The purpose of this retrospective study was to evaluate the outcome of mitral regurgitation (MR) following repair of atrioventricular septal defects (AVSDs). Echocardiograms of all survivors after AVSD surgery between 1991 and 1996 were reviewed. This study enrolled 16 patients who had had more than two postoperative color Doppler studies. On each echocardiogram, MR severity was graded on a 1+ to 4+ scale, based on the size of the MR jet. Mean age at surgery was 31.1 months (range 2.5 to 83) and mean postoperative follow-up duration was 23.6 months (range 1 to 59). Mild deterioration of mitral valve function was common. MR severity increased by one or more grades in 5 patients (31%) between the initial and final examinations. However, the deterioration in mitral valve function occurred primarily on the immediate postoperative stage. On mid-term follow-up, the MR improved, or at least became stationary, in all patients. Mitral valvuloplasty was not necessary in surviving patients. We conclude that postoperative MR remains fairly stable following AVSD repair. Serious deterioration is rare.

Child↗

PubMedDate not supplied

Effect of prokinetic agents, cisapride and metoclopramide, on the bioavailability in humans and intestinal permeability in rats of ranitidine, and intestinal charcoal transit in rats.

To investigate the effect of two prokinetic drugs, cisapride and metoclopramide, on the bioavailability of drugs, a marker drug, ranitidine, was administered to healthy volunteers following pre-treatments with or without the prokinetic agents. Cisapride or metoclopramide HCl (a respective dose of 10 mg) was administered orally 30 min prior to an oral administration of ranitidine (300 mg). Serum samples were collected for a 12 h period after the administration of ranitidine and the concentration of ranitidine was determined by an HPLC method. The bioavailability parameters of the groups with the prokinetic agent pretreatment were compared with those of the control group. In addition, the effects of these prokinetic drugs on the in vitro apparent permeability of ranitidine across the rat jejunum in the Ussing chamber, and on the in vivo intestinal transit of charcoal meals in rats were also examined. The Tmax of ranitidine in human subjects was shortened significantly by the either of the pretreatments (i.e., with cisapride and metoclopramide). The AUC(inf) of ranitidine in human subjects was also decreased significantly in the case of cisapride pretreatment. However, no changes were observed for the values of Cmax and T(1/2) by the pretreatments. Rat studies revealed that cisapride and metoclopramide had no influence on the in vitro permeability of ranitidine or the in vivo intestinal transit of charcoal meals. Therefore, these data indicated that the changes in the bioavailability parameters (i.e., Tmax and AUC(inf)) in humans are not related with the intestinal permeability or intestinal transit of ranitidine. The shortened Tmax of ranitidine appears to be due to accelerated gastric emptying of the drug. However, underlying mechanisms for the decreased AUC(inf) of ranitidine in the case of cisapride pretreatment are currently unclear.

Adult↗