Acute left ventricular (LV) or right ventricular (RV) dysfunction during repair of coarctation of aorta (CoA) is rare. Well-developed collateral circulation between branches of both the subclavian arteries (SCAs) and upper descending thoracic aorta decompress LV and prevents acute rise in afterload. An adult patient presented for CoA repair. On chest X-ray, rib notching was not seen. Magnetic Resonance Imaging showed about 7 mm long CoA distal to the origin of left common carotid artery. Reconstruction images of distal arch and descending thoracic aorta showed origin of both the SCAs from CoA segment. Transthoracic echocardiography showed 1.3 cm atrial septal defect (ASD), left to right shunt, moderately severe mitral regurgitation (MR), dilated RV, and severe pulmonary artery hypertension (PH). During cardiac catheterization, the peak gradient across CoA was 60 mmHg. On aortic-root angiography, both the common carotids and the distal arch opacified simultaneously, the CoA segment and the distal aorta opacified a little later. Both the SCAs were filling retrograde. A unique anatomy in which aortic-clamping proximal to CoA and both the SCAs would increase flow to spinal-cord as clamping of the SCAs will stop stealing of blood into the CoA but potentially increase LV afterload, MR, left to right shunt across ASD and RV volume and pressure load depending on the magnitude of flow across the CoA. The increases in LV afterload, MR, and RV afterload and volume overload were managed by controlled phlebotomy and fine-tuned by manipulating inhaled isoflurane concentration whereas the Transesophageal echocardiography (TEE) monitored and guided the management.