Abnormal CVP waveform.

Sir,

A 52-year-old male patient was scheduled for coronary artery bypass grafting. Patient's echocardiography findings revealed no tricuspid regurgitation or stenosis with good right ventricular function. Preoperatively central venous line was inserted through right internal jugular vein. After insertion, central venous pressure (CVP) waveform showed abnormal large a-c wave complex (Figure 1 – marked with red arrow) and CVP value was in the range of 10-12 mm Hg. Such wave pattern may resemble a cannon “a” wave of CVP.[12] Transesophageal echocardiography was done which demonstrated lower end of central venous catheter getting abutted with tricuspid valve early in the systole. This explained the mechanism of such abnormal CVP waveform. When central venous catheter was pulled back at the insertion point, CVP waveform showed normal waves and CVP values was in the range of 4-6 mm Hg [Figure 2]. It is important to ascertain the position of central venous line before interpreting waveform.

Figure 1

Abnormal CVP waveform marked with arrow

Figure 2

CVP waveform after pulling central venous catheter