Induction of anesthesia does not alter tricuspid annular velocities: a tissue Doppler assessment

In this prospective observational cohort study, we investigated whether tricuspid annular velocities (TAV) are altered after induction of anesthesia in patients undergoing coronary artery bypass graft (CABG) surgery.

Twenty-four elective CABG patients were assessed before and after induction of anesthesia, and a convenience sample of nine healthy volunteers was used for comparison of TAV only. Measurements included mean arterial pressure (MAP), heart rate (HR), pulmonary artery pressure (PAP), and cardiac index (CI) as assessed post-induction. Tricuspid annular plane systolic excursion (TAPSE) was measured in anatomical M-mode. The S (systolic) wave velocity and isovolemic acceleration (IVA) were measured from colour tissue Doppler (TD). Paired and unpaired Student's t tests were used to compare all variables pre-and post-induction.

In response to anesthetic induction, MAP decreased from 105 +/- 14 to 79 +/- 9 mmHg, but HR was unchanged (67 +/- 13 beats x min(-1) pre-induction compared with 67 +/- 9 beats x min(-1) post-induction). The mean PAP and CI post-induction were 20 +/- 6 mmHg and 2.3 +/- 0.4 L x min(-1) x m(-2), respectively. While there was no change post-induction in either S velocity (8.80 +/- 1.23 vs 9.0 +/- 1.92 cm x sec(-1)) or IVA (1.63 +/- 0.61 vs 1.84 +/- 0.83 m x sec(-2)), TAPSE decreased from 23 +/- 4 to 21 +/- 4 mm (P = 0.039). All pre-induction echocardiographic variables were lower in the CABG group compared with the normal group (IVA: 2.34 +/- 0.34 m x sec(-2), S wave: 11.14 +/- 2.78 cm x sec(-1), TAPSE 2D: 26 +/- 4 mm), respectively.

Induction of anesthesia for CABG surgery does not alter velocity-based parameters of RV function. There was a small decrease in TAPSE. The TD parameters were lower in CABG patients compared with the normal group.