Between January 1997 and March 1998 aortic valve replacement was performed in 36 patients whom divided in two groups. Group I consisted of 18 patients receiving either 19 or 21 mm St. Jude mechanical valves and group II consisted of 18 patients receiving either 23mm or larger sizes St. Jude mechanical valves. The clinical and echocardiographical studies were performed before the operation and postoperative period.
There was no operative or late mortality in both groups. The morbidity was similar in two groups. There was a significant reduction of transvalvular gradient in group I and group II. Left ventricular ejection fraction was slightly increased in both groups. Left ventricular end-diastolic and end -systolic diameters were not significantly changed while interventricular septum and posterior wall thickness were regressed significantly in both group.
These data show that 19 and 21 mm mechanical St. Jude valves exhibit equally favorable hemodynamic performance with minimal transvalvular gradient. The use of small aortic valve prosthese in selected cases does not adversely affect the incidence of early or late mortality or cardiac events.