Cardiac Flashcards
Cardiac Index
-More specific indicator of hemodynamic status than CO
- CI = CO/BSA
Cardiac Output
HR x SV
MAP
-Takes into account that diastole is 2/3 of cardiac cycle
- MAP = 2 (DBP) + (SBP) /3
Ejection Fraction
-Amount of blood ejected from LV compared to total available
- Should be over 50%
Bainbridge Reflex
- Reflexive hypertension caused by stretch of right atrial receptors
-Speeds up if HR becomes overloaded to equalize pressure
PAOP
Pulmonary artery obstructive pressure
- pressures in L side of heart and pulmonary filling pressures
- balloon inflates until it “wedges” into PA
-turbulence behind the balloon is blocked and it senses what is in front of it (pulmonary vascular bed) and L side of heart
- Normal is 5-12
What does high LAP indicate?
Mitral valve dysfunction
What does high RAP indicate?
Pulmonic stenosis, tricuspid regurgitation
Your pediatric patient has the following parameters.
HR 80
BP 100/60
SV 40
BSA 0.9 m2
The cardiac index for this patient is:
First calculate cardiac output, HRxSV
80x40=3200 = 3.2L/min
Then use CI=CO/BSA
3.2/0.9 = 3.55L/min/m2
Normal is 2.5-4.0 L/min/m2
Calculate the cardiac output for a 16 year old with HR of 72 and stroke volume of 70
70x40=5040=5.04L/min
What is the MAP for a patient with a BP of 110/50 and HR of 80?
MAP = 2(DBP) + (SBP) /3
2x50 = 100 + 110 = 210 /3 = MAP 70
Which of the following would be considered normal value for an ejection fraction ?
A. 25%
B. 35%
C. 40%
D. 60%
D. 60%
EF should be over 50%
EF is the amount of blood ejected from the LV compared to the total amount available. 35% or less indicates a problem with contractility, outflow, or filling
Which of the following statements is true about events that occur during a normal cardiac cycle?
A. Metabolism in the heart is unchanged during diastole.
B. Metabolism of the heart is decreased during diastole.
C. An increase in cardiac output increases diastole.
D. Diastole compromises about 40% of the cardiac cycle.
B. Metabolism of the heart is decreased during diastole, which accounts for approximately half of the cardiac cycle at birth. Shortly after birth, the diastolic phase lengthens so that it represents 2/3 of the cardiac cycle. An increase in cardiac output decreases diastole.
A reflex tachycardia caused by stretch of RA receptors is known as
A. The Herring-Sines law
B. The Bainbridge reflex
C. Starling’s law
D. The renin-angiotensin system
B. The Bainbridge reflex
Believed to occur to speed up the HR if the right side becomes overloaded and help equalize pressures in both sides.
Your patient requires placement of a LA pressure monitoring line. The pressure reads 18mmHg. This value might indicate
A. Pulmonary embolism
B. Pulmonic stenosis
C. Tricuspid regurgitation
D. Mitral valve dysfunction
D. Mitral valve dysfunction
LAP is usually 8. Pulmonic stenosis or tricuspid regurgitation would cause high RA pressures.