Why the systemic right ventricle can fail in operated TGA

Why the systemic right ventricle can fail in operated TGA

There are various reasons why a systemic right ventricle can fail in operated transposition of the great arteries in case of atrial based repairs. Basically the structure of the right ventricle is not meant to be a systemic pump. It is meant to be a low pressure generating pump for the pulmonary circulation. In atrial based repair of transposition of great arteries or in congenitally corrected transposition of great arteries, the systemic right ventricle has to face the high pressure high resistance circuit of the systemic circulation instead of the low pressure low resistance pulmonary circulation. More over coronary circulation maintained by a right coronary artery may not be adequate for the right ventricle to function as a systemic pump. Myocardial damage produced by severe hypoxia prior to surgery is another potential factor leading to myocardial dysfunction. Insufficient perioperative myocardial protection can also be another contributory factor in some cases.