Echocardiographic patterns of incomplete Shone's syndrome in adults

Whilst several cases of complete Shone's complex have been reported in children, the incomplete form--characterized by two or three components--has rarely been described in adults. Because of the wide spectrum of severity of each pattern, the correct diagnosis may be challenging. Moreover, as the hemodynamic interdependence between defects is thought to be a major determinant of clinical outcome and long-term follow up, it is crucial to consider the lesions as part of the same Shone's syndrome.

Between May 2005 and December 2009, six male patients (mean age 38 +/- 8 years) were referred to the authors' institute with progressive worsening of heart failure symptoms related to valvular disease. All patients had a clinical history of surgery for coarctation of the aorta (CoA), and all but one had a bicuspid aortic valve. Standard transthoracic and transesophageal echocardiographies were performed in all patients to identify the valvular heart disease responsible for clinical deterioration.

Unexpected findings of dysplastic mitral valvular apparatus compatible with parachute deformity of the mitral valve (PMV) or 'PMV-like' morphology were disclosed in all patients. The association with major anatomic abnormalities (bicuspid aortic valve, subaortic ridge, and previous CoA surgical repair) was highly suggestive of adult incomplete Shone's syndrome.

The findings of the present case series emphasized the need for a greater awareness regarding the rare incomplete Shone's syndrome in adulthood, as it occurs far more frequently than might be expected following a random diagnosis. The findings also highlight the additional value of a carefully performed step-by-step echocardiographic study to support the clinical decision-making in this array of left heart anomalies.