This study describes the un-natural history of a 16-year-old patient, presenting with a critical bicuspid aortic valve stenosis, who was initially treated in the neonatal period and later with a valvuloplasty. This focused the attention on palliative interventions that, in young adulthood or middle age, are usually related to several complications, until heart transplantation. The other important aspect of this case is the presence of a coronary atherosclerotic plaque producing a significant obstruction, in the setting of haemodynamic acute postoperative failure caused by the sudden aortic valve laceration and insufficiency. This favoured the transmural myocardial antero-septal evolution of the myocardial ischaemic-reperfusion damage. This case is peculiar in that it presents two unrelated entities in their natural history. The coronary lesion was an unexpected finding in an adolescent with congenital heart disease. The severity of the coronary lesion became haemodynamically significant as a combination of the hypoperfusion due to the massive aortic valve regurgitation following the acute failure of the aortic valve plasty and the vasoconstriction of the eccentric speared segment. Once again, the complete understanding of grown-up patients with congenital hart disease is mandatory together with the point that a close collaboration of a multidisciplinary team is essential for appropriate operative timing and planning the most suitable treatment option. Acquired heart diseases can rarely present in association in this group of patients and need to be taken into account.