Alteration in Cardiac Function

Question 1

Cardiac Output (CO)

Answer 1

• Amount of blood pumped out by a ventricle every minute

- 4 - 8 L/min

Question 2

Cardiac Index (CI)

Answer 2

• Cardiac output individualized to patient body surface area (size)
• 2.5 - 4.2 L/min /m2

Question 3

Central Venous Pressure (CVP)

Answer 3

• Pressure created by volume of blood in right heart used to guide assessment of fluid balance and responsiveness
• 2 - 6 mmHg

Question 4

Stroke volume (SV)

Answer 4

• Amount of blood ejected from the ventricle with each contraction
• 60 - 130 ml/beat

Question 5

Ejection Fraction (EF)

Answer 5

• Fraction of blood ejected with each heartbeat
• 60% to 70% is normal
• 30% or less very high risk for sudden cardiac death
• Very subjective. not exact measurement.

Question 6

Hemodynamic Monitoring

Answer 6

Primary goal is to assess and trend adequacy of tissue perfusion.

Noninvasive Monitoring
NIBP
JVD: Normal is 7 - 9 cm
Lactate: Normal is 0.5 - 1.6 mEq/L

IF BOUNDING NECK VEINS AT 45 HOB => VOLUME OVERLOAD

Question 7

Invasive Hemodynamic Monitoring

Answer 7

Arterial pressure monitoring
  - A-line
Pulmonary artery pressure monitoring 
  - PA catheter: “Swan Ganz”
Right atrial pressure monitoring
  - RAP / CVP 

IN ORDER TO ENSURE DATA ACCURACY, THE SYSTEM MUST BE CALIBRATED TO ATMOSPHERIC PRESSURE BY ZEROING THE TRANSDUCER. STOPCOCK PROPERLY LEVELED TO THE PHLEBOSTATIC AXIS. (4 ICS - R ATRIUM)

FLAT IS BETTER - AT 30 HOB IS OK

Question 8

Accuracy of Invasive Hemodynamic Monitoring

Answer 8

• Four major components for validating accuracy:
  
  • Patient positioning
  • Zeroing the transducer: zero reference
    > Negates atmosphere pressure
  • Zeroing stopcock is leveled at phlebostatic axis and ‘zeroed’
  • Assessing dynamic responsiveness (square wave test)

Question 9

RAP/CVP monitor

Answer 9

Right Atrial Pressure (RAP):

• Catheter in right atrium
• Proximal port of pulmonary artery catheter

Central Venous Pressure (CVP):

• Catheter in superior or inferior vena cava
• Triple lumen
• PICC

Values similar and terms interchanged

• CVP/RAP normal range: 2-6mm Hg
• Recorded at end of exhalation as mean value

Question 10

Complications of RAP/CVP

Answer 10

• Infection
• Pneumothorax or hemothorax (x-ray following insertion)
• Carotid puncture
• Heart perforation
• Dysrhythmias

Question 11

Pulmonary Artery Pressure Monitoring

Answer 11

Pulmonary artery catheter (PAC)

• Dr’s. Swan and Ganz
  
  • Swan-Ganz is a brand

Reflects left ventricular function (the only one)

Question 12

Cardiac enzymes

Answer 12

• CK (total): elevated 2 to 6 hrs; peak 18 to 36 hrs p onset of myocardial heart damage; levels return to baseline in 3 to 6 days
• CK-MB (cardiac specific): elevated 4 to 8 hrs; peak 18 to 24 hrs p onset of damage; returns to baseline in 3 days
• Troponin I and T: ELEVATED AS EARLY AS 1 HR P INJURY
• Myoglobin: Released 30 to 60 minutes after injury. Normal values are less than 72 for males and less than 58 female

Question 13

Post-catheterization care

Answer 13

• Bed rest, HOB no higher than 30 degrees
• monitor bleeding; newer collagen agents for hemostasis may be used
• monitor pulses
• antiplatelet drugs p procedure
• may be discharged in 6 to 8 hrs; depends on diagnosis and procedures done in cath lab

Question 14

CAD

Answer 14

Progressive narrowing or occlusion of coronary arteries usually due to atherosclerosis.

• CAD results in ischemia when the internal diameter of the coronary vessel is reduced by 70%
• Clinical manifestations
  
  • angina
  • acute coronary syndrome (ACS)
  • sudden cardiac death
• Risk factors
  
  • modifiable: smoking, diet, exercise
  • non-modifiable: genetics, age (males-mid 40s), gender (males)