Cardiac Anesthesia Flashcards
Considerations of LBBB
Can mask ischemic changes on intraop ECG (blurs the separation between the QRS and the T wave because repol is happening at different times in the heart. Makes ST changes harder to spot early with the naked eye)
MOA of TXA
Binds plasminogen and prevents it from becoming plamsin (this prevents fibrinolysis)
How does hypoventilation lead to hypotension?
hypoventilation–> hyperCO2 –> transient systemic HTN but also elevated PULMONARY HTN which can lead to acute RHF.
Hypoxia can also lead to bradycardia and asystole which will cause hypotension
Cardiac tamponade echo findings
Diastolic collapse of RV
Collapse of RA well into systole
Septal bowing into LV on inspiration
Equalization of chamber pressures occurs but this is seen on cath.
What is pulsus paradoxus (“exaggeratus”)
Exaggerated drop in SBP on inspiration 2/2: tamponade/pericarditis prevents RV free wall from accepting nml inc. preload so septum bows into LV, drops LV filling and thus SBP.
Induction for Critical AS
high opioid induction. Have esmolol handy. Small amount of etomidate. Maybe wait to put the PAC in until the surgeon is ready to open the chest as dysrhythmias can be deadly
What is the reflex pathway for the carotid sinus?
Afferent: Glossopharyngeal
Efferent: Vagus (to heart) and sympathetics (blood vessels)
What is the Bezold-Jarisch reflex?
Hypopnea/bradycardia/vasodilation in response to noxious ventricle stimulation.
(Think of it as the body pausing/freezing to avoid damage from something bad like hemorrhage).
What are the differences in the 2 types of HIT?
Type 1: mild Plt drop (no lower than 100) within first 2 days. normalizes with continued heparin. Nonimmune (heparin direct effect causing aggregation)
Type 2: Immune mediated (Abs attack heparin-Factor 4 complexes). 4-10 days after heparin (unless pt had heparin previously in the last month and Abs are already circulating)
ST depression V1-V4, S1Q3T3, peaked P wave in Lead 2
Right heart failure. Can also see new RBBB
Ddx: NARROW pulse pressure on a-line
Hypovolemia, AS, heart failure, tamponade, dampening
CVP waveform: a,c,x,v,y
A=atrial contraction
C=TV moves into RA. RV ctxn.
X descent = RA relaxes fills
V = RA full
Y descent = early ventricle filling
CVP: a fib
Lose a-wave. Big C wave (TV closes on a full RA
CVP: cannon a-wave
AV dissociation (RA ctxn on closed RV)
CVP: TR
Huge C wave that obliterates x-descent
