Postoperative evaluation of left ventricular peak filling rate and peak ejection rate by radionuclide ventriculography for aortic regurgitation
Natsuaki, M.; Itoh, T.; Ohteki, H.; Naito, K.; Sakai, H.; Horita, K.; Ueno, T.; Minato, N.
Nihon Kyobu Geka Gakkai 40(3): 375-381
1992
ISSN/ISBN: 0369-4739 PMID: 1583361 Document Number: 394665
Postoperative left ventricular (LV) time-activity curve and the first derivative in radionuclide method were evaluated in 28 patients with arotic regurgitation to clarify the postoperative cardiac function and to determine the adequate timing of operation. Twenty-eight patients were divided into two groups by preoperative echocardiogram. In Group I cases, echo-finding showed LV contractile dysfunction associated with both enlarged LV end-systemic dimension (LVDs) over 5 cm and depressed fractional shortening (%FS) below 25. In group II cases, the finding showed compensated cardiac function with relatively small LVDs below 5 cm or not so depressed %FS over 25%. Preoperative diastolic parameters of LV peak filling rate (PFR) in Groups II of 22 cases was depressed in comparison of normal control, although systolic parameters of peak ejection rate (PER) or ejection fraction were mildly depressed. Postoperatively, those parameters of PFR and PER were improved to normal control level (1. PFR: pre op = 206 .+-. 73 .fwdarw. post op = 311 .+-. 79, p < 0.001 2. PER: pre op = 309 .+-. 65 post op = 389 .+-. 103 %EDV/sec. p < 0.001). In contrast, the preoperative parameters of PFR and PER in Group I of 6 cases were strikingly mpaired, and post-operative those parameters were not improved to normal level (1 PFR: op = 154 .+-. 39 .fwdarw. post op = 190 .+-. 88 PER; pre op = 233 .+-. 74 .fwdarw. post op = 244 .+-. 78 %EDV/sec, NS). No postoperative complications occurred in Group II cases, in contrast 2, cases in Group I were complicated with low output syndrome or ventricular fibrillation. The ratio of end-systolic wall stress to end-systolic volume index (ESWS/ESVL ratio) as a predictor of contractile function was depressed in Group I (the ratio: Group I = 1.8 .+-. 0.5 Group II = 2.8 .+-. 1.5 Kdyn/cm2/ml/m2, p < 0.05). The ratio was correlated with preoperative PERR, and depressed PER was suggestive of contractile dysfunction. Preoperative depressed PER in Group I was not recovered to control level at one month after surgery. The operation for aortic regurgitation is strongly recommended when echographic findings show enlarged LVDs over 5 cm accompanied with depressed %FS below 25%, or radionuclide data reveal depressed PER below 250% EVD/sec.