High prevalence of baffle leaks in adults after atrial switch operations for transposition of the great arteries

To determine the prevalence of baffle leaks in adults after atrial switch operations for transposition of the great arteries, as these may predispose to paradoxical embolic events, particularly in patients with transvenous pacemaker or defibrillator leads.

We routinely perform contrast echocardiography with agitated saline in all patients after atrial switch operations. For this study, we analysed patients who had saline contrast echocardiography between 2010 and 2012. The presence of baffle leaks and the severity of right-to-left shunting were assessed. We compared baseline characteristics and oxygen saturation at rest and during exercise between patients with and without baffle leaks. A total of 65 patients (56 Senning and 9 Mustard repair) without previously known baffle leaks were included (mean age 32 ± 8 years, 77% males). Right-to-left shunting was identified in 42 patients (65%) and occurred without provocation manoeuvres in 88%. There were no differences in baseline characteristics, echocardiographic findings, or exercise capacity between patients with and without baffle leaks, except for lower oxygen saturation at peak exercise in those with baffle leaks (29% had oxygen saturations below 90% at peak exercise compared to none without baffle leaks, P = 0.011). Four patients with baffle leaks had previous implantation of transvenous pacemaker leads; one of them had suffered a stroke. Two other patients with baffle leaks had a history of potential embolic stroke.

Because of the high prevalence of baffle leaks in adults after atrial switch operations, we propose routine screening with agitated saline contrast, particularly prior to implantation of transvenous pacemaker or defibrillator leads.