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216 Cards in this Set
- Front
- Back
What types of congenital heart diseases are acyanotic?
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atrial septal defect
ventricular septal defect aortic stenosis pulmonic stenosis coarctation of the aorta patent ductus arteriosus |
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What types of congenital heart diseases are cyanotic?
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tetralogy of fallot
eisenmenger's syndrome transposition of the great arteries |
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What are the most and least common types of acyanotic defects?
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most- ventricular septal defects
least- atrioventricular septal defects |
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What is the most common type of cyanotic defects?
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tetralogy of fallot
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What cardiac conditions are associated w the highest risk of adverse outcomes from endocarditis for which prophylaxis for dental procedures is reasonable?
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1. prosthetic heart valve or prosthetic material used for cardiac valve repair
2. previous infective endocarditis 3. congenital heart diseases |
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What congenital heart diseases indicate prophylaxis for dental procedures?
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1. unrepaired congenital heart dz, including palliative shunts and conduits
2. completely repaired congenital heart defect w prosthetic material or device, whether placed by surgeon or cath intervention during first 6 mo. afterward 3. repaired congenital heart disease w residual defects at site or adjacent to site of prosthetic patch or prosthetic device (which inhibit endothelialization) 4. cardiac transplantation recipients who develop cardiac valvulopathy |
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Why is abx prophylaxis within 6 mo of repaired congenital heart defects necessary prior to dental procedures?
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because endothelialization of prosthetic material occurs within 6 mo. of procedure
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What is preferred SBE prophylaxis in a pt not allergic to PCN?
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amoxicillin
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What is preferred SBE prophylaxis in a pt allergic to PCN/ampicillin?
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cephalexin, clindamycin, azithromycin, clarithromycin
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What is preferred SBE prophylaxis for a pt not allergic to PCN but unable to take oral meds?
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IV/IM ampicillin, cefazolin or ceftriaxone
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What is preferred SBE prophylaxis in pts allergic to PCN/ampicillin and unable to take PO meds?
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IM/IV cefazolin, ceftriaxone or clindamycin
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When is SBE prophylaxis given?
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single dose 30-60 min before procedure
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______ should not be used in an individual w history of anaphylaxis, angioedema, or urticaria w PCN/ampicillin.
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cephalosporins
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Left to right shunt, incr pulm blood flow, pulm HTN, RV hypertrophy, and CHF are all characteristics of...
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acyanotic congenital heart disease
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Atrial septal defects are 2-3x more prevalent in
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females than males
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This is the communication between L and R atria, and blood enters R atria from L atria, opposite of PFO.
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atrial septal defect
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What are the classification factors for small vs large Atrial septal defect?
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small: < 0.05 cm, small shunt, usually asymptomatic
large: >/= 2 cm, incr pulm blood flow, systolic ejection murmur in 2nd ICS, afib or svt, r axis deviation on EKG, dyspnea on exertion |
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In atrial septal defect, SBE prophylaxis (is/isn't) recommended.
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is not unless a concommitant valvular abnormality (MVP/MV cleft) is present
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The anesthesia goals in atrial septal defect are?
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maintain systemic blood flow to ensure no alteration of IAs
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In atrial septal defect, IV agents may be..
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diluted, but this is unlikely
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What increases the magnitude of shunt in Atrial septal defect pts?
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drugs that produce prolonged SVR increases -- avoid!
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What does high Fi02 do in atrial septal defect pts?
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decr pulm blood flow and incr L to R shunt
volatile agents decr SVR whereas pos pressure ventilation incr PVR (both beneficial) |
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In atrial septal defect pts, it is crucial to avoid entrance of ____ into circulation.
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air!
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Anesthesia Mgmt Bottom line for atrial septal defect pts?
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1. maintain SVR in normal levels
2. use volatile agents and PosPresVent during surgery 3. avoid high Fio2 - ltd to 50% 4. regional can be considered as long as SVR maintained 5. SBE prophylaxis if in doubt |
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This is the most common congenital cardiac defect?
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ventricular septal defect
|
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Approx 70% of ventricular septal defects are located in
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membranous portion of intraventricular septum
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At the lower left sternal border, this auscultation abnormality is heard during moderate to large ventricular septal defect
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holosystolic murmur
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ventricular septal defect pts are at risk for developing
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infective endocarditis
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Is SBE prophylaxis indicated in ventricular septal defect?
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yessiree
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Are inhaled and injected drug pharmacokinetics altered in ventricular septal defect?
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nope
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Acute or persistent incr in _____ or decr in ______ should be avoided in ventricular septal defect pts. These chnges can increase the magnitude of left to right shunting, like in ASD.
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SVR, PVR
these changes are likely w incr Fi02 |
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Are pos pressure ventilation and IAs tolerated in ventricular septal defect pts?
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yep
monitor induction effects on SVR (IAs especially) |
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It is important to avoid (hypo/hyper)volemia in ventricular septal defect pts.
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hypovolemia
aggressively replace blood loss! |
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____ pts have similar surgical mgmt as ventricular septal defect pts. SBE prophylaxis should _____ be provided.
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ASD, always
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This is present when the ductus arteriosus fails to close spontaneously after birth.
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patent ductus arteriosus
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Most patent ductus arteriosus pts are asymptomatic, but if the shunt is large, then pt will have...
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LV hypertrophy
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Neonates w patent ductus arteriosus are treated with _______ because....
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indomethacin regimen, can also use ibuprofen
want to inhibit cyclooxygenase - helps facilitate closure and surgery is indicated to repair if conservative tx fails |
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Is SBE prophylaxis necessary in patent ductus arteriosus?
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yep
|
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What do decreases in SVR and positive pressure ventilation do to help in patent ductus arteriosus pts?
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improve systemic blood flow and increase PVR and decr L to R shunt
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In patent ductus arteriosus pts, it is crucial to avoid entrance of _____ into the pt.
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air into IV!
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Are IAs and PPV well tolerated in patent ductus arteriosus pts?
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yep
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Bicuspid aortic valves occur in ____% of the US population, and usually remains asymptomatic until ____.
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2-3%, adulthood
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Aortic stenosis is associated with a _____ heart sound audible over the 2nd ICS.
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systolic murmur
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What are the EKG and CXR findings in aortic stenosis?
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ST depression during exercise, LV hypertrophy
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Aortic stenosis leads to a _____ aortic valve and ____ wall of LV.
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narrowed, thickened/hypertrophic
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In aortic stenosis pts, it is crucial to maintain NSR because LV is dependent on...
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properly timed atrial contractions to ensure optimal LV filling and SV.
|
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In aortic stenosis, it is important to avoid prolonged or extreme alterations in what values?
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HR, SVR, IVFs
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In aortic stenosis pts, general anesthesia is preferred to regional in order to avoid
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sympathectomy
carefully titrate IAs to ensure no signifcant drop in BP; may use TIVA/N20/Opiate cocktail |
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Is SBE prophylaxis indicated for aortic stenosis pts?
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yes!
|
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_____ produces obstruction to R ventricle outflow and is identified by a loud systolic ejection murmur at the L 2nd ICS.
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pulmonic stenosis
|
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Side effects of pulmonic stenosis:
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dyspnea on exertion, peripheral edema, ascites
|
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What happens when there is a patent foramen ovale in the presence of pulmonic stenosis?
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R to L shunting can occur -> cyanosis and clubbing due to bypass of pulm circulation
|
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The goal of managing pulmonic stenosis pts under anesthesia is to avoid....
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RV oxygen demand increase.
|
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How do you decrease RV oxygen demand increase for better anesthesia outcomes in pts w pulmonic stenosis?
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-avoid incr HR and contractility
-pos pressure vent well tolerated (impact of changes in PVR minimized by presence of fixed obstruction in pulm valve) - aggressively treat decr BP w sympathomimetic drugs (phenylephrine/ephedrine) - aggressively treat dysrhythmias |
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Which is better tolerated in pulmonic stenosis pts, general or regional anesthesia?
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general
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This heart defect arises from diaphragm-like ridge that extends into aortic lumen just distal to the left subclavian artery.
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coarctation of the aorta
|
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In pts w coarctation of the aorta, most adults are asymptomatic until the defect is detected during this part of physical exam?
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systemic HTN is detected in arms w diminished or absent femoral pulses
|
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coarctation of the aorta results in what heart sound on auscultation?
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harsh systolic murmur along L sternal border in back
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What does Ekg reveal in coarctation of the aorta pts?
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LV hypertrophy
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What are the complications of coarctation of the aorta?
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- HTN
- LV failure - aortic dissection - ischemic heart disease - infective endocarditis - CVA |
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During surgical resection of coarctation of the aorta, what are important parts of monitoring strategy?
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-continuous BP monitoring on both upper and lower extrem
-monitor propensity of systemic HTN during cross-clamping of aorta (use nitroprusside infusion prn, assess renal and spinal cord perfusion) -assess for neuro ischemic injury (SSEP) -careful I/O, urine output |
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Is SBE prophylaxis indicated in coarctation of the aorta?
|
ye
|
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What are anesthesia post op concerns for coarctation of the aorta?
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watch for paradoxical HTN, use nipride to treat with or without esmolol
|
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Which is indicated as better technique for coarctation of the aorta, general or regional anesthesia?
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general - monitor for systemic hypo/hypertension
opioids for pain control careful titration of vasodilators during |
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What are the characteristics of cyanotic congenital heart disease?
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R to L intracardiac shunt,
decr pulm blood flow, arterial hypoxemia, erythrocytosis (HCT >70%, coag defects due to Vit K dependent clotting factors and defective platelet aggregation), brain abcess (due to hypoxic brain, mimics stroke) |
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Most pts w tetralogy of fallot are _____ From birth.
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cyanotic
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What heart sounds accompany tetralogy of fallot?
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ejection murmur along L sternal border
|
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What does a SP02 reading demonstrate in tetralogy of fallot?
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low even when 100% Fi02 admin
|
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Is SBE prophylaxis indicated in tetralogy of fallot?
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YEP
|
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What are the characteristics of compensatory erythropoiesis in tetralogy of fallot pts?
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- hyperviscosity
- risk for CVA/cerebral abcess - risk for infective endocarditis - SBE proph. |
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____ is a common positioning feature in tetralogy of fallot.
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squatting!
|
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This is the sudden onset of arterial hypoxemia in tetralogy of fallot pts.
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hypercyanotic attacks
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What is treatment for hypercyanotic attacks in tetralogy of fallot pts?
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beta adrenergic antagonists to alleviate spasm to pulm outflow tract (esmolol, propranolol)
|
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What are the 4 features of tetralogy of fallot?
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1. VSD
2. pulm stenosis (many levels of obstruction from RV to lungs) 3. overriding aorta (lies directly over VSD and RV) 4. thickened RV muscle |
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It is important to avoid increased R to L shunting in tetralogy of fallot pts because....
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increase in shunt results in decrease in pulm blood flow and PaO2.
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What actions increase R to L shunting magnitude in tetralogy of fallot pts?
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pulm blood flow is relatively fixed and inversely proportional to SVR (decr SVR, incr PVR, incr myocardial contractility)
|
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SVR can be decr in tetralogy of fallot pts by
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IAs, opioids, histamine release, ganglionic blockade, alpha adrenergic agents
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Pulm blood flow can be decr in tetralogy of fallot pts by
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pos pressure ventillation (but risk of hypoxemia outweighs risk of not using PPV), PEEP
|
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Preop considerations for tetralogy of fallot pts?
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- avoid dehydration (oral feedings)
- avoid crying (IM injections, IV starts) - continue beta adrenergic antagonists until induction - SBE prophylaxis |
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Induction technique for pts w tetralogy of fallot?
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-ketamine 3-4 mg/kg IM or 1-2 mg/kg IV (incr SVR and pulm blood flow)
-for intubation, avoid histamine releasing NMB (Atracurium), use pancuronium if ketamine not used - IA: sevo may lower SVR significantly, halothane preferred bc decr contractility and maintains SVR to greater degree |
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What are maintenance strategies for pts w tetralogy of fallot?
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- N20 and ketamine to preserve SVR, (N20 may incr PVR but offset by positive effect on SVR)
-N20 disadvantage is reduction of Fi02 w/ its use - pancuronium is preferred NMB - controlled ventillation preferred |
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This congenital heart defect occurs w L to R intracardiac shunt reversed through an ASD or VSD when the blood flow through the pulm bed equals or exceeds SVR.
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eisenmenger's syndrome
|
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This congenital heart defect manifests w cyanosis and decr exercise tolerance w/ palpitations. Also characterized by afib or flutter, visual disturbance, headache, dizzy, paresthesias.
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eisenmenger's syndrome
|
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This congenital heart defect is associated w an incr risk of CVA, brain abcess, pulm infarction, incr blood viscosity from erythrocytosis, and RV hypertrophy.
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eisenmenger's syndrome
|
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______ is characterized by a reversal of a L to R shunt into a R to L shunt caused by incr PVR to a level equal or exceeding SVR.
|
eisenmenger's syndrome
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In eisenmenger's syndrome, it is important to maintain preop levels of ____ and recognize that sudden incr in R to L shunt will occur if a sudden drop in ____ occurs.
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SVR, SVR
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What gtt is commonly used to maintain SVR in eisenmenger's syndrome pts?
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phenylephrine gtt
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It is important to avoid hypovolemia and paradoxical embolization in eisenmenger's syndrome, and _________may be indicated if HCT > 65%.
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prophylactic phlebotomy
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Laparoscopic procedures are routinely contraindicated in eisenmenger's syndrome pts because
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insufflations of peritoneal cavity w CO2 may precipitate acidosis, hypotension and dysrhythmias.
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Which anesthesia technique is preferred in eisenmenger's syndrome?
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general preferred over regional, early tracheal intubation desirable
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If you have to give an eisenmenger's syndrome pt an epidural, it is best to use a local anesthetic solution that doesn't contain _______ because....
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epinephrine,
can exaggerate decr in SVR assoc w epidural anesthesia |
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______ entails a failure of the truncus arteriosus to spiral, resulting in the aorta arising from the anterior portion of the RV and the pulm artery arising from the LV. There is complete separation of the _____ and ____ circulations.
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transposition of the great arteries,
pulmonary and systemic circ. |
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Survival is only possible in transposition of the great arteries if...
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there i sa communication between the 2 circulations in the form of a VSD, ASD, or PDA.
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______ at birth are often present w transposition of the great arteries.
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cyanosis, tachypnea, CHF
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CHF in transposition of the great arteries pts results from
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LV failure due to volume overload created by L to R shunt created for survival.
|
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What is the required treatment for transposition of the great arteries?
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surgical correction
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During repair of transposition of the great arteries, infusion of _____ is necessary to maintain patency of ductus arteriosus.
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prostaglandin E
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Admin of O2 in transposition of the great arteries helps to decrease _____.
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PVR.
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____ and ____ are drugs of choice to treat the CHF associated with transposition of the great arteries.
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diuretics and digoxin
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It is crucial that the anesthetist take into account the separation of ______ in caring for pts w transposition of the great arteries.
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pulm and systemic circulations
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How are drug doses titrated for pts w transposition of the great arteries?
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decr doses because of minimal dilution to heart and brain
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How are IAs affected by transposition of the great arteries?
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may be delayed, only small amt of inhaled drug reaches circulation
|
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What are the induction and maintenance techniques in transposition of the great arteries?
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- ketamine 1-2 mg/kg IV w NMB for intubation
- maint w ketamine 0.25-0.5 mg/kg/hr w opioids and benzos - avoid dehydration (careful I/O) - limited use of N20 due to high need for Fi02 concentration |
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Spontaneous depolarization is initiated in the ______ cells of the ____ node and as the electrical impulse moves along the conduction system, a wave of depolarization is propagated throughout the heart.
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pacemaker cells, SA node
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The ____ node is the primary site of impulse conduction, and it discharges at a rate of ____ beats/min.
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SA, 60-100 bpm
|
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The _____ node is located in the septal wall of the R atrium. Like the SA node, it is innervated by both _____ and _____ nerves.
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AV node,
sympathetic and parasympathetic |
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The AV node slows conduction velocity off the impulse allowing time for ______.
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atrial contraction
|
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Atrial kick contributes to ___% of CO.
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20-30%
|
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The _______ is a relatively thin bundle of fibers down the right ventricle that doesnt branch until the right ventricular apex. Late branching makes it more vulnerable to ____.
|
Right bundle branch (RBB),
vulnerable to interruption! |
|
The ____ divides into 2 fasciles, the L anterior and posterior fasciles.
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Left bundle branch (LBB)
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The _____ bundle branch is worse to block than the ___ bundle branch, and the former is more indicative of serious cardiac damage.
|
left more serious than right BB
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The RBB and LBB distal branches interlace into a network of _____.
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purkinje fibers
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____ bundle branch block occurs more often, and ____ bundle branch block is more serious.
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Right often, Left serious
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Cardiac dysrhythmias are classified according to ______ and _____.
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heart rate and site of abnormality
|
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What 3 things lead to cardiac dysrhythmia?
|
- incr automaticity in normal conduction tissue or in an ectopic focus
- reentry of electrical potentials through abnormal pathways - triggering of abnormal cardiac potentials due to afterdepolarizations |
|
The fastest pacemaker is the
|
SA node
|
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___ changes when the slope of phase 4 depolarization shifts or the resting potential changes.
|
automaticity
|
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____ can have abrupt onset and require 2 pathways which conduct at different velocities through accessory tracts that bypass AV node to stimulate SA. The often result in _____.
|
reentry pathways, SVT
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Triggering by _______ is the oscillation in membrane potential that occurs during or after depolarization, usually triggered by slow HR.
|
triggering by afterdepolarizations
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Afterdepolarization is treated by
|
incr HR w atropine or glycopyrrolate.
|
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_____ is caused by an accelleration through the SA node, HR between 100-160 bpm.
|
sinus tachy
|
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This is the most common dysrhythmia associated with acute MI (30-40% incidence).
|
sinus tachy
|
|
How do i treat sinus tachy?
|
1. correct underlying cause (hypovolemia, hypoxia, fever, infection, pain, MH)
2. supplemental O2 3. avoid vagolytic drugs (pancuronium, atropine, glycopyrrolate) 4. beta blockade (if pt is not hypovolemic, bronchospastic (hx of asthma), or has impaired cardiac fcn) |
|
_____ arise from ectopic foci in the atria. It is most commonly seen in pts w chronic lung disease, ischemic heart disease and digitalis toxicity.
|
premature atrial beats
|
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_____ is the second most common dysrhythmia assoc w acute MI.
|
premature atrial beats
|
|
How are premature atrial beats managed?
|
avoid excessive sympathetic stimulation,
can be suppressed w beta blockade or Ca channel blockers |
|
______ is any tachydysrhythmia initiated by tissue at or above the SA node, with avg HR of 160-180 bpm.
|
SVT
|
|
S/S of SVT
|
lightheaded, dizzy, fatigue, chest discomfort, dyspnea, syncope (15%)
|
|
How is SVT managed?
|
1. avoid factors that provoke SVT:incr sympathetic tone, electrolyte imbalances, acid-base disturbances (GI)
2. if stable, vagal maneuver 3. if unstable, AV node blockade: adenosine (can cause temp cardiac standstill), Ca channel blockers, beta blockers |
|
_____ occurs when atrial contraction rate is between 250-350 bpm, and is usually associated with structural heart disease.
|
atrial flutter
|
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Most atrial flutter pts present with ___ AV conduction, which means a ventricular rate of ______.
|
2:1 AV conduction,
150 bpm |
|
Atrial flutter is treated with....
|
1. cardioversion (50 j)
2. if present before induction of elective cases, cancel and treat by cardio 3. if occurs during anesthesia, treat based on hemodynamic stability (cardiovert w 50 j, pharm mgmt based on comorbidities: adenosine, amiodarone, diltiazem, verapamil) |
|
_____ is characterized by no uniform depolarization or contraction of atria.
|
atrial fibrillation
|
|
Rhematic heart disease, hx of rheumatic fever, HTN, COPD, ASD all predispose pts to what dysrhythmia?
|
atrial fibrillation
|
|
What is the most effective treatment for afib?
|
elective cardioversion
digoxin useful to control ventricular rate but ineffective in converting afib |
|
How is afib managed pre op?
|
postpone surgery if present prior to elective surgery in new onset pts
|
|
How is a chronic afib pt managed intraop?
|
1. maintain on antidysrhythmic drugs (amiodarone most frequently prescribed and works during phase 3; propfenone prolongs phase 0; ibutilide prolongs phase 3; sotalol prolongs phase 3)
2. monitor preop labs (electrolytes, esp Ca, K, Mg; coag profile -- pts on oral anticoag meds w afib, often coumadin, monitor for adverse events from anticoag discontinuance) |
|
_____ is the dysrhythmia that occurs when ventricles contract without accompanying atrial contraction.
|
PVCs
|
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In ______, volume of blood ejected is smaller than normal, and there is a compensatory pause longer than normal.
|
PVCs
|
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If PVCs are isolated, then in most people they are ____.
|
benign
|
|
When PVCs are ____, they are more concerning.
|
multifocal instead of unifocal.
3 PVCs together constitute vtach, 3 in a minute suggest impending vtach event bigemminy vs trigemminy |
|
How are PVCs managed?
|
1. treat for > 6 PVC/min and repetitive or if multifocal
2. treat underlying cause (acidosis, electrolyte disturbance, prodysrhythmic drugs, mechanical stimulation from intracardiac caths) 3. beta blockers, lidocaine, amiodarone |
|
Why are lidocaine gtts beneficial during open abdomen cases?
|
decr ileus 15-20 %
|
|
This dysrhythmia is present when 3+ PVCs occur at a calculated HR of > 120 bpm.
|
vtach
|
|
How is vtach managed?
|
1. during anesthesia, immediate investigation required into possible causes before it becomes sustained
2. conventional antidysrhythmics: lidocaine bolus 2 mg/kg, infusion post op |
|
_____ is irregular ventricular rhythm incompatible with life.
|
Vfib
|
|
This is the only effective method to convert vfib
|
electrical defib within 3-5 min,
also give epi 1 mg IV or vasopressin 40 u IV to improve response to defib |
|
What is the anesthetic mgmt of a vfib pt?
|
initiate CPR, ACLS protocol!
|
|
This dysrhythmia begins in early adulthood, and is characterized by paroxysmal palpitations with/without syncope, dizzy, dyspnea, and angina.
|
wolf-parkinson-white syndrome (WPW syndrome)
|
|
This is the most common tachydysrhythmia assocated with WPW syndrome.
|
AV nodal re-entry tachycardia (AVNRT) - usually triggered by a PAC or PVC
|
|
In AV nodal reentry tachycardia, ventricular preexcitation causes an earlier than normal....
|
deflection of QRS called a delta wave -- trigged by PAC or PVC
|
|
How is AV nodal reentry tachycardia classified?
|
either orthodromic (narrow QRS bc cardiac impulses conducted from atrium through normal AV node-HIS purkinje system and return to atrium through accessory pathways), more common 90-95%) or antidromic (wide QRS)
|
|
What is the anesthesia mgmt technique for WPW syndrome pts?
|
1. Pts w known WPW syndrome presenting for sx should continue to receive antidysrhythmic drugs (procainamide)
2. avoid any event w incr SNS activity (due to pain/anxiety/hypovolemia) OR drug (Digoxin) that could enhance anterograde conduction of cardiac impulses through an accessory pathway 3. electrical cardioversion is used in presence of instability |
|
What are the 2 types of prolonged QT syndrome?
|
congenital and acquired
|
|
What is the hallmark sign of long QT syndrome?
|
syncope
-- could become sudden death syndrome! |
|
How is long QT syndrome treated?
|
correct electrolyte abnormalities, particularly Mg and K
|
|
What causes acquired long QT syndrome?
|
abx, antidysrhythmics, antidepressants, antiemetics (ondansetron, droperidol), diet pills (metabolife)
|
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If a pt has history or fam hx of WPW syndrome, it is important to get a pre op ___.
|
EKG
|
|
What IAs have been shown to prolong QT?
|
isoflurane and sevoflurane
(desflurane inconclusive) |
|
Best choice for WPW anesthetic?
|
TIVA
|
|
In WPW pts, it is important to avoid abrupt increases in ______.
|
sympathetic activity
ex: pain, hypovolemia |
|
Intraop mgmt of WPW pts should ensure adequate ______ Balance, consideration of giving ____ prior to induction and laryngoscopy, and its important to have ______ available.
|
electrolyte balance, beta blocker prior to induction, defibrillator available
|
|
____ is characterized by HR < 60 due to decr in normal discharge of SA node.
|
sinus brady
|
|
Is treatment of sinus brady required while pt is asymptomatic?
|
nope
|
|
To treat symptomatic sinus brady, give....(med and dose)
|
0.5 mg IV atropine q 3-5 min to max dose of 3 mg
|
|
This is inappropriate sinus brady associated w degenerative changes in the SA node.
|
sick sinus syndrome (SSS)
|
|
Sinus brady can be associated w _____ and _____ anesthesia.
|
spinal and epidural
|
|
What is the anesthetic mgmt during sinus brady under spinal/epidural anesthesia?
|
1. assess level of block- if T5 or above, can knock out cardiac accelerators
2. probably from sympathectomy that decr venous return thereby initiating vagal response 3. treat w vagolytic medications, glycopyrrolate then atropine |
|
During anesthesia, sinus brady pts should be monitored for...
|
worsening of symptoms.
|
|
When symptoms present intraop on sinus brady pts, anesthesia mgmt entails
|
1. atropine- crosses BBB and causes visual disturbances, vasodilation, dry, crazy, disinhibition
2. glycopyrrolate 3. when severe, immediate transcutaneous pacing |
|
What are the drugs that can be given down the ETT?
|
LANE
lido, atropine, nitro, epi |
|
What is the waveform like for junctional rhythm?
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HR 40-60, regular rhythm, P wave inverted, absent or after QRS
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______ is due to activity of a cardiac pacemaker in the tissues surrounding the AV node, with an intrinsic HR of 40-60.
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junctional rhythm
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Transient junctional rhythms require ______
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no treatment
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Junctional rhythms under anesthesia are not infrequent during
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general anesthesia with halogenated agents
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The loss of _______ in junctional rhythms may be detrimental to some populations.
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atrial kick
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Junctional rhythms are treated with _______ for hemodynamically significant rhythms.
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0.5 mg IV atropine
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_____ rhythm is characterized by PR interval > 0.20 sec, normal QRS, and regular rhythm.
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1st deg AVB
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First deg AVB can be found in pts without
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heart disease
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First deg AVB may be caused by
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incr vagal tone, digitalis toxicity, inferior wall MI, and myocarditis
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What are the anesthesia techniques in first deg AVB?
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1. avoid incr vagal tone
2. assess digoxin levels 3. careful use of spinal/epidural anesthesia (Start lower) |
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What are the 2 types of 2nd deg AVB?
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1. mobitz type 1 (wenckebach): progressive prolongation of PRI until beat is dropped
2. mobitz type 2: no progressive prolongation, more indicative of serious cardiac conduction problem |
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_____ is the dysrhythmia that occurs when ventricles contract without accompanying atrial contraction.
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PVCs
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In ______, volume of blood ejected is smaller than normal, and there is a compensatory pause longer than normal.
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PVCs
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If PVCs are isolated, then in most people they are ____.
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benign
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When PVCs are ____, they are more concerning.
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multifocal instead of unifocal.
3 PVCs together constitute vtach, 3 in a minute suggest impending vtach event bigemminy vs trigemminy |
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How are PVCs managed?
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1. treat for > 6 PVC/min and repetitive or if multifocal
2. treat underlying cause (acidosis, electrolyte disturbance, prodysrhythmic drugs, mechanical stimulation from intracardiac caths) 3. beta blockers, lidocaine, amiodarone |
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What is the anesthetic mgmt of 2nd degree AVB?
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Type 1- therapeutic decisions depend on ventricular HR
Type 2- higher incidence of developing VFIB or 3rd deg AVB, so cardiac pacemaker is mandatory |
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This dysrhythmia is characterized by a complete interruption of AV conduction, signaled by syncope or vertigo.
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3rd degree AVB
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What is the treatment for 3rd degree AVB?
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transcutaneous or transvenous pacing must be in place prior to induction; isoproterenol may be needed to maint acceptable HR, caution w antidysrhythmics (may suppress ectopic pacemakers that are responsible for maint HR)
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This is the conduction disturbances that occur at various levels of the HIS-Purkinje system.
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Bundle branch blocks (BBBs)
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In pts without structural heart disease, which bundle branch block is more common?
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Right more common
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In RBBB, the waveform entails...
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1. identical P wave before each QRS
2. possibly prolonged PRI 3. widened QRS complex and rSR in V1 and V2 leads |
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How is RBBB managed in anesthesia?
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1. avoid hypotension, hypoxemia, alterations in electrolytes (disturbances can result in 3rd deg AVB)
2. can use general or regional 3. prophylactic cardiac pacer not required, but continuous EKG monitoring is! |
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In LBBB, the waveform entails...
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1. identical P wave before each QRS
2. possibly prolonged PRI 3. wide QRS w RR' in V5 |
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LBBB is often a marker for ....
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serious heart disease, HTN, CAD, aortic valve disease, cardiomyopathy
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How is LBBB managed under anesthesia?
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avoid hypotension, hypoxemia, alterations in electrolytes (disturbances can result in 3rd deg AVB)
2. can use general or regional 3. same as RBBB, special attn should be made for insertion of intracardiac cath bc can induce RBBB. |
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_____ is a temporizing measure in which you place chest and back electrodes over areas of lesser skeletal muscle mass and low density constant currents are delivered.
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transcutaneous cardiac pacing
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This is the most common indication of permanent implanted cardiac pacemakers.
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sick sinus syndrome
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This is the only long term treatment for symptomatic bradycardia, and offers different pacing modes.
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permanently implanted cardiac pacemakers
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What is the 5 letter genetic code used to describe various characteristics of cardiac pacemakers?
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1st letter: denotes cardiac chamber being paced (a atrial, v ventricular, d dual chamber)
2nd letter: denotes cardiac chamber that detects the electrical signals (A,V,D) 3rd letter: indicates response to the sensed signals (i inhibition, T triggering, D dual inhibition and triggering) 4th letter: R denotes activation of rate response features 5th letter: denotes chamber(s) in which multisite pacing is delivered |
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What are the most common pacing modes?
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AAI, VVI, DDD
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In ____ pacing, the atrial output is inhibited if an intrinsic atrial signal is sensed, and, if no ventricular activity is sensed by the end of the programmed AV interval, ventricular output is activated. If intrinsic ventricular activity is sensed then the ventricular activity is inhibited.
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DDD pacing
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Dual chamber pacemakers maintain synchrony between...
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atria and ventricles
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____ pacing minimizes the incidence of "pacemaker syndrome."
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DDD pacing
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This syndrome is a constellation of symptoms that includes weakness, orthopnea, paroxysmal nocturnal dyspnea, hypotension, and pulmonary edema.
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pacemaker syndrome
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This type of pacing involves sensing in both the atria and the ventricle but only a response to a sensed event is inhibited. It is useful in pts w frequent atrial tachydysrhythmias.
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DDI pacing
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Most cardiac pacers can be converted to an _______ by placing an external magnet over the pulse generator. Conversion may be considered prior to _____ in some pts.
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asynchronous mode, surgery
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This type of pacer is considered for pts who do not have an appropriate response to exercise.
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rate adaptive pacers
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This type of pacer uses sensors to detect physical or physiologic indices of exercise and mimics the rate response of NSR. Indices include body mvmt, minute ventilation, QT interval, and SV.
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rate adaptive pacers
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The single most important factor for survival from cardiac arrest from vfib is
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time between arrest and defibrillation
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____ respond to a dysrhythmia by delivering an internal shock within 15 sec of dysrhythmia, and may be single or dual chamber.
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ICD (implanted cardioverter defibrillator)
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Pre op eval for pts with cardiac devices should include:
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1. determine reason for pacer/ICD and its current fcn
2. coordinate plan w cardio MD 3. ICDs often switched off prior to sx 4. pacemakers usually allowed to continue functioning intraop |
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Pre-op pacemaker interventions:
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1. assess function by eval before, during and after sx
2. cxr to determine positioning of electrodes 3. change to asynchronous mode because we use bovie in OR, could cause pacer damage or confuse signals it receives |
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DO NOT place bovie grounding pads on...
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the chest!!!
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What are the intraop considerations for pacemaker pts?
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1. monitor EKG to confirm proper fcn of pulse generator
2. ensure proper equipment and meds available for ACLS and a magnet 3. intracardiac caths do not disturb epicardial electrodes fcn but may become entangled or dislodge transvenous electrodes 4. ensure proper shielding of generators from bovie (grounding eletrode placed as far away from generator as possible) 5. avoid hyperventilation to ensure normokalemia (succ use w caution) |