Premium
Validation Study of Doppler‐derived Trans m itral Valve Gradients Compared to Near Simultaneously Obtained Directly Measured Catheter Gradients Immediately After Mitral Valve Repair Surgery
Author(s) -
Vernick William J.,
Ochroch E. Andrew,
Horak Jiri,
Hammond Mary,
Hargrove W. Clark
Publication year - 2013
Publication title -
journal of cardiac surgery
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.428
H-Index - 58
eISSN - 1540-8191
pISSN - 0886-0440
DOI - 10.1111/jocs.12125
Subject(s) - medicine , preload , catheter , cardiology , mitral valve , doppler effect , cardiopulmonary bypass , doppler echocardiography , diastole , pressure gradient , hemodynamics , surgery , blood pressure , physics , astronomy , mechanics
Objective To evaluate the accuracy of Doppler‐derived transmitral valve gradients immediately after mitral valve repair by comparing them with near simultaneously obtained direct catheter gradients. Design A prospective study. Setting A tertiary care medical center. Participants Twenty elective adult surgical patients presenting for mitral valve repair surgery. Methods Mitral valve surgery proceeded in standard fashion except for the use of a smaller than usual left ventricular vent catheter (Medtronic DLP 10 French left heart vent catheter). After completion of the mitral valve repair and subsequent cardiac de‐airing, the patient was weaned from cardiopulmonary bypass. Immediately after separation, the study period began. Near simultaneous transmitral Doppler gradients were obtained with directly measured catheter gradients via the vent catheter. Results While the mean peak gradient difference of 1.1 mmHg was small (p‐value 0.18, 95% CI: −0.54 to 2.73 mmHg), the correlation between Doppler and catheter gradient measurements (Pearson correlation coefficient r = 0.54, p = 0.055) only approached statistical significance due to the large variance associated with the small sample size. In all patients with a peak gradient greater than 10 mmHg (4 of the 20 patients), overestimation of catheter gradients by Doppler occurred, with two showing a 62% to 73% discrepancy. In these two cases, there was also evidence for elevated left ventricular end‐diastolic pressure (LVEDP) along with high transmitral blood flow velocities. Conclusion Doppler‐derived transmitral gradients provide a simple, safe, and reliable measure of the true physiologic transmitral valve gradient. At the same time, it is important to recognize that significant Doppler over‐estimation of catheter gradients may occur in patients with elevated Doppler transmitral velocities. The causes of these overestimations are unknown. They may be related to technical recording errors. They may also be related to an inherent weakness in Doppler technology—its inability to account for any distal recovery of pressure, which in a select group of patients could be significant. doi: 10.1111/jocs.12125 (J Card Surg 2013;28:329–335)