Partial atrio-ventricular septal defects have an atrial septal defect and either a common atrioventricular valve or two valves. The atrioventricular valves can be stenotic or regurgitant and the atrial septal defect has a L → R shunt across it. These lesions can be asymptomatic, depending on the size of the shunt and the functionality of the valves. Late stage complications are pulmonary hypertension due to the L → R shunt as well as heart failure due to valve problems. Anaesthetic management needs to be adjusted to the individual lesion.