MedCram Lecture: Jugular Venous Pulse (JVP)

Overview

• Focus on understanding and measuring the Jugular Venous Pulse (JVP).
• Importance of JVP in diagnostic considerations and waveform interpretation.
• Concentrates on the right side of the heart, particularly the internal jugular vein and SVC.

Methods to Measure JVP

1. Central Line Output:

   • Insert a central line into the internal jugular vein extending to the SVC.
   • Direct measurement from the right atrium extension.

2. Visual Observation:

   • Observe the patient's JVP near the sternocleidomastoid (SCM) region while they are lying down.

Central Venous Pressure Measurement

• Measure at end of exhalation during both spontaneous breathing and ventilator-assisted breathing.

Spontaneous Breathing:

• Intrathoracic pressure decreases on inhalation and increases on exhalation.
• Measure at the peak of exhalation.

Ventilator Breathing:

• Intrathoracic pressure increases during inhalation due to positive pressure.
• Measure at the baseline of exhalation.

Jugular Venous Waveform Analysis

• Central line measures pressure in the internal jugular vein at the SVC tip.

Factors Affecting Pressure:

• Pressure Decrease:

  • Atrial relaxation (volume expansion).
  • Tricuspid valve opening (blood transfer to the right ventricle).

• Pressure Increase:

  • Atrial contraction (volume compression).
  • Tricuspid valve closure (increased pressure due to blood accumulation).

Waveform Components

• A wave: Atrial contraction.
• C wave: Ventricular contraction or carotid artery impact.
• X descent: Atrial relaxation.
• V wave: Filling of the right atrium ("veiling").
• Y descent: Blood transfer from atrium to ventricle.

Summary of Waveform Cycle

• A wave: Marks atrial contraction.
• C wave: Initiates with right ventricular contraction or carotid impact.
• X descent: Indicates atrial relaxation.
• V wave: Represents atrial filling.
• Y descent: Reflects atrial to ventricular blood transfer.

Conclusion

• This understanding is crucial for diagnosing various cardiac conditions.
• Future discussions will explore pathology and diagnostic utility of these waveforms.