Can 'v' waves be seen on the Central Venous Pressure (CVP) tracing in patients with Junctional Ectopic Tachycardia (JET) or Atrial Ectopic Tachycardia (AET)?

Visualization of 'v' Waves on CVP Tracing in JET and AET

Yes, 'v' waves can be seen on Central Venous Pressure (CVP) tracing in patients with Junctional Ectopic Tachycardia (JET) and Atrial Ectopic Tachycardia (AET), though their characteristics may differ from normal sinus rhythm.

Understanding CVP Waveforms in Normal and Abnormal Rhythms

• The normal jugular venous pulse (JVP) waveform, which corresponds to CVP tracing, consists of three main components: the "a" wave (atrial contraction), "c" wave (tricuspid valve closure), and "v" wave (passive atrial filling against a closed tricuspid valve) 1
• In JET, which originates from enhanced automaticity in the atrioventricular node and His bundle area, the P wave is often not visible on surface ECG because it is masked by the QRS complex 2, 3
• Despite the altered atrial activation sequence in JET, the "v" wave remains visible on CVP tracing as it represents passive atrial filling against a closed tricuspid valve, which occurs independently of the atrial activation pattern 4

Characteristics of 'v' Waves in JET

• In JET, there is often atrioventricular dissociation, with the ventricular rate typically faster than the atrial rate 2
• The "v" wave in JET may appear more prominent or altered in timing compared to normal sinus rhythm due to the dissociation between atrial and ventricular activity 4
• CVP waveform analysis can be particularly valuable in pediatric patients with JET following congenital heart surgery, where the arrhythmia mechanism can be challenging to diagnose from surface ECG alone 2

Characteristics of 'v' Waves in AET

• In AET, the atrial activation sequence is abnormal but regular, originating from an ectopic focus in the atrium 2
• The "v" wave remains present on CVP tracing in AET as the fundamental cardiac mechanics of ventricular contraction and subsequent passive atrial filling still occur 1
• The timing of the "v" wave relative to the QRS complex may be altered in AET compared to normal sinus rhythm, reflecting the changed relationship between atrial and ventricular activation 2

Clinical Significance and Detection

• CVP waveform analysis can serve as a complementary diagnostic tool to ECG in identifying and differentiating arrhythmias, especially when ECG measurements are unavailable or corrupted 4
• Recent research has shown that CVP features can reliably detect JET with comparable results to ECG-based diagnosis 4
• For accurate assessment of CVP waveforms, proper patient positioning (30-45 degrees elevation) and identification of the highest point of pulsation in the internal jugular vein are essential 1

Potential Diagnostic Challenges

• The visualization of "v" waves may be affected by factors such as tricuspid regurgitation, which can cause prominent "c-V" waves that may alter the typical appearance 1
• In patients with rapid heart rates, the individual components of the CVP waveform may become difficult to distinguish as they merge together 1
• Careful correlation with ECG and echocardiography is often necessary for accurate interpretation of CVP waveforms in complex arrhythmias 2