MRI-RADIOFREQUENCY TISSUE TAGGING IN PATIENTS WITH AORTIC-INSUFFICIENCY BEFORE AND AFTER OPERATION

Background. Magnetic resonance imaging tissue tagging is a relatively recent methodology that describes ventricular systolic function in ter ms of intramyocardial ventricular deformation. Because the analysis in volves the use of many intramyocardial points to describe systolic def ormation, it is theoretically more sensitive at describing subtle diff erences in regional myocardial fiber shortening when compared with con ventional measures of ventricular function such as wall thickening. Th e objectives of this study were (1) to define sensitive indices of ven tricular systolic deformation to assist the clinician in the surgical evaluation of patients with aortic insufficiency, and (2) to quantify differences in regional systolic deformation before and after surgery for aortic insufficiency. Methods. Magnetic resonance imaging with tis sue tagging was performed on 10 normal volunteers and 8 patients with chronic severe aortic insufficiency. Follow-up postoperative studies ( 5.4 +/- 1.1 months) were obtained in 6 patients who underwent Ross pro cedure (1 patient), David procedure (1), and St. Jude aortic valve rep lacement (4). Results. There was no significant difference in fraction al area change, overall circumferential shortening, or overall radial thickening among the normal group, the preoperative aortic insufficien cy group, or the postoperative aortic insufficiency group. However, on a regional basis, there was a decrease in posterior wall circumferent ial strains in the postoperative aortic insufficiency group (29% +/- 1 3% preoperative aortic insufficiency (n = 6) versus 24% +/- 12% postop erative aortic insufficiency (n = 6), p = 0.02). Conclusions. On regio nal analysis, there was a small but significant decrease in posterior wall circumferential shortening after operation. Magnetic resonance im aging tissue tagging is a sensitive and clinically applicable method o f quantifying regional ventricular wall function before and after inte rvention for aortic insufficiency. (C) 1998 by The Society of Thoracic Surgeons.