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Flashcards in Cardiac Physiology Deck (17):
1

Effect of volatile agents and opioids on automaticity of SA node and AV node

-volatiles depress SA node more than AV node (junctional rhythms under inhaled anesthesia)
-opioids increase AV nodal conduction but have less effect on SA node

2

How do volatiles depress myocardial contractility?

-indirectly decreasing release of calcium from SR

3

Sidedness of heart innervation

SA node- right vagus and sympathetic chain
AV node- left vagus and sympathetic chain

*during SVT, right carotid massage more likely inhibits sinus discharge and left carotid massage slows AV node

4

E to A ratio of

Impaired relaxation

E=early diastolic flow
A=peak atrial flow

A>E in diastolic dysfunction

5

Baroreceptor Reflex

Drop in BP sensed by carotid sinus and aortic arch-->decreased discharge-->less inhibition of SNS and increased inhibition of vagal tone

Increase in BP-->increase baroreceptor discharge-->increased inhibition of SNS

6

Baroreceptor Reflex

Drop in BP sensed by carotid sinus and aortic arch-->decreased discharge-->less inhibition of SNS and increased inhibition of vagal tone

Increase in BP-->increase baroreceptor discharge-->increased inhibition of SNS

7

Sensitivity of epicardium versus endocardium to ischemia

-endocardium is more sensitive to ischemia than the epicardium (ST depressions)
-epicardium ischemia (and therefore endocardial ischemia as well) usually has ST elevations

8

Sensitivity of epicardium versus endocardium to ischemia

-endocardium is more sensitive to ischemia than the epicardium (ST depressions)
-epicardium ischemia (and therefore endocardial ischemia as well) usually has ST elevations

9

Treatment for unstable a fib

Cardioversion with biphasic 120 J

10

Treatment for AV nodal re-entry

Adenosine 6 mg, then 12 mg, then 12 mg, then cardioversion

11

Most sensitive and specific monitor for intraoperative MI

TEE, then EKG

12

Tetralogy of Fallot

1. RV obstruction
2. RVH
3. VSD
4. Over-riding aorta

13

Cardiac Tamponade

-during inspiration, RV filling is enhanced, moving the septum towards the left, decreasing LV stroke volume (pulses paradoxus)
-"y" descent is absent on CVP tracing
-due to external pressure in ventricles, ventricular filling and SV are fixed, making CO heart rate dependent
-

14

1st line treatment for aortic dissection

Beta blockers, eg. esmolol gtt

-BBs reduce HR and contractility
-nicardipine or nitroprusside can be added later, but when used alone can increase both HR and CO, increasing shear forces on aorta

15

Most common location of traumatic aortic dissection in blunt trauma

Aortic isthmus- just distal to left SCA at location of ductus arteriosis

16

Active Cardiac Conditions

-acute/recent MI
-unstable or severe angina
-high grade AV block (Mobitz II or complete)
-symptomatic ventricular arrhythmias
-SVTs with uncontrolled ventricular rate
-severe valvular disease
-decompensated or new heart failure

17

Clinical Risk Factors for Cardiovascular Risk

-ischemic heart disease
-compensated CHF
-mild angina
-diabetes
-CVA
-renal insufficiency