P270 Complex cyanotic heart disease in adult patient with down syndrome accompanied by mild pulmonary hypertension

Abstract Funding Acknowledgements No funding Introduction Patients with Down syndrome and complex unrepaired cyanotic heart disease have impaired life expectancy. The clinical status of each patient depends both on the primary lesion type as well as the cummulative haemodynamic burden in the cardiovascular system. Assessment of an adult patient with complex congenital heart disease that has not been surgically repaired presents several challenges since initial haemodynamic parameters and compensatory mechanisms have to be taken into account. Case presentation A 43 year old male patient with known history of Down syndrome and no regular follow up presented to the Outpatient Department of our hospital to undergo pre-operative control for minor soft tissue surgery. The patient exhibited typical morphological features of Down syndrome as well as central cyanosis and digital clubbing. On auscultation a holosystolic type murmur 3/6 on the 3rd left parasternal border was audible. His blood gases revealed hypoxia and mild metabolic acidosis. Electrocardiogram displayed right axis deviation and signs of right ventricular hypertrophy. Transthoracic echocardiography demonstrated a large perimembranous ventricular septal defect (VSD) with normal anatomy and function of the aortic valve and no overiding aorta. Of note was excessive infundibular subpulmonary stenosis which resulted in a functionally double chambered right ventricle. Left ventricle was of normal diamater with good overall systolic function while the right ventricle was non-dilated with significant hypertrophy. Intracavitary gradient was estimated at 60 mmHg. Continuous Doppler showed mild mitral regurgitaion and mild tricuspid regurgitaion with estimated systolic pulmonary pressure of 40 mmHg. Bidirectional flow with low velocities at the level of the defect was recorded. Inferior vena cava was mildly dilated with normal respiratory variation. Discussion/ Conclusion: The natural history of large VSDs results in progressive dilatation of the right ventricle, the left ventricle and the left atrium with gradually increasing pylmonary vascular resistance and development of pulmonary hypertension, followed by right ventricular hypertrophy, flow reversal and Eisenmenger syndrome. However when RVOT obstruction at any level coexists, significant right ventricular hypertrophy develops and the incresed right ventricular systolic pressures acts protectively by minimizing the shunt at the VSD level. Thus a restrictive VSD due to a functionally double chambered right ventricle created a very fragile balance; a cyanotic heart disease with mild bidirectional flow depending on preload and afterload conditions that survived to adulthood. Abstract P270 Figure. Complex unrepaired CHD