Acquired aortic regurgitation following occlusion of the persistent arterial duct: an echocardiographic assessment.

OBJECTIVE To document the development of aortic regurgitation following occlusion of a patent arterial duct. DESIGN Case series involving nine children referred for surgical ligation of an isolated patent arterial duct. SETTING Academic referral centre. METHODS A preoperative transthoracic and transoesophageal echocardiogram was performed in theatre to look for aortic regurgitation. Thereafter, aortic flow was monitored throughout the operation by colour flow mapping with the transoesophageal probe in situ. Onset of aortic regurgitation was documented. An immediate postoperative transthoracic echocardiogram was performed on all patients and then daily until discharge on day 5. A follow up clinical and echocardiographic assessment was performed six weeks postoperatively. RESULTS With ligation of the patient arterial duct, transoesophageal echocardiography showed immediate regurgitation in seven of the nine patients, seen as a small central jet on colour flow mapping. Six of the seven patients continued to have aortic regurgitation on transthoracic echocardiography before leaving theatre. In none was aortic regurgitation audible clinically. At discharge, five patients still had evidence of aortic regurgitation; of four seen at follow up six weeks later, only one had residual regurgitation. CONCLUSIONS Ligation of the patient arterial duct results in the acute termination of the "run off" in a volume overloaded situation. This, together with a rise in the peripheral vascular resistance and the persistence of increased proximal vascular capacitance, is considered to be the underlying aetiology of the acquired aortic regurgitation.