Previous exam 1999 Flashcards Preview

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Flashcards in Previous exam 1999 Deck (36):
1

Signs and symptoms of myxoma

Constitutional signs a. fatigue b. fever c. arthralgias d. weight loss e. clubbing f. anemia g. malaise h. thrombocytopenia TIA/CAV/GI infarct/

2

Principles of surgical management of aortic valve endocarditis

Appropriate antibiotics 1. Avoidance of contamination of surgical field 2. myocardial protection --important because of prolonged cross clam time required 3. radical resection of all infected tissue 4. minimize prosthetic material 5. valve replacement is usually required aortic homograft may be most resistant to recurrent IE, however, a stented prosthesis there is no difference between bioprosthesis or mechanical 6. If aortic annulus involved resect inflammed areas before insertion defect in annulus can be repair with fresh autologous pericardium 7.If aortic root abscess and/or fistula is present radial resection with bovine pericardium bovine pericardium is resistant to colonization by micro organisms 8. Abscess in fibrous tissue between aortic and mitral valves best approached through the aortic root and roof of LA aortotomy extended into the aortic annulus and roof of LA to expose fibrous aorto-mitral curtain. Abcess excised in block. Often anterior leaflet of mitral valve needs to be excised. If anterior leaflet is excised need to reconstruct a new aorto-mitral curtain triangular shaped bovine patch is sutured to fibrous trigone. MV prosthesis is secured to post annulus and bovine patch. Roof of LA closed with separate pericardial patch Aortic prosthesis is secured to normal aortic annulus and bovine patch

3

What are options for a patient with patient prosthesis mismatch

Accept PPM (important to do EOA/BSA) to see the degree of BSA Mechanical prosthesis tend to have larger EOA than biological for example a SJM 21 mm has an EOA of 1.7 while a Mosaic has 1.2 Effects of PPM in long term are controversial likely will have persistent symptoms likely will not have as much LV mass regression effect on survival unclear Supra-annular implant tilt valve in non coronary sinus Aortic root enlargement posterior enlargement--Nicks/Manougian Anterior enlargement Stentless porcine valve, homograft, autograft

4

Surgical management of aortic regurgitation in a type A dissection

Resuspend aortic valve If valve leaflets are normal Resuspension can be accomplished with supra coronary tube graft valve preserving root replacement (reimplantation/remodelling procedures Valved Conduit Stentless aortic root replacement with supracoronary tube graft if contra-indication to mechanical valved conduit

5

Describe Stanford A, B and Debakey I, II, IIIa, and IIIb

Stanford A: any dissection involving ascending aorta or aortic arch Stanford B: dissection involves only distal to left subclavain Debakey I: Dissection begins in aorta and involves most of or entire aorta Debakey II: involves only the ascending aorta (not the arch) Debakey III: involves only the descending IIIa: starts distal to the left subclavian and does not involve adbominal aorta IIIb: starts distal to the left subclavian and extends beyond diaphragm into supre-renal and abdominal aorta

6

What is mechanism of action of aprotinin

Serine protease inhibitor from bovine lung 2 mechanisms of action a. Antifibrinolytic--inhibiting trypsin, chymotrypsin, plasmin (prevents breakdown of fibrin by plasmin) b. preservation of platelet function c. Anti-inflammatory inhibits mediators of complement and cellular activation

7

What are risk factors for paralysis with thoracic aorta surgery

Clamp time > 30 minutes Dissection greater risk then aneurysm Age Peri-operative hypotension Extent of aneurysm Emergency surgery Non use of distal perfusion Pre-op Neuro deficit

8

What is blood supply to spinal chord

Vertebral, cervical, intercostals and lumbar 3 longitundinal (1 anterior and 2 posterior spinal arteries) Vertebral supply high cord in the neck and give arise to the 3 longitudinal arteries segemental radial arteries come from intercostals and lumbars supply the thoracic and lumbar chord The anterior spinal artery is attenuated and the artery of Adamkiewicz (largest and most important radicular artery) supplies the anterior cord principally in the descending portion (usually originates between T9-L2)

9

What are strategies to prevent paraplegia

systemic hypothermia epidural cooling distal perfusion re-implantation of spinal arterties steroids avoid hyperglycemia CSF drainage barbiturates

10

What indications for various pacing modes

VVI: AV block with absence of reliable atrial function. VVIR: desire for rate variability in more active patient DDD: AV block with functional atrium but slow atrial rate provides (AV synchrony) HOCM VDD: AV block with reliable P waves and atrial function, allows AV synchrony with only a single lead

11

What % of retrograde cariodplegia that returns to the right and left ventricle

70% of flow is nutritive (ie via capillaries and returns to the coronary ostia) most goes to LV nutritive flow. RV flow is minimal but cooling occurs 25-30% of flow is non-nutritive (exits via thesbian and veno-veno- collaterals.

12

List factors that increase and decrease PVR

Increase Decrease Hypoxia High FiO2 Hypercapnia Hypocapnia Acidosis Alkalosis Atelectasis nitric oxide hypothermia vasodilators High airway pressure sedation vasoconstrictors

13

50 year old male with ASD Calculate PVR in woods units Calculate the shunt Describe if patient should undergo operation

Criteria to close ASD significant shunt > 1.5: 1 PVR < 6-8 woods untis No cyanosis (no right to left shunt)

14

What are ways to assess calcium of ascending aorta and classification on epiaortic scanning

History CXR Intra-operative inspection TEE (not very good) but disease of descending aorta >5 mm severe, correlates well with ascending aortic disease, but s not as sensitive as epi-aortic scanning Epi-aortic scan: most sensitive and specific Grading system: Normal no intimal thickening mild < 3mm without irregularities moderate > 3mm with diffuse irregularities and or calcification severe > 5 mm intimal thickening and or large mobile dibris ulcerated plaque and thrombi CT very sensitive

15

What is the source of emboli from aorta

Existing carotid disease ascending aortia athersclerosis Air Most debris is dislodged during aortic manipulation. Cannulation, clamping and unclamping.

16

What is CMV, which type of virus and effect on transplant

CMV is herpevirus, is the most common virsus post cardiac transplantation. > 75% incidence, develops 1 to 3 months post op. Infection develops because of donor transmission, reactivation of latent recipient infection or re-infection of a CMV seropositive patient with a different viral strain. The low WBC count associated with CMV is associated with other infections (CMV-pneumocystis, carinii penumonia) symptoms also include pneumoia, gastroeneritis, retinitis, and hepatitis. CMV is a possible trigger of accelerated graft atheroscleosis and brochiolitis obiterans as well as an inhibitor of cell-mediated immunity. Diagnosis is by direct culture of virus from blood, urine, or graft tissue.

17

Absolute contraindications for use of a donor heart

Serology positive HIV Death from carbon monoxide poisoning with a blood CO-Hb > 20% Intractable ventricular arrhythmias Prior MI documented Clinically significant strutural heart disease, including intracardiac tumor Occlusive CAD by angiography Global hypokinesis EF < 10% Inadeequate oxygenation with SaO2 < 80%

18

Risk factors for CVA

Age > 75 Previous CVA During CPB

19

Management of cardiac contusion

Admit to hospital---monitoring for 24 to 28 hours Analgesia-examine chest wall for steering wheel tatoo Echo CK, MB, Troponin ST changes watch for right ventricular dysfunction, non specific St-T changes,

20

Effects of non pulsatile flow pathophysiology

Many reflexes are modified when non-pulsatile. Intravascular (venous) pressure stay outside normal values Plasma colloid osmotic pressure is reduced. Capillary permeability is increased and massive fluid retention occurs pulsatile results in more energy to mircocirculation, improving lymphatic flow, reduction in vasoconstrictive,

21

What are the effects of blood contact with surfaces during CPB

When heparinized blood touches non-endotheial surface plasma proteins absorb onto the surface and form a protein layer. Hydrophobic surfaces absorb more fibinogen. It basically becomes more thrombogenic.

22

What is blood test for hemolysis

LDH (lactate dehydrogenase) Hapoglobin Bilirubin

23

What are contraindications to Ross procedure

Marfans syndrome Aortic root aneurysm abnormal pulmonary valve *possible bicuspid aortic valve* *poor outcomes withe AI/Immune-complex disorder/obesity/mitral valve disease/> 60 years of age

24

What is CMV, effect on transplant

Herpesvirus, most common virus post tranplant > 75% incidence, develops 1 to 3 months post op develops because of donor transmission, reactivation of latent recipient infection or re-infection of a CMV sero-positive pt with a different viral strain. trigger for accelerate graft atherosclerosis and brochiolitis obliterans as well as an inhibitor of cell mediated immunity.

25

Absolute contraindications for using donor heart

Fixed pulmonary hypertension TPG > 15mmHg, Pulmonary vascular resistance > 6 Primary systemic disease that may limit long-term survival (hepatic or pulmonary diseases) Renal dysfunction active infection technical issues psychosocial issues recent malignancy Morbid obesity osteoporosis DM Significant peripheral or cerbrovascular disease

26

What is pathophysiology of AF

intraatrial reentryj where multiple reentrant wavelets present in the atrium and are maintained by the inhomogenity of tissue refractoriness in atrial myocardiaum. pericardial inflammation and effusion excessive production of catecholamines and autonomic imbance during post op interstitial mobilization of fluid with resultant changes in volume and pressure affects the neurohumoral environment and electricla properties of the atria.

27

Risk factors for post op AF

increasing age valve surgery history of rheumatic fever duration of cross-clamp time and cardiopulmonary bypass method of cardioplegia abrupt stoppage of beta blocker acidosis, hypokalemia, hypoxemia

28

surgically correctable complication of acute MI

acute MR ventricular septal defect left ventricular rupture left ventricular aneursym cardiogenic shock

29

What are surgical principles for constrictive pericarditis

the release of the constriction on the right and left ventricles pericardium should be removed from phrenic to phrenic nerve anteriorly from diaphragmatic surface to the pericardial reflection leave 2 cm margin around each phrenic release the left ventricle first important to release completely the ring around the SVC and IVC

30

What are cath findings for constrictive pericarditis

equalization of end diastolic ventricular pressures elevation of mean atrial pressure square root sign of the ventricular pressure cureve elevated right ventricular end-diastolic pressure left ventricular ejection fraction > 40% elevated right ventricular end-diastolic pressure(more then 1/3 of RV systolic) prominent y descent in the right atrial tracing

31

IABP complications

limb ischemia insertion site hemorrhage and false aneursym infection aortic dissection aortic iliac perforation renal artery emobolism spinal chord injury

32

How you assess for biventricular repair in pulmonary atresia with intact septum

right ventricular dependent coronary artery ciculation size of triscuspid valve size of right ventricle Morphology of right ventricle

33

Coronary endarterectomy: indications, techniques, and complications

indications: severe diffused coronary disease; distal target unsuitable for bypass, vessel completely occluded technique: closed...small incision and peel out as much as you can. Open technique. A lengthy incision, mid portion of the artery. vein graft and then sewn a LITA into the vein graft. complication: occlusion of the vessel or other branches, dissection, emboli, myocardial infarction, leak

34

List 3 shunts that cease to function after birth

PFO ductus arteriosus ductus venosus (in the liver) umbilical vessels

35

define stunned myocardium

left ventricular dysfunction without cell death that occurs following restoration of blood flow after an acute ischemic episode. It is a reversible process over a period of 1 to 2 weeks.

36

Mechanism of rate response pacemakers? what can you track and regulate?

Pacemaker detects changes in physiologic variable and adjusts heart rate accordingly Rate modulation has 3 components: a. indicator (things that can be tracked) b. sensory (measures chosen indicator within PM generator c. rate control alogorthm Track a. respiratory rate b. body movement c. pH Regulate a. minimal HR b. Maximal HR

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