Evaluation of left ventricular function in chronical pressure load and the immediate changes after operative relief

Cardiac function and changes following surgery was studied with computerized M-mode echocardiography in 10 patients with left ventricular pressure load, mainly valvular aortic stenosis. Six of the patients were below 15 years of age. In the adults an unfavourable reduction of shortening fraction and VCF was encountered, whereas no such reaction was seen in the pediatric group. Both groups had a significant (p less than 0.005) drop in LV ejection time. In general, however, the study demonstrated a different reaction to surgery in children and adults, the peak rate of decrease of diameter (RDD) increased in children, and remained more or less unchanged in adults, and the normalized RDD acted similarly. The time for NRDD after QRS onset was reduced in all patients, but more obvious in children. The peak rate of increase of diameter (RID) was unchanged in both groups, but demonstrated an insignificant fall on the first postoperative day in adults. The study demonstrates different ways of reacting to surgery in pressure loaded adult and childhood left ventricles. We think these differences can be explained by less damaged myocardium in the pediatric age group.