Hard things to memorize

RA/LA chamber size

2-3 mm thick

RV chamber size

3-5 mm thick

LV chamber size

8-15 mm thick

TV area

7-9 cm²

MV area

4-6 cm²

AV area

2.5 - 3.5 cm²

PV area

2-4 cm²

Septal EKG leads & what they cover

V1, V2 cover LAD septal branches

Anterior Septal leads & what they cover

V3, V4 cover LAD

Lateral EKG Leads & what they cover

V5, V6, I & aVL cover LCx/ Diagonal branches

Inferior EKG leads & what they cover

V2, V3, aVF cover RCA/PDA

Lead I position

Negative Right Arm to Positive Left Arm

Lead II position

Negative Right Arm to Positive Left Leg

Lead III position

Negative Left Arm to Positive Left Leg

Atrial refractory period

150-200 ms

AV node refractory period

300-400 ms

Bundle of HIS/Purkinje Fibers Refractory Period

400-600 ms

Purkinje fibers conduction velocity

5 m/sec (Fastest)

Atrial/ventricular muscle conduction velocity

0.5 - 1 m/sec

AV node conduction velocity

0.02 - 0.05 m/sec (Slowest)

Some Believe in Acting Badly Before Performing

SA node → Bachmann’s Bundle → Internodal pathways → AV node → Bundle of HIS → Bundle Branches → Purkinje Fibers  

Isosbestic point

850 nm

oxyHgb & DeoxyHgb absorb light equally

Shock for Defibrillation

Any time in cardiac cycle

Shock for Cardioversion

30 msec after peak R wave

Macroshock threshold

5 mA

Microshock threshold

10 Micro amps

Estimated BV PEDs

• <10 kg: 85mL/kg 

• 11-20kg: 80mL/kg 

• 21-30 kg: 75mL/kg 

• 31-40 kg: 70 mL/kg 

• >40 kg: 65 mL/kg 

Kg Weight based flows / Perfusion Index (PI) PEDs

• 0-3kg: 200mL/kg/min 

• 3-10kg: 150mL/kg/min 

• 10-15kg: 125mL/kg/min 

• 15-30kg: 100 mL/kg/min 

• >30kg: 75mL/kg/min 

• >55kg: 65mL /kg/min 

1C drop in temp = metabolism

↓ 7%

1C drop in temp = pH

↑ 0.015

1C drop in temp = pCO2 & PO2

PCO2 = ↓ 4-5%

PO2 = ↓ 5%

TEE positions

Mid-esophageal

Esophageal

Transgastric

Deep Transgastric

1st centrifugation speed for PRP

5600 RPMs separates PPP layer

2nd Centrifugation speed for PRP

2400 RPMs separates PRP from buffy coat layer

1st trimester length

1st day - week 13

2nd trimester length

week 14 - week 27

3rd trimester length

Week 28 and beyond

Tocolytic drugs - inhibit uterine contractions

Terbutaline

Ritodrine

MgSO4

Drugs that cross placenta

Warfarin

Neosynephrine

Nitroprusside

Mannitol

Calcium

Drugs that don’t cross placenta

Heparin

Epinephrine

Ephedrine

Hydralazine

Lasix

Isoflurane

Antegrade root pressure CPG

50-70 mmHg

Classical pathway C3 convertase

C4b2a

Alternative pathway C3 convertase

C3bBb

IABP positioning

2-3 cm distal to LSA
2-3 cm above carina

ECMO recommended flow rates

• <7 kg: 120-200 mL/kg/min 

• 7-10kg: 100-150 mL/kg/min 

• 10-20kg: 80-120kg mL/kg/min 

• 20-25kg: 100 mL/kg/min 

• >25kg: 80 mL/kg/min 

• Adults: 60-80 mL/kg/min