Table 2. Regurgitation of Blood Flow through the Internal Jugular Vein Valve: Distribution of Patients in a Semiquantitative Five-grade Scale

Data are number of patients. Based on these raw data, diagnosis of induced valvular incompetence was made if a > 1-grade increase in regurgitation occurred after insertion of a central venous catheter into the internal jugular vein compared with the preoperative baseline finding.

* Grade 0 on the semiquantitative five-grade scale represents no regurgitation of blood flow through the internal jugular vein valve during a Valsalva maneuver, grade 5 maximal regurgitant flow (as defined in detail in Patients and Methods).

Preop = preoperative study; Postop = postoperative study.