The long-term prognosis for patients with Shone’s Complex depends on the extent of mitral valve disease, the degree to which the left ventricle is hypoplastic, or abnormally small, and the cumulative effects of surgical treatments. Older patients may experience syncope (loss of consciousness), hemoptysis (coughing up of blood), heart block and other rhythm disturbances, and/or chronic heart failure.
Arrhythmias may be treated with medications and the insertion of a pacemaker. If a valve replacement operation was performed, the valve may eventually need to be repaired or replaced. Most surgically implanted prosthetic valves will last 10-20 years before they wear out, become obstructed, or lose efficiency.