[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.