Special problems in cyanotic CHD with natural survival to adulthood
The important congenital heart diseases with cyanosis who survive without the possibility of a therapeutic intervention into adulthood are Eisenmenger syndrome, univentricular heart, Ebstein’s anomaly of the tricuspid valve. Though these individuals have a serious symptomatic cardiac problem, surgical risk is often higher than that of the natural history. Heart lung transplantation and single lung transplantation with surgical correction of the cardiac lesion may be the option in some of these cases, though with a lot of associated problems and logistic issues. Many of these patients have serious complications like profuse hemorrhage (hemoptysis), infective complications like cerebral abscess and sometimes endocarditis, tachyarrhythmias like atrial flutter and fibrillation or thromboembolic episodes. Some have symptoms due to hyperviscosity which may require venesection for relief. But venesection can lead on to a vicious cycle with decompensated erythrocytosis. This is because renal ischemia leads to enhanced erythropoietin secretion which causes an increase in the red cell mass. Several of these patients can remain stable, of course with effort intolerance. But the balance tilts unfavourably in situations like pregnancy, intercurrent illnesses or surgical procedures. They can also worsen following dehydration and exercise or even some medical interventions. Complications may need procedures like embolization of bleeding vessels in case of severe hemoptysis, neurosurgical drainage of brain abscess, mapping and ablation of cardiac arrhythmias etc.