The myocardial performance index in children with isolated left-to-right shunt lesions.
OBJECTIVE
The myocardial performance index (MPI) measures the ratio of isovolumic time intervals to ventricular ejection time. The effects of altered ventricular preload or afterload on MPI have yet to be determined. This study was designed to determine the impact of altered preload on left and right ventricular myocardial performance index in the clinical setting of left-to-right lesions.


METHODS
The left and right ventricular myocardial performance indexes were measured in 17 patients with atrial septal defect (ages 6 to 148 months), 23 patients with ventricular septal defect (ages 2 to 160 months), and 24 healthy children (ages 3 to 160 months). A complete 2- dimensional and Doppler echocardiographic examination was performed in all study groups.


RESULTS
In patients with atrial septal defect, ventricular septal defect, and control group subjects, the left ventricular MPI was 0.38, 0.37 and 0.32, respectively, and the right ventricular MPI was 0.24, 0.21, and 0.20, respectively. No significant differences in the left and right ventricular myocardial performance indexes were seen between patients with left-to-right shunt lesions and control subjects.


CONCLUSIONS
This study documents that the myocardial performance index is a quantitative measure of ventricular function that appears to be relatively independent of changes in preload.
Baysal
Tamer
T
Section of Pediatric Cardiology, Department of Pediatrics, Meram Medical Faculty, Selçuk University, Konya, Turkey. tbaysal2@yahoo.com
Oran
Bülent
B
Doğan
Mustafa
M
Cimen
Derya
D
Karaaslan
Sevim
S
D000293:Adolescent; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D018618:Echocardiography, Doppler, Color; D005260:Female; D006330:Heart Defects, Congenital / Q000000981:diagnostic imaging / Q000503:physiopathology*; D006344:Heart Septal Defects, Atrial / Q000000981:diagnostic imaging / Q000503:physiopathology*; D006345:Heart Septal Defects, Ventricular / Q000000981:diagnostic imaging / Q000503:physiopathology*; D006801:Humans; D007223:Infant; D008297:Male; D009200:Myocardial Contraction; D011237:Predictive Value of Tests; D012720:Severity of Illness Index; D016276:Ventricular Function