SPECIFIC SEQUELAE AFTER FONTAN OPERATION AT MIDTERM AND LONG-TERM FOLLOW-UP - ARRHYTHMIA, LIVER DYSFUNCTION, AND COAGULATION DISORDERS

Patients who have undergone a Fontan-type operation usually have an el evated systemic venous pressure. To determine the sequelae of this non physiologic condition, we evaluated 66 patients 1 to 14 years after a Fontan-type operation. Fifty-one patients were apparently in good clin ical condition, and 15 patients had symptoms and were restricted in th eir daily life. Bicycle exercise capacity, tested in 41 patients, rang ed from 50% to 110% (mean 85%) of the predicted value for length. In 1 6 patients, a decreased capacity (<85%) was, among others, related to arrhythmias and the presence of protein-losing enteropathy. A 24-hour ambulatory electrocardiogram was available in 56 patients and found to be normal in 32 (57%) patients. Arrhythmias were present in 21 patien ts, six of whom had symptoms. Three patients had previous pacemaker im plantation. One or more abnormalities in liver enzyme and function tes ts were present in 40 patients (61%) and in coagulation factors in 46 patients (69%). The most pronounced was a protein C deficiency, a know n thrombotic risk factor, present in 41 patients. The occurrence of ar rhythmias increased with time of follow-up (p < 0.004), the occurrence of protein C deficiency decreased with time (p < 0.0001), and the occ urrence of abnormal liver enzyme and function tests was not related to time of follow-up. With regard to age at operation, arrhythmias did n ot occur in patients who underwent operation at a mean age of 4 +/- 1. 9 years (standard deviation), in contrast to patients who underwent op eration at a mean age of 7.6 +/- 4 years (standard deviation) (p < 0.0 01). The occurrence of the two other types of sequelae was not related to the age at operation. With regard to the type of operation, only p atients with a valved right atrium-to-pulmonary artery connection had a higher prevalence of arrhythmias than patients with a nonvalved or d irect right atrium-to-pulmonary artery connection (p less-than-or-equa l-to 0.001). The latter patients also had a higher prevalence of prote in C deficiency (p less-than-or-equal-to 0.001). No relationship was f ound among the other types of operation, the underlying structure, or the hemodynamic condition measured at rest and the presence of arrhyth mias, abnormal liver enzyme and function tests, or protein C deficienc y. This point survey shows that even patients with an apparently good clinical condition are at risk for arrhythmias, abnormal liver enzyme and function tests, and coagulation factor abnormalities. Serial state ment of affairs is recommened to ensure that adequate preventive measu res can be taken.