Left Ventricular Re-training: Feasibility and Effectiveness-What Are the Limits?

ABSTRACT

The concept of 're-training' the morphologic left ventricle (mLV) is based on the crude principle of applying a fixed afterload by means of pulmonary artery banding. The complex physiological, molecular and structural responses to banding are poorly understood, and complicated by the fact that re-training is undertaken in a variety of different morphological settings and age-groups. This article reviews the evidence for re-training in different situations with particular focus on the age at banding and on the best ways to assess suitability for subsequent repair. Particular importance is placed on the role of re-training in congenitally corrected transposition as this is the commonest current indication - looking at better ways to train the mLV, the role of combined pressure and volume loading, and more sophisticated ways of assessing the adequacy of training. Current evidence suggests that age at banding has a fundamental impact on ability to re-train and long-term mLV function with the best results being achieved in infancy and concerns at any attempt beyond 2 years of age.