Intraoperative assessment of mitral regurgitation: role of phenylephrine challenge.

OBJECTIVES We defined the effects of the operative (OP) state and phenylephrine challenge on the assessment of mitral regurgitation (MR) severity. METHODS In all, 57 patients underwent transesophageal echocardiographic assessment of MR severity pre-OP (PREOP) and intra-OP. MR severity was assessed PREOP under conscious sedation and intra-OP with general anesthesia, before and after hemodynamic manipulation with vasoactive agents, to match intra-OP and PREOP transesophageal echocardiographic mean arterial blood pressures. RESULTS Intra-OP MR and mean arterial pressure were less than PREOP in 27 patients (both P < .001). When PREOP and OP blood pressures were matched using phenylephrine, there was no significant difference in MR severity between the two states (P = 1.0). Nonetheless, MR severity was still underestimated in 6 patients and overestimated in 7 patients intra-OP. CONCLUSIONS Intra-OP transesophageal echocardiography underestimates MR severity. Phenylephrine reduces, yet does not eliminate, intra-OP underestimation of MR severity.