CVT Hemodynamic Monitoring 3 — Questions and Answers
Question 1: In a patient with cardiac tamponade, which hemodynamic pattern is classically observed?
- Equalization of diastolic pressures in all cardiac chambers (Correct answer)
- Markedly elevated cardiac output
- Decreased right atrial pressure
- Widened pulse pressure
Correct answer: Equalization of diastolic pressures in all cardiac chambers
Cardiac tamponade causes equalization of right atrial, right ventricular diastolic, pulmonary artery diastolic, and PCWP pressures due to external compression.
Question 2: Which condition is most associated with an elevated pulmonary vascular resistance (PVR) with a normal PCWP?
- Primary pulmonary hypertension (Correct answer)
- Mitral stenosis
- Left ventricular failure
- Aortic regurgitation
Correct answer: Primary pulmonary hypertension
Primary pulmonary hypertension elevates PVR due to intrinsic pulmonary vascular disease while PCWP remains normal, distinguishing it from left-sided causes.
Question 3: Normal mixed venous oxygen saturation (SvO₂) is approximately:
- 60–75% (Correct answer)
- 95–100%
- 40–55%
- 80–90%
Correct answer: 60–75%
Normal SvO₂ from the pulmonary artery is 60–75%, reflecting the balance between oxygen delivery and consumption by peripheral tissues.
Question 4: A patient's SvO₂ suddenly drops from 70% to 48%. Which condition should be suspected FIRST?
- Decreased cardiac output (Correct answer)
- Pulmonary embolism causing V/Q mismatch
- Increased FiO₂
- Catheter tip in wedge position
Correct answer: Decreased cardiac output
A sudden SvO₂ drop most commonly indicates reduced cardiac output, causing tissues to extract more oxygen from a diminished supply.
Question 5: Which hemodynamic profile is consistent with hypovolemic shock?
- Low CVP, low PCWP, low CO, high SVR (Correct answer)
- High CVP, high PCWP, low CO, low SVR
- Low CVP, high PCWP, high CO, low SVR
- Normal CVP, normal PCWP, high CO, normal SVR
Correct answer: Low CVP, low PCWP, low CO, high SVR
Hypovolemic shock produces low filling pressures (CVP, PCWP), reduced cardiac output, and compensatory vasoconstriction (high SVR).
Question 6: The 'v' wave in the pulmonary artery wedge (PCWP) tracing represents:
- Passive ventricular filling with mitral valve open (Correct answer)
- Atrial contraction
- Mitral valve closure
- Isovolumetric relaxation
Correct answer: Passive ventricular filling with mitral valve open
The 'v' wave reflects passive filling of the left atrium during ventricular systole while the mitral valve is closed.
Question 7: Pulse pressure variation (PPV) >13% during mechanical ventilation most reliably predicts:
- Fluid responsiveness (Correct answer)
- Cardiac tamponade
- Pulmonary edema
- Systemic hypertension
Correct answer: Fluid responsiveness
PPV >13% in mechanically ventilated patients indicates significant preload dependence, predicting that cardiac output will increase with fluid administration.
CVT Hemodynamic Monitoring 3
In a patient with cardiac tamponade, which hemodynamic pattern is classically observed?