Cardiac Flashcards
EKG with cor pulmonale
Right atrial hypertrophy - peaked p waves II, III, aVF
RVH - right axis deviation, partial or complete bundle branch block
Goals with AS
- Maintain sinus rhythm, esp avoiding tachycardia
- Adequate preload
- Maintain after load. CPP = aDP - LVEDP
- Maintain Contractility
AS gradient requiring surgery
50mmHg
CVP 22, PA 44/25, CI 1.5L/min, what is going on?
Tamponade
- Beck’s Triad: hypotension, JVD, muffled heart sounds
- pulsus paradoxus
Tx (fast, full, tight)
- Elevated HR (CO is HR dependent)
- Fluids
- Ionotrope support (epi +/- ketamine)
- Spontaneous vent
- Alert surgeon –> back to OR
- CVP dominant x descent, minimal y descent
Hemodynamic changes with aortic cross clamp
Proximal: inc after load, inc BP, CVP, PAOP, dec CO and EF
Distal: Dec RBF and mesenteric BF
inc MvO2, acidosis,
Hypotension on CPB
Low CO from hemodilution or Low SVR
Inc flow rate or give Neo
Steps coming off bypass
Normothermia Midazolam to prevent awareness Make sure monitors, machine, alarms are on Correct lab abnormalities - anemia, electrolyte Heart de-aired Start ventilation Check TEE to assess function Have pacing on standby
Side effects of nitroprusside infusion
CN toxicity
Metabolic acidosis
Arrhythmia
Tachyphylaxis
Tx = 100%O2, hydroxycobalomin
Heparin for bypass
3-4 U/kg
ACT 300-400 (480)
Protamine 1mg/100U heparin - acid base reaction
Goals with HOCM in pregnancy
Continue beta blockers
Maintain preload
Maintain SVR
Maintain slow normal rate and SR
Avoid spinal (sympathectomy)
Epidural and GA ok
Pitocin - ok if given slow
Afib = cardioversion or esmolol
How does IABP work?
Sits in aorta, deflates during systole reducing afterload and inflates during diastole inc coronary perfusion
This dec myocardial work, inc O2 supply to myocardium
How would you evaluate an AICD preoperatively?
Baseline cardiovascular function, underlying rate and rhythm
Indication for AICD
Functioning properly, battery, any shocks
Contact manufacturer
Behavior when exposed to magnet
If within 6 inches, magnet/ manufacturer to deactivate defibrillator and place pads
Set to asynchronous DOO
Avoid cautery or use bipolar or short bursts
How to protect spinal cord perfusion during aortic cross clamp
Adequate BP Hypothermia CSF drain Shunt across clamp Avoid vasodilators that inc ICP and this spinal cord perfusion pressure
Cardiac considerations for Down syndrome
Any endocardial cushion defects
ASD, VSD, PDS, TOF
Uncorrected —> pulmonary HTN
Indications for endocarditis PPx
Dental, skin or resp procedure Prosthetic material Previous BE Unrepaird CHD Repaired CHD with 6 months Residual defect Transplant with valvulopathy
Would you delay the case to optimize blood pressure? How long?
I would look at BP trends, evidence of end-organ damage (LVH, renal, vascular disease).
Evaluate the patient for symptoms of end organ damage as well - headache, chest pain, EKG, pulmonary edema, SOB
If urgency of case did not allow optimization over several weeks, I would lower to 140/90
Centrifugal vs roller pump
Roller pump
- partial compression of tubing by two roller heads
- NOT sensitive to preload or afterload
- can deliver pulsatilla flow
- reliably delivers certain flow based on pump speed
- more RBC trauma
- potential for large air embolism
Centrifugal
- rotational force responsible for forward flow
- sensitive to preload and afterload
- will not work if senses air
- less trauma to RBCs
Alpha stat vs. pH stat, which one is preferable
Slightly better neurological outcomes with alpha-stat in adults
- hypothermia inc solubility of CO2 and dec arterial pH and partial pressure of CO2
pH stat adds CO2 to oxygenator to maintain PaCO2 of 40 and pH 7.4
- ischemia not emboli primary mechanism in peds = pH stat preferred in peds
Acute vs chronic mitral regurg
Acute = left atrial overload without compensatory ventricular dilation—> dec CO, pulm edema, RV failure
Elevated LVEDP and tachycardia increases risk of ischemia
Temp monitoring for bypass
Measure core and shell due to temp gradient that develops during cooling and rewarming
- nasopharyngeal and toe or rectal
- ensures adequate cerebral cooling and avoid large temp gradients (>10deg) that can lead to bubble formation in blood
Goals for mitral regurg
Fast full, forward
Maintain HR, preload + afterload reduction
Adequate anesthesia during laryngoscopy to avoid HTN, tach inc MR and myocardial O2 demand
Avoid over aggressive induction, hypotension, BRADYCARDIA –> worsening regurg and dec coronary perfusion
Either lead to ischemia—> AFIB
Low reservoir volume, what would you do?
Reduce pump flows
Add fluid
Look for heart manipulation, kinking, malposition of venous cannula
Why is de-airing important?
Lung re-inflation recruits alveoli, inc pulm blood flow displacing air into left heart where it can be removed with a vent
This dec end organ damage from embolization to cerebral and coronary arteries
Inc PA pressure and dec BP during bypass wean
LV failure
- inc afterload (esp after MVR)
- graft failure from clot, kink, air
- poor CBF from hypotension, emboli, spasm, tachycardia
- hypovolemia
- acidosis
- hypoxemia
Failure to wean from bypass causes and solutions
Poor pre-op EF and need for ionotropes
Aortic cross clamp time
Severe MR
Ensure adequate volume, temp
Correct acidosis, anemia, hypoxemia, labs
IABP - dec afterload, inc coronary perfusion
AICD code VVE-DDDRO
Shock - ventricular
Anti-tach pacing - ventricular
Electro gram detection
Pacing - dual Sensing - dual Triggered or inhibited response to sensing - dual Rate responsiveness Not capable of multi site pacing
What are the Debakey classifications
Type 1 - aortic dissection ascending aorta distal to abdominal aorta
Type 2 - ascending and do not extend past innominate
Type 3 - beyond left subclavian to abdominal
Would you place a lumbar drain for thoracic dissection repair?
CSF drainage could facilitate SC perfusion given inc in CSF pressure with cross clamp
Have risk benefit discussion with surgeon. Is there time to delay systemic heparinzation 60 minutes or up to 24 hours with traumatic placement?
Where would you places line for aortic dissection repair?
Consider upper and lower extremity lines to identify inadequate perfusion distal to cross clamp.
Upper extremity a-line in right to avoid interference from clamp
How does hypothermia affect coagulopathy?
Defects in platelet aggregation and adhesion
Below 33 enzyme activity is abnormal
