Costello Syndrome Complicated by Midventricular Obstruction With an Apical Aneurysm

A woman in her 30s, diagnosed with Costello syndrome in her teens via genetic testing, was referred to the cardiology department after Holter electrocardiography detected premature ventricular contractions. Chest radiography revealed a cardiothoracic ratio of 54% (Figure A). The 12-lead electrocardiogram demonstrated sinus rhythm, with high left ventricular (LV) voltage and negative T waves (Figure B). Serum B-type natriuretic peptide level was 329 pg/mL. Transthoracic echocardiography revealed a large apical aneurysm with an area of 15.7 cm² (Figure C, Supplementary Movie). Continuous-wave Doppler imaging revealed that blood flow from the LV apex to the base was interrupted during systole, but not during diastole, with a LV pressure gradient ≤66 mmHg (Figure D). The LV ejection fraction was preserved at 59%, with no LV outflow tract obstruction or significant valvular disease. The maximum LV wall thickness was 15 mm in the midventricular septum. The patient was diagnosed with Costello syndrome with an apical aneurysm complicated by midventricular obstruction resulting from LV hypertrophy (LVH).

Figure.

(A) Chest X-ray shows cardiothoracic ratio of 54%. (B) 12-lead electrocardiogram showing sinus rhythm with high left ventricular (LV) voltage and widespread negative T waves. (C) Transthoracic echocardiography of the large apical aneurysm. (D) Continuous-wave Doppler imaging showing the LV pressure gradient ≤66 mmHg.

Costello syndrome, a rare RASopathy first discovered in 1977 by the New Zealand pediatrician Dr. Jack Costello, is a genetic disorder caused by a congenital HRAS gene mutation.¹ Approximately 3% of patients with genetically confirmed RASopathy and LVH have Costello syndrome.² LVH associated with RASopathies is often mild-to-moderate, with LV outflow tract obstruction as a common phenotype. However, in this case, the midventricular obstruction led to a pressure gradient that resulted in the formation of an apical aneurysm.

To the best of our knowledge, this is the first imaging report of Costello syndrome with an apical aneurysm due to midventricular obstruction caused by LVH.

Disclosures

K.T. is a member of Circulation Reports’ Editorial Team.

Supplementary Files

Supplementary Movie

Please find supplementary file(s);

https://doi.org/10.1253/circrep.CR-24-0165

References

• 1.   Costello JM. A new syndrome: Mental subnormality and nasal papillomata. Aust Paediatr J 1977; 13: 114–118.
• 2.   Boleti O, Norrish G, Field E, Dady K, Summers K, Nepali G, et al. Natural history and outcomes in paediatric RASopathy-associated hypertrophic cardiomyopathy. ESC Heart Fail 2024; 11: 923–936.