Not Just a Pediatric Disease: Incomplete Shone’s Complex Diagnosed in Adulthood with Cardiac MRI

Description of Clinical Presentation: We present the case of a 62-year-old patient who complained of a one-month history of palpitations severe enough to interrupt her sleep. She recalled a heart murmur diagnosed in childhood that went untreated. An echocardiogram revealed complex congenital heart disease, and she was subsequently referred to our department for cardiac magnetic resonance (CMR) imaging.

Diagnostic Techniques and Their Most Important Findings: A 1.5T CMR scan was performed, revealing slightly sclerotic mitral valve leaflets. The subvalvular apparatus was abnormal, featuring an elongated anterolateral papillary muscle that reached the basal third of the left ventricle and inserted via a short chord into the middle portion of the posterior leaflet (Fig.1: B-E); and a posteromedial papillary muscle with multiple cords, causing an eccentric, ogival opening, which was considered "parachute-like" (Fig.1: B, F);. The mean gradient was 3.9 mmHg.

Additionally, the patient had juxtaductal aortic coarctation with a minimum diameter of 3.7 mm, a "gothic" arch with two angulations (58 and 60 degrees), and a 34.5 mm post-stenotic dilation.

2D and 4D phase-contrast sequences revealed an anterograde aortic flow of 72 ml, non-significant regurgitation, and a peak velocity of 1.45 m/s, with no evidence of a diastolic ramp. The Qp/Qs ratio was 0.9. The 4D flow sequences demonstrated a peak velocity distal to the coarctation site of less than 2 m/s, a calculated gradient of 14 mmHg, and mitral diastolic flow acceleration.

The integration of these morphological and functional findings suggested the diagnosis of an incomplete Shone's complex.

Learning Points from this Case: Shone's complex is a rare congenital defect characterized by a series of four obstructive lesions on the left side of the heart. The diagnosis of "incomplete" Shone's complex requires at least two of these lesions, while the "complete" form includes all four:

• Supramitral Ring


• Parachute Mitral Valve


• Subaortic Stenosis


• Aortic Coarctation

Patients may present with other cardiovascular abnormalities, most commonly bicuspid aortic valve, hypoplasia of the aortic arch and/or ventricular septal defect.

A multi-modality imaging approach is essential for a comprehensive assessment. While echocardiography is the primary tool, CMR is the gold standard for non-invasively assessing aortic anatomy, coarctation severity, ventricular function, and blood flow.

This case highlights the diagnostic spectrum of Shone's complex and the crucial role of CMR with 4D flow as a comprehensive tool capable of revealing complex, unsuspected and atypical pathologies. It also underscores the patient's remarkable survival despite the absence of a prior diagnosis and management.

Fig. 1: A.- Aortic coarctation. B.- 4 chambers with anterolateral papillary muscle elongation (long arrow), normal papillary muscle (short arrow). C.- 3 chambers with short chordae tendineae. D.- Basal short axis with presence of a papillary muscle. E.- Middle short axis with both papillary muscles. F.- Ogival and eccentric opening of the mitral valve.
Fig. 2: 4D flow of aortic coarctation with flow acceleration in stenosis and turbulent flow in post stenotic dilatation.