Previous exam 2001 Flashcards Preview

From Flashcardlet big > Previous exam 2001 > Flashcards

Flashcards in Previous exam 2001 Deck (30):
1

Indications for surgery for type B dissection

pain malperfusion limb ischemia visceral ischemia uncontrolled hypertension contained rupture of dissected segment increase in size by >1cm in 6 months Aneurysm size > 6.5cm

2

Factors affecting paraplegia during thoracic aneurysm repair

factors affecting cross clamp time perioperative hypotension location of aneurysm Crawford I (13% incidence) left subclavian to abdominal aorta (not involving renals) Crawford II (30%) Left subclavian to abdominal aorta (involving infra renals) Crawford III (7%) distal half of the descending aorta and substantial segments of abdo aorta Crawford IV 4% upper abdo aorta +/- infra renal aorta (not much descending aorta increased age replacement below T4 absence of distal perfusion emergency surgery

3

Measures to prevent paraplegia in TA repair

distal perfusion-left heart bypass (maintain SBP > 90) moderate hypothermia (30degree) re-implantation of intercostals CSF drainage (CSF < 10mmHg) epidural cooling steriods, barbiturates, mannitol avoid hyperglycemia avoid nipride-not only causes periop hypotension but also causes cerebral vasodilation and increased CSF

4

What is anatomy of spinal cord

Anterior longitudinal spinal artery is formed by joining branches from right and left vertebral arteries runs down the entire length of spinal cord supplies blood to the cervical spinal cord in the thoracic and lumbar spine this artery is fed by collaterals (anterior radicular arteries Paired posterior longitudinal spinal arteries arise from R and L vertebrals Segmental spinal arteries supply thoracic and lumbar cord originate from intercostal and lumbar arteries that join to form: Ant Radicular arteries--supply anterior longitudinal spinal artery Artery of Admkiewicz--largest radicular artery (T9-to L2)

5

Describe what happens to pH when cooling

Hypothermia decreases the tendency of weak acids and bases to dissociate Buffering capacity of blood remains constanthydroxide ions (OH-) and hydrogen ions (H+) [OH/H+] at 16:1 pH rises with hypothermia (become alkaline) ph increases 0.0134 for each degree C of hypothermia pco2 decreases 4.5% for each degree of hypothermia hypothermia leads

6

What are advantages to pH and alpha stat

Alpha stat===No further CO2 is added. Total CO2 content is constant and no adjustments are made for temp (ratio of OH/H is constant) hydroxide ions (OH-) and hydrogen ions (H+) Benefit of alpha stat allows for preservation of cerebral autoregulation as metabolism and cerebral blood flow are coupled improved myocardial contractility and metabolism increased defibrillation thresholds increased subendocardial blood flow decreased cerebral blood flow pH--exogenous CO2 is added to maintain pH at 7.40. Results in acidosis when corrected for temp. CO2 increases cerebrovasodilation and therefore increases cerebral blood flow and potential advantage of improved cooling but at higher risk of emboli and cerebreal edema.

7

List complications of vavular substitues

infection paravalvular leak patient prosthesis mismatch hemolysis structural valve deterioration thrombosis anticoagulation

8

List mechanism and side effect of OKT3, cyclosporing, azathioprine, and prenisone

OKT3: monoclonial murine antibody of T cells (Anti CD3 antibody) side effect: infection:pulmonary edema/reactive airways/bronchoconstriction Cyclosporin: inhibitor of Calcium calcineurin phosphatase, thus inhibiting gene activationof IL-2 production. More selective immunosuppresion than steroids side effect: nephrotxicity, heptotoxicity, neurotoxicity, hypertension, Gingival hyperplasia Azathioprine: inhibitis purine synthesis through all bone marrow lineages--inhibits antigen stimulated proliferation of lymphocytes side effect: bone marrow suppression (anemia/leukopenia/thrombocytopenia/pancreatitis/hepatitis/alopecia Prednisone: blocks all lines of immune response: inhibits IL1; IL3; IL 6; ICAM-which would normally increase the signal for lympohyte activation. side effect: pyschosis;HTN;poor wound;Glucose intolerance;osteoporsis;impotence

9

Side effects of amiodarone

corneal deposits, halos and blurred vision acute hypersensitivity pneumonitis hyper/hypotheyroid QT prologation AV block Hepatitis photosensivity

10

Indications for chronic MR surgery

.

11

What is mechanism for pulmonary hypertension after protamine and how do you treat

Heparin-protamine complex stimulate thromboxane A2 from pulmonary macrophages treatment stop protamine 100 fio2 stop anesthetics give heparin on CPB reasonable to give steroids because unable to know if it's type II or III If re-operation needed then Heparinase lactoferrin Methylene blue

12

Classification of interrupted aortic arch

Type A (40%) Interrupted distal to the left subclavian Type B (55%) Interrupted left carotid and the left subclavian Type C (5%) Interrupted between the inominate and the left carotid Most have a large VSD and varying degree of other left sided obstruction and hypoplasia. 40 to 50% have bicuspid aortic valve

13

5 year old girl with Turners syndrome presents with leg pain and chest pains

Higher incidence of coarctation in females with Turners. They present with with proximal hypertension (headaches, epitaxis, rupture cerebral aneurysm) or claudication surgical options resection, end to end anastomosis prosthetic patch aortoplasty prosthetic interposition graft subclavian flap aortoplasty resection with extended end to end anastomosis

14

What are risks for AV groove disruption

overzealous removal of calcium from posterior annulus of mitral valve implanting too large a prosthesis in MV position lifting the heart for de-airing after valve implantation

15

7 year old infant presents to ER with resp distress, severe metabolic acidosis, absent femoral pulses

Watch for acyanotic ductal dependent lesions with left side obstructions coarctation hyoplastic arch interrupted arch MS AS HLHS

16

Name 3 acute coronary syndromes and define them

.

17

Shown a pt with Toursade

Polymorphic VT with QRS peaks that twist around the baseline and a long QT interval. Occurs in the presence of replarisation, low Mg, low k, treat with Mg, overdrive pacing,

18

65 year old with prosthetic valve endocarditis, diagnosis, investigations, and complications

.

19

What are fatal complications of acute type a dissection

.

20

3 most common non-myxomas cardiac tumours

lipoma papillary fibroelastoma rhabdomyoma

21

What is management of baby with absent thymus

Use irradiated blood products to destroy lymphocytes and prevent graft-versus-host reaction deficits in T-cell mediated immunity Hypocalcemia hypoplasia of parathyroid grands increase risk of infection normal immunoflobulin count but decrease reaction often seen (IgG and IgA especially)

22

What is most common intracardiac defect with IAA Name two other cardiovascular associated lesions

VSD Bicuspid valve LVOT obstruction DrGeorge syndrome (15-30%) single ventricle aorto-pulmonary window

23

Name 3 class I indications for CABG

.

24

Contraindications to Off pump CABG

intra-mural LAD small target arteries Need of extensive endartectomy left main disease hemodynamic compromise/cardiogenic shock

25

Contraindications to B-Blockers and calcium channel blockers. what is the problem giving nitrates for prolonged periods of times

Beta-Blockers: 1. Smooth muscle spasm bronchospasm cold extremities 2. Exaggeration of the cardiac therapeutic actions bradycardia heart block excess negative inotropic effect 3. Central nervous penetration insomnia depression Absolute contraindications severe bradycardia/cardiogenic shock/high-degree heart block severe asthma/depression/skin necrosis/severe worsening claudication

26

What coronary cross-sectional area do you get flow decrease with exercise and at what flow do you get decrease at rest

Coronary reserve: capacity of myocardium to increase nutrient flow in response to demand. normally flow can increase 3 to 4 times with exercise Effect of stenosis 60% reduction of stenosis coronary reserve almost normal 60 to 90% coronary reserve progressively decrease capacity of the resistance vessels to dilate is used up as the proximal resistance increase > 90% coronary reserve = 0

27

What are principles for biventricular repair of TOF

Absence of LAD from RCA Absence of RV dependence on coronary circulation Good RV by pulmonary valve Z score Adequate PA Magoon ratio Nikita index

28

Methods of lower pulmonary vascular resistance

.

29

Complications of Myocardial infarction

Papillary muscle regurgitation (MR) Free wall rupture Cardiogenic shock VSD pseudoaneurysm

30

Name 3 characteristics of abnormal stress test

Symptoms of angina or shortness of breath Symptoms less then 6 METS ST changes (elevation) ST depression at < 6 METS inability to achieve HR Ventricular arrhythmias Failure to increase SBP > 120 mmHg

Decks in From Flashcardlet big Class (79):