The regurgitation fraction (RF) despite dependence on many factors remains a valuable quantitative index in chronic aortic regurgitation (AR) assessment. In order to verify échocardiographie (Echo) estimation of this parameter a comparison with radionuclide ventriculography (RNY) values was done. 35 patients with chronic pure AR, 30 male, 5 female, mean age 35.5 ± 11.2 years (18-70 years) were examined. Echo RF was calculated according to the formula: RF = [(LVSY - RVSV)/LVSV] x 100, where LVSY and RVSV are the left and right ventricular stroke volumes; LVSV or RVSV = CSA x VFI, CSA = n (D/2)^2, where CSA = aortic or pulmonary cross-sectional area, D = aortic or pulmonary ring diameter, VFI = aortic or pulmonary velocity flow integral. On the following 0-22 days (mean 7 ± 5.12), gated equilibrium RNA with red blood cell-labelled 99mTc were done. All images were obtained with a small field of view Cardiac (Siemens) gamma camera with a Max Delta computer system. The study was done with a high-sensitivity colimator and contained 6 million counts (250 thousand/frame). RF calculation is based on the visual images of the end-systolic, enddiastolic counts and stroke volume of both ventricles. RNA RF was calculated according to the formula: RNA RF = [(LVEDc - LVESc) - (RVEDc - RVESc)/(LVEDc - LVESc)] x 100, where LVEDc, RVEDc, LVESc, RVESc are the left and right ventricular end diastolic and end systolic stroke counts. The mean Echo RF value was: 54.29 ± 12.44% (21-74%) and the meanRNVRF 52.06 ± 13.16% (17—80%). The correlation coefficient between the Echo and RNV RF was r = 0.68, p < 0.0001 (Pearson’s test). Excluding 9 patients with normal left ventricular internal diastolic dimension (LVIDD) (< 5.6 cm) increased the correlation coefficient up to r = 0.84, p < 0.0001. Using paired Student’s t test no significant difference between Echo and RNV RF was found. The mean difference of the RF values obtained with the two methods was -2.23 ± 10.17%. The highest discrepancy has occurred only in 4 patients with normal LVIDD (-30 to +25%).

We present a rare complication of infective endocarditis, perforated periaortic abscess with fistulous communication between the aortic root, the left atrium, and the left ventricular outflow tract. Preoperative transthoracic echocardiographic diagnosis was confirmed intraoperatively. The patient was treated successfully by aortic homograft implantation.