[Judgement of the left ventricle retraining in the rapid two stage-switch operation].

OBJECTIVES

To Summarize the results of left ventricle retraining in rapid two-stage switch operation and to determine the estimating index of left ventricle retraining and the best time of the second stage operation.

METHODS

From September 2002 to September 2007, 21 patients underwent rapid two stage switch operation. There were 13 male and 8 female patients, ageing from 29 to 250 d [mean (103 ± 69) d, median 75 d], weighting from 3.5 to 7.0 kg [mean (5.0 ± 1.2) kg, median 5.0 kg]. After pulmonary band, bedside echocardiography was regularly done every other day. Paired t-test was used to analyze the changes of left ventricular end-diastolic dimension (LVDd), left ventricular posterior wall dimensions (LVPWd), diastolic intra-ventricular septal dimensions (IVSd), left ventricular (LV) mass and LV mass indexed for body surface area.

RESULTS

The mean interval was (9 ± 5) d. After the left ventricle preparative operation, the left ventricular to right ventricular pressure ratio (pLV/RV) raised from 0.47 ± 0.15 to 0.91 ± 0.20 (P < 0.01). LV mass indexed for body surface area raised from (30 ± 11) g/m(2) to (60 ± 20) g/m(2) (P < 0.01). Extremely significant difference of LV mass existed between pre-arterial switch operation and pre-left ventricle preparative operation, and significant difference existed in LVDd, LVDd(3), LVPWd and IVSd between the two operative timing points.

CONCLUSIONS

The left ventricular function of the transposition of the great arteries can be retraining by the left ventricle preparative operation. The interval of left ventricle retraining should be controlled in 7 to 10 d, and the pLV/RV reach 0.65 and the LV mass index over 50 g/m(2) are two important indicators of the second stage operation of arterial switch operation.