-Aldosterone system is activated and when adrenergic systems are activated.
- Metabolized by ACE- this is why people on ACE-inhibitors are predisposed to Angioedema-Because of rampant Bradykinin production!
Endothelin and Angiotensin II
- Endothelin production is stimulated by Angiotensin II
- both potent vasoconstrictors of arterioles.
- problematic in heart failure patients because it would increase the after load.
- This is why ACE-I’s are indicated for heart failure
Traumatic Aortic Rupture, Most common area?
- Aortic Isthmus
- after all of the great vessels come off
- The isthmus is attached to the L pulmonary artery by the Ligamentum arteriosum
- Classic scenario of traumatic aortic rupture is to a deceleration MVA
Pressure Volume-Loop(heart) Due to Dobutamine
- Inc Systolic LV pressure
- EDV same
- Inc SV
- Shift of curve up and to the left
Pressure Volume-Loop (heart) due to increased afterload(clamping of the aorta)
- LV pressure higher
- SV reduced
- EDV the same
- Overall curve becomes thinner and taller
Pressure Volume-Loop(heart) due to loss of myocyte contractility(systolic dysfunction)
- EDV the same
- Reduced SV
- LV pressure would not be as high or for as long as normal*
Pressure Volume-Loop(heart) increased preload
- increased in EDV
- Inc in Left Ventricular pressure
- Same ESV*
- increase SV*
Properties of Staphylococcus Epidermidis
- Catalase + (separates Staphlyococcus and Strep)
- Coagulase (+ for Staph Aureus/ - for Staph Epidermidis, Saphrolyticus, Staph. Haemolyticus.
- Saphrolyticus is the only one that is novobiocin resistant*
- Staph Aureus is the only one that makes a yellow pigment(aureus means gold)- ALSO FERMENTS MANNITOL. No other staph can.
- S. Epidermidisare capable of causing an opportunistic infection associated with foreign bodies; it is the most common cause of endocarditis in patients with prosthetic valves and septic arthritis in patients with prosthetic joints.
Transposition of the Great Vessels; PE and Echo Findings
- Echo; Aorta lying anterior and to the right to the Pulm Artery.
- Normally, aorta is behind the Pulm. artery.
- Severe cyanosis.
- Only way to survive is the some kind of shunting. Ie. Patent foramen ovale, patent ductus arteriosus, septal defect.
- in this question there was a machine like murmur- PDA.
Examples of Embryological Deficits
- Failure of proliferation results in unilateral aplasia of the fibula
- Failure of apoptosis results in autoimmune disease due to persistence of auto-reactive t/B cells.
- Failure of obliteration leads to branchial cleft cyst(2nd branchial arch)
- Failure of migration leads to Hirsch-sprung disease-failure of migration of neural crest cells that form the colonic ganglion cells
- Failure of fusion leads to hypospadias(failure of fusion of the urethral folds)
